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390 SUNSET AVE N.PDFiiiiiiii lill 11 13366 390 SUNSET AVE N �1�0 Z N, 0204000 INLE 91 2703240 jCONTRIBUTING' AREA: 1235 SF INLET �2 CONTRIBUTING AREA: 1497 0 kpn r-tRAIN CONTRIBUTING AREA: 1301 E F C I HAMFkR TRIBUTAR�AREA 27032400204206' s 4, C2 145 SF — N01-,S-F,-rw14-4a('c& I 17"73 7 sr- DA TE: BY. JC McDONNELL, PE 612312015 OWL ENGINEER SCALE. 7,'j.C.NicDONNELL-5E5�-3� 1:20 EN =;�eaem-s - Lwmh-� LET 43 CONTRIBUTING AREA: 648 ;7Z '90 SUNSE UE '3�M.32402 CONTRIBUTING 'AREA: A ^ r ^ 0 �--- JOB NO. STORM WATER EXHIBIT 05930 390 SUNSET AVE DRAMNG NO. EX I May. 12,2015 Neuman SFR On -Site Storm Analysis GRAVELLESS CHAMBER DISTRIBUTION OVER SITE JUN 23 201b BUILDING DWAR71VIENT CITY OF EDNIONDS m 9 F-1 j ;7 SOIL DESCRIPTION 9 -6 R E-1 r- 4) Standard Penetration Resistance E CL =1 C 2 (140 lb. weight, 30-Inch drop) N- C10 D_ t A Blows per foot Surface Elevation: Approx. 28.3 Ft. 0 Q 0 20 40 60 Medium dense to dense, reddish -brown, ....... ......... slightly gravelly, silty SAND to sandy SILT; X ': ......... ......... ........ I I ........ I . . moist; abundant Iron -oxide staining; (Fill) I ...... Ar ......... . SM/ML, 2_17 5014"A 6.6 ..... .. .... ......... .. ...... .... 10011111A Very dense, gray -brown, gravelly, silty SAND/sandy SILT; scattered pockets of clean, 31 . .... ......... fine to medium sand; scattered Iron -oxide 4= 10 W5% staining; SM/ML. ........ ....... I . ......... ......... ..... ......... .......... ......... ..... . . ......... ......... 601511A ......... 18.5 7= ..... .... ......... ......... ... .. ... ........ ...... 50/15!A ........ Very dense, reddish -gray to brown, silty SAND grading to slightly silty SAND, trace of gravel; 20-0— .. . ........... ......... ....... 64, moist becoming wet at 23 to 24 feet; T ...... ......... ......... ......... ....... ......... SM/SP_SM. ......... .... I .... ......... 25 ......... ......... ..... 881111�A 30.5 10= 30 ......... . I ....... P ........ ......... .......... ......... Very dense, gray, trace to slightly silty SAND; wet; gravelly 37.5 to 42.5 feet; becomes fine ......... I I ....... ....... to medium sand, trace of silt below 42.5 feet; ......... .......... ... SP. 35 — ......... ........ ........ ......... ......... 63A ......... 12= 40 ......... ......... 0 A . ..... . 46.0' 45 .. ... ........ .... .... .... .... DW5,A .......... ......... Very dense, gray and brown, Interbedded, silty fine SAND, fine sandy SILT; becoming ... .......... .... ....... increasingly organic at 60.5 feet, grading to 141 60 . . ........ organic slit or silty peat at 51 feet; ...... I .. ......... ......... ..... \SM/MUOUPT. BOTTOM OF BORING COMPLETED 9/19/2001 65 .... ..... LEGEND 0 20 40 60 Sample Not Recovered EM Surface Sea] 0 % Water Content 2-Inch O.D. Split Spoon Sample Annular sealant Plastic Limit 1 0 Liquid Limit IE 3-Inch O.D. Shelby Tube Sample Plazometer Screen Natural Water Content EM Bentonite Grout V. Ground Water Level ATD Edmonds Lift Station No. I I Ground Water Level In Well 450 Sunset Avenue Edmonds, Washington NOTES 1. The stratification lines represent the approximate boundaries between aoll types, and the transition may be gradual. . LOG OF BORING B-1 I I he discussion In the text o I this report Is necessary lot a proper understanding of the nature of the subsurface materials. 3. Groundwater level, It Indicated above, Is for the date specified and may very, - October 2001 21-t 4. Refer to KEY (or explanatlon of 'Symbols' and definitions. 6. USCS designation Is based on visual-manuall classification and selected SHANNON & WILSON, IN c - T F7j%!A42r:� 21 FGeolechnical i laboratory Index testing. and FnYllonmental Consultants B-1 ground surface elevation of about 26 feet relative to topographic information presented or BUILDING DERA ,the Site & Exploration Plan, Figure 1. C17Y OF En-l� ,7.4 E N Y NDS SUBSURFACE EXPLORATIONS COMPLETED BY OTHERS Our evaluation included a review of the exploration log for boring B-1 completed in Sunset Avenue North about 40 feet north of the site by Shannon & Wilson, Inc. in 2001. The log of boring B-1 and .associated laboratory test results are Included in this appendix. APPENDIX C SUBSURFACE EXPLORATIONS COMPLETED BY OTHERS R E S,� U-) �4 JUN 2 3 2015 BUILDING DEPA7,77AE1615 cny OF EDWOMM 100 90 80 70 60 .w z 50 z w 0 W 40 w IL 30 20 10 0 100 GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422, USDA SIZE OF OPENING IN INCHES 3(r ir 61 3- 1 11r 314" 3/8. 