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161129 MAD (Hydrogeologic Report).pdfExcellence. Innovation. Service, Value. Hydrogeologic Report New Madrona K-8 Project 9300 236th Street SW Edmonds, Washington k1w=11 *��l Submitted To: Ms. Taine Wilton Edmonds School District #15 20420 681h Avenue West Lynnwood, Washington 98036 By: Shannon & Wilson, Inc. 400 N 34th Street, Suite 100 Seattle, Washington 98103 21-1-22082-003 TABLE OF CONTENTS 1.0 INTRODUCTION --------------------------------------1 2.0 SITE DESCRIPTION ............................................................................................................ 2 2] Site Topography -----------------------------------2 2.2 Site Drainage and Wetlands ....................................................................................... 2 3.0 GEOLOGIC CONDITIONS --------------------------------..2 3.1 Regional Geology and -------------------------..2 3.2 Local Geology and Hydrogeology -------------------------.'4 4.0 SUBSURFACE EXPLORATION AND TESTING .............................................................. h 4.1 Drilling and Testing ----------------------------.h 4-2 Findings ---------------------------------------.7 4.2] Observed Geologic Conditions .................................................................... 7 4.2.2 Groundwater Levels and Monitoring -------------------..N 4.2.3 Aquifer Properties -----------------------..4 4-2/4 Groundwater Quality ---------------------------l0 4.2.5 Pilot -scale Injection Well Testing .............................................................. 0 4.2.6 Full-scale Injection Well ---------------------l0 5.0 GROUNDWATER MODELING OF PLANNED INJECTION WELLPlELD.................. |l 5.1 Overview .................................................................................................................. ll 5.2 Conceptual Site Model (CSM)................................................................................. }} 5.3 Model Development and Calibration ....................................................................... l2 5.4 Model Simulation (Base Case) ................................................................................. l2 5.5 Sensitivity Analysis --------------------------------.]3 6.0 STORMWATER QUALITY DlSC\JSSl()N.-----------------------]3 7.0 CONCLUSIONS AND RECOMMENDATIONS ---------------------l4 7.1 Injection Well -------------------------]4 7l1 Geuecu1----------------------------------]4 7].2 Well Design ---------------------.]5 7.1.3 Injection Well Materials ............................................................................ l7 0.0 LIMITATIONS --------------------------------------.. 20 0.0 REFERENCES..................................................................................................................... 22 2/'/-22082-003'n/o°pmn 21'1-22082'883 TABLE OF CONTENTS (cont.) 1 2 3 4 5 6 7 8 9 10 FIGURES Vicinity Map Site and Exploration Plan Surficial Geologic Map Deer Creek Water Supply Protection Area Map Generalized Subsurface Profile A -A' Generalized Subsurface Profile B-B' Inflow Test Results at Pilot UIC Well IW-1 Inflow Test Results at UIC Well IW-2 Conceptual UIC Well Design Proposed UIC Well Array Map APPENDICES Subsurface Explorations Geotechnical Laboratory Testing Hydrogeologic Data and Analyses Groundwater Modeling Important Information About Your Geotechnical/Environmental Report 21-1-22082-003-Rlfwp/]kn 21-1-22082-003 11 SHANNON , INC. HYDROGEOLOGIC REPORT NEW MADRONA K-8 PROJECT 9300 236TH STREET SW EDMONDS, WASHINGTON 1.0 INTRODUCTION The Edmonds School District No. 1.5 (the District) contracted Shannon & Wilson, Inc. (Shannon. & Wilson) to conduct a preliminary hydrogeologic analysis for the new Madrona K-8 Project (the project), located in Edmonds, Washington (Figure 1). The project is located within the NE '/4 of the SE '/4 of Section 36, Township 27 N, Range 4 E, Willamette Meridian, at 9300-236tn Street SW (Snohomish County tax parcel 27033600404600). The District plans to construct the new M. adrona K-8 School on the east portion of the approximately 40-acre property. New stormwater management facilities will be required for approximately 1.3 acres of the site. The purpose of this study was to evaluate the feasibility of using dry wells (or underground injection control [UIC] wells) for project stormwater flow control. Our scope of services, presented in our proposals to the District dated March 16, 2016, August 1.5, 2016, and September 27, 2016,. included: ■ Observation well drilling, installation, and development at two location (designated OW-1 and OW-2); ■ Observation well sampling and field hydraulic conductivity (slug) testing (well OW-1); ■ Observation well groundwater level monitoring (wells OW-1 and OW-2); ■ Pilot and full-scale UIC well drilling, installation, and inflow testing (designated as UIC wells IW-1 and IW-2, respectively); ■ Laboratory testing of selected soil samples for grain size analysis and moisture content; ■ Groundwater modeling to evaluate the proposed UIC well spacing and layout, groundwater mounding, and seepage potential for the nearby ravine slope; ■ Meetings with the District; and ■ Preparation of this report, which includes the results of our subsurface explorations, field and laboratory testing, and hydrogeologic analyses. Our scope of services was authorized by the District's Purchase Order No. 2001500281, dated March 25, 2016; Purchase Order No. 2001500440, dated August 23, 2016; and Purchase Order No. 2001600097, dated October 12, 2016. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 1 SHANNON MILSON, INC. 2.0 SITE DESCRIPTION 2.1 Site Topography The approximately 40-acre property includes two steeply sloped wooded areas aligned north to south; one is a ravine located along the eastern property boundary, and the other is a forested incline located near the middle of the property (Figure 2). The existing Madrona Elementary School is located in the northeast corner of the property, and the former Woodway Elementary School is located in the opposite southwest corner of the property. We understand that the planned new construction will occupy the east half of the property, where the existing grade elevation is currently approximately 445 to 455 feet. The project's elevation datum is referenced to the North American Vertical. Datum of 1988.(NAVD88). In addition to school buildings and parking lots, the property currently includes a running track, a baseball field, and soccer fields. The areas surrounding the property consist primarily of residential developments. 2.2 Site Drainage and Wetlands A series of catch basin grates exist along the inside of the track. The project survey performed by Penhallegon Associates Consulting Engineers, Inc. (PACE) shows that these storm drains, along with storm drainage from the existing Madrona Elementary School, discharge to the top of the steep wooded slope in the middle of the property. The survey also identified storm drain discharges to the top of the wooded ravine located on the eastern property boundary. As indicated in Figure 2, three wetland areas were identified in our recent Wetland and Stream Delineation Report (Shannon & Wilson, 2016a). Wetlands A and C are on the wooded slope in the middle of the property and are downgradient from the track storm drain discharges. Seepage emerges within these wetlands, which were delineated between about elevations 410 and 398 feet on this slope. We concluded in our wetland report that these wetlands are supported predominantly by groundwater seeps. Wetland B, which is within the wooded ravine located on the eastern property boundary, is located downgradient of the storm drain outlets associated with the existing Madrona Elementary School and the play fields. We concluded that Wetland B is likely supported by surface flow from the surrounding ravine, the storm drain inputs from the school, and a seasonally high groundwater table. 3.0 GEOLOGIC CONDITIONS 3.1 Regional Geology and Hydrology The project site is located in the Puget Lowland, an elongated topographic and structural depression filled with a sequence of glacial and nonglacial sediments that unconformably overlie 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 2 SHANNON MILSON, INC. bedrock. The area has been glaciated seven or more times in the past 2.4 million years. During the last glacial advance, known as the Vashon stade, the ice was greater than 3,000 feet thick in the project area. The Vashon ice sheet receded from the area about 16,500 years ago, leaving topography characterized by low -rolling relief about 500 feet above sea level, with some deeply cut ravines and broad valleys. Since then, present-day geologic processes, such as erosion and deposition by streams, landslides, and human activities, have modified the ground surface. The primary geologic units of significance for the project in the area are summarized as follows: Vashon Ablation Till (Qvat). Ablation till soils were deposited by one of several depositional processes that take place along the margins of glacial ice and have variable characteristics. Qvat is commonly composed of stratified or irregular bodies, including a heterogeneous mixture of loose to dense gravel, sand, silt, and clay. Qvat may contain scattered cobbles and boulders. Qvat is commonly reworked or modified through sediment slumping or stream action after initial deposition. Seasonally perched groundwater is common near the base of this unit. Vashon Lodgement Till (Qvt). Vashon lodgement till soils were deposited at the base of an advancing glacial ice sheet and were subsequently overridden by the ice. Qvt is typically a nonsorted diamict consisting of very dense, silty sand with gravel and silty gravel with sand; fines are typically nonplastic to low -plasticity. Qvt has a consistency and strength similar to very soft rock. Qvt may contain interbeds, dikes, and lenses of cohesionless silt, sand, and gravel, as well as cohesive clay and silt. This unit can also contain fractures, and cobbles and boulders are common. Perched groundwater may be encountered within this unit. Vashon Till -Like Deposits (Qvd). Vashon till -like deposits are nonsorted to poorly sorted diamicts and are intermediate between glacial till and glacial outwash. These sediments may have been reworked by subglacial streams flowing in channels beneath the ice. Qvd soils have a similar grain size distribution to Qvt (although generally lower fines content), but are generally more variable in composition. Perched groundwater may occur within this unit. Vashon Advance Outwash Deposits (Qva). Vashon advanced outwash consists of glaciofluvial sediment deposited as the glacial ice advanced through the Puget Lowland. Deposits of Qva consist of dense to very dense, poorly graded sand to well -graded sand to silty sand, with varying amounts of gravel and scattered cobbles. Saturated Qva deposits form a productive regional aquifer, and the formation is known to heave when encountered during drilling. Layers of relatively coarse sand within the unsaturated Qva tend to cave during drilling. Where layers of low - permeability soil exist, localized perched groundwater may occur in the Qva above the regional aquifer. Transitional Bed Deposits (Qtb). Transitional bed deposits are transitional between. Vashon glacial and pre-Vashon nonglacial deposits. They are typically fine-grained, 21-1-22082-003-Rlfwp/]kn 21-1-22082-003 SHANNON MILSON, INC. consisting mostly of thick or thin beds and laminae of clay, silt, and fine sand (Minard, 1983). The major surface water features in project area are Echo Lake and Lake Ballinger (approximately 4,700 southeast and 6,000 feet east of the project, respectively), and Deer Creek, about 5,500 feet northwest of the project. 3.2 Local Geology and Hydrogeology The following summarizes the local surficial and subsurface geology based on published reports, databases, and previous studies: ■ According to a published geologic map (Minard, 1983; Figure 3) and our previous 22 project test pits and 11 shallow soil borings (Shannon & Wilson, 2016b), the project site is underlain at a shallow depth by glacial till. The top of the till was identified by our previous test pits and shallow borings as starting at between ground surface and 10 feet deep. ■ The transition from glacial lodgement till (Qvt) to glacial advance outwash (Qva) occurs at approximately elevation 380 to 400 feet on the steep wooded slope in the middle of the property (Minard, 1983). ■ Boring logs for the nearby Brightwater Project (CDM, 2006) and other nearby wells indicate that the Qva is laterally extensive in the area. ■ Based on Brightwater Project borings MW-4 and E-106 (drilled about 1,500 feet south of the project site along 244th Street SW), transitional bed (Qtb) deposits underlie the Qva soils locally at about elevation 201 feet (CDM, 2006). The following summarizes the local groundwater conditions based on published reports, online databases, and previous studies: The online Washington. State Department of Ecology (Ecology) water resources and well log databases (Ecology, 2016a and 2016b) identify multiple irrigation and domestic wells in southwest Edmonds vicinity that are completed in the Qva aquifer. With one possible exception, none of these wells appears to be within'/4-mile of the portion of the site undergoing redevelopment. No municipal water supply wells are reported to be within'/4-mile of the site. We identified one domestic use groundwater right that has been registered for a well in the vicinity of Firdale Village (Ecology, 2016a). The well's location was not specified on the water right documentation, but the owner's address (9619 - 242" d Place SW, Edmonds) is within'/4-mile of the site, cross -groundwater gradient to the project (Figure 4). 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 4 SHANNON MILSON, INC. ■ The top of the Qva aquifer occurs between elevations 288 and 278 feet in the vicinity of Brightwater Project exploratory boring MW-4, in the Firdale Village area (CDM, 2006). ■ The groundwater level in the Qva aquifer is at approximately elevation 259 to 261 feet in City of Edmonds observation well A-2, located approximately 4,500 feet west of the project site (Shannon & Wilson, 2013). ■ Prior to our current site work, we estimated the hydraulic gradient in the Qva aquifer in the southwest Edmonds area to be to the west at about 0.008 foot per foot (foot/foot). The expected annual groundwater level fluctuation in the Qva aquifer is between about 2 and 5 feet (Shannon & Wilson, 2013; CDM, 2006). ■ The project site straddles the mapped ten-year time -of -travel zone for a Class A municipal water supply protection area (Figure 4; PACE, 2002). This water source consists of a spring that produces water from the basal Qva aquifer in the Deer Creek ravine. Olympic View Water and Sewer District (Olympic View) owns the Deer Creek water supply and treatment facility. Figure 4 indicates that the hydraulic gradient for the Qva aquifer is approximately west/northwest in the project vicinity. Thomas and others (1997).rated the Qva aquifer in the Project site and most of the vicinity of southwest Edmonds as having a low sensitivity to contamination, based on aquifer characteristics. However, the Deer Creek water supply protection plan states that the Washington State Department of Health assigned the Deer Creek source a high susceptibility rating and established a testing program. The Deer Creek source susceptibility analysis included a review of both geologic and land use factors (PACE 2002). We understand from Robinson Noble, Inc. (Robinson Noble), Olympic View's hydrogeologic consultant, that the Deer Creek source testing is currently performed after the supply has been treated. Robinson Noble also stated that Deer Creek has multiple monitoring wells located upgradient of the spring source, which are currently not being sampled. From our conversations with Olympic View and Robinson Noble, we understand that Olympic View recently drilled a test well at 8605-2281h Street SW and that they are in the process of developing a new water supply well in this vicinity (Figure 4). The test well was reportedly drilled to about 700 feet deep, and it is located about 3,300 feet northeast of the project site. As of the date of this report, its log was not yet available on the online Ecology well log viewer. Mr. Max Wills of Robinson Noble stated that the intake zone was revised (made more shallow) after the test well's initial construction and testing. He said that the well is now screened within the Qva aquifer. Olympic View personnel said it may soon be supplemented by a second new well. Olympic View personnel stated that they are not currently using this or other wells in the project vicinity. We suggested to Olympic View, via Robinson Noble, the advantage of working together with them to obtain concurrent Qva aquifer water level measurements at the test well and the Madrona K-8 Qva wells. These measurements could assist in better defining the local Qva gradient. As of the date of this report, we have not received a response from Olympic View. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 5 SHANNON MILSON, INC. 4.0 SUBSURFACE EXPLORATION AND TESTING 4.1 Drilling and Testing Program Our drilling and testing program consisted of the following: Subcontracted Holt Services, Inc. to drill three borings, including installation of two observation wells and one pilot dry well. These were drilled using the sonic core drilling method: — Observation well OW-1, drilled to 185.5 feet below ground surface (bgs); screened 175.4 to 185 feet bgs. Pilot dry well IW-I, drilled to 91.2 feet bgs; screened 63.3 to 90.4 feet bgs. IW-1 is located approximately 25 feet east of OW-1. Observation well OW-2, drilled to 190 feet bgs; screened 179.2 to 183.9 feet bgs; vibrating wire piezometers (VWPs) at 66.3 feet (VWP1) and 146.3 feet (VWP2). Subcontracted Malcolm Drilling Company, Inc. to complete one full-scale dry well, using the auger drill method: Full-scale dry well, IW-2, drilled to 120.4 feet bgs; screen exposed to formation from about 62 to 119.7 feet bgs. IW-2 is located approximately 14 feet northwest of OW-2. ■ Observed construction of observation wells OW-1 and OW-2 and pilot dry well IW-1. Construction details for the wells and VWPs are presented in the boring logs and in Tables A-1 and A-2 in Appendix A. ■ Observed construction of full-scale dry well IW-2. Well construction details are presented in the boring log and in Table A-1 in Appendix A. ■ Logged and photographed the sonic core soil samples and logged the auger cuttings. Collected sub -samples for laboratory geotechnical analysis. ■ Estimated the approximate well locations and reference elevations based on field measurements. ■ Developed observation wells OW-1 and OW-2 using an inertial -style pump (Waterra) equipped with a combination surge block and check valve. Measured groundwater quality field parameters during well development at OW-1, and observed purge water sediment content during well development at OW-2. ■ Collected groundwater samples from observation well OW-1 to establish baseline groundwater quality in the Qva aquifer. Analyzed the sample for petroleum hydrocarbon -related constituents and primary and secondary drinking water parameters. Measured groundwater quality field parameters immediately before sample collection. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 6 SHANNON MILSON, INC. Performed a "slug" test in OW-1 to estimate the hydraulic conductivity of the Qva aquifer. ■ Commenced long-term groundwater level monitoring in. OW-1 in. April 2016.by installing a Levelogger and a data logging barometer (Barologger). Commenced long-term groundwater level monitoring in the well at OW-2 in August 2016,. installing a Levelogger. Performed periodic data downloads, coupled with manual readings of the OW-2 VWPs and dry wells IW-1 and IW-2. Performed an inflow test in pilot dry well IW-1 by adding water at known rates for a selected time periods and monitoring water levels at IW-1 and OW-1 before, during, and after the inflow test. — Step testing —performed four inflow steps at approximately 14, 38, 72, and 103 gallons per minute (gpm), maintaining each rate for approximately 1 hour; and Short-term constant rate injection test, lasting about 4.3 hours, at an average rate of about 11.0 gpm. ■ Performed an inflow test in full-scale dry well IW-2 by adding water at known rates for a selected time periods and monitoring water levels at IW-2, OW-2, and OW-1. before, during, and after the inflow test. Step testing — performed four inflow steps at approximately 87, 11.4, and 128 gpm, maintaining each rate for approximately 39 to 99 minutes; and Short-term constant rate injection test, lasting about 15.9 hours, at an average rate of about 141 gpm. 4.2 Findings 4.2.1 Observed Geologic Conditions Appendix A presents the exploration logs and includes a Soil Description and Log Key that explains the terms used in the soil classifications and descriptions. Figures 5 and 6 present in profile generalized illustrations of the subsurface conditions we observed at the four borings. The results of these borings and hydrogeologic information interpreted from other studies in the vicinity are summarized as follows: ■ Near -surface soils consisting primarily of Qvat and weathered Qvt extend to a depth of about 10 and 14 feet. Some surficial fill is also present. ■ Interbedded Vashon lodgement till (Qvt) and till -like deposits (Qvd) occur beneath the near -surface soils to about 38 to 50 feet bgs. Interbedded Qva and Qvd layers are present below approximately 38 to 50 feet, to about 60 to 72 feet bgs. Perched groundwater was observed to about 61 feet bgs in these deposits. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 7 SHANNON MILSON, INC. Below about 60 to 61 feet bgs, encountered soils consisted predominantly of Qva, which are present to the maximum explored depth of 190 feet (approximately elevation 255 feet). Scattered layers of silty sand are present within the unsaturated Qva, particularly at and below about 134 to 147 feet (OW-1 and OW-2, respectively); some of these layers appear to be intermediate between Qva and Qvd. ■ Transitional bed deposits (Qtb) were not encountered by the project borings, but they may be present below the maximum exploration depth of 190 feet. Based on other deep explorations in the vicinity, Qtb deposits might be expected to occur below about 244 feet bgs (about elevation 201 feet). Soil treatment capacities of the Qva between the target UIC depth of about 120 feet and the top of the Qva regional aquifer are low to medium, as defined by the Guidance for UIC Wells that Manage Stormwater (Ecology, 2006). These treatment capacity rankings are based on the grain size analyses presented in Appendix B and summarized in Appendix C, Table C-4: OW-1 vicinity: We observed approximately 10 cumulative feet of medium treatment capacity soils between 120 feet bgs and the top of the Qva regional aquifer; the remaining soils (about 37 feet cumulative thickness) have a low treatment capacity. OW-2 vicinity: We observed approximately 1.4 cumulative feet of medium treatment capacity soils between 120 feet bgs and the top of the Qva regional aquifer; the remaining soils (about 33 feet cumulative thickness) have a low treatment capacity. 4.2.2 Groundwater Levels and Monitoring As indicated in the boring logs in Appendix A, we observed shallow wet seams and layers in the Qvat/weathered Qvt deposits at IW-1, OW-1, and OW-2. These were as shallow as 5.5 to 8.5 feet bgs in OW-1, about 9 to 1.4 feet bgs in IW-1, and about 1.2 feet bgs at OW-2. Similarly, we observed additional wet seams and layers within the Qvt/Qvd soils in the 0W-2/IW-2 vicinity at about 23, 35, and 45 feet bgs. Perched groundwater may be feeding the wetlands identified on the site slopes (Shannon & Wilson, 2016a). We encountered a possible perched groundwater zone within the interbedded Qvd/Qva soils, between about 48 and 57 feet bgs at IW-1 and at about 50 to 53 feet bgs at OW-1. Perched water was present at IW-2 within the interbedded Qvd/upper Qva soils from about 49 to 61 feet bgs. Soil within this zone caved during drilling at IW-2, necessitating the installation of temporary surface casing. A possible zone of perched water was encountered at approximately 1.32.5 to 136.5 feet bgs at OW-1, associated with a silty sand Qva layer. However, this saturated zone may also have been associated with residual water introduced during the drilling process. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 8 SHANNON MILSON, INC. Hydrographs of the Qva aquifer groundwater levels measured to date at OW-1 and OW-2 are presented in Appendix C. The highest observed levels to date in the regional Qva aquifer at the site are approximately 167.1 to 1.67.3 feet bgs (elevation 278.0 to 277.4 feet) at OW-1 and OW-2, respectively. The range of fluctuation in the Qva aquifer water level observed to date is about 1.8 feet (April to November 2016 at OW-1). Apart from during and immediately after their respective injection well testing periods, wells IW-1 and IW-2 have been dry to date. The VWP installed at 66.3 feet bgs at OW-2 has also been dry, including during the IW-2 test. The VWP installed at 1.46.3 feet bgs at OW-2 measured water temporarily mounding at that depth during and immediately after the IW-2 test, as shown in Appendix C. The top of the unsaturated portion of the Qva unit is about 60 to 61 feet bgs (elevation. 385 or 384 feet) in the OW-1/OW-2 vicinity. The unsaturated thickness of the targeted Qva infiltration receptor soils is about 72 feet (if perched water is present in the Qva at 132.5 feet bgs at OW-1) or about 1.06 feet (based on the highest groundwater level measured to date at OW-1). We estimated the Qva aquifer gradient by comparing groundwater elevations measured at the project wells to the approximate groundwater elevation we measured during a previous study at City of Edmonds observation well A-2 (Shannon & Wilson, 201.3). Well A-2 is located about 4,500 feet west of the site. Based on these data, the Qva aquifer gradient beneath the project site is about 0.002 foot/foot to the west/northwest (Figure 4). 4.2.3 Aquifer Hydraulic Properties We performed single -well "slug" tests in observation well OW-1 to determine the local horizontal hydraulic conductivity (Kh) of the Qva aquifer (Appendix Q. The OW-1 test results indicate a Kh of 55 feet/day (3.8 x 10-2 feet/minute). We estimated the Kh for soil samples collected from project borings IW-2, OW-1, and OW-2 using empirical methods (Table C-4, Appendix Q. The results indicated the following: • The estimated Kh value for the till -like deposits (Qvd) sample from OW-1 was less than 0.01 foot/day. The Kh estimates for the 21 Qva unit samples range from 0.05 to 626 feet/day (3 x 10-5 to 0.43 feet/minute). Excluding the highest value as an outlier, the arithmetic and geometric mean Kh values of the remaining 20 samples are 38 and 1.1 feet/day (2.3 x 10-2 and 7.4 x 1.0-3 feet/minute), respectively. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 9 SHANNON MILSON, INC. 4.2.4 Groundwater Quality In general, the OW-1 sample indicates that the groundwater quality of the Qva aquifer groundwater quality is good beneath the project site. An exception is the relatively high concentration of manganese, 344 parts per billion (ppb), which is almost seven times the secondary (aesthetic) drinking water standard of 50 ppb. Manganese occurs naturally in soil and groundwater. The extent to which manganese dissolves into groundwater depends on the amount of oxygen in the water and, to a lesser extent, upon the pH of the water. If the oxygen content of groundwater is low, manganese tends to dissolve more readily. The zone from which the OW-1 groundwater sample was collected contains scattered organics, the decomposition of which depletes the oxygen content of the groundwater. This may contribute to the relatively high groundwater manganese concentration. Table C-1 in Appendix C summarizes the laboratory test results for the OW-1 groundwater sample and comparable drinking water standards. Appendix C also contains the associated laboratory data report. 4.2.5 Pilot -scale Injection Well Testing Figure 7 presents the results of the pilot -scale injection well test at IW-1. During the first four injection steps (approximately 1 hour each, at about 14, 38, 72, and 1.03 gpm), the water column height in IW-1 ranged from approximately 2 to 1.8 feet (89 to 72 feet bgs). However, these four steps did not run long enough for the water level to stabilize. The fifth step lasted approximately 4.3 hours. The inflow rate varied between about 107 and 1.26 gpm during this step, with an average inflow rate of 110 gpm. At this inflow rate, the IW-1 water column height stabilized at approximately 24 feet, which is 67 feet below grade and 4 feet below the top of the well screen. Based on these data, and as summarized in Table C-3 (Appendix C): ■ The observed injection specific capacity of IW-1 is approximately 4.6 gpm/foot of water level rise and the approximate K for the tested zone is 24 feet/day (1.7 x 10-2 feet/minute). ■ The test did not cause the groundwater level in nearby observation well OW-1 to increase by a measurable amount. 4.2.6 Full-scale Injection Well Testing Figure 8 presents the results of the full-scale injection well test at IW-2. During the first three injection steps (which lasted between 39 and 99 minutes each at rates of 87, 1.1.4, and 128 gpm), the peak water column heights in IW-2 ranged from approximately 12 to 17 feet (or 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 10 SHANNON MILSON, INC. 108 to 103 feet bgs). However, the water level did not stabilize during these steps. The fourth step lasted for 15.9 hours, at an average inflow rate of about 141 gpm. At this inflow rate, the IW-2 water level was relatively stable at about 99 feet below grade, representing a head rise above the borehole bottom of about 21 feet. Based on these data, and as summarized in Table C- 3 (Appendix C): The observed injection specific capacity of IW-2 is approximately 6.7 gpm/foot of water level rise and the approximate K for the tested zone is 30 feet/day (2.0 x 10-2 feet/minute. The test caused the groundwater level in OW-2 VWP2 to rise by 5 feet at the end of the injection phase of the test. This rise fully dissipated during the subsequent 3.5 days. A small increase in the groundwater level (less than 0.3 foot) occurred in observation well OW-2 in response to the test. 5.0 GROUNDWATER MODELING OF PLANNED INJECTION WELLFIELD 5.1 Overview We performed groundwater modeling to determine the feasibility of the planned UIC wellfield. In particular, the modeling was conducted to evaluate potential groundwater mounding, well operational constraints, and the potential for seepage to occur at the slopes to the west of the UIC wellfield. The modeling consisted of the following: 1. Establishing a detailed conceptual site model; 2. Developing and calibrating the numerical model; 3. Simulating the planned 16-well UIC wellfield for a specified storm event; and 4. Testing the sensitivity of the model results to parameter uncertainty. Appendix D presents the full details of the modeling approach, results, and limitations. 