1' U.S. STANDARD SIEVE SIZE I HYDROMETER 4 10 20 40 60 140 200 325 f.000 100.000 10.000 1.000 0.100 0.010 0,0 USDA PARTICLE SIZE IN MILLIMETERS )i STONES COBB ES GRAVEL SAND Slit - chly Comments: Exploration Sample Depth (feeQ Moisture Fines (%) Description TP-3 S-3 6.0 17.5 10.3 Sand Project No,: 1482.01 PROJECT NAME: Zipper Geo Associates, LLC Geotechnical and Envlronmental Consultants DATE OF TESTING: 5/29/2015 Neuman Residence 100 90 80 70 60 w z 50 z w 0 O� 40 LLI (L 30 20 10 GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422, USDA SIZE OF OPENING IN INCHES ir 6" 3- 1 11r 3/4' 3/8' U.S. STAADARD SIF-TE blLt n T Xr,'JURIC 1 F-FN 4 10 20 40 60 140 200 325 11 IN HIM I Hill HIS INS 1111111 111111111111 111111111 1111 I III IN 11 1 hill 111111111111 1 11 IIN 11 11 11111111 111111111111 IME 1111111111 101111 111111 111111111 liiiiiiislillillisillilill 111111111 1111110 0 . 1000.000 100.000 10.000 I.uuu "' "J'J USDA PARTICLE SIZE IN MILLIMETERS STONES COBBLES GRAVEL SAND Slit Comments: 0.001 Exploration Sample Depth (feet) Moisture Fines (9/6) 1 Lietbiurl UU11 TP-3 S-1 1.5 23.5 56.6 Silt Loam Project No.: 1482.01 PROJECT NAME: Zipper Geo Associates, LLC GGotechnical and Environmental Consultants DATE OF TESTING: 5/29/2015 Neuman Residencm F C!TY OF EDYCNDS 100 90 80 70 60 z 50 z U.1 40 LU (L 30 20 10 0 1000.000 GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422, USDA SIZE OF OPENING IN INCHES 36* ir 6- 3" 1 1rr 3/4' 3/8. U.S. STANDARD SIETE SIZE 4 10 20 40 60 140 200 326 100.000 10.000 1.000 0.100 0.010 0.001 USDA PARTICLE SIZE IN MILLIMETERS STONES COBBLES GRAVEL SAND slit Clay Comments: Exploration Sample Depth (feet) Moisture (%) Flnes Description TP-2 S-4 7.5 13.8 19.5 Loamy Sand Project No.: 1482.01 PROJECT NAME: Zipper Geo Associates, LLC Neuman Residence Geotechnfeal'and Environmental Consultants DATE OF TESTING: 5/29/2015 100 90 80 ru 70 IX 60 LU z 50 z w 0 O� 40 UJ CL 30 20 10 0 100 GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422, USDA SIZE OF OPEAIRG IN INCHES 36' Ir 6. 3- 11/2' 3/4' 3/8* U.S. STANDARD SIEVE SIZE I HYDROMETER 10 10 40 10 1411 2110 321 11.000 100.000 10-000 1.000 0100 fail 41 ilif USDA PARTICLE SIZE IN MILLIMETERS STONES COBBLES . GRAVEL SAND Slit . - CI-Y] I Comments: Exploration Sample Depth (feet) Moisture Fines (%) Description TP-2 S-3 5.0 13.1 13.8 Sand/Loamy Sand Project No.: 1482.01 PROJECT NAME: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants DATE OF TESTING: 5/29/2015 NeumanResidenc. RE JUNI 1 - I( � A 21 2015 bUILLAMM CITY OF ED, 100 90 80 70 to W 60 w z 50 z UJ L) W 40 w CL 30 20 10 0 100 GRAINSIZE ANALYSIS Test Results Summary 61 ASTM D 422, USDA SIZE OF OPENING IN INCHES 36' 12" V 3- 1 1/2' 3/4* 3W U.S. STANDARD SIETE SIZE I M't IN1111t I tF% 4 10 20 40 60 140 200 325 I t Ills I 1! 011 ill 11 Hill liiiiiiiiiiiiii 11111111 oil 11 11 llloill NUNN i Ili ME ililliLlillill 1111111 millillillillilli millillillillilliwillilill !L'fT 11,1111 111411, 1.000 0.100 0,010 01 USDA PARTICLE SIZE IN MILLIMETERS STONES COBBLES GRAVEL SAND Slit Clay Comments: Di Exploration Sample Depth (feet) Moisture Fines Description TIP-1 S-5 7.0 10.2 13.4 Sand/Loamy Sand Project No.: 1482.01 PROJECT NAME: Zipper Geo Associates, LLC Geotechnical and Environmental Consultants DATE OF TESTING: 5/29/2015 Neuman Residence GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422, USDA I 100 90 80 LLI 70 ca W 60 w z 50 z LLI U W 40 w IL 30 20 10 0 1000.000 100.000 10.000 1.000 0.100 0.010 0.001 USDA PARTICLE SIZE IN MILLIMETERS STONES COBBLES I GRAVEL SAND Slit clay Comments: Exploration Sample Depth (feet) Moisture Fines (%) Description TP-1 S-4 5.0 20.3 6.2 1 Sand Project No.: 1482.01 PROJECT NAME: RE Zipper Geo A sociates, LLC Geotechnical and Environmental Consultants DATE OF TESTING: 5/29/2015 Neuman Residence JUN I 100 90 80 x 0 Mu 70 60 w z M p- 50 z w 0 W 40 w IL 30 20 10 0 1000.000 GRAIN SIZE ANALYSIS Test Results Summary ASTM D 422, USDA SIZE OF OPENING IN INCHES I 36* Ir 6. 3- 1 1/2- 314- 318- ' U.S. STAADARD SIETE SlZh I rIT SMITRIC 1 r-r% 4 10 20 40 60 UO 200 325 I Ills millillill I 1 11 loll 1111 NOR 1 101 1 1 Ills iiimiiiiii 0 I Mills 100.000 10.000 i.uuu Muu V.V I U USDA PARTICLE SIZE IN MILLIMETERS V.uV I STONES COBBLES GRAVEL SAND sill Clay Comments: Exploration Sample Depth (fast) Moisture(%) j_Flnes(%) j_ Description TP-1 S-3 4.o 26.0 1 53.8 1 Silt Loam Project No.: 1482.01 PROJECT NAME: Zipper Geo Associates, LLC DATE OF TESTING: 5/29/2015 Neuman Residence Geolachnical and Environmental Consultants LABORATORY TESTING PROCEDURES A series of laboratory tests were performed during the course of this study to evaluate the index and geotechnical engineering properties of the subsurface soils. Descriptions of the types of tests performed are given below. visual Classification Samples recovered from the exploration locations were visually classified in the field during the exploration program. Representative portions of the samples were carefully packaged in moisture tight containers and transported to our laboratory where the field classifications were verified or modified as required. Visual classification was generally done in accordance with ASTM D2488. Visual soil classification includes -evaluation of color, relative moisture content, soil type based upon grain size, and accessofy soil types included in the sample. Soil classifications are presented on the exploration logs in Appendix A. Moisture Content Determinations Moisture content determinations were performed on representative samples obtained from the explorations in order to aid in identification and correlation of soil types, The determinations were made in general accordance with the test procedures described in ASTM D-2216. Moisture contents are presented on the exploration logs in Appendix A. Grain Size Analysis A grain size analysis indicates the range in diameter of soil particles included in a particular sample. Grain size analyses were performed on representative samples in general accordance with ASTM: D-422. For this project, the grain size analyses tests were completed on that portion of the sample passing the U.S. Number 10 sieve and used a U.S. Number 325 sieve to delineate the break between sand and fine grained soils (slit and clay) in accordance with the USDA Soil Textural Triangle Classification requirements. The results of the grain size determinations for the samples were used in classification of the soils, and are presented in this appendix. Fa JUN,, 2015 SUP'01We OEpAF,�-MEWT - Et)V.ONDr- or APPENDIX B LABORATORY TESTING PROCEDURES AND RESULTS ZIPPER GEO ASSOCIATES9 LLC 19023 361 Avenue West, Suite D, Lynnwood, Washington 98036 Test Pit TP-3 Location: See Site And Exploration Plan, Figure 1. Approidmate Ground Elevation: Approximately 27 feet. Project: Neuman Residence Project No: 1482.01 Date Drilled: May 29.,2015 Depth Material Description Sample Nc %M Testing Medium stiff, wet, gray -brown, sandy SILT, trace to some clay. (Fine -Grained Whidbey Formation) ...................................................... Medium dense, moist, brown SAND, some silt (Coarse -Grained Whidbey Formation) ------------------------------------------------------ Medium stiff��et, grg- rown, sandy silt �l --------------------------------- Medium dense, moist, brown SAND, some silt (Coarse -Grained Whidbey Formation) 24 GSA 2 3 4 5 S-2@5.61 24 6 S-3@6' 18 GSA Test pit completed at 7 feet. No groundwater seepage observed at time of exploration. 8 Note: Nc is the Dynamic Cone Penetrometer blow count per Special Publication #399. JUN 2 12J 2015 4410ING DEPAP,,WENT ozfY OF EDMONDS ZIPPER GEO ASSOCIATESt LLC 19023 36h Avenue West, Suite D, Lynnwood, Washington 98036 Test Pit TP-2 Location: See Site And Exploration Plan, Figure I - Approximate Ground Elevation: Approximately 27 feet. Project: Neuman Residence Project No; 1482.01 Date Drilled: May 29,2015 Depth Material Description Sample Nc %M Testing Medium dense, moist, gray, sandy GRAVEL, to gravelly SAND trace to some silt. (Crushed Rock Import Fill) ----------------- Medium stiff, wet, gray -brown, sandy SILT to silty SAND, trace to some clay. (Fill) ------------------------------------------------------ Medium dense, moist, brown SAND, some silt (Coarse -Grained Whidbey Formation) S - I @ Y'.' 