5.2 Conceptual Site Model (CSM) Based on the four deep borings and our understanding of the local hydrogeology, we have developed the following CSM for the project site: ■ Relatively low permeability Qvt and Qvd soils are situated above a thick layer of relatively permeable Qva sand. ■ The upper Qva deposits are interbedded with Qvd soils down to a depth of 60 to 72 feet (elevation 385 to 373 feet). The base of the perched zone observed within the interbedded Qva/Qvd zone is 61 feet bgs (elevation 384 feet). The Qva is predominantly unsaturated from 61 to 1.67 feet bgs (elevations 384 to 278 feet). 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 11 SHANNON MILSON, INC. ■ The regional. Qva aquifer extends from 1.67 feet bgs (elevation 278 feet) to at least 244 feet bgs (elevation 201 feet) ■ Potentially perching layers of silty sand are scattered within the generally unsaturated Qva. These layers occur primarily below 147 feet bgs (elevation 298 feet) at OW-1 and OW-2, and possibly as shallow as 134 feet bgs (elevation 311 feet) at OW-1. At each deep UIC well, a surface casing and seal will be installed to isolate the overlying Qvt, Qvd, and saturated upper Qva layers from the unsaturated underlying Qva soils (Figure 9). Stormwater discharge to the UICs will be directed into the unsaturated Qva soils to a maximum depth of about 120 feet (about elevation 325 feet). 5.3 Model Development and Calibration The model uses the U.S. Geological Survey's numerical groundwater flow code MODFLOW- 2005 (Harbaugh, 2005) to simulate the unsaturated zone and groundwater flow system in the project area. The model occupies an area 2,400 feet by 2,000 feet, and it extends from land surface to elevation 225 feet. The model uses the following three layers to simulate the subsurface soils described in the CSM: ■ Layer I — unsaturated Qva outwash (land surface to elevation 298 feet) ■ Layer 2 — a 5-foot thick, low permeability perching layer (from elevation 298 to 293 feet) ■ Layer 3 — saturated Qva outwash (elevation 293 to 225 feet) We calibrated the model transiently to the full-scale injection test performed using UIC well IW-2. This involved adjusting the material properties of the three layers to enable the model to best reproduce the observed changes in groundwater levels. Table D-1 in Appendix D present the final modeled material properties. 5.4 Model Simulation (Base Case) We used the calibrated model to simulate the planned UIC wellfield for a specified storm event. This Base Case involved the following: ■ 1.6 UIC wells, grouped in four areas (Areas 1 through 4), each with three to five wells spaced at 30 to 50 feet (Figure 10); ■ The UIC wells inject water into model layer 1; and ■ The simulated injection was for a 100-year, 24-hour storm event. The peak hourly injection rate for each well ranged from 1.02 to 130 gpm. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 12 SHANNON MILSON, INC. The results indicate that the simulated storm event would temporarily raise water levels by up to 1.1 feet (to a peak elevation 310 feet) at the center of UIC Area 2 (1.35 feet bgs), and by up 7 feet (to elevation 306 feet) at the center of the three other UIC areas (139 feet bgs). Although some mounding interference would occur between adjacent UIC wells in each area, the operational groundwater level would not be higher than the top of the designed well screens (at elevation 375 to 380 feet). The model also predicts that the groundwater would not increase to less than 70 feet below land surface at the slope to the west of the wellfield areas. 5.5 Sensitivity Analysis To evaluate the effect on the Base Case results of key model parameter uncertainty, we performed three sensitivity cases. These involved the re -simulating the 24-hour storm with (a) the Qva aquifer Kh and Kv values reduced by a factor of 10, (b) the elevation of the 5-foot thick perching layer increased by 15 feet, and (c) a combination of (a) and (b). The most conservative case (c) results indicate that the induced perched water table would rise to a peak of elevation 328 feet at the center of UIC Area 2, which is 117 feet bgs. The water would remain more than 50 feet below the toe of the slope to the west of UIC Area 2. 6.0 STORMWATER QUALITY DISCUSSION We understand that the District plans to employ source controls and to treat site stormwater based on the expected pollutant loads, in accordance with the local stormwater code requirements (City of Edmonds, 2010; Ecology, 2005 and 2006). We understand that the District plans to incorporate bioretention for treatment and infiltration of some site stormwater, with drainage from the bioretention being routed to some of the UIC wells. This best management practice (BMP) will target shallow, unsaturated soils with moderate permeability, e.g., Qvat, fill, and weathered Qvt. In areas where these soils have sufficient permeability, some flow control benefit will be realized by this BMP. Additional flow control will be provided by the proposed UIC wells. The introduction of nutrients into UIC wells may contribute to biofouling of the wells, thereby reducing their effective life span (National. Research Council [NRC], 1.994). To manage phosphorus and nitrogen at the bioretention facilities, we recommend incorporating the following elements into the bioretention facility BMP design, in accordance with the applicable stormwater code (City of Edmonds, 2010).and as described in the Low Impact Development Technical. Guidance Manual for Puget Sound (Puget Sound Action Team, 2005; Puget Sound Partnership, 2012): 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 13 SHANNON MILSON, INC. Use only mature, stable compost, without biosolids or manure constituents. Employ elevated under -drains to create a fluctuating anoxic/aerobic zone below the drain pipes. We contacted Ecology (Ms. Mary Shaleen-Hansen, Water Quality Section; Mr. Douglas Howie, Senior Stormwater Engineer) to discuss UIC management and common reasons for UIC well failure. Ms. Shaleen-Hansen recommended that the site UIC well management plan address coliform, pesticides, and herbicides (i.e., through source control) to prevent introduction of these contaminants into the UIC wells. Although Mr. Howie was not familiar with UIC well fouling due to the introduction of nutrients, he stated that UIC well failures are typically due to the introduction of total suspended solids (TSS). In our experience, TSS-fouled UIC wells are challenging to redevelop, even more so than biofouled wells. Therefore, sediment fouling should be avoided whenever possible. Part of an effective TSS management policy is to prevent construction site runoff from entering UIC wells, as it can have elevated TSS levels. UIC wells should be also protected from receiving runoff from recently landscaped areas until those areas have stabilized, in accordance with the locally applicable stormwater manual. 7.0 CONCLUSIONS AND RECOMMENDATIONS Based on our observations at the current borings and our previous site test pits and shallow borings, the infiltration potential of the site's shallow native soils is generally low. Infiltration of some stormwater at dispersed facilities is feasible on portions of the site (Shannon & Wilson, 201.6b). In general, shallow site soils are not feasible for the concentrated infiltration of large volumes of stormwater, but infiltration into the underlying unsaturated, relatively low -fines - content Qva soils is feasible. 7.1 Injection Well Recommendations 7.1.1 General We recommend that the UIC well construction activities of the District's drilling contractor be observed by the District's own hydrogeologic/geotechnical representative, under separate contract to the District. We recommend that the selected drilling contractor submit a drill plan and qualifications to the District's hydrogeologic/geotechnical representative for approval prior to beginning work. During UIC well installation, we recommend that we provide field observation of UIC well installation and field testing, as the District's representative, so that timely adjustments to array layout can be made, if needed. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 14 SHANNON MILSON, INC. Based on the IW-1 and IW-2 inflow tests, the use of UIC wells at the project site is feasible for stormwater management. The top of the target infiltration zone (unsaturated, sandy Qva soils with predominantly low fines content) is about 60 to 61 feet bgs at the locations explored by OW-1, OW-2, IW-1, and IW-2. The depth to this contact may vary across the site. Based on the OW-1 log, perched groundwater may be present in the Qva at about 132.5 feet bgs in that area. The top of the regional Qva aquifer is at about 167 feet bgs. Ecology does not allow stormwater to be discharged directly into an aquifer via UIC wells. We recommend that the UIC well depths be limited to about 1.15 to 120 feet (approximately 330 to 325 feet), which will allow for up to about 47 feet of separation between the UIC wells and the top of the Qva aquifer. We understand that the District proposes to install UIC wells in four array clusters, with. UIC wells spaced approximately 30 to 50 feet apart (Figure 10). We recommend the wells be spaced no closer than 30 feet on center in order to reduce interference between the wells. Greater spacing creates less interference and results in more efficient UIC well operation. We recommend that the newly installed UIC wells be flow tested shortly after installation in order to confirm the expected UIC performance assumptions. 7.1.2 Well Design Recommendations There are two general types of deep UIC well designs in common use locally. These include: (a) large -diameter boreholes filled with sand and/or gravel infiltration media (with or without a vertical transmission casing and screen), and (b) traditional screened wells, which have a smaller filter -packed zone around the well screen or no artificial filter pack at all. Based on our communication with the project team, we understand that the former, option a, is planned for the project, and we have based our design recommendations on this understanding. Auger rigs are commonly used to perform this type of drilling. Auger drilling and installation techniques typically involve drilling a cased hole through the zone through which a seal will be placed and an open or temporarily cased hole in the infiltration receptor zone. Drilling is typically accomplished with a solid stem or bucket auger. Unit cost estimates for drilling and installing this type of UIC well are roughly $30,000 to $40,000, excluding surface vault and distribution system completion, spoils handling, well development, and field testing. Unit well drilling costs are greater if few wells are installed. Based on our explorations and testing and assuming similar conditions as encountered at by the four deep site borings, the recommended full-scale UIC well short-term specific capacity estimate is 6.7 gpm/foot of screen. Assuming good control over TSS and nutrients and relatively 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 15 SHANNON MILSON, INC. uniform site conditions, we recommend applying a divisive correction factor (CF) of 2 to this UIC well capacity. Applying this CF results in a UIC well design specific capacity of about 3.3 gpm/foot of screen in the unsaturated Qva. This assumes the UICs will have similar construction to IW-2, with a minimum diameter of 24 inches and total depth of about 1.1.5 to 1.20 feet. Our UIC well design recommendations are presented below and are illustrated in Figure 9. Figure 9 conceptually illustrates construction aspects of a hybrid UIC well that combines infiltration media backfill with a vertical transmission casing and screen. The actual well depths and construction methods and details may differ, based on encountered hydrogeologic conditions and project goals. Construction steps include the following: ■ Drill a large -diameter hole (e.g., 36- to 40-inch) to facilitate construction of a surface seal. This borehole should be drilled to about 1 to 5 feet below the base of the Qvt/Qvd/saturated upper Qva soils (contact estimated to be about 60 to 65 feet bgs, or about elevation 385 to 380 feet). Maintain an open borehole through this upper zone using a temporary casing. The borehole diameter should be at least 4 inches larger than the nominal diameter of the planned permanent surface casing. Drill a smaller diameter hole (e.g., 24-inch) from the depth of the bottom of the planned permanent surface casing to about 50 to 60 feet into the unsaturated Qva soils (total depth of about 1.1.5 to 1.20 feet, or to about elevation 330 to 325 feet). Alternatively, temporary casing may be used to drill to the bottom of the hole. No drilling additives should be used, with the possible exception of water. Install a permanent 30- to 36-inch inside diameter (I.D.) steel casing. This casing should be installed to about 1 to 5 feet below the base of the larger diameter hole. Construct a surface seal between the permanent casing and the borehole annulus. The intent of the surface seal is to (a) protect the Qva infiltration receptor soils from direct inflows of surface water and (b) prevent the draining of the overlying perched zones. Depending on drilling approach, the permanent surface casing and seal may be placed before or after the boring is drilled to its final depth and the vertical transmission casing/screen assembly is installed. We recommend the lower portion of the surface seal consist of bentonite chips (minimum 10 feet thick). Then place additional sealing material (bentonite, neat cement, or neat cement grout, in accordance with Washington Administrative Code (WAC) 173-160 sealing requirements) from the top of the bentonite chip seal to the ground surface. The lower bentonite chip seal should be installed in such a way so as to prevent the upper annular sealants from intruding into the target infiltration soils or the interior of the permanent surface casing. Install the vertical transmission casing. We recommend using 8-inch LD casing and screen. Concurrently install to the same depth a polyvinyl chloride (PVC) observation pipe casing and screen. (The purpose of the PVC pipe is to facilitate measurement of the water level in the UIC well during periods of stormwater inflow 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 16 SHANNON MILSON, INC. Use steel centralizers on the 8-inch T.D. casing and screen, on about 20-foot centers, and secure the PVC pipe to the centralizers. Backfill the 24-inch borehole around the 8-inch I.D. screen with washed, rounded, UIC 4x8 filter sand. If temporary casing was not used to drill the lower borehole, it may be necessary to tremie the filter into place in order to reduce borehole wall caving. Extend the UIC 4x8 filter sand to about 5 feet above the depth of the permanent surface casing. Once the UIC 4x8 filter sand has been placed, we recommend using water to settle it around the screened zone, topping off the UIC 4x8 sand as necessary to bring it back to about 5 feet inside the permanent casing. We recommend placing UIC gravel around the pipes within the permanent surface casing, to approximately 4 feet below the planned invert of the inlet pipe into the permanent storm drain manhole (SDMH). Perform flow testing after the UIC gravel has been emplaced, topping off the gravel as necessary. During installation of the permanent SDMH, we recommend placing two layers above the UIC gravel, consisting of a 6-inch minimum layer of UIC 4x8 filter sand and a 6-inch minimum layer of UIC filter sand. The intent of the UIC filter sand is tc provide supplementary filtering of low -quantity UIC inflows. The UIC filter sand should be replaced as it becomes clogged. To protect the upper UIC filter sand from erosion, we recommend placing a pad of quarry spalls (approximately 6 inches thick) within the SDMH, with the top of the pad about 6 inches below the inlet pipe elbow. The permanent steel surface casing should be cut off approximately 3 feet below the invert of the inlet pipe to the SDMH. To maintain UIC well function, it is critically important to protect the UIC wells from TSS loading while the site is under construction, as well as during normal site use. No construction -related stormwater should be discharged to the UICs, and the site should be fully stabilized prior to bringing the UICs online. Accordingly, we recommend that, while the site is under construction and not fully stabilized, and prior to installation of the permanent SDMH over a UIC, the UIC's steel surface casing be left temporarily slightly above grade. We recommend that the top of the surface casing be temporarily protected with a welded top plate or a locking monument until the permanent SDMH is installed. During UIC operation, we recommend a combination of source control measures and pre-treatment to the site stormwater to remove or reduce the expected types and quantities of pollutants prior to its being discharged to the UIC arrays, in accordance with the local stormwater code (City of Edmonds, 2010).and the UIC Guidance (Ecology, 2006). 7.1.3 Injection Well Materials We recommend the following materials be used for UIC well construction: ■ UIC Vertical Transmission Casing, Screen, and Bottom Cap. Due to its high durability and high open area relative to PVC machine -slotted screen, we recommend using stainless steel screen in the UIC wells. The recommended UIC vertical 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 17 SHANNON MILSON, INC. transmission casing, screen, and bottom cap material is 8-inch I.D., 304 stainless steel, with threaded or welded • The recommended screen is continuous -slot (0.020-inch slots), approximately 50 feet long. Steel centralizers on approximately 20-foot centers are recommended to facilitate placement of the casing in the center • the borehole. We recommend that the screened interval be installed in a borehole with a diameter of approximately 24 to 36 inches. UIC Observation Pipe Casing, Screen, and Bottom Cap. The recommended Ul vertical •• pipe casing, screen, and •i cap material is 2-inch I.D., Schedule 40 or Schedule 80 PVC with threaded joints. The recommended screen i factory machine -slotted (0,020-inch slots), approximately 10 feet long. We recommend that the top of the pipe be equipped with a removable watertight plug. We • that the PVC pipe be •1 to the transmission casing centralize] UIC Surface Casing and Seal. The recommended UIC surface casing is steel, 30- to 36-inch I.D., meeting ASTM International A53 A or B, with 0.375-inch wall thickness and with welded or threaded joints. We recommend the surface casing be -• in a borehole that is at least 4 inches larger in • than the nominal surface casing diameter. We recommend seal materials meeting the WAC 173-160 Sealing Material Standard • placed in the annulus •' the permanent steel surface casing and the borehole wall. We recommend that the bottom of the annular seal material • of • chips (minimum 10 feet thick). Above the bentonite chips, we recommend that the annular seal consist of neat cement, neat cement grout, or bentonite, in accordance with WAC 173-160. medium specification, with a recommended gradation of: U.S. Standard Sieve Size Percent Passing % (9.5 millimeter [mm]) 100 4 (4.75 mm) 95 to 100 8 (2.36 mm) 70 to 100 16 (1.18 mm) 40 to 90 30 (0.60 mm) 25 to 75 50 (0.30 mm) 2 to 25 100 (0.15 mm) <4 200 (0.075 mm) <2 draining, rounded, granular material, with a gradation of: 21-1-22082-003-R] fwp/lkn 21-1-22082-003 18 SHANNON MILSON, INC. MT, % (9.5 mm) 4 (4.75 mm) 8 (2.36 mm) 30 (0.60 mm) 200 (0.075 mm) In UIC Gravel. We recommend the UIC gravel consist of free -draining, rounded, granular material, with a gradation of. 1/2(1.2.5mm) % (9.5 mm) 4 (4.75 mm) 8 (2.36 mm) 100 (0.1.5 mm) Percent Passing 100 80 to 100 5 to 15 0 to 10 0 to 0.6 Filter materials used in UIC construction should be should be: ■ Free from organics, debris, or other deleterious material. ■ Stockpiled in such manner that they are protected from contamination by other site materials (e.g., fine sediment) and from segregation by rainfall, as appropriate. 7.2 Additional Recommendations We recommend that the performance of the UIC clusters be monitored so that UIC array performance over time can be tracked and appropriate maintenance or UIC well rehabilitation scheduled. We recommend the installation and monitoring of data logging transducers in some or all of the wells, coupled with periodic manual water level measurements. We recommend that a regular and perpetual maintenance program be performed for all of the site infiltration facilities to reduce siltation and bio-fouling, in accordance with the local stormwater code requirements. Groundwater observation wells should be protected through the facility construction process and be used to facilitate measurement of facility performance. If the wells are damaged during construction, they should be repaired or properly abandoned, in accordance with WAC 173-160. If the District desires to monitor the downstream effects of the planned UIC array, then we would recommend the installation of downgradient observation wells prior to the UIC arrays being brought online. Such wells could function as monitoring points for measuring variations in Qva aquifer water levels (and, if desired, for tracking aquifer water quality over time). Appropriate locations for such wells are to the west/northwest of the planned UIC arrays. These might be 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 19 SHANNON MILSON, INC. drilled at or beyond the toe of the slope but still on the District property. If these wells are installed, then an additional observation well installed upgradient (east) of the UIC array would also be useful in measuring Qva aquifer water levels and possibly background water quality. As indicated by Figure 4, the project site is within the mapped ten-year time -of. -travel zone of the water supply protection area for the Deer Creek municipal water supply surface water source. We recommend coordinating stormwater infiltration efforts in the project area with the Olympic View to facilitate their compliance with Washington State Department of Health source water protection requirements established under the Watershed Control Program. Olympic View's water supply protection plan (plan) for Deer Creek (PACE, 2002) notes that Olympic View does not maintain any authority over land use regulations and requirements. However, Olympic View's plan recommends the following regulatory and protective measures be considered by land use agencies (i.e., City of Edmonds), as applicable to the ten-year capture zone illustrated in Figure 4: ■ Encourage public education as being critical to the overall effectiveness of protecting the Deer Creek water supply. ■ Discourage use of chemical fertilizers. ■ Require that oil- and detergent -based waste materials be treated by the sanitary sewer system, as appropriate. ■ Encourage protection of surface water bodies and groundwater wells through public awareness. ■ Cooperate with land use and emergency response agencies (i.e., implement a spill response plan, with accompanying notification of the proper authorities and Olympic View of potential threats to the water supply system). 8.0 LIMITATIONS The analyses, conclusions, and recommendations contained in this report are based on site conditions as they presently exist. We assume that the current field explorations are representative of the subsurface conditions at the proposed infiltration facilities; i.e., the subsurface conditions everywhere in the vicinity of the proposed infiltration facilities are not significantly different from those disclosed by the field explorations. Within the limitations of the scope, schedule, and budget, the analyses, conclusions, and recommendations presented in this report were prepared in accordance with generally accepted professional geotechnical and hydrogeologic principles and practice in this area at the time this report was prepared. We make no other warranty, either express or implied. These conclusions and recommendations were based on our understanding of the project as described in this report and the site conditions as 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 20 allANNON &WILSON, INC interpreted from the field explorations. Regulatory agencies may reach different conclusions than Shannon & Wilson. Unanticipated soil conditions are commonly encountered and cannot be fully determined by merely taking soil samples or completing test explorations. Such unexpected conditions frequently require that additional expenditures be made to attain a properly constructed project. Therefore, a contingency fund is recommended to accommodate such potential extra costs. This report was prepared for the exclusive use of the District. It should be made available to prospective contractors for information on factual data only, and not as a warranty of subsurface conditions such as those interpreted from the exploration logs and presented in the discussions of subsurface conditions included in this report. Shannon & Wilson has prepared Appendix E, "Important Information About Your Geotechnical/Environmental Deport," to help you understand the use and limitations of our report. Apart from the baseline Qva aquifer groundwater sampling at well OW-1, the scope of our services did not include an environmental assessment or evaluation regarding the presence or absence of hazardous or toxic materials in the soil, surface water, groundwater, or air, on or below or around the site, Shannon & Wilson has qualified personnel to assist you with these services should they be necessary. 3030 ast Paul L. Van Horne, LHG Martin Pages PE, LEG Senior Hydrogeologist Vice President TM Geotechnical Engineer, LEER, AP, DBIA PV :SDT:MWP/pvh Report elements related to hydrogeology, geology, and geologic unit designations and descriptions were prepared by or under the direct supervision of Paul L. Van Horne, LHG. General report quality assurance and report elements related to soil descriptions were provided by Martin W. Page, PE, LEG. 21-1-22082-003-RIfiwpnkn 21-1-22082-003 21 SHANNON MILSON, INC. 9.0 REFERENCES CDM, 2006, Geotechnical data report, Brightwater conveyance system, west contract, Report prepared for King County Department of Natural Resources and Parks, Wastewater Treatment Division, by CDM, Bellevue, Wash., July. City of Edmonds, 2010, Stormwater code supplement to Edmonds Community Development Code Chapter 18.30: Edmonds, Wash., April 20. Harbaugh, A.W., 2005, MODFLOW-2005: the U.S. Geological Survey modular ground -water model -- the ground -water flow process: U.S. Geological Survey Techniques of Water - Resources Investigations :Book 6, Chapter A1.6, 1 v., available: https-.//pubs,us s,gov/tm/2005/tm6A16/. Minard, J.P., 1983, Geologic map of the Edmonds east and part of the Edmonds west quadrangles, Washington: U.S. Geological Society MF-1541, 1:24,000 scale. National Research Council (NRC), 1994, Ground water recharge using waters of impaired quality: Committee on ground water recharge, Water science and technology board, Commission on geosciences, environment, and resources: National Academy Press, Washington, D.C., 304 p. Penhallegon Associates Consulting Engineers, Inc. (PACE), 2002, Deer Creek water supply protection plan: Report prepared by PACE, Kirkland, Wash., for Olympic View Water & Sewer District, Edmonds, Wash. Puget Sound Action Team, 2005, Low impact development technical guidance manual for Puget Sound: Olympia, Wash., publication no. PSAT 05-03, May. Puget Sound Partnership, 2012, Low impact development technical guidance manual for Puget Sound: Tacoma, Wash., December. Shannon & Wilson, Inc. (Shannon & Wilson), 2013, Final infiltration study report, SW Edmonds basin study projects #1 and #3, Edmonds, Wash.: Report prepared by Shannon & Wilson, Inc., Seattle, Wash., project no. 21-1-21768-001, for City of Edmonds, Edmonds, Wash., April 5. Shannon & Wilson, Inc. (Shannon & Wilson), 2016a, Revised wetland and stream delineation report, New Madrona .K-8 Project, City of Edmonds, Wash.: Report prepared by Shannon. & Wilson, Inc., Seattle, Wash., project no. 21-1-22082-002, for Edmonds School District #1.5, Lynnwood, Wash., August 4. 21-1-22082-003-Rlfrwp/]kn 21-1-22082-003 22 SHANNON MILSON, INC. Shannon & Wilson, Inc. (Shannon & Wilson), 2016b, Geotechnical engineering report, New Madrona K-8 Project, 9300 236th Street SW, Edmonds, Wash.: Report prepared by Shannon & Wilson, Inc., Seattle, Wash., project no. 21-1-22082-004, for Edmonds School District #15, Lynnwood, Wash., October 31. Thomas, B. E.; Wilkinson, J. M.; and Embrey, S. S., 1997, The ground -water system and ground- water quality in western Snohomish County, Washington: U.S. Geological Survey Water - Resources Investigations Report 96-4312, 218 p., 9 plates. Washington State Department of Ecology (Ecology), 2005, Stormwater management in Western Washington: Olympia, Wash., publication no. 05-10-31, 5 v., February. Washington State Department of Ecology (Ecology), 2006, Guidance for UIC wells that manage stormwater: Olympia, Wash., publication no. 05-10-067, December. Washington State Department of Ecology (Ecology), 2016a, Washington State water resources explorer: Available: htts://fortress,wa,ovlec�lwaterresourceslmap/WCLSWebMa�lWaterResourcesExplorer.as x , accessed November 17, 2016. Washington State Department of Ecology (Ecology), 2016b, Washington State well log viewer: Available: htt s:llfozess.wa. ovlec lwaterresourceslma 1WCLSWebMa /default.as x , accessed November 17, 2016. 21-1-22082-003-Rlfwp/]kn 21-1-22082-003 23 O LEGEND 0 200 400 .. Data Point and Designation Wetland Boundary Scale in Feet Wetland Buffer ow ® Observation Well Designation and Approximate Location N iw-j 0 Dry Well Designation and Approximate Location At Generalized SITE A Subsurface Profile NOTE Map adapted from aerial imagery provided by Google Earth Pro, reproduced by permission granted by Google Earth TM Mapping Service. 0 0 J O 0 2000 4000 Approximate Scale in Feet LEGEND MI - Modified Land QJg - Landslide Deposits QVr - Vashon RecessionalOutwash QVt - Vashon Till QVa - Vashon Advance Outwash Qtb - Transitional Beds QW - Whidbey Formation PROJECT SITE NOTE Map adapted from 1:24,000 USGS geologic map of the Edmonds East and Part of the Edmonds West, WA quadrangle, dated 1983. Filename: J:\211\22082-003\21-1-22082-003 Fig 4.dwg Date: 11-18-2016 Login: SAC NOTES 1. Base map taken from Deer Creek Water Supply Protection Plan, (PACE, 2002). 