3 ------------------------------------- 2 3 S-2@3' 25 4 5 S-3@5' 13 GSA 6 7 S-4@7%' 14 GSA 8 Test pit completed at 7V2 feet. No groundwater seepage observed at time of exploration. 9 � INote: Nc is the Dynamic Cone Penetrometer blow count per ASTM Special Publication #399. Depth (ft) 1 2 4 ZIPPER GEO ASSOCIATES, LLC . 19023 36#1 Avenue West, Suite D, Lynnwood, Washington 98036 Test Pit TP-1 Location: See Site And Exploration Plan, Figure I Approximate Ground Elevation: Approximately 26Y2 feet, Material Description Medium dense, moist, gray, sandy GRAVEL, trace to some silt. (Pit Run Import Fill) (Non -woven geotextile filter fabric observed at I foot) ---------- ------------------------------------------ Medium stiff, wet, gray -brown, sandy SILT, trace to some clay. (Fine -Grained Whidbey Formation) 51 ----------------------------------------------------- Medium dense, moist, brown SAND, some silt (Coarse -Grained Whidbey Formation) Project: Neuman Residence Project No: 1482.01 Date Drilled: May 29, 2015 Sample 7Nc7 'AM7 S-2@1'i 7-21— �__ 2-1 Testing S-3@3' 26 GSA S-3@4' d 6 1 GSA 6 ------------ ----------------------------------------- Medium stiff, wet, gray -brown, sandy silt --------- --------------------------------------------- - Medium dense, moist, brown SAND, some silt 7 (Coarse -Grained Whidbey Formation) r S-5@7' 10 GSA 8 Test pit completed at 8 feet. No groundwater seepage observed at time of exploration. 9 Note: Nc is the Dynamic Cone Penetrometer blow count per ASTM Special Publication #3 99. JUN 2 3 2015 BUILDING DEPARF'NEN-1 cITY OF ED,'SONDS FIELD EXPLORATION PROCEDURES Field Exploration Description Our field exploration for this project included three test pits completed on May 29, 2015. The approximate exploration locations are presented on the enclosed Site and Exploration Plan, Figure 1. Exploration locations were determined in the field by measuring distances from existing site features with a fiberglass tape relative to an undated topographic site plan provided by J.C. McDonnell Engineering. Ground surface elevations at the explorations were determined using a hand level relative to the elevation of the sidewalk shown on the topographic site plan. As such, the exploration locations and elevations should be considered accurate only to the degree implied by the measurement method. The following sections describe our procedures associated with the explorations. Descriptive logs of the explorations are enclosed in this appendix. Test Pit Procedures An independent contractor working for Babbit Neuman Construction Company excavated the test pits through the use of a small, rubber -tracked excavator. An engineering geologist from our ' firm continuously observed the test pit excavations, to , ged the subsurface conditions, and obtained 9 representative soil samples. The samples were stored in moisture tight containers and transported to our laboratory for further visual classification and testing. After we logged each test pit, the operator backfilled the test pit with excavated soils tamped into place. Some settlement of the backfill should be expected over time. The enclosed test pit logs indicate the vertical sequence of soils and materials encountered in each test pit, based primarily on our field classifications and supported by our subsequent laboratory testing. Where a soil contact was observed to be gradational or undulating, our logs indicate the average contact depth. We estimated the relative density and consistency of in situ soils by means of the excavation characteristics and by the sidewall stability. Our logs also indicate the approximate depths of any sidewall caving or groundwater seepage observed in the test pits, as well as all sample numbers and sampling locations. APPENDIX A FIELD EXPLORATION PROCEDURES AND LOGS JUN 23 231s BUILDING DEpAFZ%EmT cil Y or- FDv.