2. Aquifer gradient direction based on project wells and City of Edmonds Well A-2. Approximate gradient equals 0.002 feet/foot. 0 2000 4000 Approximate Scale in Feet ONon -Project Well Designation and Approximate Location Approximate Aquifer ww Gradient Direction A West 500 450 ME m m LL c 0 a � 350 w m co E X 0 Q Q Q M 250 W11 150 Project Area A' East 500 450 400 m m ILL c 0 350 w m E X 0 is CL Q M WE M 150 LEGEND OW-1 — Observation Well Designation IW-1 —. Dry Well Designation (Proj. 9' S) — Projection Distance and nirartinn Ground Surface Possible Perched Zone Approximate Geologic Contact Vibrating Wire Piezometer Filter Pack Well Screen Bottom of Well --r-o Seep 1 Regional Groundwater Level Perched Groundwater Level GEOLOGIC UNIT Hf Fill Qvat Vashon Ablation Till Qvt Vashon Lodgement Till Qvd Vashon Till -like Deposits Qva Vashon Advance Outwash Qtb Transitional Beds (Fine Grained) 0 50 100 Vertical Scale in Feet 0 200 400 Horizontal Scale in Feet Vertical Exaggeration = 4X Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington GENERALIZED SUBSURFACE PROFILE A -A' November 2016 21-1-22082-003 SHANNON & WILSON, INC. FIG. 5 Geotechnical and Environmental Consultants B South 500 460 420 380 m W 340 300 260 220 180 140 B' North 500 460 420 :I 340 W 260 220 180 140 0 E X 0 CL 0_ Q LEGEND OW-1 Observation Well Designation JW_J .. Dry Well Designation (Proj. 9' S) — Projection Distance and nirarfinn Ground Surface Possible Perched Zone Approximate Geologic Contact Vibrating Wire Piezometer Filter Pack Well Screen Bottom of Well --r-o Seep 1 Regional Groundwater Level Perched Groundwater Level GEOLOGIC UNIT Hf Fill Qvat Vashon Ablation Till Qvt Vashon Lodgement Till Qvd Vashon Till -like Deposits Qva Vashon Advance Outwash Qtb Transitional Beds (Fine Grained) 0 40 80 7 - Vertical Scale in Feet 0 100 200 Horizontal Scale in Feet Vertical Exaggeration = 2.5X 61 E - - ' 130 120 --` _ _ -'___- E i ;... j -*- '----- - -'--- -" , r fr yl t5},tilt i314j}jt}ir t{}}Yj {{ji�}4 i fkti£ft?ui �15,#,t{tFf}Z I}f�t+ri3£})}£7.Ft{4{l Slt{7E;3}tyff„Si�tZ tr> jf ,£IStY i{4r}t{tzk i...rf#, _- y, F. , + Fa �f �l S � t 3 S �, � ��tl i £ �Z F} t rf�t S$�}•li���j4Yij�{�"'���j i�+ i� tt {' t fl� fr{ ' 66 tt2 /,ram 11 `tij {R{ } i}£ tti tlY.F il,{ .- - ­- ------ .. .... ._. ------ ­- - ­-­ -­--­ - ------o e n Depth Top of Screen 100 , n 71 - - — — Bottom of Screen Depth 90 E .J o Q- a) a, - - ; IW-1 Transducer Data 80 76 Approximate Inflow Rate 70 c o _. - - m- - m 60 E Q 0 X 0 81 _ u u 50 CL C 40 86 _ _ - -- - - 30 .. -, 91 10 0 100 200 300 400 500 600 700 800 900 1000 Elapsed Time (Minutes) NOTES Hydrogeologic Report New Madrona K-8 Project 1. The dry well injection test at test well IW-1 was performed from 10:03 to 18:34 on 4/25/2016. Edmonds, Washington IW-1 is screened at approximately 63.3 to 90.4 feet below grade, with filter pack from 59.2 to 91.2 feet deep. Borehole diameter was approximately 10.5 inches, drilled to 91.2 feet. INFLOW TEST T RESULTS AT 2. Tap water (44,107 gallons) was introduced at the top of the 6-inch-diameter PVC casing, using a fire hydrant. 1gpm = gallons per minute PLOT UIC WELL IW-1 -n 4. Fire hydrant flow became inconsistent late in test, possibly due to increased local water demand. G) 5. Black and white reproduction of this color original may lead to incorrect interpretation. November 2016 21-1-22082-003 y SHANNON & WILSON, INC. FIG. 7 Geotechnical and Environmental Consultants IW-1-IW-1 Plot LL-11/22/2016-pvh 50 M go a� 80 am 90 0 a) m s 100 m is 110 120 140 120 100 a� m 80 c a� m E 60 0 CL CL Q CIi] 20 130 W 0 0 200 400 600 800 1000 1200 Elapsed Time (Minutes) NOTES 1. The injection test at dry well IW-2 was performed from 10/11/2016 9:09 to to 4:09 on 10/12/2016. IW-2 screen is approximately 28.3 to 119.7 feet below grade, with filter pack from about 3 to 120.4 feet deep. Filter -packed hole diameter is 30 inches from 0 to about 44 feet and approximately 24 inches from 44 to 120.4 feet. Steel 30-inch-diameter surface casing was sealed in place to 60.5 feet deep. The surface seal extends down to about 62 feet deep. 2. Tap water (153,933 gallons) was introduced at the top of the filter -packed borehole, using a fire hydrant. 8-inch stainless steel screen (20-slot) is exposed to the formation from about 62 to 119.7 feet. 3. gpm = gallons per minute 4. Black and white reproduction of this color original may lead to incorrect interpretation. were .fie .fie IW-2-IW-2 Plot LL-11/22/2016-pvh W 0 N N N N (6 UIC Filter Sand for Supplementary Filtering (Min. 6" Thick, To Replace as Needed) N uarry Spalls Pad (-6" Thick) UIC 48 Filter Sand, Washed, Rounded \ (Min. 6" Thick) Base of QvVQvd or 2" 0 Threaded, Sch. 40 or Sch. Base of Perched 80 PVC Blank Casing, Top Min. Qvd/Qva Aquifer, 6" Above Top of 8" 0 Casing Whichever is Deeper- ? Unsaturated Qva 1-5' Below Contact Deposits 8" 0, 304 Stainless Steel Blank Casing, Threaded or Welded Joints i Geologic Contact (Est. Depth 60-70', As Identified by Engineer's Representative) —10' of 2" 0, Threaded, Machine Slotted, Sch. 40 or Sch. 80 PVC Screen (0.020" Slots) 2" 0 Threaded PVC End Cap Temporary UIC Well Vault with Welded or Locking Cover (To Be Replaced Later By Storm Drain Manhole) Bentonite, Neat Cement, or Neat Cement Grout Seal 8" 0 Threaded or Welded 304 Stainless Steel End Cap Minimum 5' —115-120' Seasonal High Qva Aquifer Water Level— Qva Aquifer Not to Scale NOTES Surface casing and seal to conform to WAC 173-160. 2. Employ best management practices, as appropriate and following approved stormwater manual, to provide any required pre-treatment to water discharged to UIC wells. 3. Provide steel centralizers for 8" 0 casing and screen, installed on approximately 20' spacing. Stormwater from Distribution Manifold, Pretreated As Appropriate 36-40" 0 Borehole, Min. 4" Larger Than Surface Casing Bentonite Chip Seal (Min. 10' Thick) Steel Surface Casing (30-36" 0, 0.375" Wall Thickness) UIC Gravel, Washed, Rounded 24"-36" 0 Borehole UIC 4x8 Filter Sand, Washed, Rounded —50' of 8" 0, Continuous -Slot, 304 Stainless Steel Screen (0.020" slots), Threaded or Welded Joints. * (Required separation may be greater depending on pre-treatment, groundwater mounding potential, vadose zone treatment capacity, and pollutant loading.) q2tAD AVIE gi E%X 77`5 ....... . ....... .... .. .. ----- - - - - - ® - - - - - - - - - g so C OBS-4 Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington PROPOSED UIC WELL ARRAY MAP November 2016 21-1-22082-003 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants I FIG. 10 SHANNON WLSON, INC SUBSURFACE EXPLORATIONS 21-1-22082-003 APPENDIX A SUBSURFACE EXPLORATIONS • : a 0 Page A.1 GENERAL...................................................................................................................... A-1. A.2 SOIL BORINGS............................................................................................................. A-1 A.2.1 Sonic Core Borings........................................................................................... A-1. A.2.2 Auger Boring.................................................................................................... A-2 A.3 SOIL SAMPLING AND LOGGING............................................................................. A-3 A.4 WELL AND VIBRATING WIRE PIEZOMETER (VWP) INSTALLATION ............. A-3 A-1 Summary of Well Installation Details A-2 Summary of Vibrating Wire Piezometer Installation Details FIGURES A-1 Soil Description and Log Key (3 sheets) A-2 Log of Sonic Core IW-1 A-3 Log of Boring IW-2 A-4 Log of Sonic Core OW-1 A-5 Log of Sonic Core OW-2 21-1-22082-003-Rlf-AA/wp/lk 21-1-22082-003 A-i SHANNON WILSON, APPENDIX A SUBSURFACE EXPLORATIONS The subsurface exploration program for the project was conducted by Shannon & Wilson, Inc. (Shannon & Wilson). The purpose of the exploration program was to evaluate the feasibility of deep underground injection control (UIC) wells for use in project site stormwater management. The subsurface exploration program consisted of three sonic core soil borings and one auger boring. The sonic core borings included a pilot UIC well (IW-1) and two observation wells (OW-1 and OW-2). Holt Services, Inc. (Holt) of Edgewood, Washington, completed the sonic core borings between April 4 and 21, 2016 (OW-1, IW-1), and between August 1.7 and 1.9, 2016. (OW-2), under subcontract to Shannon & Wilson. A full-scale UIC well (IW-2) was installed in the auger boring. Malcolm Drilling Company, Inc. (Malcolm) of Kent, Washington, completed IW-2 between October 5 and 6, 2016,.under subcontract to Shannon & Wilson. We measured the approximate well locations in relation to previously mapped site features. PACE Engineers, Inc. provided surveyed well monument lid elevations for OW-2 and IW-2, and we measured the approximate monument and grade elevations at IW-1 and OW-1 based on the data provided for OW-2. Figure 2 shows the approximate exploration locations. Figure A-1 presents a Soil Description and Log Key that explains the terms used in the soil classifications and descriptions. The logs of the soil borings are presented as Figures A-2 through A-5. Approximate grade elevations are presented on the logs. A.2 SOIL BORINGS A.2.1 Sonic Core Borings Holt drilled the sonic core soil borings using a track -mounted, Terra Sonic International 150CC Compact Crawler sonic drill rig. Observation well boring OW-1 was completed on April 7, 2016, to a depth of 185.5 feet below ground surface (bgs). The pilot UIC well boring (IW-1) was completed on April 21, 2016, to 91.2 feet bgs. Observation well boring OW-2 was completed on August 19, 2016, to 190 feet bgs. Holt used the rotosonic (sonic) drilling method to drill the borings. Sonic drilling uses high -frequency vibratory motion applied to the top of the drill column, along with down pressure 21-1-22082-003-Rlf-AA/wp/lk 21-1-22082-003 A-1. SHANNON WILSON, and rotation, to obtain nearly continuous core samples of soil. Soil samples were obtained using a 4-inch inside diameter (I.D.) core barrel for the observation well installation and a 7-inch I.D. core barrel for the pilot UIC well installation. As the drill column was advanced into the ground, soil entered the core barrel. After advancing the core barrel (termed a core "run"), the core barrel was removed from the borehole, and the soil core was extracted from the core barrel into labelled plastic bags. Each core run was typically about 10 feet long, although shorter runs were used in harder drilling situations. After retrieval of the soil core for a specific interval, a temporary casing was vibrated to the bottom of the sampled interval. The casing was then cleared of slough, and the drill column and core barrel were advanced, starting at the bottom of the temporary casing. Drilling and sampling progress was generally easier at the larger diameter sonic core boring, IW-1, where the 7-inch core barrel was used, than at OW-1 and OW-2, where the 4-inch core barrel was used. The fines content in some samples appeared to be lower in the larger diameter IW-1 sonic core samples that in the smaller diameter sonic core samples collected from OW-1 at the same depths. Holt's opinion was that the larger diameter tooling used at IW-1 allowed coarse gravels and cobbles to more easily enter the core barrel during sampling. When penetrating unsaturated soils, sonic core drilling and sampling were also easier if water was added during the sampling runs. Generally, the sonic core runs were drilled without adding water, so that the locations of perched groundwater zones, if any, could better be estimated. Holt drummed the sonic core drill cuttings and spoils, removing them for disposal after the completion of each sonic core boring. A.2.2 Auger Boring Malcolm completed the full-scale UIC well IW-2 on October 6, 2016,.to 1.20.4 feet bgs. Malcolm used a Bauer BG-24 track -mounted auger drill rig to drill IW-2. Malcolm initially drilled open -hole to about 56 feet bgs. Some caving occurred at 51 to 56 feet, so Malcolm proceeded to install temporary (one -meter diameter) casing to maintain an open borehole to 61 feet. Malcolm drilled the remainder of the boring open -hole with 24-inch auger. Malcolm used a crane to install the permanent steel surface casing to 60.5 feet deep prior to completing the drilling of the boring. Malcolm placed the 30-inch I.D. steel surface casing to 60.5 feet deep and sealed it in place. Before placing the permanent surface casing, a bentonite chip seal was installed at 59.5 to 62 feet. The 30-inch I.D. casing was then temporarily backfilled with cuttings to 30 feet deep and cemented in place. The temporary one -meter diameter casing was then removed, and the cement was allowed to cure overnight. The top of cement was 1.0 feet bgs the 21-1-22082-003-Rlf-AA/wp/lk 21-1-22082-003 A-2 SHANNON WILSON, next morning, and bentonite chip seals were placed from 7 to 10 feet bgs and at 0 to 1 foot. The temporary backfill placed at 1 to 7 feet consisted of filter sand. The upper 10 feet of temporary annular backfill will be replaced when the project moves to construction. Cement was found to have intruded the temporary spoils inside the 30-inch casing up to about 44 feet below grade; this material was drilled out using a 24-inch solid stem auger and was separately stockpiled from the other borehole cuttings. Some caving was experienced during drilling at about 51 feet and again at about 99 feet; these zones are identified on the boring log. Malcolm switched from a solid stem auger to a bucket auger at 101.5 feet deep to reduce caving. Auger boring IW-2 was drilled without adding water. We noted that the fines content of the auger cuttings appeared to be lower than that observed in the samples collected from similar depths at adjacent the OW-2 sonic core boring (Appendix B). Most of the auger spoils from the IW-2 boring were disposed of by Clearcreek Contractors, Inc., of Marysville, Washington. Auger spoils that were intruded by cement during the installation of the permanent IW-2 surface casing seal were disposed of by Bravo Environmental NW, Inc., of Seattle, Washington, under subcontract to Malcolm. A.3 SOIL SAMPLING AND LOGGING Shannon & Wilson representatives observed and logged the drilling operations at each of the sonic core borings (IW-1, OW-1, and OW-2) and the auger boring (IW-2). We photographed and collected sub -samples of the IW-1 and OW-2 soil cores in field, and also logged cuttings and collected grab samples from the auger boring, IW-2. Shannon & Wilson geologists logged and photographed the OW-1 soil cores in Shannon & Wilson's warehouse. Shannon & Wilson geologists also reviewed the IW-1, IW-2, and OW-2 photographs and samples. We transferred representative soil samples collected from the soil cores and auger cuttings to our Seattle, Washington, laboratory for analysis (see Appendix B). The boring logs in this report represent our interpretation of the field logs. A.4 WELL AND VIBRATING WIRE PIEZOMETER (VWP) INSTALLATION For the sonic core borings IW-1, OW-1, and OW-2, the wells were installed through the temporary casing, which was withdrawn as the annular backfill was placed. The wells were constructed of threaded Schedule 40 polyvinyl chloride (PVC) casing and machine -slotted (0.020-inch) PVC screen. The PVC casing was 6-inch I.D. for IW-1 and 2-inch I.D. for OW-1. and OW-2. The screened intervals were filter -packed with No. 10-20 Colorado silica sand. A bentonite chip surface seal was placed above each well's filter -packed zone. 21-1-22082-003-Rlf-AA/wp/lk 21-1-22082-003 A-3 SHANNON WILSON, In addition to the observation well, two VWPs were installed in OW-2. VWP1 was placed in a zone suspected of potentially containing perched water (at 66.3 feet bgs). VWP2 was placed in a zone where water might be expected to perch during an inflow test (at 146.3 feet bgs). The vertical transmission casing for UIC well IW-2 was constructed of threaded, 304 stainless steel, 8-inch I.D. blank casing and continuous -slot (0.020-inch) screen, with steel centralizers. Malcolm used a crane to install the 8-inch I.D. casing and screen after the borehole was completed to 120.4 feet bgs. The inside of the permanent 30-inch I.D. surface casing and the borehole annulus below the surface casing were filled with CalPortland Product 8700 (4x8) filter sand. A vertical observation pipe consisting of threaded, 2-inch I.D., PVC blank casing and machine -slotted screen (0.020-inch slots) was placed in the same borehole as the 8-inch I.D. casing and secured to the steel centralizers. Well construction details are presented on the boring logs in (Figures A-2 through A-5) and in Table A-1. Details of the VWP installations are presented in Table A-2. See Appendix C for further groundwater -related discussions. 21-1-22082-003-Rlf-AA/wp/lk 21-1-22082-003 A-4 SHANNON & WILSON, INC. TABLE A-1 SUMMARY OF WELL INSTALLATION DETAILS .. Olen A porn � . ; � � � � . , l?P rot; anax !n t? aln A ro' PP ,, . . AP' r x. � . " ry , l} h ► ; `. A r Rc rl . . . ; r o f d tic u ; M nuri ein l .- , ll mite t c dr vt l + s' ° . T of Otto T B 3 Filer l' creer Screen � cr r en : :, B. e . : W 1 and . Ee Flo Well Su gee Abo Run Bo a 0 e , ,a C in � � � . Be c► �i 1n � �� :, � fftek� A , �� �nt : � l�v�iti�� � �� � � � � l a>I ';'�o +� tv � le��tlt�n � +cree si�i . �B�tto burn Well T . .:. Inst llatxo Fle tan Grade E e t a x D Teter z Male l l l i a en El *allot z �jR,0 e � � Dept zt P o a ' Size- l 1[ ,t to Ran e , :Len % l rz Ele a on ., N ate eeh et (letnehes ces)eel... €eet) . e feet feet feet , £I chef} , (feet} (fet fe et . ; .{fet (lel} . Meet (eet lW-1 BJZ 272 4/21/2016 444.9 2.65 447.6 10.5 6; PVC 0.56 447.0 No. 10-20 59.2 91.2 385.7 - 353.7 0.020 63.3 90.4 381.6 - 354.5 27.1 93.0 354.1 0.45 8; Stainless IW-2 None 10/6/2016 444.4 0.30 444.7 24 Steel3 0.93 443.8 No. 4-8 2.0 120.4 442.4 - 324.0 0.020 28.3 119.7 416.1 - 324.7 91.4 120.3 323.5 0.58 OW-1 BJZ 265 4/7/2016 445.1 3.04 448.2 6.0 2; PVC 0.38 447.8 No. 10-20 170.0 185.5 275.1 - 259.6 0.020 175.4 185.0 269.8 - 260.1 9.7 188.0 259.7 0.34 OW-2 BJX 262 8/19/2016 444.7 0.00 1 444.7 6.0 2; PVC 0.83 443.8 No. 10-20 174.8 1 184.0 269.9 - 260.7 0.020 179.2 1 183.9 265.4 - 260.8 4.6 184.1 1 259.8 0.20 Notes: I Elevations based on client electronic survey file dated October 13, 2016, and on differential levels shot with reference to well OW-2 at north end of running track. The reference vertical datum is North American Vertical Datum of 1988 (NAVD 88). 2 Value shown was based on hand measurements during well construction. Unless otherwise noted, depths are referenced to ground surface. 3 At IW-2, a permanent surface casing (30-inch-diameter steel) was installed to 60.5 feet deep and cemented in place. The top of the 8-inch screen was extended up inside the 30-inch surface casing, and the interior of the 30-inch casing was filled with filter material. A 2-inch polyvinyl chloride (PVC) observation pipe was also installed at IW-2 within the 30-inch surface casing to 120.4 feet deep, screened from 60.3 - 120.2 feet deep with a 0.2-foot sump. Well OW-1 was developed on April 12, 2016, using a check valve -type inertial pump equipped with a surge block (Waterra); approximately 68 gallons of water were removed. Well OW-2 was developed on August 24, 2016, using a check valve -type inertial pump equipped with a surge block (Waterra); approximately 37 gallons of water were removed. Approx. = Approximate Ecology = Washington State Department of Ecology No. = Number 21-1-22082-003-R1 F TA-1 /wp/1k 21-1-22082-003 SHANNON & WILSON, INC. TABLE A-2 SUMMARY OF VIBRATING WIRE PIEZOMETER INSTALLATION DETAILS " Instrn�n+ent Inform Uyjm :Px t Gr'ounil " Bottom `ippi. nrfr b+ptf� Top" of itr arYri ► ; : Befa . Pro . Flits " . 11t r , , 'Pu L�ine�r atnrate� � � Ff � end VWP." Monument ,Ground' .'; l*aci; �'ac.' Eievatron Pressure Gage' Tlir�rit`. ; " fro Info l cio Qin, tunLI} rrface Eteaiio>Q '' itiage,' < eer Tmp?WP ature , " D " " j/digit}s OW-2 VWP1 BJX 262 8/19/2016 444.7 66.3 378.4 64.2 68.5 380.5 - 376.2 1624163 50 -0.01636 -0.01331 8930.3 20.7 OW-2, VWP2 BJX 262 8/19/2016 444.7 146.3 298.4 140.8 146.3 303.9 - 298.4 1624739 100 -0.02383 -0.002972 8879.9 20.9 Notes: I VWP = vibrating wire piezometer 2 Based on electronic client file provided on October 20, 2016. The reference vertical datum is the North American Vertical Datum of 1988. 3 Value shown was based on hand measurements during VWP construction. 4 Instrument is Geokon Model 4500S. 'Celsius = degrees Celcius /=per Approx. = approximate Ecology = Washington State Department of Ecology No. = Number psi = pounds per square inch 21a-22092-003-xtf TA-2/wpak 21-1-22082-003 PARTICLE SIZE DEFINITIONS Shannon & Wilson, Inc. (S&W), uses a soil identification system modified from the Unified Soil Classification System (USCS). Elements of the USCS and other definitions are provided on this and the following pages. Soil descriptions are based on visual -manual procedures (ASTM D2488) and laboratory testing procedures (ASTM D2487), if performed. S&W INORGANIC SOIL CONSTITUENT DEFINITIONS z CONSTITUENT Major FINE-GRAINED SOILS (50% or more fines)' Silt, Lean Clay, Elastic Silt, or Fat Clay3 COARSE -GRAINED SOILS jless than 50% finest_ Sand or Gravel' Modifying (Secondary) 30% or more More than 12% Precedes major coarse -grained: fine-grained: constituent Sandy or Grave11y4 Silty or Clayey3 15% to 30% 5% to 12% coarse -grained: fine-grained: Minor with Sand or with Silt or Follows major with Gravel4 with Clad constituent 30 or more total /o coarse -grained and 15% or more of a lesser coarse- second coarse - grained constituent grained constituent: is 15% or more: with Sand or with Sand or with Gravel s with Gravel s 'All percentages are by weight of total specimen passing a 3-inch sieve. 2The order of terms is: Modifying Major with Minor. 3Determined based on behavior. 4Determined based on which constituent comprises a larger percentage. 'Whichever is the lesser constituent. MOISTURE CONTENT TERMS Dry Absence of moisture, dusty, dry to the touch Moist Damp but no visible water Wet Visible free water, from below water table STANDARD PENETRATION TEST (SPT) SPECIFICATIONS Hammer: 140 pounds with a 30-inch free fall. Rope on 6- to 10-inch-diam. cathead 2-1/4 rope turns, > 100 rpm NOTE: If automatic hammers are used, blow counts shown on boring logs should be adjusted to account for efficiency of hammer. Sampler: 10 to 30 inches long Shoe I.D. = 1.375 inches Barrel I.D. = 1.5 inches Barrel O.D. = 2 inches N-Value: Sum blow counts for second and third 6-inch increments. Refusal: 50 blows for 6 inches or less; 10 blows for 0 inches. NOTE: Penetration resistances (N-values) shown on boring logs are as recorded in the field and have not been corrected for hammer efficiency, overburden, or other factors. DESCRIPTION SIEVE NUMBER AND/OR APPROXIMATE SIZE FINES < #200 (0.075 mm = 0.003 in.) ------------- SAND -- --------- Fine #200 to #40 (0.075 to 0.4 mm; 0.003 to 0.02 in.) Medium #40 to #10 (0.4 to 2 mm; 0.02 to 0.08 in.) Coarse #10 to #4 (2 to 4.75 mm; 0.08 to 0.187 in.) --------------- GRAVEL Fine #4 to 3/4 in. (4.75 to 19 mm; 0.187 to 0.75 in.) Coarse 3/4 to 3 in. (19 to 76 mm) COBBLES 3 to 12 in. (76 to 305 mm) BOULDERS > 12 in. (305 mm) RELATIVE DENSITY / CONSISTENCY COHESIONLESS SOILS COHESIVE SOILS - N, SPT, RELATIVE N, SPT, RELATIVE BLOWS/FT. DENSITY BLOWS/FT. CONSISTENCY < 2 Very soft < 4 Very loose 4-10 Loose 2-4 Soft 10-30 Medium dense 4-8 Medium stiff 30-50 Dense 8 - 15 Stiff > 50 Very dense 15 - 30 Very stiff > 30 Hard WELL AND BACKFILL SYMBOLS Bentonite <> Surface Cement Cement Grout >��.� Seal Bentonite Grout Asphalt or Cap Bentonite Chips Slough Silica Sand 11 r Inclinometer or l I Non -perforated Casing Perforated or Screened Casing m Vibrating Wire Piezometer PERCENTAGES TERMS'' z Trace < 5% Few Little 5 to 10% 15 to 25% Some 30 to 45% Mostly 50 to 100% 'Gravel, sand, and fines estimated by mass. Other constituents, such as organics, cobbles, and boulders, estimated by volume. 2Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org. MAJOR DIVISIONS GROUP/GRAPHIC SYMBOL TYPICAL IDENTIFICATIONS GW • 66 Well -Graded Gravel; Well -Graded Gravel with Sand Gravel GP o a° Poorly Graded Gravel; Poorly Graded Gravels (less than 5% fines) (more than 50% o D Gravel with Sand of coarse fraction retained on No. 4 sieve) Silty or Clayey GM ' Silt Gravel; Silt Gravel with Sand y y Gravel GC Clayey Gravel; Clayey Gravel with COARSE- 2/ (morethan fines) 1 Sand SOILS SW Well -Graded Sand; Well -Graded Sand (more than 50% retained on No. 200 sieve) Sand with Gravel (less than 5% fines) SP Poorly Graded Sand; Poorly Graded Sands Sand with Gravel (50% or more of coarse fraction passes the No. 4 Silty or SM Silty Sand; Silty Sand with Gravel sieve Clayey Sand (more than 12% fines) SC Clayey Sand; Clayey Sand with Gravel ML Silt; Silt with Sand or Gravel; Sandy or Gravelly Silt Inorganic Silts and Clays CL Lean Clay; Lean Clay with Sand or (liquid limit less Gravel; Sandy or Gravelly Lean Clay than 50) Organic OL =— Organic Silt or Clay; Organic Silt or Clay with Sand or Gravel; Sandy or FINE-GRAINED SOILS _ _ — — — Gravelly Organic Silt or Clay (50% or more passes the No. 200 sieve) MH Elastic Silt; Elastic Silt with Sand or Gravel; Sandy or Gravelly Elastic Silt Inorganic CH Fat Clay; Fat Clay with Sand or Gravel; Silts and Clays (liquid limit 50 or Sandy or Gravelly Fat Clay more) Organic Silt or Clay; Organic Silt or Organic OH / Clay with Sand or Gravel; Sandy or Gravelly Organic Silt or Clay HIGHLY - ORGANIC Primarily organic matter, dark in PT Peat or other highly organic soils (see SOILS color, and organic odor ASTM D4427) NOTE: No. 4 size = 4.75 mm = 0.187 in.; No. 200 size = 0.075 mm = 0.003 in. NOTES 1. Dual symbols (symbols separated by a hyphen, i.e., SP-SM, Sand with Silt) are used for soils with between 5% and 12% fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. Graphics shown on the logs for these soil types are a combination of the two graphic symbols e.g., SP and SM). 2. Borderline symbols Lsymbols separated by a slash, i.e., CUML, Lean Clay to $ilt; SP-SUW Sand with Silt to Silty Sand) indicate that the soil properties are close to the defining boundary between two groups. Poorly Graded Narrow range of grain sizes present or, within the range of grain sizes present, one or more sizes are missing (Gap Graded). Meets criteria in ASTM D2487, if tested. Well -Graded Full range and even distribution of grain sizes present. Meets criteria in ASTM D2487, if tested. CEMENTATION TERMS' Weak Crumbles or breaks with handling or slight finger pressure. Moderate Crumbles or breaks with considerable finger pressure. Strong Will not crumble or break with finger pressure. DESCRIPTION APPROX. PLASITICITY VISUAL -MANUAL CRITERIA INDEX RANGE Nonplastic A 1/8-in. thread cannot be rolled < 4 at any water content. Low A thread can barely be rolled and 4 to 10 a lump cannot be formed when drier than the plastic limit. Medium A thread is easy to roll and not 10 to 20 much time is required to reach the plastic limit. The thread cannot be rerolled after reaching the plastic limit. A lump crumbles when drier than the plastic limit. High It takes considerable time rolling > 20 and kneading to reach the plastic limit. A thread can be rerolled several times after reaching the plastic limit. A lump can be formed without crumbling when drier than the plastic limit. Mottled Irregular patches of different colors. Bioturbated Soil disturbance or mixing by plants or animals. Diamict Nonsorted sediment; sand and gravel in silt and/or clay matrix. Cuttings Material brought to surface by drilling. Slough Material that caved from sides of borehole. Sheared Disturbed texture, mix of strengths. Angular Sharp edges and unpolished planar surfaces. Subangular Similar to angular, but with rounded edges. Subrounded Nearly planar sides with well-rounded edges. Rounded Smoothly curved sides with no edges. Flat Width/thickness ratio > 3. Elongated Length/width ratio > 3. ATD At Time of Drilling Diam. Diameter Elev. Elevation ft. Feet FeO Iron Oxide gal. Gallons Horiz. Horizontal HSA Hollow Stem Auger I.D. Inside Diameter in. Inches lbs. Pounds MgO Magnesium Oxide mm Millimeter MnO Manganese Oxide NA Not Applicable or Not Available NP Nonplastic O.D. Outside Diameter OW Observation Well pcf Pounds per Cubic Foot PID Photo -Ionization Detector PMT Pressuremeter Test ppm Parts per Million psi Pounds per Square Inch PVC Polyvinyl Chloride rpm Rotations per Minute SPT Standard Penetration Test USCS Unified Soil Classification System q� Unconfined Compressive Strength VWP Vibrating Wire Piezometer Vert. Vertical WOH Weight of Hammer WOR Weight of Rods Wt. Weight Interbedded Alternating layers of varying material or color with layers at least 1/4-inch thick; singular: bed. Laminated Alternating layers of varying material or color with layers less than 1/4-inch thick; singular: lamination. Fissured Breaks along definite planes or fractures with little resistance. Slickensided Fracture planes appear polished or glossy; sometimes striated. Blocky Cohesive soil that can be broken down into small angular lumps that resist further breakdown. Lensed Inclusion of small pockets of different soils, such as small lenses of sand scattered through a mass of clay. Homogeneous Same color and appearance throughout. 'Reprinted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org. 2Adapted, with permission, from ASTM D2488 - 09a Standard Practice for Description and Identification of Soils (Visual -Manual Procedure), copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be obtained from ASTM International, www.astm.org. Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington SOIL DESCRIPTION AND LOG KEY November 2016 21-1-22082-003 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants Total Depth: 912 ft. mnnhing: Drilling Method: Sonic Core Holooian.: 10, 5 io__� ropElevauon:_— 4£4.92 ft^_ sas ng: Drilling Company: nodoiam.: NIAL___ Vert. Datum: _�NAVQ 28 Station: Drill Rig Equipment: Terrasonic Hammer Typo:NIA_____ I U Hon�oomm: Offset: Other Comments: Refer to the report text for a proper understanding of the (D 0 %Water Content subsurface materials and drilling methods. The stratification -5- E E 2 cz -5- lines indicated below represent the approximate boundaries a) r) (1) (0 U) (D a) 0 between material types, and the transition may be gradual. 0 20 40 60 Gray -brown, Silty Sand Wht-h Gravel (SM); fine to coarse sand; nonplastic fines; diamict. ........... ... Hand -excavated to 1 foot. Standing water ............... about 1 foot below IW-11 grade in adjacent Gray -brown, Silty Sand with Gravel (SM); wet; fine, subrounded to subangular gravel; fine to coarse sand; diamict pockets. Weathered Till (Qvt) _�z Perched groundwater at about 11 feet during Y., ......... 12 Gray -brown to gray, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; . X Iron oxide staining from 14 to 18 feet. X. 18 LEGEND Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) 7771 Bentonite-cement Grout Bentonite Chips/Pellets Bentonite Grout * Ground Water Level ATD Hydrogeologic Report * Ground Water Level in Well New Madrona K-8 Project NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and clefiniflom. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE IWA Geotechnical and Environmental Consultants Sheet 1 of 5 REV -ApprnvedfovSubnvitba Total Depth: 912 ft. mnnhing: Drilling Method: Sonic Core Holooian.: 10, 5 io__� ropElevauon:_— 4£4.92 ft^_ sas ng: Drilling Company: nodoiam.: NIAL___ Vert. Datum: _�NAVQ 28 Station: Drill Rig Equipment: Terrasonic Hammer Typo:NIA_____ I U Hon�oomm: Offset: Other Comments: Refer to the report text for a proper understanding of the (D 0 %Water Content subsurface materials and drilling methods. The stratification -5- E E 2 cz -5- lines indicated below represent the approximate boundaries a) r) (1) (0 U) (D a) 0 between material types, and the transition may be gradual. 0 20 40 60 22 24 26 Gray to gray -brown, Silty Sand with Gravel and ............... Cobbles (SM) to Silty Gravel with Sand (GM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; few . W Iron oxide staining from 31 to 32 feet. 32 34 36 Gray -brown, Silty Sand with Gravel and Cobbles (SM) to Silty Gravel with Sand and Cobbles (GM); moist; fine, subrounded to .... ......... LEGEND Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) 7771 Bentonite-cement Grout Bentonite Chips/Pellets Bentonite Grout a Ground Water Level ATD Hydrogeologic Report Y Ground Water Level in Well NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and clefiniflom. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE IWA Geotechnical and Environmental Consultants Sheet 2 of 5 REV -ApprnvedfovSubnvitba Total Depth: 912 ft. mnnhing: Drilling Method: Sonic Core Holooian.: 10, 5 io__� ropElevauon:_— 4£4.92 ft^_ sas ng: Drilling Company: nodoiam.: NIAL___ Vert. Datum: _�NAVQ 28 Station: Drill Rig Equipment: Terrasonic Hammer Typo:NIA_____ I U Hon�oomm: Offset: Other Comments: (D Refer to the report text for a proper understanding of the -5- E cz -5- 0 %Water Content subsurface materials and drilling methods. The stratification E 2 lines indicated below represent the approximate boundaries a) r) (1) (0 U) (D a) 0 between material types, and the transition may be gradual. 0 20 40 60 subangular gravel; fine to coarse sand; trace ......... ......... ..... to few subrounded cobbles; nonplastic fines; 44 Till -Like Deposits/Advance Outwash Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM) to Silty Sand with Gravel ........... (SM); wet; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; few silty sand pockets. Advance Outwash/Till-Like Deposits 52 54 56 57.5 58 Gray, Silty Sand with Gravel (SM); moist; fine, subrounded to subangular gravel; fine to Till -Like Deposits (Qvd) LEGEND Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) 770 Bentonite-Cement Grout Bentonite Chips/Pellets Bentonite Grout a Ground Water Level ATD Hydrogeologic Report Y Ground Water Level in Well NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and clefiniflom. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE IWA Geotechnical and Environmental Consultants Sheet 3 of 5 REV -ApprnvedfovSubnvitba Total Depth: 91.2 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 10,5 in. Top Elevation: — 444.92 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Gray -browny Poorl Graded Sand with Gravel Y � Y 61.0 (SP), Poorly Graded Sand (SP), and Poorly 62 Graded Sand with Silt (SP-SM); moist; fine, suban ular raver fine to subrounded to 9 9 coarse sand; nonplastic fines. Advance Outwash (Ova) 64 ...:...:...:...:...:...:...:...:...:......:...:...:...:..............................................:...:...:...:...:... :...:. ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:...... :...:...:...:...:...:...:...:...:... :.•. :..66 ............... :..... 68 .... ......... ...... - Pockets of silty sand at 69 to 69.5 feet. 70 .... .... .... .... .... .... .... ....... :. 72 ... . :...... ...:....... ...... :...:...:...:...:...:...:...:...:... 74 :...:...:...:...:...:...:...:...:...... :...:...:...:...:...:...:...:...:... :...:. .................................................................................:...:...:...:...:...:...:...:...:... 76 n 78 Layer of silty sand at 78 to 78.5 feet. ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... z = Gray -brown, Poorly Graded Sand (SP) to 79.0 ' :.: 0 ... ° Poorly Graded Sand with Silt SP-SM • moist; ........20.........40........60 CONTINUED NEXT SHEET 0 LEGEND Sample Not Recovered Well Screen and Sand Filter N[21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well New Madrona K-8 Project $ U) NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. N 0 2. Groundwater level, if indicated above, is for the date specified and may vary. N 3. USCS designation is based on visual -manual classification and selected lab testing. N LOG OF SONIC CORE IWA Lu o November 2016 21-1-22082-003 W SHANNON & WILSON, INC. FIG. A-2 Geotechnical and Environmental Consultants Sheet 4 of 5 REV 3 - Approved for Submittal Total Depth: 91.2 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 10,5 in. Top Elevation: — 444.92 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: SOIL DESCRIPTION 4� o -a O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB -5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 fine to medium sand; trace subrounded gravel; nonplastic fines. P ::.. ...................................................................................................... Advance Outwash (Qva) - Last sample on 4/19/2016 was to 80 feet; 82 ' ....................... ......... ............... ... hole was cased to 70 feet. Dry to bottom of open hole (80 feet) at start of day on ..................................................................................................................... 4/20/2016. ..................................................................................................... 84 .... .... .... .... ....... .... .... .... .... .... .... .... .... ....... :. 86 :...:...:...:...:...:...:...:...:...... ... . - Trace cobbles below 87.5 feet. 88 :.•. ............................... 91.2 ' BOTTOM OF BORING COMPLETED 04/20/2016 92 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... ......................... .. .. .. NOTE: Well installed on 4/21/2016. Bottom of sump cap was perforated with 5 small holes for drainage; approximately 1 inch of sediment 94 ...:...:...:...:...:...:...:...:..........:...:...:...:...:...:...:...:..........:...:...:...:...:...:...:...:....... ..................................................................................................................... accumulated in the sump during 4/25/2016 injection test, plugging the drain holes. ................... .... .... .... .... ....... .... .... .... .... .... .... .... .... ....... J96 ........ ......... ......... a z ll ...:...:...:...:...:.:.:.:.:. r98 c 0 0 J 0 20 40 60 LEGEND Sample Not Recovered Well Screen and Sand Filter N[21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well New Madrona K-8 Project $ U) NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. N 0 2. Groundwater level, if indicated above, is for the date specified and may vary. N 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE IWA N LU o November 2016 21-1-22082-003 W SHANNON & WILSON, INC. FIG. A-2 Geotechnical and Environmental Consultants Sheet 5 of 5 REV 3 - Approved for Submittal Total Depth: 120.4 ft,_ mnnhing: Drilling Method: Bucket Au er Holooian.: �4 in. ropElevauon:_— 4£4.41 ft._ sas ng: Drilling Company: nodoiam.: NIAL___ U Vert. Datum: _�NAVQ 28 Station: Drill Rig Equipment: Hammer Typo:NIA_____ I Horiz. Datum: Offset: Other Comments: 39-in. (1-m.) hole from 0 to 61 ft. Geotechnical and Environmental Consultants Sheet 1 of 7 Total Depth: 120.4 ft. Northing: Drilling Method: Bucket Auger Hole Diam.: 24 in. Top Elevation: — 444.41 ft. Easting: Drilling Company: Malcolm Drilling Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Bauer BG-24 Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 39-in. (1-m.) hole from 0 to 61 ft. SOIL DESCRIPTION 4� o -a O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. n 9n e n Fn 22 ......... ...... :...:...:...:...:...:...:...:...:... . Seepage from about 23 to 26 feet with trace boulders to 15-inch-diameter. ;= 24 - ....... ....... ........ .... .... .... .... ....... 26 . X. 28 .......................... :...:...:...:...:...:...:...:...:...... :...:...:...:...:...:...:...:...:... . . ,. 30 32 :...:...:...:...:...:...:...:...:...... :...:...:...:...:...:...:...:...:... 34 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... J 36 37.0 L Gray,Silt Sand with Gravel and Cobbles Y (SM); moist; fine to coarse, subrounded to 38 r subangular gravel; fine to coarse sand; nonplastic more dense and fines diamict� c p , less sand than above . a ) J CONTINUED NEXT SHEET 0 20 40 60 LEGEND Sample Not Recovered Well Screen and Sand Filter ® Grab Sample ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well $ New Madrona K-8 Project NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. ni 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. v LOG OF BORING IW-2 w o November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-3 Geotechnical and Environmental Consultants Sheet 2 of 7 REV 3 - Approved for Submittal Total Depth: 120.4 ft,_ mnnhing: Drilling Method: Bucket Au er Holooian.: �4 in. ropElevauon:_— 4£4.41 ft._ sas ng: Drilling Company: nodoiam.: NIAL___ U Vert. Datum: _�NAVQ 28 Station: Drill Rig Equipment: Hammer Typo:NIA_____ I Horiz. Datum: Offset: Other Comments: 39-in. (1-m.) hole from 0 to 61 ft. Geotechnical and Environmental Consultants Sheet 3 of 7 Total Depth: 120.4 ft. Northing: Drilling Method: Bucket Auger Hole Diam.: 24 in. Top Elevation: — 444.41 ft. Easting: Drilling Company: Malcolm Drilling Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Bauer BG-24 Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 39-in. (1-m.) hole from 0 to 61 ft. SOIL DESCRIPTION 4 o a -a O% Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries a) � (D between material types, and the transition may be gradual. 0 20 40 60 Brown, Clayey Gravel with Sand (GC); wet; 6 G fine to coarse, suban9 ular to subrounded 61.0 ravel fine to coarse sand medium lasticit g p y fines; diamict pockets. 62 ' Deposits Till -Like Qvd) p � : : 0 Gray -brown, Poorly Graded Sand with Gravel (SP), • moist; trace silt; little fine to coarse rounded to subrounded gravel; fine to coarse :::: 64 ...:...:...:...:...:. :. :. :. :. ..................................................................................................................... ......... ........ sand; nonplastic fines. ' " ' ..................................................................................................................... Advance Outwash Qva - Drilled 24-inch pilot hole from 61 to 91 feet. Temporarily backfilled with cuttings from 62 to 66 ...:...:...:...:...........:...:...:..............:...:...:...:...:...:...:..................:...:...:...:...:...:... 91 feet. Placed bentonite chip seal from 59.5 to 62 feet. Installed permanent 30-inch steel surface casing to 60.5 feet. Temporarily filled 68 . 30-inch casingwith additional spoils to 30 feet P ::.;. deep, and grouted 30-inch casing in place. ::, a G ..................................................................................................................... Grout intruded up through spoils to about 44 feet deep inside 30-inch casing. :.. :.::.: 70 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... ......... ......... ...:...:...:...:...:...:...:...:...:............... . - Interbedded with poorly graded sand with silt 72 and gravel from about 72 to 74 feet. G9 :...:...:...:...:...:...:...:...:... 76 a ................... .... .... .... .... ....... .... .... .... .... .... .... .... .... ....... .... .... .... .... .... .... .... .... .... 78 ... :...:...:...:...:...:.............. t..................................................................................................................... 0 0 CONTINUED NEXT SHEET 0 20 40 60 LEGEND Sample Not Recovered Well Screen and Sand Filter N® Grab Sample ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well New Madrona K-8 Project $ U) NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. N 0 2. Groundwater level, if indicated above, is for the date specified and may vary. N 3. USCS designation is based on visual -manual classification and selected lab testing. N LOG OF BORING IW-2 Lu o November 2016 21-1-22082-003 W SHANNON & WILSON, INC. FIG. A-3 aGeotechnical and Environmental Consultants Sheet 4 of 7 � REV 3 - Approved for Submittal Total Depth: 120.4 ft. Northing: Drilling Method: Bucket Auger Hole Diam.: 24 in. Top Elevation: — 444.41 ft. Easting: Drilling Company: Malcolm Drilling Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Bauer BG-24 Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 39-in. (1-m.) hole from 0 to 61 ft. SOIL DESCRIPTION 4� o -a 4� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 - Trace to little gravel and trace mica below :.. 10 .................................................................................................................. about 80 feet. - Pocket -6-inch of black organic silt at about 81 feet. 82 ' 84 .... 86.0 86 Gray brown, Poorly Graded Sand with Gravel SP to Poorly Graded Sand with Silt and Gravel (SP-SM); moist; little, fine to coarse, rounded to subrounded gravel; fine to coarse 88 ' sand; nonplastic fines, trace mica. 11 G Advance Outwash (Qva) 90 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... - On 10/6/2016, continued drilling with 24-inch auger, removing cuttings from 30-inch casing :... 12G N and then continuing to bottom of hole (120.4 ................ .... ....................... feet). Drilled open hole below 60.5 feet. :: z o - Trace cobbles below about 92 feet. 94 ...................................................................................................... ..:...:...:...:...:......:...:...:...:...:...:...:...:...:............... ... 13� 5 96 98.0 •' 14 G 98 y r Gray -brown, Poorly Graded Sand with Gravel ........... .... .... .... .... .... ...... .. � SP •moist• some fine to coarse rounded to ....................................... ' subrounded gravel; fine to coarse sand; .•::: ............ ............... ...... J..• :... CONTINUED NEXT SHEET 0 20 40 60 LEGEND Sample Not Recovered Well Screen and Sand Filter ® Grab Sample ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well $ New Madrona K-8 Project NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. ni 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. v LOG OF BORING IW-2 w o November 2016 21-1-22082-003 SHANNON & WILSON, INC. FIG. A-3 aGeotechnical and Environmental Consultants Sheet 5 of 7 � REV 3 - Approved for Submittal Total Depth: 120.4 ft. Northing: Drilling Method: Bucket Auger Hole Diam.: 24 in. Top Elevation: — 444.41 ft. Easting: Drilling Company: Malcolm Drilling Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Bauer BG-24 Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 39-in. (1-m.) hole from 0 to 61 ft. SOIL DESCRIPTION 4� o -a 4� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 nonplastic fines. Advance Outwash Qva 101.0 ° .......................................................................................................... - Caved during open -hole drilling. °o ..................................................................................................................... Gray -brown, Well Graded Sand with Silt and 0 o0 0 102 ......... ......... ...:...:...:...:...:...:...:...:...:............... . Gravel (SW-SM) to Well Graded Sand with Silt SW-SM; moist; few to little fine to coarse ..................................................................................................................... rounded to subrounded gravel; fine to coarse o0 0 ...:...:...:...:..............................................:...:...:...:..............................:...:...:... sand; nonplastic fines; trace seams of silty o> > 104 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... ......... ......... sand; trace mica. °o 0 ......... ..................................................................................................................... ......... ......... Advance Outwash Qva c ) 15 G - Switched from solid stem auger to bucket auger at 101.5 feet to reduce caving.106 au 9° 00 ...:...:...:...:...:...:...:...:..........:...:...:...:...:...:...:...:..........:...:...:...:...:...:...:...:....... - Trace organics at about 105 feet. 9 0 ..:...:...:...:...:...:...:...:...:... 108 110 ....................................................... .... .... .... .... .... . 16 G 0 112 °o 0 > o 0 114 o 17 G J 116 ... .................... ....................... .... Q o o ...:...:...:...:...:...:...:...:...:......:...:...:... o 118 Y ...:...:...:...:...:...:...:...:...:......:.......:... t 0 0 .............................................................................. . . . . . . . . . . . . 1 0 18G J CONTINUED NEXT SHEET 0 20 40 60 LEGEND Sample Not Recovered Well Screen and Sand Filter N® Grab Sample ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well New Madrona K-8 Project $ U) NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. N 0 2. Groundwater level, if indicated above, is for the date specified and may vary. N 3. USCS designation is based on visual -manual classification and selected lab testing. N LOG OF BORING IW-2 Lu o November 2016 21-1-22082-003 W SHANNON & WILSON, INC. FIG. A-3 aGeotechnical and Environmental Consultants Sheet 6 of 7 � REV 3 - Approved for Submittal Total Depth: 120.4 ft. Northing: Drilling Method: Bucket Auger Hole Diam.: 24 in. Top Elevation: — 444.41 ft. Easting: Drilling Company: Malcolm Drilling Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Bauer BG-24 Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 39-in. (1-m.) hole from 0 to 61 ft. SOIL DESCRIPTION 4� o a -a L _t� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the Q E Q t co • % Water Content subsurface materials and drilling methods. The stratification Q E 5- O lines indicated below represent the approximate boundaries a) (1) (D between material types, and the transition may be gradual. 0 20 40 60 120A BOTTOM OF BORING COMPLETED 10/6/2016 NOTE: Well casing and screen: 8-inch 122 threaded 304 stainless steel, with 4 centralizers on about 30-foot centers. Surface casing: 30-inch steel to 60.5 feet deep. Well screen (0.020-inch 124 continuous -slot) from approximately pp Y 28.3 feet deep (top is inside 30-inch surface casing)to 119.7 feet deep, P with 0.6-foot sump. 24-inch borehole 126 ...:...:...:...:...:...:...:...:..........:...:...:...:...:...:...:...:.............................................. ..................................................................................................................... and interior of 30-inch casing filter -packed with 4x8 sand. Observation pipe (2-inch Schedule 40 PVC) installed in filter pack adjacent 128 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... ..................................................................................................................... to 8-inch casing and screen, with 0.020-inch machine -slotted screen from approximately 60.3 to 120.2 feet 130 deep, and a 0.2-foot sump. Approximately 1.2 feet of sediment accumulated in the 8" sump and screen during the 10/11-10/12/2016 132 injection test. 134 ... 136 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:...... ... 138 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:...... ... 0 20 40 60 LEGEND * Sample Not Recovered ( Well Screen and Sand Filter ® Grab Sample ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF BORING IW-2 November 2016 21-1-22082-003 SHANNON & WILSON, INC. ( FIG. A-3 Geotechnical and Environmental Consultants Sheet 7 of 7 REV 3 - Approved for Submittal Total Depth: 185.5 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 445.11 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. SOIL DESCRIPTION 4� o a -a _t� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the Q (D L t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries a) (1)(D between material types, and the transition may be gradual. 0 20 40 60 Gray -brown, Silty Sand with Gravel (SM); moist; subrounded to g suban ular ravel; fine 9 to coarse sand; nonplastic fines; diamict p , pockets; few poorly graded sand pockets. 2 ' Fill/Ablation Till/Weathered Till (Hf/QvaUQvt) ; - Hand -excavated to 2 feet. Standing water about 1 foot below OW-1 grade in adjacent g J Swale. 4 - Wet pocket at about 5.5 feet. ............... .... ................ .... .... .... .... ....... .... .... .... .... .... .... .... .... ....... .... .... .... .... .... .... .... .... .... • 8:::i:::i:::i::: - Wet below about 8.5 feet. o ............................................................... 10.0 .. ': 0 1 ................................................................................. ......... Gray brown, Silty Sand with Gravel (SM); :.: ...:...:...:...:...:...:...:...:.........:...:...:...:...:...:...:...:.........:...:...:...:...:...:...:...:...... moist; fine to coarse, subrounded to suban ular ravel fine to coarse sand g 9 nonplastic fines; diamict. 12 ' Till/Till-Like Deposits (Qvt/Qvd) 14 ........ . 5 16 :::i:: n a u 18 19.0 = Gray, Silty Sand with Gravel and Cobbles SM to Silty Gravel with Sand and Cobbles ........20.........40........60 CONTINUED NEXT SHEET 0 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF SONIC CORE OW-1 November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-4 Geotechnical and Environmental Consultants Sheet 1 of 10 REV 3 - Approved for Submittal Total Depth: 185.5 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 445.11 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. SOIL DESCRIPTION 4� o a -a _t� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the Q (D L t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries a) (1) (D between material types, and the transition may be gradual. 0 20 40 60 (GM); moist; trace to few subrounded cobbles; fine to coarse, subrounded to suban9 ular gravel; fine to coarse sand; nonplastic fines; diamict. 22 ' Till (Qvt ) - Bottom of temporary 7-inch casing set at 20 .: feet. .. 24 ...:...:...:...:...:...:...... - gray Gray -brown to below 25 feet. Y g Y 26 ............... .... .... .... .... ....... . 28 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:... . 30 ...:...:...:...:...:...:...:...:...:...... :...:...:...:...:...:...:...:...:...... .... ,. .,.. 32 ...................... :...:...:...:...:...:...:...:...:...... 34 ...:...:...:...:...:...:...:...:...:...... :...:...:...:.......................... 5 36 n a u 38 39.0 ' = Gray -brown, Silt Sand with Gravel SM to Y Y ( ) Silty Gravel with Sand (GM); moist; fine to ........20.........40........60 CONTINUED NEXT SHEET 0 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF SONIC CORE OW-1 November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-4 Geotechnical and Environmental Consultants Sheet 2 of 10 REV 3 - Approved for Submittal Total Depth: 185.5ift, mnnhing: Drilling Method: Sonic Core Holooian.: 6 in. Top Elevation: _— 445. 11 ft._ sas ng: Drilling Company: nodoiam.: NIAL___ U Vert. Datum: NAUVD 88�_ Station: Drill Rig Equipment: Terrasonic Hammer Typo:NIA_____ I Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. Geotechnical and Environmental Consultants Sheet 3 of 10 Total Depth: 185.5 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 445.11 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. SOIL DESCRIPTION Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual. Gray -brown, Poorly Graded Sand with Silt (SP-SM); moist; few fine to coarse, subrounded to subangular gravel; fine to medium sand; nonplastic fines. Advance Outwash (Qva) - Layer of poorly graded gravel with sand from 62.1 to 62.5 feet. - Layer of silty sand with gravel from 62.5 to 63 feet. Gray -brown, Poorly Graded Sand with Gravel and Cobbles (SP); moist; trace subrounded cobbles; fine to coarse, subrounded to subangular gravel; fine to coarse sand; trace nonplastic fines. Advance Outwash (Qva) Gray -brown, Poorly Graded Sand (SP) to Silty Sand (SM); moist; few fine, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; few diamict pockets. ,Advance Outwash (Qva) Gray -brown, Poorly Graded Gravel with Silt, Sand, and Cobbles (GP -GM); moist; trace subangular cobbles; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines. (Advance Outwash (Qva) Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM) to Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; fines content may be elevated due to drilling method. Advance Outwash (Qva) - Hard drilling 77 to 80 feet. - Added water during cleanout run at 70 to 80 feet. Drior to samDle run 10. O % Fines (<0.075mm) o L • % Water Content Q U) 0 65.0 68.5 70.0 72.5 CONTINUED NEXT SHEET LEGEND * Sample Not Recovered ( Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF SONIC CORE OW-1 November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-4 Geotechnical and Environmental Consultants Sheet 4 of 10 REV 3 - Approved for Submittal Total Depth: 185.5ift, mnnhing: Drilling Method: Sonic Core Holooian.: 6 in. Top Elevation: _— 445. 11 ft._ sas ng: Drilling Company: nodoiam.: NIAL___ U Vert. Datum: NAUVD 88�_ Station: Drill Rig Equipment: Terrasonic Hammer Typo:NIA_____ I Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. Geotechnical and Environmental Consultants Sheet 5 of 10 Total Depth: 185.5 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 445.11 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. SOIL DESCRIPTION Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual. Gray -brown, Silty Sand with Gravel and Cobbles (SM); moist; trace subrounded cobbles; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines. Advance Outwash (Qva) Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM) to Poorly Graded Sand (SP); moist; fine subrounded to subangular gravel; fine to coarse sand; nonplastic fines. Advance Outwash (Qva) Layer of silty sand from 101 to 101.3 feet. Gray -brown, Poorly Graded Sand with Gravel (SP) to Poorly Graded Sand with Silt and Gravel (SP-SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines. (Advance Outwash (Qva) Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM) to Silty Sand (SM); moist; trace to few, fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; fines content may be elevated due to drilling method. Advance Outwash (Qva) - Added water during cleanout run from 100 to 110 feet and during extraction of sample run 13. Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM) to Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; few silty sand pockets. Advance Outwash (Qva) O % Fines (<0.075mm) o L • % Water Content Q U) 0 105.0 '•. 107.5 112.5 CONTINUED NEXT SHEET LEGEND * Sample Not Recovered ( Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. 102 ........ ..................................................................................................................... ......... ......... 104 106 ... .... .... .... .... ....... .... .... .... .... .... .... .... .... ....... 108 ........................................................................... 110 .... .... .... .... .... .... .... ....... .... .... .... .... .... .... .... .... ....... 112 114 ........ ..................................................................................................................... ......... ......... ......... ......... ......... 116 ..................................................................................................................... ......... ..................................................................................................................... ......... ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:...... ......... ......... ......... ......... 118 ........ ......... ......... 0 20 40 60 Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF SONIC CORE OW-1 November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-4 Geotechnical and Environmental Consultants Sheet 6 of 10 REV 3 - Approved for Submittal Total Depth: 185.5 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 445.11 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. SOIL DESCRIPTION Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual. - Tried adding second 10-foot core barrel so could sample and clean out at same time. Coring hard and slow. Added water during extraction of sample run 14. Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM); moist; fine to coarse, subrounded to subangular gravel; fine to medium sand; nonplastic fines. ;Advance Outwash (Qva) Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Poorly Graded Sand (SP); moist; trace to few fine, subrounded to subangular gravel; fine to medium sand; nonplastic fines; few silty sand pockets from 123 to 125 feet. Advance Outwash (Qva) - Added water during cleanout run from 120 to 130 feet and during extraction of sample run 15. Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Silty Sand (SM); moist; trace subangular, fine gravel; fine to medium sand; nonplastic fines; few silty sand clasts. Advance Outwash (Qva) - Last sample on 4/5/2016 was to 140 feet; hole was cased to 130 feet. Possible perched water measured at 132.5 feet at start of day on 4/6/2016 (hole had caved to 133.5 feet). Gray -brown, Silty Sand (SM); wet; trace fine, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; slight diamict texture. (Advance Outwash (Qva) Gray -brown, Silty Sand (SM) to Poorly Graded Sand with Silt (SP-SM); moist; trace fine, O % Fines (<0.075mm) o L • % Water Content Q U) 0 122.0 1�3�7e� 130.0 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. 122 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:...... ..................................................................................................................... ......... ........ ......... ......... ......... ......... 124 126 ...................... .... .... .... .... ....... ... .... .... .... .... .... .... 128 ... 130 ........ ......... ......... 132 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:...... 134 ...:...:...:...:...:...:...:...:...:......:...:...:...:...:...:...:...:...:...... ...:...:...:...:.:...:...:...:...:..... 136 ...................... ................... .... .... .... .... ....... ..................................................................................................................... ......... ........ ......... ......... ......... ......... 