�DMDS -p 77 4peJ�f Amk /q, f 10 1 , j G if" B-1 8 gw NEIJ��Et 7' 27032400204200 REFERENCE: UNDATED TOPOGRAPHIC SITE PLAN PROVIDED BY BABBtT NEUMAN CONSTRUCTION COMPANY LEGEND 19TP-1 TEST PIT NUMBER AND APPROMMATE LOCA`TION COMPLETED BY ZGA FOR "I THIS PROJECT B-1 BORING NUMBER AND APPROXIMATE LOCATION COMPLETED BY SHANNON & WILSON IN 2001 27032400204000 TP-1 SUNSET A UE N?4002bi , G.P." STP-3 liZi N 23 0 10 A sQmEWFWr 21liver Geo Associates, LLC Neuman Residence Infiltration Study Project No. 1482.01 June 3, 2015 CLOSURE The analysis and recommendations presented In this report are based, in part, on the explorations completed for this study, The number, location, and depth of the explorations were completed within the constraints of budget and site access so as to yield the Information to formulate our recommendations. Project plans were In the preliminary stage at the time this report was prepared. We therefore recommend we be provided an opportunity to review the final plans and specifications when they become available in order to assess that the recommendations and design considerations presented In this report have been properly interpreted and Implemented Into the project design. The performance of infiltration facilities depends greatly on proper subgrade preparation and construction procedures. We recommend that Zipper Geo Associates, LI-C be retained to provide geotechnical engineering services during Infiltration subgrade preparation and construction for the project, If variations in subsurface conditions are observed at that time, a qualified geotechnical engineer could provide additional geotechnical recommendations to the contractor and design team In a timely manner as the project construction progresses. This report has been prepared for the exclusive use of Babbit Neuman Construction Company, and its agents, for specific application to this project and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranties, express or implied, are Intended or made. Site safety, excavation support, and dewatering requirements are the responsibility of others, In the event that changes In the nature, design, or location of the project as outlined In this report are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Zipper Geo Associates, LI-C reviews the changes and either verifies or modifies the conclusions of this report In writing. JU *N 2 33 2 0 15 Page 6 BUILDING DEpA7��7MEM7 ,�,ITY 05: FDV,0,1,IDS Zipper Geo Associates, LLC Neuman Residence Infiltration Study Project No. 1482.01 June 3, 2015 CONCLUSIONS AND RECOMMENDATIONS We understand that the design of infiltration systems for this project will be completed in accordance with City of Edmonds Bulletin # E72B and Appendix C of the City of Edmonds Stormwater Supplement. We understand that Infiltration systems currently under consideration Include permeable pavement, rain gardens, and drywells, with drywells being the preferred system at this time. Based on the results'of our subsurface explorations and laboratory tests, it is our opinion th ' at Infiltration of site stormwater into the coarse -grained Whidbey Formation soils encountered at a depth of about 41/z feet below grade Is feasible from a geotechnical perspective. Given the depth of the receptor soils, we anticipate that deeper Infiltration systems such as drywells or buried chamber systems, such as StormTech systems, would be appropriate. Due to the low permeability of the fine-grained Whidbey Formation deposits generally encountered In the upper 41/2feet of the site, we do not recommend the use of shallow Infiltration systems such as permeable pavement or rain gardens. Geotechnical design recommendations for site infiltration are presented below. Infiltration Facility Depth: We recommend that the coarse -grained Whidbey Formation deposits typically encountered at a depth of about 4Y2 feet below existing site grade be utilized as the receptor soils for the site infiltration system. However, Test pits TP-1 and TP-3 encountered a 3- to 4-inch thick seam of lower permeability sandy silt within the coarse -grained Whidbey Deposit at depths of about Vito 6 feet below the ground surface. As such, we recommend that the base of the Infiltration facility be located below the lower permeability silt layer and at least 5Y2 to 6 feet below grade and. Long -Term design Infiltration Rate: The coarse -grained Whidbey Formation receptor soils have USDS Textural Triangle Soil Classifications ranging from Sand to Loamy Sand. Based on the City of Edmonds Stormwater Supplement, Appendix C, Table C-1, we recommend a design long- term Infiltration rate of 0.5 Inches per hour. The design long-term Infiltration rate Includes a Correction Factor (CF) of at least 4. Seasonal High 'Groundwater Groundwater was not observed In the test pit explorations completed for this study, which extended to a maximum depth of about 8 feet. Boring B-1 completed by in Sunset Avenue North about 40 feet north of the site encountered groundwater at a depth of about 23 feet at the time of drilling. Groundwater was measuredin the borings monitoring well at a depth of about 20 feet 6 days after drilling. Relative to the project datum, Boring B-1 appears to have a ground surface elevation of about 26 feet. This correlates to time of drilling and post -drilling groundwater elevations of about 3 feet and 6 feet, respectively. Based on the recorded groundwater conditions in borings B-1, and anticipated groundwater response to tidal fluctuations and seasonal variations in precipitation, we recomm end the use of a seasonal high groundwater elevation of 12 feet for Infiltration design purposes. Page 5 Zipper G Bo A moclates, LWC Neuman Residence Infiltration Study Project No. 1482.01 June 3, 2016 installed In the boring and groundwater was measured In the monitoring well at a depth of about 20 feet 6 days after drilling. Relative to the project datum, Boring B-1 appears to have a ground surface elevation of about 26 feet, This correlates to time of drilling and post -drilling groundwater elevations of about 3 feet and 6 feet, respectively. Given the elevation of the recorded groundwater table and the borings proximity of Puget Sound, we anticipate that the groundwater table will be subject to tidal fluctuations. LABORATORY TESTING Laboratory testing was completed on select Soil samples obtained from the borings. Laboratory testing Included moisture contenf and grain size analyses. The results of the moisture content tests are shown on the test pit logs enclosed In Appendix A. Grain size analysis test results are provided in Appendix B. Moisture Content Tests: Moisture contents of the surficial import fill encountered In TP-1 and TP- 2 ranged from about 3 to 5 percent while the underlying sandy slit to silty sand fill encountered in TP-2 had a moisture content of about 25 percent. The native fine-grained Whidbey Formation soils had moisture contents ranging from about 21 to 26 percent. The underlying native coarse - grained Whidbey Formation soils had moisture contents ranging from about 6 to 18 percent. Grain Size nalyses: Grain size analyses were completed on representative samples of the fine- grained and coarse -grained Whidbey Formation deposits. For this project, the grain size analysis tests were completed on that portion of the sample passing the U.S. Number 10 sieve and used a U.S. Number 325 sieve to delineate the break between sand and fine-grained soils (silt and clay) In accordance with the USDA Soil Textural Triangle Classification System. A summary Of the test results and resulting USDA Soil Textural Triangle Classification are summarized In the table below. Page 4 T." N 2 3 2015 BUILDING DEPAF-MENT .01-rY OF ENVIONDS Zipper Geo Associates, LLC Neuman Residence Infiltration Study Project No. 1482.01 June 3, 2015 to thetest pit logs in Appendix A for a more detailed description of the conditions encountered at the exploration locations. Our evaluation also included a review of the exploration log for boring B-1 completed in Sunset Avenue North about 40 feet north of the site by Shannon & Wilson, Inc. in 2001, Boring B-1 extended about 51 Meet below grade. The approximate location of boring B-1 Is shown on the enclosed Site and Exploration Plan, Figure 1. A Copy of the boring log and associated laboratory test results are enclosed In Appendix C. In general, the explorations encountered fill soils over native fine-grained deposits over native coarse -grained deposits. The native silt and sand deposits are interpreted as Whidbey Formation soils. A more detailed description of each material and soil type is presented below. a�B Fill soils were encountered in test pits TP-1 and TP-2. Both explorations encountered about I Y2feet of sandy gravel to gravelly sand with trace to some silt interpreted as Import pit -run and crushed rock fills. In test pit TP-2, fill consisting of medium stiff, sandy silt to silty sand with trace to some clay was encountered below the surficial 1 1/2feet of Import fill and extended to a depth of about 4Y7 feet below grade. Fine -Grained Whidbey Format!gn_22ML: Primarily fine-grained Whidbey Formation soils were encountered at the ground surface in test pit TP-3 and below the surficial 1 Y? feet of import fill in TP- 1. In general, the soil consisted of medium stiff, sandy silt with trace to some clay and extended to a depth of about 4Y2feet below grade. Based on our grain size analyses, the fine-grained Whidbey Formation deposits had a USDA Soil Textural Triangle Classification of Silt Loam. Coarse -Grained Whidbey Formation Depgs—Its: Primarily coarse -grained Whidbey Formation soils were encountered at a depth of about 4Y. feet and extended to the total depth explored of 8 feet below existing grade. In general, the soil consisted of medium dense sand with some silt. Based on our grain size analyses, the coarse -grained Whidbey Formation deposits had a USDA Soil Textural Triangle Classification ranging from Sand to Loamy Sand. Test pits TP-1 and TP-3 encountered a 3- to 4-Inch thick seam or.lense of sandy silt within the coarse -grained Whidbey Deposit at depths of about 6 and 5Y2feet below the ground surface, respectively. This silt seam was not observed in test pit TP-2. Groundwater Conditions Groundwater was not observed in the test pit explorations completed for this projec t. Due to the fine-grained nature of the upper Whidbey Formation soils we expect that near -surface perched groundwater may develop during periods of extended precipitation or high I . ntensity precipitation. Boring B-1, completed In Sunset Avenue North about 40 feet north of the site, encountered groundwater at a depth of about 23 feet at the time of drilling. A monitoring well was reportedly Page 3 I tes. LLC leb, YLAAJ Neuman Residence infiltration Study Project No. 1482.01 June 3, 2015 PROJECT UNDERSTANDING We understand that the project Includes construction of a new single-family residence with concrete flatwork and driveway pavement along the west and north sides of the residence. We further understand that connection to the City stormwater system is impeded by an existing sewer main In Sunset Avenue North and would therefore require a pumped stormwater system crossing several adjacent private properties and the acquisition of associated permanent easements. As such, Infiltration of site stormwater water Is currently under consideration. We understand that the design of Infiltration systems will be completed In accordance with the City of Edmonds Bulletin # E72B and Appendix C of the City of Edmonds Stormwater Supplement. We understand that infiltration systems currently under consideration include permeable pavement, rain gardens, and drywells, with drywells being the preferred system at this time. SUBSURFACE CONDITIONS Published Geologic Mapping We assessed the geologic setting of the site and surrounding vicinity by reviewing the Geologic Map of the Edmonds East and Part of the Edmonds West Quadrangles, Washington, U.S. Geological Survey Map MF-1541, 1983. The geologic map Indicates the site and immediate vicinity are underlain by Quaternary Whidbey Formation deposits (Qw). The Whidbey Formation is described as typically consisting of bedded, compact, commonly oxidized, medium to coarse grained sand with lesser amounts of silt and clay. Soil Conditions The subsurface exploration for this project included three test pits (TP-1 through TP-3) located In landscape and pavement areas around the planned residence. The test pits extended approximately 7 to 8 feet below the existing ground surface. The approximate exploration locations are shown on the enclosed Site and Exploration Plan, Figure 1. Soils were visually classified In general accordance with the Unified Soil Classification System. Soils were also classified In general accordance with the USIDS Soil Textural Triangle Classification system for correlation to design infiltration rates. Detailed, descriptive logs of the subsurface explorations and the procedures utilized In the subsurface exploration program are lized descriptions of subsurface soil conditions observed at the presented In Appendix A. Genera exploration locations are presented below. The stratification and horizontal extent of the soil types