138 0 20 40 60 Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF SONIC CORE OW-1 November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-4 Geotechnical and Environmental Consultants Sheet 7 of 10 REV 3 - Approved for Submittal Total Depth: 185.5 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 445.11 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. SOIL DESCRIPTION Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual. L unded to subangular gravel; fine to e sand; nonplastic fines; few silty sand ce Outwash (Qva) Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Poorly Graded Sand (SP); trace fine, subrounded to subangular gravel; fine to medium sand; nonplastic fines. Advance Out (Qva) Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines. dvance Outwash (Qva) Gray -brown, Poorly Graded Sand with Silt (SP-SM); moist; fine to medium sand; nonplastic fines. dvance Outwash (Qva) Gray -brown, Silty Sand (SM); moist; fine sand; nonplastic fines. dvance Outwash (Qva) Gray -brown to gray, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; fines content may be elevated due to drilling method. dvance Outwash (Qva) Gray -brown, Poorly Graded Sand with Silt and Gravel (SP-SM) to Poorly Graded Sand with Gravel (SP); moist; fine subrounded to subangular gravel; fine to medium sand; u nonplastic fines. y dvance Outwash (Qva) Y Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Poorly Graded Sand (SP); moist; trace to few fine, subrounded to subangular O % Fines (<0.075mm) o L • % Water Content Q U) 0 157.0 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF SONIC CORE OW-1 November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-4 Geotechnical and Environmental Consultants Sheet 8 of 10 REV 3 - Approved for Submittal Total Depth: 185.5ift, mnnhing: Drilling Method: Sonic Core Holooian.: 6 in. Top Elevation: _— 445. 11 ft._ sas ng: Drilling Company: nodoiam.: NIAL___ U Vert. Datum: NAUVD 88�_ Station: Drill Rig Equipment: Terrasonic Hammer Typo:NIA_____ I Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. Geotechnical and Environmental Consultants Sheet 9 of 10 Total Depth: 185.5 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 445.11 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: Terrasonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 20 ft. SOIL DESCRIPTION 4� o -a 4� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 - Pockets of silty sand with gravel from 173.5 to 175 feet. - Seam of silty sand with gravel at 176.3 feet. 182 ......... ................ ........ ......... ............................................................... ......... Brown, Poorly Graded Sand with Silt and Gravel (SP-SM) to Silty Sand with Gravel ( SM),; weft fine to coarse subrounded to ..................................................................................................................... subangular gravel; fine to medium sand; ...:...:...:...:..............................................:...:...:...:..............................:...:...:... ......... ......... nonplastic fines; trace organics and mica. :•= 184 ...:...:...:...:...:...:...:...:...:................................................................................. Advance Outwash (Qva) - Last sample was to 179 feet on 4/6 2016; casingwas at 168.5 feet. Caved to 168 feet 185.5 ' by start of day 4/7/2016; water level 166.5 186 feet. Added water during cleanout run prior to sample run 21. 188 Brown, Poorly Graded Sand with Silt and Gravel SP-SM Poorly Graded Sand SP and Poorly Graded Gravel with Sand (GP); wet; fine to coarse, rounded to subangular gravel; fine to coarse sand; trace to few 190 nonplastic fines. Advance Outwash Qva - Heaved 10 feet during retrieval of sample run 21. Cased to 185 feet and added water 192 to wash out heave to 185.5 feet, prior to well installation. 194 BOTTOM OF BORING COMPLETED 4/7/2016 NOTE: Well installed on 4/7/2016. 196 a z ll 198 .........................................................................................:...:...:...:...:...:...:... Y..................................................................................................................... C 0 0 J 0 20 40 60 LEGEND Sample Not Recovered Well Screen and Sand Filter N[21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well New Madrona K-8 Project $ U) NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. N 0 2. Groundwater level, if indicated above, is for the date specified and may vary. N 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE OW-1 N LU o November 2016 21-1-22082-003 W SHANNON & WILSON, INC. FIG. A-4 aGeotechnical and Environmental Consultants � Sheet 10 of 10 REV 3 - Approved for Submittal Total Depth: 190 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 444.67 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: TerraSonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 50 ft. SOIL DESCRIPTION 4� o -a O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB -5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 Grass and Topsoil Fill (Hf) 0.4 1.5 ......... ......... ......... ......... ......... ......... Brown, Silty Sand with Gravel (SM); moist; fine, subrounded to subangular gravel; fine to - ......................................................................................................... ......... ......... ......... coarse sand; nonplastic fines; trace organics. ......... ......... Fill (Hf) :. 5 Gray -brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to 5.5 subangular gravel; fine to coarse sand; ......... ......... nonplastic fines; diamict. :.'•: ..... ......... Fill (Hf) 8.0 ......... ......... ......... With pockets of organics below 5 feet. 10 to red -brown, Silty Sand with Gravel JBrown SM); moist; fine to coarse, subrounded toubangular gravel; fine to coarse sand; onplastic to low plasticity fines; diamict. : ........................................................................ blation Till/Weathered Till (Qvat/Qvt) 0 Gray -brown, Silty Sand with Gravel (SM) to Silty Gravel with Sand (GM); moist; fine to coarse, subrounded to subangular gravel; fine 15 ......... ......... ......... to coarse sand; nonplastic fines; diamict. Weathered Till/Till/Till-Like Deposits (Qvt/Qvd) - With scattered wet seams below 12 feet. ...................................................................................................... 20 25.0 25 Gray, Silty Sand with Gravel and Cobbles (SM) to Silty Gravel with Sand and Cobbles ..................................................................................................................... (GM); moist; trace subrounded cobbles; fine to Y' ;, ..... ......... coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; diamict. ...... Till (Qvt) • : � CONTINUED NEXT SHEET 0 20 40 60 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout * Ground Water Level ATD Hydrogeologic Report s Ground Water Level in Well New Madrona K-8 Project Ground Water Level in VWP NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE OW-2 November 2016 21-1-22082-003 SHANNON & WILSON, INC. FIG. A-5 Geotechnical and Environmental Consultants Sheet 1 of 7 REV 3 - Approved for Submittal Total Depth: 190!ft. mnnhing: Drilling Method: Sonic Core Holooian.: 6 in. ropElevauon:_— 444.67 ft,_ sas ng: Drilling Company: nodoiam.: NIAL___ U Vert. Datum: NAUVQ 88�_ Station: Drill Rig Equipment: TerraSonic Hammer Typo:NIA_____ I Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 50 ft. Geotechnical and Environmental Consultants Sheet 2 of 7 Total Depth: 190!ft. mnnhing: Drilling Method: Sonic Core Holooian.: 6 in. ropElevauon:_— 444.67 ft, _ sas ng: Drilling Company: nodoiam.: NIAL___ I U Vert. Datum: NAUVQ 88�_ Station: Drill Rig Equipment: TerraSonic Hammer Typo:NIA_____ Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 50 ft. Geotechnical and Environmental Consultants Sheet 3 of 7 Total Depth: 190 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 444.67 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: TerraSonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 50 ft. SOIL DESCRIPTION 4� o a -a L _t� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the Q E (D t cB • % Water Content subsurface materials and drilling methods. The stratification Q E 5- O lines indicated below represent the approximate boundaries a) (1) (D between material types, and the transition may be gradual. 0 20 40 60 Gray -brown, Poorly Graded Sand with Silt and 90.0 Gravel (SP-SM) to Silty Sand with Gravel (SM); trace to little, fine to coarse, subrounded to subangular gravel; fine to coarse sand; nonplastic fines; fines content may be elevated ..................................................................................................................... due to drilling method. Advance Outwash (Qva) :• 95 100.0 . >' f.1 J 100 ... Gray -brown, Well Graded Sand with Silt and Gravel (SW-SM); moist; fine to coarse, 00 subrounded to subangular gravel; fine to ° ° 00 coarse sand; nonplastic fines; few silty sand seams; fines content may be elevated due to .................................................................................... drilling method. oXN Advance Outwash (Qva) xo 105 0 oo ° 00 o° ..... 0:.. :...:...:...:...:... - With layers of poorly graded sand with silt ....................................................... below 109 feet. 110 111.5 >° ° Gray -brown, Well Graded Sand with Silt, Gravel, and Cobbles (SW-SM); moist; trace M ..................................................................................................................... subrounded cobbles; fine to coarse, . ........ ......... . subrounded to subangular gravel; fine to ................................................................................... ' coarse sand; nonplastic fines; fines content 00 115 may be elevated due to drilling method. ......... ......... ......... Advance Outwash (Qva) .................... Y Layer of poorly graded sand with silt and ................................................................ gravel from approximately 118.3 to 119 feet. 00 CONTINUED NEXT SHEET 0 20 40 60 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water level ATD S Ground Water Level in Well -L Ground Water Level in VWP NOTES 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. Hydrogeologic Report New Madrona K-8 Project Edmonds, Washington LOG OF SONIC CORE OW-2 November 2016 21-1-22082-003 SHANNON & WILSON, INC. I FIG. A-5 Geotechnical and Environmental Consultants Sheet 4 of 7 REV 3 - Approved for Submittal Total Depth: 190 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 444.67 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: TerraSonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 50 ft. SOIL DESCRIPTION 4� o -a 4� O % Fines (<0,075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 v - Sampled to 126 feet and cased to 110 feet on 8/17/2016. No recovery from 121 to 126 ......... ......... feet (sample fell out of core barrel). Hole °° was open and dry to 118 feet on morning of ° 8/18/2016. o 125 - Added water prior to sample run 15 to assist 126.0 ° with sample retrieval. ......... ................................................................................ ......... Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Silty Sand (SM); moist; few fine, ..... subrounded to subangular gravel; fine to ..................................................................................................................... coarse sand; nonplastic fines; few poorly 130.0 , 130 , , : ......... ......... ......... graded sand with silt seams; fines content may ......... ......... be elevated due to drilling method. ......................................................................................................... Advance Outwash (Qva) ..................................................................................................................... Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Silty Sand (SM); moist; trace to 0 .................................................................................................. ..... few, fine to coarse, subrounded to subangular 135 gravel; fine to medium sand; nonplastic fines. Advance Outwash (Qva) ..................................................................................................................... - Layer of silty sand at 136.5 to 137 feet. *� 140 142.0 . ; X. ......... ......... ......... ......... ......... Gray -brown, Silty Sand with Gravel (SM); moist; fine to coarse, subrounded to ..... .............................................................. ......... ......... subangular gravel; fine to medium sand; nonplastic fines; fines content may be elevated 145 due to drilling method. 145.5 •' , ; . Advance Outwash (Qva) . Y. o..... ...... ......... Gray, Silty Sand (SM); moist; few fine to coarse, subrounded to subangular gravel; fine .................................................................................................................. ......... ......... ......... to coarse sand; nonplastic fines; few baked, silty, fine sand clasts- fines co may b . o ........20.........40........60 CONTINUED NEXT SHEET 0 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout * Ground Water Level ATD Hydrogeologic Report s Ground Water Level in Well New Madrona K-8 Project Ground Water Level in VWP NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE OW-2 November 2016 21-1-22082-003 SHANNON & WILSON, INC. FIG. A-5 Geotechnical and Environmental Consultants Sheet 5 of 7 REV 3 - Approved for Submittal Total Depth: 190 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 444.67 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: TerraSonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 50 ft. SOIL DESCRIPTION 4� o -a 4� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E O cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 elevated due to drilling method. Advance Outwash (Qva) J, '' ................................................................ sed silt below 147 feet. 152.0 " d water prior to sample run 19. o 0 ......... ......... ....................... ......... ......... ....................................... ......... ......... ....................... :...:...:...:... own, Silty Sand with Gravel (SM); ine to coarse, subrounded to ular gravel; fine to coarse sand; Lelevated o 155 ......... ......... ......... o ......... ......... ......... tic fines; diamict; fines content may be 156.5 ......... ......... ......... ......... ......... ......... d due to drilling method. Deposits/Advance Outwash va) ................................................................................... -brown, Poorly Graded Gravel with Silt Sand (GP -GM) to Poorly Graded Gravel 160.0 •' 160 , ; . Sand (GP); moist; fine to coarse, ......... ......... ......... unded to subangular gravel; fine to ......... ......... ......... e sand; nonplastic fines. nce Outwash (Qva) ................................................................ .................................. , Silty Sand with Gravel (SM); wet; fine,unded to subangular gravel; fine to .:• 165 e sand; nonplastic fines (possibly baked ..g drilling); few diamict clasts; trace silts; fines content may be elevated due to ................................................................................... .................................. drilling method. Advance Outwash/Till-Like Deposits ..................................................................................................................... (Qva/Qvd) 170 ......... ......... ......... Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Silty Sand (SM); moist; few fine to coarse, subrounded to subangular gravel; fine 172.5 ..................................................................................................................... to medium sand; nonplastic fines; few sandy silt seams; trace mica. Advance Outwash (Qva) : •. 175 - Saturated below about 169 feet, and drilled ......... ......... ......... hard/tight from 170 to 172 feet. X. Gray -brown, Poorly Graded Sand with Silt (SP-SM) to Poorly Graded Sand (SP); wet; trace to few fine gravel; nonplastic fines; fine CONTINUED NEXT SHEET 0 20 40 60 LEGEND * Sample Not Recovered Well Screen and Sand Filter [21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout * Ground Water Level ATD Hydrogeologic Report s Ground Water Level in Well New Madrona K-8 Project Ground Water Level in VWP NOTES Edmonds, Washington 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. 2. Groundwater level, if indicated above, is for the date specified and may vary. 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE OW-2 November 2016 21-1-22082-003 SHANNON & WILSON, INC. FIG. A-5 Geotechnical and Environmental Consultants Sheet 6 of 7 REV 3 - Approved for Submittal Total Depth: 190 ft. Northing: Drilling Method: Sonic Core Hole Diam.: 6 in. Top Elevation: — 444.67 ft. Easting: Drilling Company: Holt Services Inc. Rod Diam.: N/A Vert. Datum: NAVD 88 Station: Drill Rig Equipment: TerraSonic Hammer Type: N/A Horiz. Datum: Offset: Other Comments: 7-in. hole from 0 to 50 ft. SOIL DESCRIPTION 4� o -a 4� O % Fines (<0.075mm) Refer to the report text for a proper understanding of the -Q Q L C ( t • % Water Content subsurface materials and drilling methods. The stratification Q E E 2 cB 5- lines indicated below represent the approximate boundaries � U (D between material types, and the transition may be gradual. 0 20 40 60 to coarse sand; trace mica. 180.0 Advance Outwash (Qva) ......... . - Layer of silty, fine to medium sand (SM) :: " ..................................................................................................................... from 175.5 to 176 feet. - Cased to 180 feet before sample run 22. : N Gray -brown, Poorly Graded Sand (SP); wet; nonplastic fines; fine to coarse sand (trace to 185 few coarse sand); no to trace fine to coarse, :.. ......... ..................................................................................................................... ..... ......... ......... ......... ......... ......... subrounded gravel; trace mica.' ......... ......... ......... Advance Outwash (Qva) - Heaved to 172 feet after sample run 22. ......... ......... ......... Cased to 185 feet and washed out heave prior to well installation. 190.0 190 ......... ......... ......... ......... ......... ......... ......... ......... ......... ......... ......... ......... BOTTOM OF BORING COMPLETED 8/19/2016 NOTE: Well installed on 8/19/2016. 195 200 205 :...:...:...:......:...:...:...:...:...:...:...:...:... i :...:...:...:......:...:...:...:...:...:...:...:...:... Y .................................................................. S O J 0 20 40 60 LEGEND Sample Not Recovered Well Screen and Sand Filter N[21 Soil Core (as in Sonic Core Borings) ® Bentonite-Cement Grout ® Bentonite Chips/Pellets ® Bentonite Grout SZ Ground Water Level ATD Hydrogeologic Report Z S Ground Water Level in Well Q New Madrona K-8 Project _ 7 Ground Water Level in VWP � NOTES Edmonds, Washington IL 1. Refer to KEY for explanation of symbols, codes, abbreviations and definitions. N 0 2. Groundwater level, if indicated above, is for the date specified and may vary. N 3. USCS designation is based on visual -manual classification and selected lab testing. LOG OF SONIC CORE OW-2 N LU o November 2016 21-1-22082-003 W SHANNON & WILSON, INC. FIG. A-5 Geotechnical and Environmental Consultants Sheet 7 of 7 REV 3 - Approved for Submittal I 21-1-22082-003 SHANNON 6WIUSON, ING GEOTECHNICAL LABORATORY TESTING TABLE OF CONTENTS Page B.1 VISUAL CLASSIFICATION ......................................................................................... B-1 B.2 WATER CONTENT DETERMINATION ...................................................................... B-I B.3 GRAIN SIZE DISTRIBUTION ANALYSIS .................................................................. B-1 BACONSIDERATIONS ....................................................................................................... B-2 B.5 REFERENCES ................................................................................................................ B-2 Laboratory Terms Sample Types Laboratory Test Summary TABLES TESTS Grain Size Distribution Plot, Boring IW-2 Grain Size Distribution Plot, Boring OW-1 Grain Size Distribution Plot, Boring OW-2 21-1-22082-003-R] f-ABiwp/lk 21-1-22082-003 B-i ING GEOTECHNICAL LABORATORY TESTING We performed geotechnical laboratory testing on selected soil samples retrieved from the three borings completed for the New Madrona K-8 Project's Geotechnical Report. The laboratory testing program included tests to classify the soil and provide data for hydrogeologic studies related to underground injection control well feasibility and design. We performed visual classification on retrieved samples. Our laboratory testing program included water content determinations and grain size distribution analyses. The following sections describe the laboratory test procedures. B.1 VISUAL CLASSIFICATION We visually classified soil samples retrieved from the borings using a system based on ASTM International (ASTM) D2487-11, Standard Test Method for Classification of Soil for Engineering Purposes (ASTM, 2011), and ASTM D2488-09a, Standard Recommended Practice for Description of Soils (Visual -manual Procedure) (ASTM, 2009). Appendix A summarizes our classification system. We assigned a Unified Soil Classification System (USCS) group name and symbol, based on our visual classification of particles finer than 76.2 millimeters (3 inches). We revised visual classifications using results of the index tests discussed below. We tested the water content of selected samples in accordance with ASTM D221.6-10, Standard Method for Laboratory Determination of Water (Moisture) Content of Soil, Rock, and Soil - aggregate Mixtures (ASTM, 2010). Comparison of the water content of a soil with its index properties can be useful in characterizing soil unit weight, consistency, compressibility, and strength. The tables in Appendix B and boring logs in Appendix A include the water content test results. B.3 GRAIN SIZE DISTRIBUTION ANALYSIS Grain size distribution analyses separate soil particles through mechanical or sedimentation processes. Grain size distributions are used to classify the granular component of soils and can. correlate with soil properties, including frost susceptibility, permeability, shear strength, liquefaction potential, capillary action, and sensitivity to moisture. Appendix B includes grain. size distribution analysis results in graphical format. Grain size distribution plots provide tabular 21-1-22082-003-R] f-ABiwpilk 21-1-22082-003 B-1 ING information about each specimen, including: USCS group symbol and group name, water content, constituent (i.e., cobble, gravel, sand, and fines) percentages, coefficients of uniformity and curvature, if applicable, personnel initials, ASTM standard designation, and testing remarks. Constituent percentages are presented in the Laboratory Test Summary in this appendix and fines contents are plotted as data points in borings logs in Appendix A. Sieve Analysis: We performed mechanical sieve analyses on selected soil specimens to determine the grain size distribution of coarse -grained soil particles, in accordance with. ASTM C136/C1.36M-1.4, Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates (ASTM, 201.4). BA CONSIDERATIONS Drilling and sampling methodologies may affect the outcome of prescribed geotechnical laboratory tests. Refer to the field exploration discussion in this report for a discussion of these potential effects. Instances of limited recovery may have resulted in test samples not meeting specified minimum mass requirements, per ASTM standards. Test plots show which samples do not meet ASTM: specified minimum mass requirements. B.5 REFERENCES ASTM International (ASTM), 2009, Standard practice for description and identification of soils (visual/manual procedure), D2488-09a: West Conshohocken, Pa., ASTM International, Annual book of standards, v. 04.08, soil and rock (I): D420 - D5876, 11 p., available: www.astm.org. ASTM International (ASTM), 2010, Standard test methods for laboratory determination of water (moisture) content of soil and rock by mass, D2216-10: West Conshohocken, Pa., ASTM International, Annual book of standards, v. 04.08, soil and rock (I): D420 - D5876, 7 p., available: www.astm.org. ASTM International (ASTM), 2011, Standard practice for classification of soils for engineering purposes (unified soil classification system), D2487-11: West Conshohocken, Pa., ASTM International, Annual book of standards, v. 04.08, soil and rock (I): D420 - D5876, 12 p., available: www.astm.org. ASTM International (ASTM), 2014, Standard test method for sieve analysis of fine and coarse aggregates, C136-14: West Conshohocken, Pa., ASTM International, Annual book of standards, v. 04.02, concrete and aggregates, 5 p., available: www.astrp ors. 21-1-22082-003-R] f-ABiwpilk 21-1-22082-003 B-2 SHANNON & WILSON, INC. ARNAMANUM % Percent * Sample specimen weight did not meet required minimum mass for the test method ASTM Std. ASTM International Standard Ce Coefficient of curvature Cla -size Soil particles finer than 0.002 millimeter cm Centimeter cm Square centimeter Coarse -grained Soil particles coarser than 0.075 min (cobble-, gravel- and sand -sized particles) Cobbles Soil particles finer than 305 min and coarser than 76.2 min C Coefficient of uniformity CU Consolidated Undrained s Axial strain Fine-grained Soil particles finer than 0.075 min (silt- and clay -sized articles) ft Feet 7m Wet unit weight Gravel Soil particles finer than 76.2 min and coarser than 4.75 min G, Specific gravity of soil solids H,, Initial height AH Change in height Alllead End of load increment deformation in Inch in Cubic inch LL Liquid Limit min Minute min Millimeter µm Micrometer MPa Mega -Pascal NP Non -plastic OC Organic content p Total stress p' Effective stress Pa Pascal pcf Pounds per cubic foot PI Plasticity Index PL Plastic Limit psf Pounds per square foot q Deviatoric stress Sand Soil particles finer than 4.75 min and coarser than 0.075 min sec Second Silt Soil particles finer than 0.075 min and coarser than 0.002 min t Time to n% primary consolidation tload Duration of load increment tsf Short tons per square foot USCS Unified Soil Classification System UU Unconsolidated-Undrained WC Water content 21-1-22082-003-R1-AB-Lab Tables -Terms and Test Summary/wp/lk 21-1-22082-003 SHANNON & WILSON, INC. SAMPLE TYPES 2SS 2.5" O.D. Split Spoon Sample 2ST 2" O.D. Thin -Walled Tube 3HSA 3" CME HSA Sampler 3SS 3" O.D. Split Spoon Sample 4SS Soil particles finer than 0.002 millimeter 6SS 6" LD. Split Spoon Sample CA MC Modified California Sampler CA SPT Standard Penetration Test (SPT) CORE Rock Core DM + 3.25" O.D. Split Spoon Sample DMR 3.25" Sampler With Internal Rings GRAB Grab Sample GUS 3.0" O.D. GUS Sample OSTER 3.0" O.D. Osterberg Sample PITCHER 3" O.D. Pitcher Sample PMT Pressuremeter Test (f=failed) PO Porter Penetration Test Sam le PT 2.5" O.D. Thin -Walled Tube ROCK Rock Core Sample SCORE Soil Core (as in Sonic Core Borings) SHI 1" Plastic Sheath SH2 2" Plastic Sheath with Soil Recovery SH3 2" Plastic Sheath with no Soil Recovery SPT 2.0" O.D. Split Spoon Sample SS Split Spoon ST 3" O.D. Thin -Walled Tube STW 3" O.D. Thin -Walled Tube TEST Sample Test Interval TR TR Test TW Thin Wall Sample UNDIST Undisturbed Sample VANE Vane Shear WATER Water sample for Probe Lous 21-1-22082-003-R1-AB-Lab Tables -Terms and Test Summary/wp/lk 21-1-22082-003 SHANNON & WILSON, INC. LABORATORY TEST SUMMARY . .................. . F Bc►ritx ep# (feet tIS .. ' (� ° " ° .Iz trscripiici ". IW-2 91 5-12 GRAB SP 7.3 17* 78* 4.3* 4.0 0.8 Poorly Graded Sand with Gravel IW-2 98 S-14 GRAB SP 3.3 37* 62* 0.8* 8.5 0.5 Poorly Graded Sand with Gravel IW-2 111 5-16 GRAB SW-SM 5.1 21* 71* 8.6* 7.9 1.3 Well -graded Sand with Silt and Gravel IW-2 119 S-18 GRAB SW-SM 5.0 11 81 8.7 6.3 1.4 Well -graded Sand with Silt OW-1 Soil particles finer than 0.002 millimeter R-7 SCORE SM 5.2 22 56 22 Silty Sand with Gravel OW-1 63.5 R-8 SCORE SP-SM 4.8 7* 84* 9.5* 4.8 2.2 Poorly Graded Sand with Silt OW-1 87.5 R-10 SCORE SP 9.1 34* 61* 4.5* 17.9 0.4 Poorly Graded Sand with Gravel OW-1 108 R-11 SCORE SM 4.7 7* 74* 19* Silty Sand OW-1 125 R-14 SCORE SP-SM 6.5 2 90 8.1 3.8 1.6 Poorly Graded Sand with Silt OW-1 135 R-15 SCORE SM 9.2 4* 70* 26* Silty Sand OW-1 153 R-17 SCORE SP-SM 5.0 4* 88* 8* 4.1 1.5 Poorly Graded Sand with Silt OW-1 182 R-21 SCORE SP-SM 18.6 7 88 5.1 2.3 1.2 Poorly Graded Sand with Silt OW-2 12 R-2 SCORE 10.8 OW-2 56 R-7 SCORE SP-SM 10.4 19* 74* 7.3* 5.6 0.8 Poorly Graded Sand with Silt and Gravel OW-2 72 R-9 SCORE SP-SM 15.2 2* 89* 9* 4.2 1.7 Poorly Graded Sand with Silt OW-2 82 R-10 SCORE SM 6.3 5* 78* 16* Silty Sand OW-2 91.5 R-11 SCORE SM 8.8 12* 68* 20* Silty Sand OW-2 107 R-12 SCORE SW-SM 3.8 26* 62* 12* Well -graded Sand with Silt and Gravel OW-2 128 R-15 SCORE SM 4.7 14* 70* 16* Silty Sand OW-2 137.5 R-17 SCORE SP-SM 4.3 5* 88* 7.4* 3.1 2.6 Poorly Graded Sand with Silt OW-2 151.5 R-19 SCORE SM 6.2 10* 56* 34* Silty Sand OW-2 154 R-19 SCORE SP-SM 1.8 36* 58* 5.2* 15.3 0.5 Poorly Graded Sand with Silt and Gravel OW-2 182.5 R-22 SCORE SP 15.1 10* 87* 2.8* 3.0 1.0 Poorly Graded Sand 21-1-22082-003-RI-AB-Lab Tables -Terms and Test Suimnary/wp/lk 21-1-22082-003 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Hydrogeologic Report New Madrona K-8 Project BORING IW-2 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV W 1 O O O O O O O O MO 0� ^O ry0 p0 00 ,�00 � O� O� O� 100 0 95 5 90 „ .. .., , .. ........�... .. ......... .. ........ .... ....... ........ . �. ......... , . ......... ............10 85 .... .... ..... ... ...., ...... ._. 15 80„ ..... ..... ... .. ... ............. . ................ ....... ....................... ...... ....................... ........ . , .......... ..20 75 ...... ......... _ , 25 70 ........ .... ... .......... ..........., .. .......... ....... .. '. .... ,,,,,,,,,,,,,,,,,,,,, ... ........... -"30 65 .... .... .. .. ... ,. ... .. , .... " "" 35 0 60 40 CD CD 55 . ... ... ... .... ... - ..48 c80, .. ........ ....... .. ........... ..... .. .. .......... .. .... ....... ..... ........ ... ......... ........ ..,....... ....... .. _. ..50 N IL N G 45 ... .. ... .... ... ... " "" 55 40 ......... ...... .. .. ....., .. ............ .� ...... ,,,,,,, .. .............. ......... ... ... 60 � v N 35 _ - _ .-65 30 .. ...... .... _ . .. _,. 70 25 _.. 75 20 .... ..... ..... ..... .........., ......... ......... ............ .. ....... .... ..... "... ....... .. ......... ... ......, <.......,. ... . .. 80 ..... ..._ ...... ...... _ ... ....... ..._ ...... ....... ..... 10 .. ._. ..... .. _ 90 5 95 p — -- ry o 0 0 0 o ro ¢i h a M ti ro <o a M �° �` M ry p O O O O ry O y ¢i a M ry ro o a ry 100 ^0• o o o o o o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (ft) Symbol Group Name % % % % % % By By Std. 0 IW-2, S-12* 91.0 SP Poorly Graded Sand with Gravel 17 78 4.3 7.3 AKV C136 N 0 ■ IW-2, S-14' 98.0 SP Poorly Graded Sand with Gravel 37 62 0.8 3.3 AKV C136 IW-2, S-16' 111.0 SW-SM Well -Graded Sand with Silt and Gravel 21 71 8.6 5.1 SAB C136 N �? IW-2, S-18 119.0 SW-SM Well -Graded Sand with Silt 11 81 8.7 5.0 AKV C136 >J_ Test specimen did not meet minimum mass recommendations. a N O O N N N Z <1 U) v 0 0 N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Hydrogeologic Report New Madrona K-8 Project BORING OW-1 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters ti o 0 0 0 00 00 0° oa o' o� o oo� o00 00° ooM oory o0 �a �ro 100 0 95 ... _.,_._ 5 90 .... .... ....... ........ ... ........ .. ......... .......... .. 10 80 ... ... ...... ...... ... .... ....... .............. .........,. ....... ....................... ...... ....................... ........ , . , ..,,,,,,,,. ..20 75 �. -25 70, ...... ....... ... ............. ..... ,' .......... ...... .. .... ,,,,,,,,,,,,,,,,,,,,, .. ........... -.30 65 .. .. �. �. .. �. .. ...... -.. 35 co 60 .. .._ ... .... -.. N ' 40 CD CD 55 ... . ... ... ... _ ... .... ... -..48 c80, .. ........ ....... .. ........... ......... ...... ., ... .. ....... ...... ..... ........ ... ......... ........ ..,....... ....... .. .. .,, p 50 N IL N 45 _ -55 U _ `G N40 ......... ...... .. .. ...., .. ..... .. ,.. ......... ....... .. ........--- ......... .... 60 � d � � N 35 . .... ..... _ ...._. . _,65 N 30 .. ... -. .._ . .. _,. 70 25 ....... ......... ........ ................... ......... ........ ......... ........ ._. ... s. .... ......... ......... ........ ......... ..... 75 20 ......... ..... ..... ............ . .. ._ .. ............. .... .. ..... .......... ......... ... ...... , <......., . ... ... 80 15 .. _ . !.. _ . ........ -85 10 -90 5 95 0 _ ry o 0 0 0 o ro ¢i h a M N v cp a M �° �` M ry '� p O Q, O O ry O O y co O^ o a M ry ro o a ry 0 0 0 0 0- 100 ^0• o o o o Z) o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (ft) Symbol Group Name % % % % % % By By Std. OW-1, R-7 55.7 SM Silty Sand with Gravel 22 56 22 5.2 JCS JFL D422 N 0 ■ OW-1, R-8' 63.5 SP-SM Poorly Graded Sand with Silt 7 84 9.5 4.8 AKV JFL C136 OW-1, R-10* 87.5 SP Poorly Graded Sand with Gravel 34 61 4.5 9.1 JCS JFL C136 N OW-1, R-11' 108.0 SM Silty Sand 7 74 19 4.7 JCS JFL C136 >J_> Z O OW-1, R-14 125.0 SP-SM Poorly Graded Sand with Silt 2 90 8.1 6.5 JCS JFL C136 x n El OW-1, R-15' 135.0 SM Silty Sand 4 70 26 9.2 JCS JFL C136 a 0 OW-1, R-17' 153.0 SP-SM Poorly Graded Sand with Silt 4 88 8.0 5.0 JCS JFL C136 N V OW-1, R-21 182.0 SP-SM Poorly Graded Sand with Silt 7 88 5.1 18.6 JCS JFL C136 N Z Q Test specimen did not meet minimum mass recommendations, a a� v 0 0 N O O N N N SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 .111 SHANNON FaWILSON, INC. GRAIN SIZE DISTRIBUTION PLOT Hydrogeologic Report New Madrona K-8 Project BORING OW-2 Edmonds, Washington Gravel Sand Fines Coarse Fine Coarse Medium Fine Silt Clay -Size Mesh Opening in Inches Mesh Openings per Inch, U.S. Standard Grain Size in Millimeters XV W 1 O O O O O O O� 100 0 95 - ..5 .. .. .. .. 90 ........... ........ ... .. .... ......... ......... ....... . . ........ ... ......... ........................... ......... ............10 85 .. ..� .. .. --15 801, ... ..... ..... .,... ........ ....... .............. .. ...... ......... ......... ........ . , .,,,,,,,,,, ..20 75 .. ..:� ... -_ . ... -25 70 ...... ...... ...... ......... ....... .... ..... ....... .. '. .... ,,,,,,,,,,,,,,,,,,,,, ... ........... -.30 65 _: - -- --. .... - 35 co 60- '40 CD Z3 55 ... .... ... . ... .... ... -.. 45 0 = 50, .. ........ .... ..... .... ........... .. ....... ... . .. ....... .. .. .... ....... ..... ........ ........ .... .. .„50 O N IL �„ N G 45 ... .. �. �. ... .. 55 a, U � � N40 ......... ... ...... .......... ... ....� ... ,,,, .. ........--- ......... .... 60 � N 35 _ \�_... _ ...._. . _.68 N 30 ...... _ ... ........ .... . .. _,. 70 25 _.. 75 20 .... ..... ..... ..... .......... ............, .. ... .......... ........ .. ... ....... .. .......... ... ......, <.......,. ... . .. 80 15 .. --... _ . ........ -85 10, 5 .- _.. 95 0 _ ry o 0 0 0 o ro ¢i h a M N v <p a M ry �° �` M ry '� p O O O O O O y m O^ o a ry ro o 0 0 0 o O- O- a � ry o� 1 oS Q5 100 ^0• o o o o Z) o• o' Grain Size (mm) Sample Depth USCS Group USCS Gravel Sand Fines < 20pm < 2pm WC Tested Review ASTM Identification (ft) Symbol Group Name % % % % % % By By Std. 0 OW-2, R-7* 56.0 SP-SM Poorly Graded Sand with Silt and Gravel 19 74 7.3 10.4 AKV JFL C136 N 0 ■ OW-2, R-9' 72.0 SP-SM Poorly Graded Sand with Silt 2 89 9.0 15.2 AKV JFL C136 OW-2, R-10* 82.0 SM Silty Sand 5 78 16 6.3 AKV JFL C136 N OW-2, R-11' 91.5 SM Silty Sand 12 68 20 8.8 AKV JFL C136 >J_> Z O OW-2, R-12' 107.0 SW-SM Well -Graded Sand with Silt and Gravel 26 62 12 3.8 AKV JFL C136 x n El OW-2, R-15' 128.0 SM Silty Sand 14 70 16 4.7 AKV JFL C136 a 0 OW-2, R-17' 137.5 SP-SM Poorly Graded Sand with Silt 5 88 7.4 4.3 AKV JFL C136 V N OW-2, R-19' 151.5 SM Silty Sand 10 56 34 6.2 AKV JFL C136 Z A OW-2, R-19' 154.0 SP-SM Poorly Graded Sand with Silt and Gravel 36 58 5.2 1.8 AKV JFL C136 2 U* OW-2, R-22' 182.5 SP Poorly Graded Sand 10 87 2.8 15.1 AKV JFL C136 < v 0 0 N O O N N N Test specimen did not meet minimum mass recommendations. SHANNON & WILSON, INC. - 400 NORTH 34TH STREET - SUITE 100 - SEATTLE, WASHINGTON - 98103 - MAIN (206) 632-8020 - FAX (206) 695-6777 A APPENDIX C HYDROGEOLOGIC DATA AND ANALYSES 21-1-22282-003 APPENDIX C HYDROGOLOGIC DATA AND ANALYSES Page C'4 GROUNDWATER LEVEL MONITORING ----------------------(�-3 (�/4.lMonitoring Wells andInstrumentation --------------------.C-3 C.4-2 Results ............................................................................................................... C-3 C.5 PILOT DRY WELL IVV-1FIELD TESTING ................................................................. C-4 C.5.1 Test Procedure ................................................................................................... C-4 C.6 FULL-SCALE DRY WELL lW-2 FIELD TESTING .-----------------.C-5 [.h.l Test Procedure ................................................................................................... C-5 C.7 GRAIN SIZE -BASED HYDRAULIC CONDUCTIVITY (K) ESTIMATES ................ C-6 C.8 REFERENCES................................................................................................................ (-7 C-1 Baan!inn(lW-l Groundwater Quality Data C-2 Summary of OW-1 Slug Test n C-3 Summary oflW-1 and lW-2 Inflow Test Results C-4 Summary of Soil Analyses 2/'/-22082-003'n/f-Ariwvxk 21'1'22082'003 TABLE OF CONTENTS (cont.) FIGURES SHANNON , INC. C-1 Slug Tests — Observation. Well OW-1. C-2 Falling Head Slug Test 1 — Observation Well OW-1 C-3 Rising Head Slug Test 1 — Observation Well OW-1 C-4 Falling Head Slug Test 2 — Observation Well OW-1 C-5 Rising Head Slug Test 2 — Observation Well OW-1. C-6 Falling Head Slug Test 3 — Observation Well OW-1 C-7 Rising Head Slug Test 3 — Observation Well OW-1 C-8 Observation Well OW-1 Groundwater Depth with Precipitation Data C-9 Observation Well OW-1 Groundwater Depth with Barometric Pressure Data C-10 Observation Well OW-2 Groundwater Depth with Precipitation Data C-11 Observation Well OW-2 Groundwater Depth with Barometric Pressure Data C-12 Barometric Efficiency Estimate for Observation Well OW-1 C-13 Barometric Efficiency Estimate for Observation Well. OW-2 C-14 Observation Well OW-1 Response to IW-1 Test C-15 OW-2 Observation Well and VWP2 Response to IW-2 Test LABORATORY REPORT Fremont Analytical, Inc. Report, Lab ID: 1604140, dated April 21, 2016 (29 pages) 21-1-22082-003-Rlf-AC/wp/lk 21-1-22082-003 C-ii SHANNON WILSON, HYDROGEOLOGIC DATA AND ANALYSES C.1 OBSERVATION WELL DEVELOPMENT We developed observation wells OW-1 and OW-2 on April 12 and August 24, 2016, respectively. We developed each well to remove sediment from the screened zone and filter pack and to improve hydraulic connection to the Vashon advance outwash (Qva) aquifer soils. We developed both wells using an inertial -style pump (Waterra) equipped with a clean, acetal combination surge block and check valve that was attached to high -density polyethylene tubing. We measured field parameters (pH, specific conductance, temperature, and turbidity) during development of OW-1 using a YSI model 556 multi -parameter meter and an HF Scientific, Inc. turbidity meter. We measured sediment content of the discharged water during development of OW-2. We surge -blocked the screened intervals, purging approximately 68 (OW-1) and 37 gallons (OW-2) during development. A smaller volume was purged from OW-2 due to its shorter screen length (4.6 versus 9.7 feet at OW-1). Measured field parameters stabilized during development, and the screens were cleared of sediment. C.2 OBSERVATION WELL SAMPLING On April 14, 2016, we collected a groundwater sample from observation well OW-1 to measure baseline groundwater quality in the regional. Qva aquifer before performing infiltration testing. We sampled well OW-1 using the same equipment that we used during development, with the exception that a clean, stainless steel check valve was used instead of the Acetal combination surge block/check valve. We purged OW-1 before sampling and collected the groundwater sample after field parameters had stabilized. We purged approximately 1.2.5 gallons of water (about 4.5 well casing volumes) from well OW-1 prior to sample collection. We delivered the groundwater sample under chain -of -custody procedures to a subcontracted laboratory, Fremont Analytical in Seattle. The sample was tested for petroleum hydrocarbon - related constituents and primary and secondary drinking water parameters. Table C-1 presents the field parameters measured immediately before sample collection and a summary of the laboratory test results. Table C-1 also provides a comparison to Washington State groundwater quality standards. The laboratory data report is also presented in this appendix. In general, the OW-1 sample results indicate that the Qva aquifer groundwater quality onsite is good. An exception was the relatively high concentration of manganese, 344 parts per billion 21-1-22082-003-Rlf-AC/wp/lk 21-1-22082-003 C-1 SHANNON WILSON, (ppb), which is almost seven times higher than the secondary (aesthetic) drinking water standard of 50 ppb. Manganese occurs naturally in soil and groundwater in the Puget Sound region. The extent to which manganese dissolves into groundwater depends on the amount of oxygen in the water and, to a lesser extent, upon the pH of the water. If the oxygen content of groundwater is low, manganese tends to dissolve more readily. The zone from which the OW-1 groundwater sample was collected contains scattered organics, the decomposition of which depletes the oxygen content of the groundwater. This may contribute to the relatively high groundwater manganese concentration. C.3 OBSERVATION WELL SLUG TESTING On. April 1.4, 2016,.we performed single -well field "slug" tests in observation well. OW-1 to estimate the horizontal hydraulic conductivity (Kh) of the Qva aquifer. A slug test estimates the Kh of the saturated sediments immediately surrounding the screened zone of a well. The testing involved inducing a rapid change in water level in the well by introducing or removing a sealed, internally weighted, polyvinyl chloride (PVC) slug. Raising the water level was achieved by lowering the slug below the static water level to displace water within the well casing. This procedure is termed a "falling head test" because the water level falls with time back to the static level. Lowering the water level was achieved by quickly removing the slug from the well. This is termed a "rising head test" because the water level rises back to the static level after the slug is removed. We measured the water level recovery rate back to static using a data logging pressure transducer (Levelogger), supplemented by manual readings. Figure C-1 presents the slug test data for the three falling head and three rising head tests for well OW-1. We analyzed the slug test data using the method developed by Bouwer and Rice (1976), as modified by Bouwer (1989). We used the computer modeling software program AQTESOLV for Windows (HydroSOLVE, Inc., 2010) to plot and interpret the six test data sets. Figures C-2 through C-7 present the slug test interpretation plots and Table C-2 summarizes the slug test results. The Kh results range between 52 and 77 feet per day (feet/day), or 3.2 x 10-2 to 5.4 x 10-2 feet/minute; the average Kh is 55 feet/day (3.8 x 10-2 feet/minute). This range is towards the low end of the Kh estimated from grain size data for two Qva aquifer soil samples collected at 182 and 182.5 feet deep at OW-1 and OW-2, respectively (64 and 92 feet/day, Table C-4). 21-1-22082-003-Rlf-AC/wp/lk 21-1-22082-003 C-2 SHANNON WILSON, CA GROUNDWATER LEVEL MONITORING C.4.1 Monitoring Wells and Instrumentation We have performed groundwater level monitoring in observation wells OW-1 and OW-2 since shortly after their installation. We deployed data logging transducers (Leveloggers) in wells OW-1 and OW-2 to collect frequent groundwater level data, and we installed a barometer (Barologger) in well OW-1 to collected barometric pressure data. The Leveloggers measure absolute pressure (atmospheric plus water pressure); we used the Barologger data to remove the atmospheric pressure contribution to the Levelogger readings. The data logging transducers continue to measure groundwater levels in wells OW-1 and OW-2. C.4.2 Results Figures C-8 through G11 are groundwater level, barometric pressure, and local precipitation hydrographs for the period up to November 5, 2016. Figures C-9 and C-I I show that the groundwater levels in wells OW-1 and OW-2 responded to barometric pressure changes. We evaluated the barometric efficiencies of wells OW-1 and OW-2 by comparing well water level variations to changes in atmospheric pressure. We calculated the barometric efficiencies of wells OW-1 and OW-2 to be approximately 90 and 86 percent, respectively (Figures C-12 and C-13). This means that when the atmospheric pressure increases, the well water level decreases by a similar amount. Conversely, when the atmospheric pressure decreases, the well water level increases. During the April 12 to November 5, 2016, monitoring period, the measured groundwater level in well OW-1 ranged from 167.1 to 168.9 feet below grade, or Elevation 277.0 to 276.2 feet, representing a fluctuation range of about 1.8 feet (Figures C-8 and C-9). During the August 24 to November 5, 2016, monitoring period, the measured groundwater level in well OW-2 ranged from 167.3 to 168.9 feet below grade or Elevation 277.4 to 275.8 feet, representing a fluctuation range of about 1.6 feet (Figures C-10 and C-11). Two vibrating wire piezometers (VWPs) were installed in boring OW-2 at depths of approximately 66.3 (VWPI) and 146.3 feet (VWP2). The shallow VWPI was dry throughout the monitoring period (August 24 to November 5, 2016). The deeper VWP2 was also dry during part of the monitoring period. However, VWP2 occasionally measured water about %2-inch above the sensor tip. In our experience, this is consistent of a VWP installed above the water table, and the occasional "wet" reading does not necessarily indicate the presence of perched 21-1-22082-003-Rlf-AC/wp/lk 21-1-22082-003 C-3 SHANNON WILSON, groundwater. Alternatively, it may indicate a passing wetting front or the effects of varying barometric pressure on the VWP readings. We also collected occasional manual readings at dry wells IW-1 and IW-2. Both wells have been dry to date, except during and immediately following their respective inflow tests (see sections C.5 and C.6). Air blows audibly from the IW-1 and IW-2 well casings at times, in response to changing atmospheric pressure. These wells sometimes also develop slight suction, also in response to changing atmospheric pressure. C.4.3 Local Groundwater Flow and Gradient We estimated the local Qva aquifer gradient by comparing August 26, 2016, groundwater elevations measured at the project wells to the approximate groundwater elevation we measured during a previous study at City of Edmonds observation well A-2 (Shannon & Wilson, Inc., 2013). Observation well A-2 is located about 4,500 feet west of the site (Figure 4). The on -site groundwater elevations on August 26, 2016, were approximately 277.30 and 276.46 feet (OW-1 and OW-2, respectively). On October 2, 2012, the A-2 well groundwater elevation was approximately 259.46 feet, based on an approximate A-2 grade elevation of 31.5 feet. Based on these data, the Qva aquifer gradient beneath the project site is about 0.002 foot/foot to the west/northwest (Figure 4). C.5 PILOT DRY WELL IW-1 FIELD TESTING C.5.1 Test Procedure We performed an inflow test in pilot underground injection control (UIC) well IW-1 on April 25, 2016. This test consisted of directing water from a hydrant through a 2.5-inch-diameter fire hose and 2-inch-diameter PVC pipe into the dry well. We conducted the inflow testing for a period of 8.5 hours. We measured the inflow to the well using an inline flow meter. We measured the water level in IW-1 manually through a stilling pipe and by using Leveloggers installed at the well bottom. We also measured the groundwater level in OW-1 before, during, and after the IW-1 inflow test, both manually and using a Levelogger. We conducted the IW-1 inflow test as a series of steps, with each step representing a higher average flow rate into the well. We performed the first four inflow steps at approximately 14, 38, 72, and 103 gallons per minute (gpm); we maintained these inflow rates for approximately 1 hour each (Figure 7). However, these four steps did not run long enough for the water level to stabilize. The fifth step lasted for 4.3 hours. The fifth step's inflow rate was more variable, initially reaching a maximum of approximately 126 gpm, which was sufficient to 21-1-22082-003-Rlf-AGwp/lk 21-1-22082-003 C-4 SHANNON WILSON, completely submerge the screened interval of the well. However, the flow rate from the hydrant began to fluctuate and drop off, possibly due to late afternoon increased domestic use of water at the adjacent apartment complex. The fifth step stabilized between 1.1.6 and 107 gpm, averaging 1.1.0 gpm over the last hour of the test. At this inflow rate, the IW-1 water level was approximately 67 feet below grade, or 4 feet below the top of the well screen, representing a head rise above the borehole bottom of 24 feet. C.5.2 Results We used the calculated OW-1 barometric efficiency to filter the OW-1 groundwater level data so that the OW-1 well response to the IW-1 inflow test could be analyzed (Figure C-1.4). Based on these data, the observed specific capacity of IW-1 is approximately 4.6 gpm/foot, and the Kh for the tested zone is 24 feet/day (1.7 x 10-2 feet/minute) (Table C-3). The groundwater level measured in well. OW -I did not immediately respond to the inflow test performed in IW-1. After adjusting the raw OW-1 groundwater level data for barometric efficiency, it was apparent that there was a slight antecedent rising trend in the OW-1. groundwater level during the test. This rising trend continued for a day after the IW-1 test and served to mask any effect of the IW-1 test on the groundwater level measured in OW-l. The OW-1 groundwater level rose again slightly (0.1 foot), starting about four days after the test and peaking six days after the test; in our opinion, this change is too small to definitely attribute to the inflow test. Based on these observations, the interbedded silty sand layers within the Qva unit (e.g., between about 134 and 160 feet deep) likely delayed the vertical infiltration of water into the Qva regional aquifer in the IW-1 test area. C.6 FULL-SCALE DRY WELL IW-2 FIELD TESTING C.6.1 Test Procedure We performed an inflow test in full-scale UIC well IW-2 on October 11 to 12, 2016 (Figure 8). This test consisted of directing water from a hydrant through a 2.5-inch-diameter fire hose and 2-inch-diameter PVC pipe into the dry well for 19 hours. We measured the inflow to the well using an inline flow meter. We measured the water level in IW-2 manually through the 2-inch-diameter observation pipe installed in the filter pack and electronically using Leveloggers installed at the bottom of the 2- and 8-inch-diameter casings. We also manually and electronically measured the groundwater level in wells OW-2 and OW-1 before, during, and after the IW-2 inflow test. We recorded VWP readings at OW-2 using data loggers during and after the inflow test period. 21-1-22082-003-Rlf-AGwp/lk 21-1-22082-003 C-5 SHANNON WILSON, C.6.2 Results We used OW-1 water levels measured during and after the IW-2 inflow test to filter out the effects of barometric pressure changes and other trends from the water levels measured at observation well OW-2 (Figure C-15). This enabled us to analyze the OW-2 well response to the IW-2 test. OW-2 is located approximately 1.4 feet from IW-2. Little change in groundwater level occurred in observation well. OW-2 (an increase in water level of about 0.3-foot during the three days following the IW-2 test). The shallow VWP1 installed 66.3 feet below grade at OW-2 has remained dry to date. During and immediately after the IW-2 inflow test, water temporarily mounded at the interval measured by the deep V WP2 (installed at 146.3 feet deep at OW-2). This mound dissipated and VWP2 was dry again three and a half days after the end of the IW-2 test (Figure C-1.5). Based on these observations, the interbedded silty sand layers within the Qva (e.g., between about 147 and 160 feet deep) likely delay the vertical infiltration of water into the Qva regional aquifer in the IW-2 test area. C.7 GRAIN SIZE -BASED HYDRAULIC CONDUCTIVITY (K) ESTIMATES We performed grain size analyses (Appendix B) on selected soil samples from IW-2, OW-1, and OW-2. Table C-4 presents grain size -based estimated K values for selected soil samples, based on the Hazen (1893) approach. The estimated K value for the tested till -like deposits (Qvd) sample from OW-1 (at 55.7 feet deep) was less than 0.01 foot/day. The grain size -based K estimates for the 21 Qva unit samples range from 0.05 to 626 feet/day (3 x 10-5 to 0.43 feet/minute), which is a variation of over four orders of magnitude. If the highest value is considered an outlier and is excluded, the arithmetic and geometric mean K values of the remaining 20 Qva samples are 38 and 11 feet/day (2.3 x 10-2 and 7.4 x 10-3 feet/minute), respectively. We suspect that the process of driving the sonic core barrel through unsaturated granular Qva soils resulted in some degree of sample pulverization, thereby increasing the fines content of some of the samples above their natural state. We have identified on the logs presented in Appendix A those sample cores where portions of the sample appeared dusty, indicating potential sample degradation due to the sampling process. We observed less apparent sample degradation in the larger diameter core samples collected at IW-1, as well as where samples were 21-1-22082-003-R1 f-AC/wp/lk 21-1-22082-003 C-6 SHANNON WILSON, collected within saturated zones and where water was added during the drilling process. A comparison of sample grain size distributions for samples collected from auger boring IW-2 and those from similar depths collected from adjacent sonic core OW-2 indicates that the fines content of the auger samples was typically lower than that of the sonic core samples (Appendix B and Table C-4). C.8 REFERENCES Bouwer, Herman, 1989,.The Bouwer and Rice slug test — an update: Ground Water, v. 27, no. 3, p. 304-309. Bouwer, Herman, and Rice, RC., 1976. A slug test method for determining hydraulic conductivity of unconfined aquifers with completely or partially penetrating wells: Water Resources Research, v. 12, no. 3, p. 423-428. Hazen, A., 1893, Some physical properties of sands and gravels, with special reference to their use in filtration: Massachusetts State Board of Health 24th Annual Report, pub. doc. no. 34, p. 539-556. HydroSOLVE, Inc., 2010,.AQTESOLV/Pro!, v. 4.50.002: Reston, Va., HydroSOLVE, Inc. Shannon & Wilson, Inc., 2013, Final infiltration study report, SW Edmonds basin study projects #1 and #3, Edmonds, Wash.: Report prepared by Shannon & Wilson, Inc., Seattle, Wash., 21-1-21.768-001, for City of Edmonds, Edmonds, Wash., April 5. 21-1-22082-003-Rlf-AGwp/lk 21-1-22082-003 C-7 SHANNON & WILSON, INC. TABLE C-1 BASELINE OW-1 GROUNDWATER QUALITY DATA G4bstiktterit ., 3eihud :'I ", per, 17 " 0 At a r96 296' MICA Metlibd A Cfommli,EvVet par 1fii3 , .�i 1 Sample No. Cl Y.: 1- 04141 ; ! (Cattieted, 414/k rE j . Field Parameters PH Field 6.5-8.5 7.1 Temperature IT) Field 10.9 Specific Conductance (uS/em) Field 700 330 Dissolved Oxygen (mg/L) Field 4.1 Turbidity (NTU) Field 1.5 Total Metals (ug/L) Antimony EPA Method 200.8 6 ND<0.2 Arsenic EPA Method 200.8 0.05 5 ND<I Barium EPA Method 200.8 1,000 28.6 Beryllium EPA Method 200.8 4 ND<0.2 Cadmium EPA Method 200.8 5 5 ND<0.2 Chromium EPA Method 200.8 50 50 1.67 Copper EPA Method 200.8 1,000 ND<0.5 Iron EPA Method 200.8 300 ND<100 Lead EPA Method 200.8 AL=15 15 ND<I Manganese EPA Method 200.8 50 344 Mercury EPA Mehod 245.1 2 2 ND<0.1 Nickel EPA Method 200.8 100 2.94 Selenium EPA Method 200.8 10 ND<l Silver EPA Method 200.8 50 ND<0.2 Sodium EPA Method 200.8 RL=20,000 12,900 Thallium EPA Method 200.8 2 ND<0.2 Zinc EPA Method 200.8 5,000 27.3 Anions (mg/L) Chloride EPA Method 300.0 250 6.38 Cyanide, Total SM 4500-CN C, E 0.2 ND<0.05 Fluoride EPA Method 300.0 2 or 4 ND<0.1 Nitrite-N EPA Method 300.0 1 0.159 Nitrate-N EPA Method 300.0 10 1.01 Total Nitrate and Nitrite EPA Method 300.0 10 1.17 Ortho-phosphate EPA Method 300.0 ND<0.2 Sulfate EPA Method 300.0 250 22.6 Phosphorous, Total (as P) EPA Method 365.3 ND<0.2 Other Color (Color Units) SM 2120B 15 ND Total Dissolved Solids (mg/L) SM 2540C 500 182 Petroleum Hydrocarbons (ug/L) Diesel (Fuel Oil) NWTPH-Dx/Dx Ext. 500 ND<50 Heavy Oil NWTPH-Dx/Dx Ext, 500 ND<100 Gasoline NWTPH-Gx 1,000 ND<50 Volatile Organic Compounds (ug/L) Benzene EPA Method 8260C 1 5 ND<1 Toluene EPA Method 8260C 1,000 ND<1 Ethylbenzene EPA Method 8260C 700 ND<I m,p-Xylene EPA Method 8260C 1,000 (Total Xylenes) ND<I o-X lene EPA Method 8260C ND<1 Notes: bold = constituent exceeded regulatory standard <= less than AL = action level established by the U.S. Environmental Protection Agency (EPA) for water distribution system C = Celsius cm = centimeters L = liter MCI., = maximum contaminant level mg = milligrams MTCA=Model Taxies Control Act NTU = Nephelometric turbidity units NWTPH-Dx/Dx Ext. =Northwest Total Petroleum Hydrocarbons-Diesel/Diese-extended NWTPH-Gx = Northwest Total Petroleum Hydrocarbons -Gasoline ND = not detected RL = EPA -recommended level for those on a sodium -restrict diet SM = Standard Method ug = micrograms US = nicroSiemens WAC= Washington Administrative Code 21-1-22082-003-RIf-TC-I/wp/ik 21-1-22082-003 SHANNON & WILSON, INC. TABLE C-2 SUMMARY OF OW-1 SLUG TEST ANALYSES "'Predominant- CJb er iion t ti t': ter d tlnlie auclu+ rir it (far ii atropil+. oil Type nterpr t ?eli .aie 1 e.. L1le1 Gtse;/Th--01Sereete Gertoge Number = ' . Tested ` Number = :fet b s} fetlda + fel/mir 11t F?ell 1Tiit Tested Falling Head Test 1 45 1.6E-02 3.2E-02 Rising Head Test 1 50 1.8E-02 3.5E-02 Falling Head Test 2 54 1.9E-02 3.7E-02 OW-1 4/14/2016 Rising Head Test 2 168.3 52 1.8E-02 3.6E-02 SP-SM/SP Qva Falling Head Test 3 55 2.0E-02 3.8E-02 Rising Head Test 3 77 2.7E-02 5.4E-02 Geomean 55 1.9E-02 3.8E-02 Notes: bgs = below ground surface cm/sec = centimeters per second Kh = horizontal hydraulic conductivity K, = vertical hydraulic conductivity min = minute 21-1-22082-003-R1 f TC-2/wp/lk 21-1-22082-003 SHANNON & WILSON, INC. TABLE C-3 SUMMARY OF IW-1 AND IW-2 INFLOW TEST RESULTS plrrurluuate A trroxlrttaIle' op ofTest - Bottom nY . approximate:.' T est Soe iitE . ter'' ' hydraulic; Fl draidicdraidie•: Approximate, liseltar e, Itt charge Specific , seelion legit eetron .Test Section, Betlom TessScetien ; Colmun -Borehole Uoirtlttetivityt Cant�netivi y,;z irutiuetisity;t Tntrrpreted Fell '' Grl e Efewat eau Dates, Raul . Ratet paeitj-- l)e h - . 7epth. Top,F�luwat%u- of Leis ` -Iteig6t, h Radius; r e+llag a„ tunbet fcit'NA8S}i,Tegted.(gitrn) ;:(cuday)'gpm/fbat}' `,{feei) ,.`feed .:fee."#eet) ttoe ":'.Ecetl iegt),.(foffdal ..:,entlsec}fectlrain) . Uuit�"estecl IW-1 444.9 4/25/2016 110 21174 4.6 67.4 91.2 377.5 353.7 23.8 23.9 0.44 24 8.4E-03 1.7E-02 Qva IW-2 444.4 10/11-10/12/2016 141 27141 6.7 99.3 120.4 345.1 324.0 21.1 21.1 1.00 30 LOE-02 2.0E-02 va Notes: I Discharge to well (q) is the average measured over the last approximately one hour of the test period. 2 Equation for K estimation is from U.S. Department of the Interior, 1990. Procedure for constant head hydraulic conductivity tests in single drill holes, U.S. Bureau of Reclamation 7310-89, in Earth Manual, Part 2, 3rd ed. p. 1255, Equation 2 (for L> 1Or). L= Water Column Height (H), which is the approximately stabilized water height in the well above the total drilled depth. cm/sec centimeters per second cu ft = cubic feet gpm gallons per minute min = minute NAVD 88 — North American Vertical Datum of 1988 k In r, where L E I Or (2) or — H sink-r 2r where lOr� r (3) where: hydraulic conducriviry, ft/yr or cm/s 9 `— ccuistant rate of flow into the test. interval, fr3/yr or cm3✓s Llength of the LeSL interval, It or Cin 1-1„ differential 'heard cxf water at test interval, ft or cm r rodi ss of the borcholc, ft or crli In — natural logarithm, log, shah i — inverse hyt!rlrolic sure: sinksx9n(x4 x3-I-]) 21-1-22082-003-R1t=TC 3nvpnk 21-1-22082-003 SHANNON & WILSON, INC. TABLE C-4 SUMMARY OF SOIL ANALYSES . ..Pprux male Gamuiativa ;. �S .' . Slcve 3cksielts ierceut i5uer; Appruximale Hydrauli c Gnaductie ity, T `: p t ftxte 124 & Slevlsrds T' P u .' Fltpl$#3' Yadyser nc. irerpretetl . .And Dee s A'ui%i. Rnz3ng a �di tjkg ru a> urrr er ' Yeet , Drllliu 4cthrrd Grxtx el lu.; ' Sand !tierce °fo , • ` ", 98 S n lQ"l l rtlrrtated? ; ' ,friday ' 'emhsec} ' {[eet m1a) urltal, 1 a aci [ alttsted {iset) IW-2 91 Auger 17 79 4.3 0.46 0.17 82 2.9E.-02 5.7E-02 SP Low Qva IW-2 98 Auger 37 62 0.8 2.10 0.47 626 22E-01 43E Ol SP Low Qva IW-2 III Auger 21 71 8.6 0.56 0.099 28 9.8E-03 1 9R-02 SW SM Medmm Qva IW-2 119 Auger 1l 81 8.7 n 44 0.094 25 8.8E-03 1.7E-02 SW-SM Low va 55.7 Sonic Cora. 22I 56 22 0.95': 0.0015 +. Yes 0.0064 2.3E-06 4.4E 06 SM Medium Qvd OW-1 635 Sonic Core 7 84 9.5 033 0.080 18 6AE-03 1.3E-02 SP-SM Medium Qva OW-1 87.5 Sonic Core 34 62 4.5 1.4 0.17 82 2.9E-02 57E-02 SP Low Qva OW I 108 Sonic Core 7 74 19 0 33 O o21 Yes 1.3 4 4E 04 8 7E 04 SM Medium Qva 10 OW-1 125 Sonic Core 2 90 8.1 030 0.088 22 7.7E-03 1.5E-02 SP-SM Low Qva OW-1 135 Sonic Core 4 70 26 028 OA080 Yes 018 6AE-05 1.3E-04 SM Medium Qva OW-1 153 Soon Corz 5 88 8.0 0.33 0.092 24 8.5E-03 17E-02 SP-SM L.ow Qva OW-1 182 Sonic Core 7 88 5.1 0 32 2 L5 Yes 64 23E-02 4.4E-02 SP SM Below water table Qva OW-2 56 Sonic Core 19 74 7.3 0.58 0.15 64 2.3E.-02 4.4E-02 SP-SM Low Qva OW-2 72 Sonic Core 2 89 9.0 030 OA83 20 6.9E-03 1.4E-02 SP-SM Low Qva OW-2 82 Sonic Core 5 78 17 0.30 0.029 Yes 2.4 8AE-04 1 7E-03 SM Medium Qva OW-2 9L5 Sonic Core 12 68 20 031 0.014 Yes 0.6 2.0E-04 39E-04 SM Medium Qva OW-2 107 Sonic Core 26 62 12 1.2 0.047 Yes 6.3 2.2F. 03 4 3E 03 SW SM Medium Qva 14 OW-2 128 Sonic Core W 70 16 O42 11024 Yes 1.6 5.8E-04 1.1E-03 SM Medium Qva OW-2 137.5 Sonic Core 5 88 7.4 0.36 0.13 48 1.7E-02 3 3E-02 SP SM Low Qva OW-2 151.5 Sonic Core 10 56 34 0.27 OB040 Yes 0.045 L6E-05 3.1E-05 SM Medium Qva/Qvd OW-2 154 Sonic Core 37 58 5.2 2.2 0.25 177 6.3E-02 1 2E 0I SP SM Low Qva OW-2 182.5 Sonic Core to 87 2.8 041 0.18 1 92 32E-02 6.4E-02 SP Below water table Qva Geomean of Qva Samples 1 13 4.6E-03 9.0E-03 Notes; ' Treatment capacity classification from Table 5.2: Vadose Zone Treatment Capacity, in Guidance for UIC Wells that Manage Stormwater (Washington State Department of Ecology, 2006). Hazen, A, 1893, Sonic physical properties of sands and gravels: Massachusetts State Board of Health, 24th Annual Report. % = percent ASTM = ASTM International cm/sec = centimeters per second man minute mm = millhnetcrs UIC = undergr-rd injection control USCS = Unified Soil Classification System 21-1-22082-003-Rif-TC-4/wp/lk 21-1-22082-003 LEGEND A---- Falling Head Test #1 Rising Head Test #1 —Falling Head Test #2 Rising Head Test #2 Falling Head Test #3 .. Rising Head Test #3 0 2 4 6 8 10 12 14 16 18 Time (Seconds) OW-1 Slug Analysis-OW-1 Slug Test Plot-11/23/2016-pvh OW-1 Slug Analysis-OW-1 FH1 -1 1/23/2016-pvh OW-1 Slug Analysis-OW-1 RH 1 -1 1/23/2016-pvh OW-1 Slug Analysis-OW-1 FH2-11/23/2016-pvh OW-1 Slug Analysis-OW-1 RH2-11/23/2016-pvh OW-1 Slug Analysis-OW-1 FH3-11/23/2016-pvh OW-1 Slug Analysis-OW-1 RH3-11/23/2016-pvh 167.0 — - -- - - -- - - - -- - - - 2.0 167.2 - OW-1 Transducer Data 1.8 ■ OW-1 Manual Data 167.4 - — - IW-1 Testing — n _ - — — — — _ 1.6 - - alloness-lW-2 Testing s 167 6 — ■ Brugger's Bog Daily Precipitation'- 1'� in 167�8 __ ___ w _ w _�_�_�: o __ - c (� I o 0 168.0 - - - _ LL. - - 1.0 - -- _Q m _ .. . . .-- .... — ._... . ... ■. ... U 168�2 0.8 0 � is co 168.4 - — - -- - � I — 0.6 o ;t -4 : m . .... t 168.E 1�` _ _ - y 0,4 ... � i j �■ - _ - -_ _ 3F 4 _ S �f f i ; �l ; j [ it _ _ - 168 8 r i` 0.2 < I sm �t� 4 t1 p i q i at_ 169.0 -! 0.0 4/11/16 4/25/16 5/9/16 5/23/16 6/6/16 6/20/16 7/4/16 7/18/16 8/1/16 8/15/16 8/29/16 9/12/16 9/26/16 10/10/16 10/24/16 11/7/16 Date (Local Time) Hydrogeologic Report New Madrona K-8 Project NOTES Edmonds, Washington 1. The screen in observation well OW-1 is approximately 175.4 to 185.0 feet below ground surface, (approximately elevation 269.8 to 260.1 feet NAVD88). OBSERVATION WELL OW-1 2. Brugger's Bog precipitation data are from GROUNDWATER DEPTH WITH -n htt :// reen.kin count . ov/wlr/waterres/h drolo 1®ataDownload.as x PRECIPITATION DATA n 3. Black and white reproduction of this color original may lead to incorrect interpretation. ' November 2016 21-1-22082-003 n co SHANNON & WILSON, INC. FIG. C-8 Geotechnical and Environmental Consultants OW-1 Water Levels -Figure C-8 - OW-1 Precip-11/23/2016-pvh 166.5 34 33.8 " 167.0 33.6 U .' i N 33.4 � a 0 167.5 --- - - - - - o - - m - - - 33.2 o co- - - to to 33 p 168.0 _ _ _ ! _ _ ___ _ _ _ _ _ .-_-_ _ _ - _ _ _ a� CU 32.8 E m _ 0 - OW-1 Transducer Data - (D . 32.6 168.5 ® OW-1 Manual Data ® - -IW-1 Testing IW-2 Testing 32.4 Barometric Pressure 169.0 y -L- + . _ _ - - - - . _ - - w +_-w _ - . L w L -- w- 32.2 4/11/16 5/2/16 5/23/16 6/13/16 7/4/16 7/25/16 8/15/16 9/5/16 9/26/16 10/17/16 11/7/16 Date (Local Time) Hydrogeologic Report New Madrona K-8 Project NOTES Edmonds, Washington 1. The screen in observation well OW-1 is approximately 175.4 to 185.0 feet below ground surface, OBSERVATION WELL OW-1 (approximately elevation 269.8 to 260.1 feet NAVD88). GROUNDWATER DEPTH WITH -n 2. Black and white reproduction of this color original may lead to incorrect interpretation. BAROMETRIC PRESSURE DATA i G ' November 2016 21-1-22082-003 n �p SHANNON & WILSON, INC. FIG. C-9 Geotechnical and Environmental Consultants OW-1 Water Levels -Figure C-9 - OW-1 BP-11/23/2016-pvh OW-2 Water Levels -Figure C-10 - OW-2 Precip-11/23/2016-pvh 167.0 34.0 167.2 ._ _._ , — w _ _ :. a rt _ , _ u . _ _ ._ _:r . .... .... .. .... . .... .... . .... ... .... - - 33.8 167.4 33.6 167.E 33.4 ,2 co 167.8 . ._. , , ,- 33.2 o - - - - - 168.0 33.0 �aoi rn.............. . , a , , . , ..... _. ........ .... p 168.2 L _ 32.8 ai i_hco _ ° L -0 168.4 _ __ � 32 6 cc Alk 168.E _ , a __ _ __ �: - - -' - 32.4 168.8 -T T T-- OW-2 Well Transducer Data ® OW-2 Manual Data - 32.2 I AIIW-2 Testing Period Barometric Pressure 169.0 32.0 8/22/16 8/29/16 9/5/16 9/12/16 9/19/16 9/26/16 10/3/16 10/10/16 10/17/16 10/24/16 10/31/16 11/7/16 Date (Local Time) Hydrogeologic Report NOTES New Madrona K-8 Project Edmonds, Washington 1. The screen in observation well OW-2 is approximately 179.2 to 183.9 feet below ground surface, (approximately elevation 265.4 to 260.8 feet (NAVD88)). OBSERVATION WELL OW-2 2. Groundwater level data for the OW-2 well were filtered using OW-1 data to remove the effects of regional GROUNDWATER DEPTH WITH 77 aquifer trends during and after the IW-2 test period. BAROMETRIC PRESSURE Gi 3. Black and white reproduction of this color original may lead to incorrect interpretation. n November 2016 21-1-22082-003 0 SHANNON $ WILSON, INC. FIG. C-11 Geotechnical and Environmental Consultants OW-2 Water Levels -Figure C-11 - OW-2 BP-11/23/2016-pvh 0.3 0.2 -0.2 -0.3 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 Change in Barometric Pressure (Feet of water) NOTES 1. The screen in observation well OW-1 is approximately 175.4 to 185.0 feet below ground surface, (approximately elevation 269.8 to 260.1 feet (NAVD88)). 2. Barometric efficiency estimate of approximately 90% based on data collected between 5/6/16 and 5/10/16. OW-1 Water Levels -Figure C-12 - OW-1 BE Plot-11/23/2016-pvh 0.2 0.2 0.1 SIV -0.2 -0.3 -0.4 -0.3 -0.2 -0.1 0.0 0.1 Change in Barometric Pressure (Feet of water) NOTES The screen in observation well OW-2 is approximately 179.2 to 183.9 feet below ground surface, (approximately elevation 265.4 to 260.8 feet (NAVD88)). Barometric efficiency estimate of approximately 86% based on data collected between 9/6/16 and 9/18/16. OW-2 Water Levels -Figure C-13 - OW-2 BE-11/23/2016-pvh OW-1 Water Levels -Figure C-14 - OW-1 IW-1 Test-11/23/2016-pvh 140.0 145.0 a� c> 150.0 c 0 ..__ _. _ _._ IW-2 Testing Period 0 —�°� 155.0 OW-2 VWP2 Data m Q - . OW-2 VWP2 Sensor Depth m 0 OW-2 Well Transducer Data, Unadjusted for Regional Aquifer 160.0 Trends OW-2 Well Transducer Data, Adjusted for Regional Aquifer Trends 0 0 165.0 1. The screen in observation well OW-2 is approximately 179.2 to 183.9 feet below ground surface, (approximately elevation 265.4 to 260.8 feet (NAVD88)). 2. Dry well IW-2 was completed at 120.4 feet deep (approximately elevation 324.0 feet). The IW-2 Infiltration test was performed from 10/11/16 9:09 to 10/12/16 4:09. 3. Groundwater level data for the OW-2 well were filtered using OW-1 data to remove the effects of regional aquifer trends during and after the IW-2 test period. 4. The OW-2 VWP2 sensor is approximately 146.3 feet deep (approximately elevation 298.4 feet). 5. The OW-2 VWP1 sensor is approximately 66.3 feet deep (approximately elevation 378.4 feet). It has remained dry during the monitoring period to date (8/24-11/5/16). 6. Black and white reproduction of this color original may lead to incorrect interpretation. OW-2 Water Levels -Figure C-15 - OW-2 Test-11/23/2016-pvh 3600 Fremont Ave. N. Seattle, WA 98103 T: (206) 352-3790 F: (206) 352-7178 info fremontanalytical.com Shannon & Wilson Paul Van Horne 400 N. 34th Street, Suite 100 Seattle, WA 98103 RE: Madrona K-8 School Lab ID: 1604140 April 21, 2016 Attention Paul Van Horne: Fremont Analytical, Inc. received 2 sample(s) on 4/14/2016 for the analyses presented in the following report. Color by SM2120 Cyanide by SM 4500-CN C, E Diesel and Heavy Oil by NWTPH-Dx/Dx Ext. Gasoline by NWTPH-Gx ton Chromatography by EPA Method 300.0 Mercury by EPA Method 245.1 Total Metals by EPA Method 200.8 Total Dissolved Solids (TDS) by SM 2540C Total Phosphorous by EPA Method 365.3 Volatile Organic Compounds by EPA Method 8260C This report consists of the following: - Case Narrative - Analytical Results - Applicable Quality Control Summary Reports - Chain of Custody All analyses were performed consistent with the Quality Assurance program of Fremont Analytical, Inc. Please contact the laboratory if you should have any questions about the results. Thank you for using Fremont Analytical. Sincerely, DoD/ELAP Certification #L2371, /SOACC 17025:2005 ORELAP Certification: WA 100009-007 (NELAP Recognized) Revision v1 www.fremontanalvtical.com Mike Ridgeway President DOD/FLAP Certification #L2371, ISO11CC 17025:2005 ORELAP Certification: WA 100009-007 (NELAP Recognized) Revision vl www.f rem p nta nal�,lb-calIx-om CLIENT: Project: Lab Order: Lab Sample ID 1604140-001 1604140-002 Shannon & Wilson Madrona K-8 School 1604140 Client Sample ID OW-1-041416 Trip Blank Date: 0510512016 Work Order Sample Summary Date/Time Collected 04/14/2016 11:18 AM 04/13/2016 12:48 PM Date/Time Received 04/14/2016 4:07 PM 04/14/2016 4:07 PM Revision v1 Note: If no "Time Collected" is supplied, a default of 12:00AIVI is assigned t=- 1-11aa, CLIENT: Shannon & Wilson Project: Madrona K-8 School I. SAMPLE RECEIPT: Samples receipt information is recorded on the attached Sample Receipt Checklist. Case Narrative W O#: 1604140 Date: 4/21 /2016 11. GENERAL REPORTING COMMENTS: Results are reported on a wet weight basis unless dry -weight correction is denoted in the units field on the analytical report ("mg/kg-dry" or "ug/kg-dry"). Matrix Spike (MS) and MS Duplicate (MSD) samples are tested from an analytical batch of "like" matrix to check for possible matrix effect. The MS and MSD will provide site specific matrix data only for those samples which are spiked by the laboratory. The sample chosen for spike purposes may or may not have been a sample submitted in this sample delivery group. The validity of the analytical procedures for which data is reported in this analytical report is determined by the Laboratory Control Sample (LCS) and the Method Blank (MB). The LCS and the MB are processed with the samples and the MS/MSD to ensure method criteria are achieved throughout the entire analytical process. III. ANALYSES AND EXCEPTIONS: Exceptions associated with this report will be footnoted in the analytical results page(s) or the quality control summary page(s) and/or noted below. 1604140-001 E C-COLOR has been Sub Contracted. Revision v1 Qualifiers & Acronyms W O#: 1604140 Date Reported: 4/21/2016 Qualifiers: * - Flagged value is not within established control limits B - Analyte detected in the associated Method Blank D - Dilution was required E - Value above quantitation range H - Holding times for preparation or analysis exceeded I - Analyte with an internal standard that does not meet established acceptance criteria J - Analyte detected below Reporting Limit N - Tentatively Identified Compound (TIC) Q - Analyte with an initial or continuing calibration that does not meet established acceptance criteria (<20%RSD, <20% Drift or minimum RRF) S - Spike recovery outside accepted recovery limits ND - Not detected at the Reporting Limit R - High relative percent difference observed Acronyms: %Rec - Percent Recovery CCB - Continued Calibration Blank CCV - Continued Calibration Verification DF - Dilution Factor HEM - Hexane Extractable Material ICV - Initial Calibration Verification LCS/LCSD - Laboratory Control Sample / Laboratory Control Sample Duplicate MB or MBLANK - Method Blank MDL - Method Detection Limit MS/MSD - Matrix Spike / Matrix Spike Duplicate PDS - Post Digestion Spike Ref Val - Reference Value RL - Reporting Limit RPD - Relative Percent Difference SD - Serial Dilution SGT - Silica Gel Treatment SPK - Spike Surr - Surrogate Revision v1 __ wfre ntar al i alm 0fremont U ; r Analytical Report W O#: 1604140 Date Reported: 4/21/2016 Client: Shannon & Wilson Collection Date:4/14/2016 11:18:00 AM Project: Madrona K-8 School Lab ID: 1604140-001 Matrix: Groundwater Client Sample ID: OW-1-041416 Analyses Result RL Qual Units DF Date Analyzed Diesel and Heavy Oil by NWTPH-Dx/Dx Ext. Batch ID: 13481 Analyst: CM Diesel (Fuel Oil) ND 50.0 pg/L 1 4/19/2016 11:45:00 PM Heavy Oil ND 100 pg/L 1 4/19/2016 11:45:00 PM Surr: 2-Fluorobiphenyl 73.5 50-150 %Rec 1 4/19/2016 11:45:00 PM Surr: o-Terphenyl 77.5 50-150 %Rec 1 4/19/2016 11:45:00 PM Gasoline bV NWTPH-Gx Batch ID: R28812 Analyst: NG Gasoline ND 50.0 pg/L 1 4/15/2016 4:35:49 AM Surr: 4-Bromofluorobenzene 99.4 65-135 %Rec 1 4/15/2016 4:35:49 AM Surr: Toluene-d8 98.8 65-135 %Rec 1 4/15/2016 4:35:49 AM Volatile Organic Compounds by EPA Method 8260C Batch ID: R28811 Analyst: NG Benzene ND 1.00 pg/L 1 4/15/2016 4:35:49 AM Toluene ND 1.00 pg/L 1 4/15/2016 4:35:49 AM Ethylbenzene ND 1.00 pg/L 1 4/15/2016 4:35:49 AM m,p-Xylene ND 1.00 pg/L 1 4/15/2016 4:35:49 AM o-Xylene ND 1.00 pg/L 1 4/15/2016 4:35:49 AM Surr: Dibromofluoromethane 102 45.4-152 %Rec 1 4/15/2016 4:35:49 AM Surr: Toluene-d8 94.3 40.1-139 %Rec 1 4/15/2016 4:35:49 AM Surr: 1-Bromo-4-fluorobenzene 97.2 64.2-128 %Rec 1 4/15/2016 4:35:49 AM Ion Chromatography by EPA Method 300.0 Batch ID: R28832 Analyst: MW Fluoride ND 0.100 mg/L 1 4/15/2016 12:09:00 PM Chloride 6.38 0.100 mg/L 1 4/15/2016 12:09:00 PM Nitrite 0.159 0.100 mg/L 1 4/15/2016 12:09:00 PM Nitrate 1.01 0.100 mg/L 1 4/15/2016 12:09:00 PM Nitrate+Nitrite 1.17 0.100 mg/L 1 4/15/2016 12:09:00 PM Ortho-Phosphate ND 0.200 mg/L 1 4/15/2016 12:09:00 PM Sulfate 22.6 0.300 mg/L 1 4/15/2016 12:09:00 PM Mercury by EPA Method 245.1 Batch ID: 13469 Analyst: MW Mercury ND 0.100 pg/L 1 4/18/2016 3:00:59 PM Total Metals by EPA Method 200.8 Batch ID: 13468 Analyst: TN Antimony ND 0.200 pg/L 1 4/15/2016 2:29:17 PM Revision v1 Ofremont U ; r Analytical Report W O#: 1604140 Date Reported: 4/21/2016 Client: Shannon & Wilson Collection Date:4/14/2016 11:18:00 AM Project: Madrona K-8 School Lab ID: 1604140-001 Matrix: Groundwater Client Sample ID: OW-1-041416 Analyses Result RL Qual Units DF Date Analyzed Total Metals by EPA Method 200.8 Batch ID: 13468 Analyst: TN Arsenic ND 1.00 pg/L 1 4/15/2016 2:29:17 PM Barium 28.6 0.500 pg/L 1 4/15/2016 2:29:17 PM Beryllium ND 0.200 pg/L 1 4/15/2016 2:29:17 PM Cadmium ND 0.200 pg/L 1 4/15/2016 2:29:17 PM Chromium 1.67 0.500 pg/L 1 4/15/2016 2:29:17 PM Copper ND 0.500 pg/L 1 4/15/2016 2:29:17 PM Iron ND 100 pg/L 1 4/15/2016 2:29:17 PM Lead ND 1.00 pg/L 1 4/15/2016 2:29:17 PM Manganese 344 2.00 pg/L 1 4/15/2016 2:29:17 PM Nickel 2.94 0.500 pg/L 1 4/15/2016 2:29:17 PM Selenium ND 1.00 pg/L 1 4/15/2016 2:29:17 PM Silver ND 0.200 pg/L 1 4/15/2016 2:29:17 PM Sodium 12,900 100 pg/L 1 4/15/2016 2:29:17 PM Thallium ND 0.200 pg/L 1 4/15/2016 2:29:17 PM Zinc 27.3 1.50 pg/L 1 4/15/2016 2:29:17 PM Cyanide by SM 4500-CN C, E Batch ID: 13500 Analyst: NG Cyanide, Total ND 0.0500 mg/L 1 4/21/2016 10:03:00 AM Total Phosphorous by EPA Method 365.3 Batch ID: 13510 Analyst: KT Phosphorus, Total (As P) ND 0.200 mg/L 1 4/21/2016 2:25:00 PM Total Dissolved Solids (TDS) by SM 2540C Batch ID: R28863 Analyst: KT Total Dissolved Solids 182 5.00 mg/L 1 4/19/2016 4:04:00 PM Revision v1 11 SPECTRA Laboratories ......... .... .. ....... . .... 2221Rcuss Waye 0 TaconiaWA98421 a (253)272-4850 'N' Fax(253)572-9838 0 www,spectra-lab.co in 05/05/2016 Fremont Analytical 0 Seattle, WA 98103 Attn: Mike Ridgeway SPECTRA LABORATORIES Steve Hibbs. Laborat'+-c,1Lwow n M VA Client ID: 1604140-001 E Sample Matrix: Groundwater Date Sampled: 04/14/2016 Date Received: 04/18/2016 i'opectra Project: 2016040430 Spectra Number: I Result its Method ND Color Units SM 2120B Page I of I 10 rammuffm 1-lu-vu'q VIV 1- u n I VV Y HECURD L_!!wg! COM 233 PAGE; i OF. soon&M, IMMA SUB CON7RATOP- Spectra COMPANY. -ZD�RUSS - 2221 as Way CrrY. STATE, ap: TRc0ma, WA 98421 PHONE, (253) 272-4950 FAX (253) 572-9838 ACCO1W#.- rrEM 0 SAMPLE ID 1604140-DOIE C-COLOR mfiKh qA t U-10%fob un b SPECTRA Laboratories SPECUL INFIWOTTONs / comMEM: Please cmail resUlts to Nficfiaef Fidgeway and Chelso if CLIENT SAMPLE n) BOTTLE TYPE MATRIX DATE COLLECTED NUMBER OF CONTAINERS ARDRESS FremontAnalyncal, Inc. 360OFFemontAve. N. Seattle, WA 98103 TEL: 206-352-3 790 FU.• 206352-7178 Webme: www.fremontanalyttcal.com COMMENTS-, MeLhanof dWeWft HOT Sany*Nofvho Addmomf Sample D..1ptmm. Date: 412112016 QC SUMMARY REPORT Cyanide by SM 4500-CN C, E Sample ID: MB-13500 SampType: MBLK Units: mg/L Prep Date: 4/20/2016 RunNo: 28891 Client ID: MBLKW Batch ID: 13500 Analysis Date: 4/21/2016 SegNo: 543216 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Cyanide, Total ND 0.0500 Sample ID: LCS-13500 SampType: LCS Units: mg/L Prep Date: 4/20/2016 RunNo: 28891 Client ID: LCSW Batch ID: 13500 Analysis Date: 4/21/2016 SegNo: 543205 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Cyanide, Total 0.250 0.0500 0.2500 0 99.8 80 120 Sample ID: 1604152-001ADUP SampType: DUP Units: mg/L Prep Date: 4/20/2016 RunNo: 28891 Client ID: BATCH Batch ID: 13500 Analysis Date: 4/21/2016 SegNo: 543209 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Cyanide, Total ND 0.0500 0 20 Sample ID: 1604152-001AMS SampType: MS Units: mg/L Prep Date: 4/20/2016 RunNo: 28891 Client ID: BATCH Batch ID: 13500 Analysis Date: 4/21/2016 SegNo: 543210 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Cyanide, Total 0.274 0.0500 0.2500 0.02350 100 80 120 Sample ID: 1604152-001AMSD SampType: MSD Units: mg/L Prep Date: 4/20/2016 RunNo: 28891 Client ID: BATCH Batch ID: 13500 Analysis Date: 4/21/2016 SegNo: 543211 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Cyanide, Total 0.205 0.0500 0.2500 0.02350 72.6 80 120 0.2741 28.8 30 S NOTES: S - Outlying spike recovery(ies) observed. A duplicate analysis was performed and recovered within range. Revision v1 Page 11 of 29 Date: 412112016 QC SUMMARY REPORT Ion Chromatography by EPA Method 300.0 Sample ID: MB-R28832 SampType: MBLK Units: mg/L Prep Date: 4/15/2016 RunNo: 28832 Client ID: MBLKW Batch ID: R28832 Analysis Date: 4/15/2016 SegNo: 541986 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Fluoride ND 0.100 Chloride ND 0.100 Nitrite ND 0.100 Nitrate ND 0.100 Nitrate+Nitrite ND 0.100 Sulfate ND 0.300 Sample ID: LCS-R28832 SampType: LCS Units: mg/L Prep Date: 4/15/2016 RunNo: 28832 Client ID: LCSW Batch ID: R28832 Analysis Date: 4/15/2016 SegNo: 541987 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Fluoride 2.09 0.100 2.000 0 105 90 110 Chloride 2.88 0.100 3.000 0 96.0 90 110 Nitrite 2.97 0.100 3.000 0 98.9 90 110 Nitrate 3.03 0.100 3.000 0 101 90 110 Nitrate+Nitrite 6.00 0.100 6.000 0 100 90 110 Sulfate 15.6 0.300 15.00 0 104 90 110 Sample ID: 1604140-001DDUP SampType: DUP Units: mg/L Prep Date: 4/15/2016 RunNo: 28832 Client ID: OW-1-041416 Batch ID: R28832 Analysis Date: 4/15/2016 SegNo: 541989 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Fluoride ND 0.100 0 20 Chloride 6.37 0.100 6.376 0.133 20 Nitrite 0.161 0.100 0.1594 0.874 20 Nitrate 1.02 0.100 1.011 0.709 20 Nitrate+Nitrite 1.18 0.100 1.171 0.732 20 Sulfate 22.6 0.300 22.62 0.142 20 Revision v1 Page 12 of 29 Date: 412112016 QC SUMMARY REPORT Ion Chromatography by EPA Method 300.0 Sample ID: 1604140-001DMS SampType: MS Units: mg/L Prep Date: 4/15/2016 RunNo: 28832 Client ID: OW-1-041416 Batch ID: R28832 Analysis Date: 4/15/2016 SegNo: 541990 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Fluoride 2.08 0.100 2.000 0.06680 101 80 120 Chloride 8.98 0.100 3.000 6.376 86.7 80 120 Nitrite 3.05 0.100 3.000 0.1594 96.5 80 120 Nitrate 3.95 0.100 3.000 1.011 98.1 80 120 Nitrate+Nitrite 7.01 0.100 6.000 1.171 97.3 80 120 Sulfate 37.2 0.300 15.00 22.62 97.3 80 120 Sample ID: 1604140-001DMSD SampType: MSD Units: mg/L Prep Date: 4/15/2016 RunNo: 28832 Client ID: OW-1-041416 Batch ID: R28832 Analysis Date: 4/15/2016 SegNo: 541991 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Fluoride 2.09 0.100 2.000 0.06680 101 80 120 2.084 0.161 20 Chloride 8.97 0.100 3.000 6.376 86.3 80 120 8.978 0.136 20 Nitrite 3.04 0.100 3.000 0.1594 96.2 80 120 3.053 0.286 20 Nitrate 3.92 0.100 3.000 1.011 97.0 80 120 3.953 0.792 20 Nitrate+Nitrite 6.97 0.100 6.000 1.171 96.6 80 120 7.006 0.571 20 Sulfate 37.0 0.300 15.00 22.62 95.8 80 120 37.22 0.623 20 Revision v1 Page 13 of 29 Date: 412112016 QC SUMMARY REPORT Total Phosphorous by EPA Method 365.3 Sample ID: MB-13510 SampType: MBLK Units: mg/L Prep Date: 4/21/2016 RunNo: 28899 Client ID: MBLKW Batch ID: 13510 Analysis Date: 4/21/2016 SegNo: 543434 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Phosphorus, Total (As P) ND 0.200 Sample ID: LCS-13510 SampType: LCS Units: mg/L Prep Date: 4/21/2016 RunNo: 28899 Client ID: LCSW Batch ID: 13510 Analysis Date: 4/21/2016 SegNo: 543435 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Phosphorus, Total (As P) 2.17 0.200 2.000 0 109 65 135 Sample ID: 1604140-001HDUP SampType: DUP Units: mg/L Prep Date: 4/21/2016 RunNo: 28899 Client ID: OW-1-041416 Batch ID: 13510 Analysis Date: 4/21/2016 SegNo: 543437 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Phosphorus, Total (As P) ND 0.200 0 30 Sample ID: 1604140-001HMS SampType: MS Units: mg/L Prep Date: 4/21/2016 RunNo: 28899 Client ID: OW-1-041416 Batch ID: 13510 Analysis Date: 4/21/2016 SegNo: 543438 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Phosphorus, Total (As P) 1.90 0.200 2.000 0.01800 94.2 65 135 Sample ID: 1604140-001HMSD SampType: MSD Units: mg/L Prep Date: 4/21/2016 RunNo: 28899 Client ID: OW-1-041416 Batch ID: 13510 Analysis Date: 4/21/2016 SegNo: 543439 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Phosphorus, Total (As P) 2.18 0.200 2.000 0.01800 108 65 135 1.902 13.5 30 Revision v1 Page 14 of 29 Date: 412112016 QC SUMMARY REPORT Total Dissolved Solids (TDS) by SM 2540C Sample ID: MB-R28863 SampType: MBLK Units: mg/L Prep Date: 4/19/2016 RunNo: 28863 Client ID: MBLKW Batch ID: R28863 Analysis Date: 4/19/2016 SegNo: 542617 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Total Dissolved Solids ND 5.00 Sample ID: LCS-R28863 SampType: LCS Units: mg/L Prep Date: 4/19/2016 RunNo: 28863 Client ID: LCSW Batch ID: R28863 Analysis Date: 4/19/2016 SegNo: 542618 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Total Dissolved Solids 304 10.0 300.0 0 101 65 135 Sample ID: 1604140-001DDUP SampType: DUP Units: mg/L Prep Date: 4/19/2016 RunNo: 28863 Client ID: OW-1-041416 Batch ID: R28863 Analysis Date: 4/19/2016 SegNo: 542620 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Total Dissolved Solids 203 5.00 182.0 10.9 30 Revision v1 Page 15 of 29 Date: 412112016 QC SUMMARY REPORT Total Metals by EPA Method 200.8 Sample ID: MB-13468 SampType: MBLK Units: pg/L Prep Date: 4/15/2016 RunNo: 28822 Client ID: MBLKW Batch ID: 13468 Analysis Date: 4/15/2016 SegNo: 541791 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Antimony ND 0.200 Arsenic ND 1.00 Barium ND 0.500 Beryllium ND 0.200 Cadmium ND 0.200 Chromium ND 0.500 Copper ND 0.500 Iron ND 100 Lead ND 1.00 Manganese ND 2.00 Nickel ND 0.500 Selenium ND 1.00 Silver ND 0.200 Sodium ND 100 Thallium ND 0.200 Zinc ND 1.50 Sample ID: LCS-13468 SampType: LCS Units: pg/L Prep Date: 4/15/2016 RunNo: 28822 Client ID: LCSW Batch ID: 13468 Analysis Date: 4/15/2016 SegNo: 541792 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Antimony 4.52 0.200 5.000 0 90.4 85 115 Arsenic 101 1.00 100.0 0 101 85 115 Barium 99.3 0.500 100.0 0 99.3 85 115 Beryllium 5.16 0.200 5.000 0 103 85 115 Cadmium 5.70 0.200 5.000 0 114 85 115 Chromium 92.5 0.500 100.0 0 92.5 85 115 Copper 96.2 0.500 100.0 0 96.2 85 115 Iron 1,090 100 1,000 0 109 50 150 Lead 45.3 1.00 50.00 0 90.7 85 115 Revision v1 Page 16 of 29 Date: 412112016 QC SUMMARY REPORT Total Metals by EPA Method 200.8 Sample ID: LCS-13468 SampType: LCS Units: pg/L Prep Date: 4/15/2016 RunNo: 28822 Client ID: LCSW Batch ID: 13468 Analysis Date: 4/15/2016 SegNo: 541792 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Manganese 100 2.00 100.0 0 100 85 115 Nickel 95.5 0.500 100.0 0 95.5 85 115 Selenium 9.94 1.00 10.00 0 99.4 85 115 Silver 4.66 0.200 5.000 0 93.2 85 115 Sodium 991 100 1,000 0 99.1 50 150 Thallium 2.27 0.200 2.500 0 90.7 85 115 Zinc 100 1.50 100.0 0 100 85 115 Sample ID: 1604116-001CDUP SampType: DUP Units: pg/L Prep Date: 4/15/2016 RunNo: 28822 Client ID: BATCH Batch ID: 13468 Analysis Date: 4/15/2016 SegNo: 541794 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Antimony 0.202 0.200 Arsenic ND 1.00 Barium 38.1 0.500 Beryllium ND 0.200 Cadmium ND 0.200 Chromium 0.722 0.500 Copper ND 0.500 Iron ND 100 Lead ND 1.00 Manganese 5.17 2.00 Nickel 0.939 0.500 Selenium ND 1.00 Silver ND 0.200 Sodium 54,300 100 Thallium ND 0.200 Zinc 2.95 1.50 NOTES: R - High RPD observed. The method is in control as indicated by the LCS. 0.4710 80.1 30 R 0 30 37.74 0.955 30 0 30 0 30 0.5610 25.1 30 0.5540 10.9 30 0 30 0 30 5.155 0.320 30 0.7520 22.1 30 0 30 0 30 57,370 5.44 30 0 30 2.528 15.5 30 Revision v1 Page 17 of 29 Date: 412112016 QC SUMMARY REPORT Total Metals by EPA Method 200.8 Sample ID: 1604116-001CMS SampType: MS Units: pg/L Prep Date: 4/15/2016 RunNo: 28822 Client ID: BATCH Batch ID: 13468 Analysis Date: 4/15/2016 SegNo: 541795 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Antimony 22.8 0.200 25.00 0.4710 89.3 70 130 Arsenic 532 1.00 500.0 0.8205 106 70 130 Barium 530 0.500 500.0 37.74 98.5 70 130 Beryllium 24.9 0.200 25.00 0 99.7 70 130 Cadmium 28.0 0.200 25.00 0.01600 112 70 130 Chromium 517 0.500 500.0 0.5610 103 70 130 Copper 489 0.500 500.0 0.5540 97.8 70 130 Iron 5,250 100 5,000 45.56 104 50 150 Lead 220 1.00 250.0 0.07550 87.9 70 130 Manganese 508 2.00 500.0 5.155 100 70 130 Nickel 492 0.500 500.0 0.7520 98.3 70 130 Selenium 51.5 1.00 50.00 0 103 70 130 Silver 17.0 0.200 25.00 0 67.8 70 130 S Sodium 60,500 100 5,000 57,370 62.9 50 150 Thallium 11.2 0.200 12.50 0.006500 89.4 70 130 Zinc 508 1.50 500.0 2.528 101 70 130 NOTES: S - Outlying spike recovery(ies) observed. A duplicate analysis was performed and recovered within range. Sample ID: 1604116-001CMSD SampType: MSD Units: pg/L Prep Date: 4/15/2016 RunNo: 28822 Client ID: BATCH Batch ID: 13468 Analysis Date: 4/15/2016 SegNo: 541796 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Antimony 22.7 0.200 25.00 0.4710 89.1 70 130 22.79 0.171 30 Arsenic 525 1.00 500.0 0.8205 105 70 130 531.7 1.30 30 Barium 522 0.500 500.0 37.74 96.9 70 130 530.4 1.55 30 Beryllium 24.0 0.200 25.00 0 96.0 70 130 24.92 3.79 30 Cadmium 27.9 0.200 25.00 0.01600 111 70 130 28.03 0.560 30 Chromium 497 0.500 500.0 0.5610 99.4 70 130 516.6 3.79 30 Copper 482 0.500 500.0 0.5540 96.3 70 130 489.4 1.55 30 Iron 5,310 100 5,000 45.56 105 50 150 5,246 1.13 30 Revision v1 Page 18 of 29 Date: 412112016 QC SUMMARY REPORT Total Metals by EPA Method 200.8 Sample ID: 1604116-001CMSD SampType: MSD Units: pg/L Prep Date: 4/15/2016 RunNo: 28822 Client ID: BATCH Batch ID: 13468 Analysis Date: 4/15/2016 SegNo: 541796 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit Hight-imit RPD Ref Val %RPD RPDLimit Qua[ Lead 216 1.00 250.0 0.07550 86.4 70 130 219.8 1.76 30 Manganese 507 2.00 500.0 5.155 100 70 130 507.5 0.177 30 Nickel 493 0.500 500.0 0.7520 98.4 70 130 492.2 0.156 30 Selenium 49.2 1.00 50.00 0 98.3 70 130 51.48 4.62 30 Silver 18.7 0.200 25.00 0 75.0 70 130 16.96 10.0 30 Sodium 60,100 100 5,000 57,370 54.7 50 150 60,510 0.679 30 Thallium 11.1 0.200 12.50 0.006500 88.5 70 130 11.18 1.03 30 Zinc 507 1.50 500.0 2.528 101 70 130 508.0 0.150 30 Revision v1 Page 19 of 29 Date: 412112016 QC SUMMARY REPORT Mercury by EPA Method 245.1 Sample ID: MB-13469 SampType: MBLK Units: lag/L Prep Date: 4/18/2016 RunNo: 28842 Client ID: MBLKW Batch ID: 13469 Analysis Date: 4/18/2016 SegNo: 542145 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit Hight-imit RPD Ref Val %RPD RPDLimit Qua[ Mercury ND 0.100 Sample ID: LCS-13469 SampType: LCS Units: lag/L Prep Date: 4/18/2016 RunNo: 28842 Client ID: LCSW Batch ID: 13469 Analysis Date: 4/18/2016 SegNo: 542146 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Mercury 2.27 0.100 2.500 0 90.8 85 115 Sample ID: 1604092-001ADUP SampType: DUP Units: lag/L Prep Date: 4/18/2016 RunNo: 28842 Client ID: BATCH Batch ID: 13469 Analysis Date: 4/18/2016 SegNo: 542148 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Mercury ND 0.100 0 20 Sample ID: 1604092-001AMS SampType: MS Units: lag/L Prep Date: 4/18/2016 RunNo: 28842 Client ID: BATCH Batch ID: 13469 Analysis Date: 4/18/2016 SegNo: 542149 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Mercury 2.41 0.100 2.500 0 96.4 80 120 Sample ID: 1604092-001AMSD SampType: MSD Units: lag/L Prep Date: 4/18/2016 RunNo: 28842 Client ID: BATCH Batch ID: 13469 Analysis Date: 4/18/2016 SegNo: 542150 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Mercury 2.40 0.100 2.500 0 96.0 80 120 2.410 0.416 20 Revision v1 Page 20 of 29 Date: 412112016 QC SUMMARY REPORT Diesel and Heavy Oil by NWTPH-Dx/Dx Ext. Sample ID: MB-13481 SampType: MBLK Units: pg/L Prep Date: 4/18/2016 RunNo: 28866 Client ID: MBLKW Batch ID: 13481 Analysis Date: 4/19/2016 SegNo: 542740 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Diesel (Fuel Oil) ND 50.0 Heavy Oil ND 100 Sum 2-Fluorobiphenyl 50.6 80.00 63.3 50 150 Sum o-Terphenyl 53.8 80.00 67.3 50 150 Sample ID: LCS-13481 SampType: LCS Units: pg/L Prep Date: 4/18/2016 RunNo: 28866 Client ID: LCSW Batch ID: 13481 Analysis Date: 4/19/2016 SegNo: 542739 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Diesel (Fuel Oil) 676 50.0 1,000 0 67.6 65 135 Sum 2-Fluorobiphenyl 58.8 80.00 73.5 50 150 Sum o-Terphenyl 60.5 80.00 75.6 50 150 Sample ID: 1604132-002BDUP SampType: DUP Units: pg/L Prep Date: 4/18/2016 RunNo: 28866 Client ID: BATCH Batch ID: 13481 Analysis Date: 4/19/2016 SegNo: 542716 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Diesel (Fuel Oil) ND 51.8 Diesel Range Organics (C12-C24) 559 51.8 Heavy Oil 2,270 104 Sum 2-Fluorobiphenyl 65.9 82.88 79.6 Sum o-Terphenyl 59.4 82.88 71.6 NOTES: R - High RPD observed. The method is in control as indicated by the LCS. DRO - Indicates the presence of unresolved compounds eluting from dodecane through tetracosane (C12-C24). 0 30 459.7 19.5 30 878.6 88.5 30 R 50 150 0 50 150 0 Revision v1 Page 21 of 29 Date: 412112016 QC SUMMARY REPORT Diesel and Heavy Oil by NWTPH-Dx/Dx Ext. Sample ID: 1604140-001BMS SampType: MS Units: pg/L Prep Date: 4/18/2016 RunNo: 28866 Client ID: OW-1-041416 Batch ID: 13481 Analysis Date: 4/20/2016 SegNo: 542718 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qua[ Diesel (Fuel Oil) 668 49.9 998.9 37.33 63.2 65 135 S Surr:2-Fluorobiphenyl 59.0 79.91 73.8 50 150 Surr: o-Terphenyl 58.9 79.91 73.7 50 150 NOTES: S - Outlying spike recovery(ies) observed. A duplicate analysis was performed and recovered within range. Sample ID: 1604140-001BMSD SampType: MSD Units: pg/L Prep Date: 4/18/2016 RunNo: 28866 Client ID: OW-1-041416 Batch ID: 13481 Analysis Date: 4/20/2016 SegNo: 542719 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Diesel (Fuel Oil) 714 49.8 996.3 37.33 67.9 65 135 668.4 6.56 30 Sum 2-Fluorobiphenyl 59.8 79.71 75.1 50 150 0 0 Surr: o-Terphenyl 61.5 79.71 77.2 50 150 0 0 Sample ID: 1604155-005EDUP SampType: DUP Units: pg/L Prep Date: 4/18/2016 RunNo: 28866 Client ID: BATCH Batch ID: 13481 Analysis Date: 4/20/2016 SegNo: 542729 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Diesel (Fuel Oil) ND 50.0 0 30 Heavy Oil ND 100 0 30 Surr:2-Fluorobiphenyl 55.2 79.97 69.0 50 150 0 Surr: o-Terphenyl 56.7 79.97 70.9 50 150 0 Revision v1 Page 22 of 29 Date: 412112016 QC SUMMARY REPORT Gasoline by NWTPH-Gx Sample ID: LCS-R28812 SampType: LCS Units: lag/L Prep Date: 4/14/2016 RunNo: 28812 Client ID: LCSW Batch ID: R28812 Analysis Date: 4/14/2016 SegNo: 541564 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit Hight-imit RPD Ref Val %RPD RPDLimit Qua[ Gasoline 502 50.0 500.0 0 100 65 135 Surr: Toluene-d8 24.4 25.00 97.8 65 135 Surr:4-Bromofluorobenzene 25.0 25.00 99.9 65 135 Sample ID: MB-R28812 SampType: MBLK Units: lag/L Prep Date: 4/14/2016 RunNo: 28812 Client ID: MBLKW Batch ID: R28812 Analysis Date: 4/14/2016 SegNo: 541565 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Gasoline ND 50.0 Surr: Toluene-d8 24.9 25.00 99.8 65 135 Sum 4-Bromofluorobenzene 24.9 25.00 99.7 65 135 Sample ID: 1602099-051AMS SampType: MS Units: lag/L Prep Date: 4/15/2016 RunNo: 28812 Client ID: BATCH Batch ID: R28812 Analysis Date: 4/15/2016 SegNo: 541555 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Gasoline 540 50.0 500.0 0 108 65 135 H Surr: Toluene-d8 25.2 25.00 101 65 135 H Surr: 4-Bromofluorobenzene 25.4 25.00 101 65 135 H Sample ID: 1602099-051AMSD SampType: MSD Units: lag/L Prep Date: 4/15/2016 RunNo: 28812 Client ID: BATCH Batch ID: R28812 Analysis Date: 4/15/2016 SegNo: 541556 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Gasoline 557 50.0 500.0 0 111 65 135 540.1 3.07 30 H Surr: Toluene-d8 24.6 25.00 98.2 65 135 0 0 H Surr:4-Bromofluorobenzene 24.6 25.00 98.6 65 135 0 0 H Revision v1 Page 23 of 29 Date: 412112016 QC SUMMARY REPORT Gasoline by NWTPH-Gx Sample ID: 1604115-005ADUP SampType: DUP Units: pg/L Prep Date: 4/15/2016 RunNo: 28812 Client ID: BATCH Batch ID: R28812 Analysis Date: 4/15/2016 SegNo: 541558 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit Hight-imit RPD Ref Val %RPD RPDLimit Qua[ Gasoline ND 50.0 0 30 Surr: Toluene-d8 25.0 25.00 99.8 65 135 0 0 Surr:4-Bromofluorobenzene 25.4 25.00 101 65 135 0 0 Revision v1 Page 24 of 29 Date: 412112016 QC SUMMARY REPORT Volatile Organic Compounds by EPA Method 8260C Sample ID: LCS-R28811 SampType: LCS Units: pg/L Prep Date: 4/14/2016 RunNo: 28811 Client ID: LCSW Batch ID: R28811 Analysis Date: 4/14/2016 SegNo: 541551 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit Hight-imit RPD Ref Val %RPD RPDLimit Qua[ Benzene 17.2 1.00 20.00 0 86.1 69.3 132 Toluene 19.3 1.00 20.00 0 96.4 61.3 145 Ethylbenzene 18.2 1.00 20.00 0 91.1 72 130 m,p-Xylene 37.0 1.00 40.00 0 92.6 70.3 134 o-Xylene 18.6 1.00 20.00 0 93.0 72.1 131 Surr: Dibromofluoromethane 23.1 25.00 92.2 45.4 152 Surr: Toluene-d8 27.4 25.00 110 40.1 139 Sum 1-Bromo-4-fluorobenzene 25.6 25.00 102 64.2 128 Sample ID: MB-R28811 SampType: MBLK Units: pg/L Prep Date: 4/14/2016 RunNo: 28811 Client ID: MBLKW Batch ID: R28811 Analysis Date: 4/14/2016 SegNo: 541552 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Benzene ND 1.00 Toluene ND 1.00 Ethylbenzene ND 1.00 m,p-Xylene ND 1.00 o-Xylene ND 1.00 Surr: Dibromofluoromethane 26.0 25.00 104 45.4 152 Surr: Toluene-d8 23.7 25.00 94.9 40.1 139 Surr:1-Bromo-4-fluorobenzene 24.6 25.00 98.3 64.2 128 Sample ID: 1602099-051AMS SampType: MS Units: pg/L Prep Date: 4/14/2016 RunNo: 28811 Client ID: BATCH Batch ID: R28811 Analysis Date: 4/14/2016 SegNo: 541536 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Benzene Toluene Ethylbenzene m,p-Xylene 20.1 1.00 20.00 0 101 65.4 138 18.4 1.00 20.00 0 91.8 64 139 19.5 1.00 20.00 0 97.4 64.5 136 39.9 1.00 40.00 0 99.8 63.3 135 Revision v1 Page 25 of 29 Date: 412112016 QC SUMMARY REPORT Volatile Organic Compounds by EPA Method 8260C Sample ID: 1602099-051AMS SampType: MS Units: pg/L Prep Date: 4/14/2016 RunNo: 28811 Client ID: BATCH Batch ID: R28811 Analysis Date: 4/14/2016 SegNo: 541536 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit Hight-imit RPD Ref Val %RPD RPDLimit Qua[ o-Xylene 20.0 1.00 20.00 0 100 65.4 134 H Surr: Dibromofluoromethane 26.3 25.00 105 45.4 152 H Surr: Toluene-d8 24.1 25.00 96.4 40.1 139 H Sum 1-Bromo-4-fluorobenzene 24.9 25.00 99.8 64.2 128 H Sample ID: 1602099-051AMSD SampType: MSD Units: pg/L Prep Date: 4/14/2016 RunNo: 28811 Client ID: BATCH Batch ID: R28811 Analysis Date: 4/14/2016 SegNo: 541537 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Benzene 20.3 1.00 20.00 0 101 65.4 138 20.12 0.693 30 H Toluene 18.4 1.00 20.00 0 92.0 64 139 18.36 0.218 30 H Ethylbenzene 20.8 1.00 20.00 0 104 64.5 136 19.48 6.41 30 H m,p-Xylene 41.5 1.00 40.00 0 104 63.3 135 39.90 3.88 30 H o-Xylene 20.8 1.00 20.00 0 104 65.4 134 20.02 3.92 30 H Surr: Dibromofluoromethane 25.9 25.00 104 45.4 152 0 0 H Surr: Toluene-d8 23.8 25.00 95.1 40.1 139 0 0 H Surr:1-Bromo-4-fluorobenzene 25.5 25.00 102 64.2 128 0 0 H Sample ID: 1604115-005ADUP SampType: DUP Units: pg/L Prep Date: 4/15/2016 RunNo: 28811 Client ID: BATCH Batch ID: R28811 Analysis Date: 4/15/2016 SegNo: 541544 Analyte Result RL SPK value SPK Ref Val %REC Lowl-imit HighLimit RPD Ref Val %RPD RPDLimit Qual Benzene ND 1.00 0 30 Toluene ND 1.00 0 30 Ethylbenzene ND 1.00 0 30 m,p-Xylene ND 1.00 0 30 o-Xylene ND 1.00 0 30 Surr: Dibromofluoromethane 25.5 25.00 102 45.4 152 0 Surr: Toluene-d8 23.1 25.00 92.4 40.1 139 0 Sum 1-Bromo-4-fluorobenzene 24.9 25.00 99.4 64.2 128 0 Revision v1 Page 26 of 29 Date: 412112016 QC SUMMARY REPORT Volatile Organic Compounds by EPA Method 8260C iample ID: 1604115-005ADUP SampType: DUP Units: pg/L Prep Date: 4/15/2016 RunNo: 28811 'Iient ID: BATCH Batch ID: R28811 Analysis Date: 4/15/2016 SegNo: 541544 knalyte Result RL SPK value SPK Ref Val %REC LowLimit Hight-imit RPD Ref Val %RPD RPDLimit Qual Revision v1 Page 27 of 29 7 {p Sample Log -In Check List Client Name: Sw Work Order Number: 1604140 Logged by: Erica Silva Date Received: 4/14/2016 4:07:00 PM Chain of Custod 1. Is Chain of Custody complete? Yes ] No Not Present 2. How was the sample delivered? Client Lop In 3. Coolers are present? Yes lv4 No ❑ NA ❑ 4. Shipping container/cooler in good condition? Yes 1,01� No ❑ 5. Custody Seals present on shipping container/cooler? Yes ❑ No ❑ Not Required (Refer to comments for Custody Seals not intact) 6. Was an attempt made to cool the samples? Yes No ❑ NA ❑ 7. Were all items received at a temperature of >0°C to 10.0°C * Yes EV] No ❑ NA �❑ 8. Sample(s) in proper container(s)? Yes V No El 9. Sufficient sample volume for indicated test(s)? Yes No ❑ 10. Are samples properly preserved? Yes IV] No ❑ 11. Was preservative added to bottles? Yes d❑ No ❑ NA ❑ H2SO4 to 001 H 12. Is there headspace in the VOA vials? Yes _ No NA _. 13. Did all samples containers arrive in good condition (unbroken)? Yes d❑ No ❑ 14. Does paperwork match bottle labels? Yes IV No 15. Are matrices correctly identified on Chain of Custody? Yes 1 No ❑ 16. Is it clear what analyses were requested? Yes IV No ❑ 17. Were all holding times able to be met? Yes ❑ No ❑ Special Handling (if applicable) 18. Was client notified of all discrepancies with this order? Yes ❑ No ❑ NA Person Notified:— Date: --- --- --- ----- By Whom: Via: ❑ eMail ❑ Phone ❑ Fax ❑ In Person Regarding: Client Instructions: 19. Additional remarks: Item Information Item # Temp °C Cooler 5.0 ISample 4.2 (Temp Blank 2.4 * Note: DoD/FLAP and TNI require items to be received at 4°C +/- 2°C Revision v1 N 6 w ar Chain of Custody Record OFremont F _ S e C" C t Uftded zjw ROPWIt Tim 1 e . 7 I: - `bAWN madam6s Ali, , =Agaa = walk, r, F- Prradu , S a Sa'vl, S�­ di K- 5011 , W - al . D = : laxg , W-GrowdWates, SW storm Water. Ww= Ic Wafer -y'`" Sample sardol* Tw Swnple e Date Time (Ma ') g " 'i y , G d' £ "Metalla Anallysis 9 dej; - RCR" TAIL ImdIw k 9 p 1 Cr Cu-pl� Mg N Mg M , I, p " r i I 'A o ), w4r1w larlde . if tZAd� R��sp#�al.� Iku #rMqNlIFAt Turn -wound . - fariamples Specia emad a: Y l bytab (f v a an tke fohoWng busftwn daV - F a¢ Re clWs te/nme R imed @ate rite _.. " TAT 4 SvrncNVI IdeaOW �[). � Y F� APPENDIX D GROUNDWATER MODELING 21-1-22082-003 GROUNDWATER MODELING TABLE OF CONTENTS Page D.1 INTRODUCTION.......................................................................................................... D-l. D.2 MODELING APPROACH............................................................................................. D-1 D.3 MODEL STRUCTURE AND LAYERING................................................................... D-2 DA HYDRAULIC PARAMETERS..................................................................................... D-2 D.5 BOUNDARY CONDITIONS AND INITIAL GROUNDWATER LEVELS ............... D-2 D.6 UNDERGROUND INJECTION CONTROL WELL RECHARGE SIMULATIONS.. D-3 D.7 SUMMARY.................................................................................................................... D-4 D.8 REFERENCES............................................................................................................... D-4 TABLE D-1 Modeled Hydrostratigraphic Layers and Hydraulic Properties .......................... D-2 FIGURES D-1 Model Domain and Boundaries D-2 Planned UIC Wells D-3 Model Mesh in Northern UIC Wellfield Area D-4 Model Sections North -South and West -East Through Well IW-2 D-5 Model Input Hydrograph & Predicted Groundwater Levels at UIC Areas — Base Case D-6 Predicted Groundwater Levels Along Transect Through UIC Area 2 — Base Case D-7 Model Input Hydrograph & Predicted Groundwater Levels at UIC Area 2 — Sensitivity Cases D-8 Predicted Groundwater Levels Along Transect Through UIC Area 2 — Sensitivity Case 3 21-1-22082-003-R] f-AD/wpnk 21-1-22082-003 D-i • 1 1 GROUNDWATER MODELING D.1 INTRODUCTION We developed a three-dimensional groundwater model (model) based on the site explorations and our conceptual hydrogeologic model. The objective of the model was to predict the likely groundwater response to the planned underground injection control (UIC) wellfield operation. In particular, the model was used to evaluate water mounding above potential perching layers and the potential for seepage to occur at the slopes to the west and east of the school property. This appendix provides a description of the model setup and a summary of the modeling results. The proposed UIC wellfield consisting of 16 wells in 4 clusters of either 3 or 5 wells each. The UIC well spacing within the clusters ranged from 30 to 50 feet, based on the proposed layout provided by KPFF Consulting Engineers. We simulated the recharge occurring into the unsaturated zone of the Vashon advance outwash (Qva) unit that overlies a 5-foot-thick perching layer and a deeper, saturated Qva aquifer. D.2 MODELING APPROACH The model was constructed using numerical modeling techniques to simulate unsaturated zone and groundwater flow conditions for the project area. The model approach included: ■ Selecting an appropriate numerical model and the supporting software. ■ Constructing a three-dimensional representation of the model area that includes the hydrogeologic framework, hydraulic properties, and boundary conditions. ■ Performing simulations for one base and three sensitivity case scenarios. ■ Evaluating model results. We used the U.S. Geological Survey's numerical groundwater flow code MODFLOW-2005 (Harbaugh, 2005) to simulate the groundwater flow system in the project area. We used the graphical interface program Groundwater Vistas version 6 (Environmental Simulations Incorporated, 2016) as a pre- and post -processor to create and manage model input and output files for MODFLOW-2005. 21-1-22082-003-R] f-AD/wpnk 21-1-22082-003 D-1 1 1IM11IRKI Figure D-1 shows the model domain which has dimensions 2,400 feet by 2,000 feet. The model grid consists of computational cells with dimensions ranging from 30 feet by 30 feet to 2.5 feet by 2.5 feet in plan view, with the smallest cells assigned at and near the planned UIC wells (Figure D-2). The model's upper surface (top of layer 1) was established by interpolating a digital elevation map dataset for the area to the model grid (Figure D-3). Vertically, the model thickness ranges from about 230 feet thick beneath the school property to 125 feet in the valley area west of the school (Figure D-4). The model base is at Elevation 225 feet. The vertical thickness of the model is divided into three layers based on the conceptual hydrogeologic profiles. The main hydraulic parameters in the model are hydraulic conductivity (horizontal and vertical) and storage coefficients (unconfined and confined). We assigned the model hydraulic conductivity values based on empirical correlations with grain size test results from samples collected during Shannon & Wilson, Inc.'s subsurface explorations at the site, slug test results, and the two pilot -scale recharge tests. As no formal testing was performed to estimate the storage coefficients, we used professional judgment to assign parameter values. Table D-1 presents the modeled parameters for each layer. TABLE D-1 MODELED HYDROSTRATIGRAPHIC LAYERS AND HYDRAULIC PROPERTIES The model uses MODFLOW Constant Head boundary conditions along the northern and southern limits of the domain to simulate groundwater inflow and outflow, and to establish initial 21-1-22082-003-R] f-AD/wpnk 21-1-22082-003 D-2 (existing) groundwater conditions. For the purpose of this evaluation, these heads were Elevations 299 and 300 feet, respectively. Therefore, the existing groundwater levels are slightly above the base of layer 1. D.6 UNDERGROUND INJECTION CONTROL WELL RECHARGE SIMULATIONS For the Base Case model run, we simulated a total stormwater recharge hydrograph that we were provided by the design engineers KPFF Consulting Engineers. This hydrograph represents a 1.00-year, 24-hour storm event. We distributed this flux between the 16 wells that are part of the four clusters of UIC wells (Areas 1, 2, 3, and 4; Figure D-2). The recharge flux was assigned to model layer 1. We used 24 hourly model stress periods to simulate the storm event. The peak hourly recharge rate per well ranged from 102 to 130 gallons per minute. Figure D-5 shows the model -predicted water level response to the 24-hour storm event at the centers of the four UIC Areas and the total input hourly hydrograph. These modeled responses represent the anticipated temporary perching of infiltrating water above the lower permeability silty sand layer that is situated above the regional aquifer. The results indicate that the storm event would temporarily raise water levels to a peak of Elevation 31.0 feet at the center of UIC Area 2 (which has five UIC wells), and to below Elevation 306 feet at the center of the three other UIC areas. Figure D-6 shows the predicted hydrograph for four points along a 400-foot-Long east -west transect extending from the center of UIC Area 2 (OW-2) to the bottom of the ravine located west of the UIC arrays (which is at about Elevation 370 feet). The results indicate that the mounding effect of the storm would diminish to the west of OW-2, and the temporarily perched water table would come within 70 feet of the slope surface. To evaluate the effect that uncertainty of key model parameters on the Base Case results, we performed three sensitivity cases. These involved the re -simulating the 24-hour storm with the following changes to the Base Case model: ■ Sensitivity Case 1 — lower the Qva aquifer Kh and Kv to 3 and 0.3 feet per day, respectively; Sensitivity Case 2 — increase the elevation of the 5-foot-thick perching layer by 15 feet; and ■ Sensitivity Case 3 — combination of Cases 1 and 2. Figure D-7 shows the predicted results for the three sensitivity cases and the Base Case at the center of UIC Area 2 (OW-2), and Figure D-8 shows the predicted hydrographs for four points along the east -west transect from OW-2. The results indicate that the induced perched water table would rise to a peak of Elevation 328 feet at the center of UIC Area 2 (for the most conservative Sensitivity Case 3), which is 1.17 feet below ground surface. As with the Base 21-1-22082-003-R] f-AD/wpnk 21-1-22082-003 D-3 Case, the water would remain more than 50 feet below the toe of the slope to the west of UIC Area 2 for Sensitivity Case 3. D.7 SUMMARY For the Base Case scenario, the model predicts that the water table will rise by between 7 and II feet at the center of the four UIC areas during a 100-year, 24-hour storm event. The resulting mound would be 70 feet or more below the surface of the nearby ravine slope. We ran a limited sensitivity analysis of the Base Case involving reducing the hydraulic conductivity of the Qva unit by a factor of 1.0 and increasing the elevation of the perching unit by 1.5 feet. The most conservative sensitivity case resulted in the peak rise in the water table at the UIC area of up to 14 feet, to a maximum elevation of 328 feet (which is 117 feet below ground surface). The resulting mound would be 50 feet or more below the surface of the nearby ravine slope for the most conservative sensitivity case. Our model provides a framework for estimating how much groundwater mounding may result during the given storm assuming the UIC wells are 1.00 percent efficient. The Base Case modeling predicted an operating water level of up to about 18 feet inside the UIC wells during the design storm event. However, depending on the well drilling method, development, and maintenance practices, the actual initial. UIC well efficiencies will be less (e.g., 50 to 75 percent). Additionally, UIC well efficiency typically decreases with time of operation, depending on the degree of inflow water quality control and well maintenance frequency. Therefore, we would expect the operating water level in the UIC wells to increase in the future. For example, at 50 percent well efficiency, the operating water level inside the UIC wells might be closer to about 36 feet for the modeled storm. D.8 REFERENCES Environmental Simulations Incorporated (ESI), 2012,.Groundwater Vistas, v. 6: Reinholds, Pa., Environmental Simulations Incorporated. Harbaugh, A. W., 2005, MODFLOW-2005: the U.S. Geological Survey modular ground -water model --the ground -water flow process3: U.S. Geological Survey Techniques of Water - Resources Investigations Book 6, Chapter A16, 1 v., available: https-.//pubs.usZs. gov/tin/2005/tm6A 16/. 21-1-22082-003-R] f-AD/wpnk 21-1-22082-003 D-4 Southern Constant Northern Constant Head boundary Head boundary (elev. 300ft) (elev. 299ft) South Well OW-2 North 455' 0 > Unsaturated Qva unit Q) 293' Low K layer Qva aquifer 225' H 1111 West Well OW-2 East 400'-- Unsaturated Qva unit 293 - Low K layer 225fl..J. Qva aquifer Hydrogeologic Report New Madrona K-8 Project 0 250 500 Edmonds, Washington MODEL SECTIONS NORTH -SOUTH & Scale in Feet WEST -EAST THROUGH WELL IW-2 Vertical exaggeration = x2 2016 21-1-22082 November -003 4. SHANNON & WILSON, INC. FIG. D-4 Geotechnical and Environmental Consultants ffi 315 2000 Input Hydrograph OBS-1 (UIC Areal) OW-2 (UIC Area 2) OBS-3 (UIC Area 3) OBS-4 (UIC Area 4) 310 1500 a c Va o M M ,,,, { Uj 305 _ ... 1000 Q- v � 0 3 c W � ��. _ 0 L �. m L C7 0 300 .............. ................ . ......... ............... ....... ......... ......... ......... .............................. 500 295 —--------- 0 -I N m d' Ln 1,0 r, 00 0) O r-i N ro d' Ln to r\ 00 M O r-I N m lzr Ln 1,0 r- 00 Ol O rH N ro d' Ln to r, oo of O rH N m d. Ln to r, oo `-I r-i rH r-1 rH r4 i H rH �H i H N N N N N N N N N N m m m m m m m m m m d' d- d' d' zT d' 'zr d' d' Time (hours) Hydrogeologic Report Notes: New Madrona K-8 School Edmonds, Washington 1. Observation point locations shown on Fiqure 10 MODEL INPUT HYDROGRAPH & 2. Input hydrograph provided by KPFF PREDICTED GROUNDWATER LEVELS AT -n UIC AREAS - BASE CASE November 2016 21-1-22082-003 v SHANNON & WILSON, INC- FG FIG. D-5eotechnical and Environmental Consultants ffi 315 2000 Input Hydrograph OW-2 (UIC Area 2) 71t OBS-5 (70 ft west of OW-2) OBS-6 (100 ft west of OW-2) 310 OBS-7 (400 ft west of OW-2) 1500 a an o a, 41 M > 41 a, +1 305 ..__._.. 1000 io Ji{{% � x�t}t 3 -o o C.w ..,u.. _. (� O r r' 300 ------------ ------ 500 295 0 .-I N M Ch Ln lD r- 00 0) O -4 N M 1t Ln lD r, 00 Ol O r-4 N M CP Ln tD t\ 00 M O r-j N M CP Ln lD r, oo M O c-I N M ch Ln ID n 00 r-i ri c-1 r-I ci 1-4 -1 r-i r-i r-1 N N N N N N N N N N M M M M M M M M CO M ct d' dt .1' Ct ct' d' Time (hours) Hydrogeologic Report Notes: New Madrona K-8 School Edmonds, Washington 1. Observation point locations shown on Fiqure 10 PREDICTED GROUNDWATER LEVELS 2. Input hydrograph provided by KPFF ALONG TRANSECT -n 3. OW-2 elev = 445 feet; OBS-5 = elev. 444 ft; OBS-6 = elev. 450 ft; OBS-7 = elev. 370 ft THROUGH UIC AREA 2 - BASE CASE November 2016 21-1-22082-003 v SHANNON & WILSON, INC. FIG. D-6 FG eotechnical and Environmental Consultants ffi 340 2000 Input Hydrograph Base Case (OW-2) Sensitivity Case 1 Sensitivity Case 2 Sensitivity Case 3 330 1600 4� i�r S3 R CL 0 320 qi 1200 41 M W r' CL N C _ 3 2 310 ....................... ............. ....... ..................... 800 LA., O i C7 0 300 -___________________________________________________________________________ 400 290 0 ,4 N M 'It L l 1,0 r� oo a) O —I N M d" Ln l0 r, oo a) O r H N M-�t m lD I, co m O r i N M-;t m w r� oo m O r H N Mzt m Lo r, oo ci 14 ci rH ci N N N N N N N N m M m M m M m M m M d' -;t d- IzT '- Time (hours) Hydrogeologic Report Notes: New Madrona K-8 School Edmonds, Washington 1. Observation point locations shown on Fiqure 10 MODEL INPUT HYDROGRAPH & 2. Input hydrograph provided by KPFF PREDICTED GROUNDWATER LEVELS AT -n UIC AREA 2 - SENSITIVITY CASES November 2016 21-1-22082-003 v 44 FeSHANNON & WILSON, INC. FIG. D-7 otechnical and Environmental Consultants Madrona Model Aoo D tables and ffizures11-16- 340 2000 E= Input Hydrograph --Ar— OW-2 (U IC Area 2) 335 OBS-5 (70 ft west of OW-2) 0 BS-6 (100 ft west of OW-2) --*—OBS-7 (400 ft west of OW-2) 1500 330 E CL .2 4a M 4, M Uj 325 1000 CL 41 M .2 U. 0 320 . ............................................................................................................................................................................................................................................................................. ...................... 0 . ...... .... 500 315 310 - 0 -4 N m ct Ln to r, oo a) c) r-i (N ro t Ln .o r, oo a) c) ci N m -;t m CO n m m c) rH rH 1-4 rH r-i ­4 rH rH rH r-i r-1 N r4 N C4 N CN (N (N N C4 rn M N m � Ln i.D r, oo cy) o —i cN rn � Ln to r, oo M rn M M M rn rn ro 't -t It 1;T d' dt � Time (hours) Hydrogeologic Report Notes: New Madrona K-8 School Edmonds, Washington 1. Observation point locations shown on Fiqure 10 2. Input hVdroqraph provided by KPFF PREDICTED GROUNDWATER LEVELS ALONG TRANSECT -n 3. OW-2 elev = 445 feet; OBS-5 = elev. 444 ft; OBS-6 = elev. 450 ft; OBS-7 = elev. 370 ft THROUGH UIC AREA 2 - SENSITIVITY CASE 3 November 2016 21-1-22082-003 zo SHANNON & WILSON, INC. Feotechnical FIG. D-8 G and Environmental Consultants APPENDIX E IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL REPORT 21-1-22082-003 SHANNON & WILSON, INC. Attachment to and part of Report 21-1-22082-003 Geotechnical and Environmental Consultants Date: November 29, 2016 To: Ms. Taine Wilton Edmonds School District #15 IMPORTANT INFORMATION ABOUT YOUR GEOTECHNICAL/ENVIRONMENTAL REPORT .%7►1;��1711r1 [014:1Z41TA 3*3_\:I=11111:24OVUM,14111MO 44:2X9311101allNaGM*3_1►INJMs]:IMax911•[«ZS"I=IZ11&1 Consultants prepare reports to meet the specific needs of specific individuals. A report prepared for a civil engineer may not be adequate for a construction contractor or even another civil engineer. Unless indicated otherwise, your consultant prepared your report expressly for you and expressly for the purposes you indicated. No one other than you should apply this report for its intended purpose without first conferring with the consultant. No party should apply this report for any purpose other than that originally contemplated without first conferring with the consultant. THE CONSULTANT'S REPORT IS BASED ON PROJECT -SPECIFIC FACTORS. A geotechnical/environmental report is based on a subsurface exploration plan designed to consider a unique set of project -specific factors. Depending on the project, these may include: the general nature of the structure and property involved; its size and configuration; its historical use and practice; the location of the structure on the site and its orientation; other improvements such as access roads, parking lots, and underground utilities; and the additional risk created by scope -of -service limitations imposed by the client. To help avoid costly problems, ask the consultant to evaluate how any factors that change subsequent to the date of the report may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: (1) when the nature of the proposed project is changed (for example, if an office building will be erected instead of a parking garage, or if a refrigerated warehouse will be built instead of an unrefrigerated one, or chemicals are discovered on or near the site); (2) when the size, elevation, or configuration of the proposed project is altered; (3) when the location or orientation of the proposed project is modified; (4) when there is a change of ownership; or (5) for application to an adjacent site. Consultants cannot accept responsibility for problems that may occur if they are not consulted after factors which were considered in the development of the report have changed. SUBSURFACE CONDITIONS CAN CHANGE. Subsurface conditions may be affected as a result of natural processes or human activity. Because a geotechnical/environmental report is based on conditions that existed at the time of subsurface exploration, construction decisions should not be based on a report whose adequacy may have been affected by time. Ask the consultant to advise if additional tests are desirable before construction starts; for example, groundwater conditions commonly vary seasonally. Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or groundwater fluctuations may also affect subsurface conditions and, thus, the continuing adequacy of a geotechnieal/environmental report. The consultant should be kept apprised of any such events, and should be consulted to determine if additional tests are necessary. IllJ� hJd• ki117_N I Mki6T-13N=1:J ael;y_-l�LZr]J� 1 • L1 11 &IJ Site exploration and testing identifies actual surface and subsurface conditions only at those points where samples are taken. The data were extrapolated by your consultant, who then applied judgment to render an opinion about overall subsurface conditions. The actual interface between materials may be far more gradual or abrupt than your report indicates. Actual conditions in areas not sampled may differ from those predicted in your report. While nothing can be done to prevent such situations, you and your consultant can work together to help reduce their impacts. Retaining your consultant to observe subsurface construction operations can be particularly beneficial in this respect. Page 1 of 1/2016 A REPORT'S CONCLUSIONS ARE PRELIMINARY. The conclusions contained in your consultant's report are preliminary because they must be based on the assumption that conditions revealed through selective exploratory sampling are indicative of actual conditions throughout a site. Actual subsurface conditions can be discerned only during earthwork; therefore, you should retain your consultant to observe actual conditions and to provide conclusions. Only the consultant who prepared the report is fully familiar with the background information needed to determine whether or not the report's recommendations based on those conclusions are valid and whether or not the contractor is abiding by applicable recommendations. The consultant who developed your report cannot assume responsibility or liability for the adequacy of the report's recommendations if another party is retained to observe construction. THE CONSULTANT'S REPORT IS SUBJECT TO MISINTERPRETATION. Costly problems can occur when other design professionals develop their plans based on misinterpretation of a geotechnical/environmental report. To help avoid these problems, the consultant should be retained to work with other project design professionals to explain relevant geotechnical, geological, hydrogeological, and environmental findings, and to review the adequacy of their plans and specifications relative to these issues. BORING LOGS AND/OR MONITORING WELL DATA SHOULD NOT BE SEPARATED FROM THE REPORT. Final boring logs developed by the consultant are based upon interpretation of field logs (assembled by site personnel), field test results, and laboratory and/or office evaluation of field samples and data. Only final boring logs and data are customarily included in geotechnical/environmental reports. These final logs should not, under any circumstances, be redrawn for inclusion in architectural or other design drawings, because drafters may commit errors or omissions in the transfer process. To reduce the likelihood of boring log or monitoring well misinterpretation, contractors should be given ready access to the complete geotechnical engineering/environmental report prepared or authorized for their use. If access is provided only to the report prepared for you, you should advise contractors of the report's limitations, assuming that a contractor was not one of the specific persons for whom the report was prepared, and that developing construction cost estimates was not one of the specific purposes for which it was prepared. While a contractor may gain important knowledge from a report prepared for another party, the contractor should discuss the report with your consultant and perform the additional or alternative work believed necessary to obtain the data specifically appropriate for construction cost estimating purposes. Some clients hold the mistaken impression that simply disclaiming responsibility for the accuracy of subsurface information always insulates them from attendant liability. Providing the best available information to contractors helps prevent costly construction problems and the adversarial attitudes that aggravate them to a disproportionate scale. READ RESPONSIBILITY CLAUSES CLOSELY. Because geotechnical/environmental engineering is based extensively on judgment and opinion, it is far less exact than other design disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem, consultants have developed a number of clauses for use in their contracts, reports, and other documents. These responsibility clauses are not exculpatory clauses designed to transfer the consultant's liabilities to other parties; rather, they are definitive clauses that identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions. The preceding paragraphs are based on information provided by the ASFE/Association of Engineering Firms Practicing in the Geoseienees, Silver Spring, Maryland Page 2 of 2 1 /2016