observed in our explorations may vary between explorations. The nature and extent of variations between the explorations may not become evident until construction. Stratification boundaries on the exploration logs represent the approximate depth of changes In soil types, although the transition between materials may have been gradual. If variations become apparent during construction, It may be necessary to reevaluate the recommendations of this report. Please refer Page 2 JUN 2 3 2015 BUILDING DEPAR71VIENT cITY OF EDMONDS GEOTECHNICAL ENGINEERING REPORT NEUMAN RESIDENCE INFILTRATION STUDY 390 SUNSET AVENUE NORTH EDMONDS, WASHINGTON Project No. 1482.01 June 3, 2015 INTRODUCTION This report documents the surface and subsurface conditions encountered at the site and our geotechnical engineering recommendations for surface water Infiltration for the Neuman Residence located at 390 Sunset Avenue North In Edmonds, Washington, The project description, site conditions, and our geotechnical conclusions and design recommendations are presented in the text of this report. Supporting data including detailed exploration logs, field exploration procedures, results of laboratory testing, and other supporting information are presented as appendices. Our geotechnical engineering scope of services for the project Included a site reconnaissance, subsurface evaluation, laboratory testing, geotechnical analysis, and preparation of this report. The subsurface evaluation consisted of completing three test pit explorations (designated TP-1 through TP-3) located in landscape and pavement areas around the planned residence. The test pits extended approximately 7 to 8 feet below the existing ground surface. our evaluation also Included a review the exploration log of a 51%foot deep geotechnical boring completed by others in Sunset Avenue North near the site. SITE DESCRIPTION The site is a relatively level single-family residential lot located at 390 Sunset Avenue North In Edmonds, Washington. Site grades appear to range from about elevation 27 to 28 feet based on a topographic site plan provided by J.C. McDonnell Engineering. The site is bounded by the north, south, and east by existing, developed, single-family residential properties and to the west by Sunset Avenue North, The nearby residences do not appear to Include basements. Two sets of BNSF railroad tracks are located on a bench at about elevation 18 feet along the west side of Sunset Avenue North with the shoreline of Puget Sound along the western margin of the railroad corridor at about elevation 5 feet. The site topography and nearby features are shown on the enclosed Site and Exploration Plan, Figure 1. Aerial Images available online through Google Earth Indicate that the site formerly supported a one- story, single-family residence with a partial basement located in the west central portion of the parcel. Street view images suggest that the basement floor was about 2 to 3 feet below the surrounding site grade. At the time of our site visit, the residence had been demolished and the majority of the site appeared to be mantled by about 1 to 1 Y2feet of import granular fill placed over a non -woven geotextile. TABLE OF CONTENTS INTRODUCTION.................................... I .... I ........... I ............................................... I ... I ............. I... ............... I ................. I .............. I ..... 1.1 SITEDESCRIPTION ...................................................... ...... I ..................................... 2 PROJECTUNDERSTANDING ..................................................... 2 SUBSURFACECONDITIONS ................................... I .................. ................................ I ........... 2 Published Geologic Mapping .................................................................................................. SoilConditions ....................................................................................................................... 3 GroundwaterConditions ......................................................................................................... 4 LABORATORYTESTING ........................................................................................................... CONCLUSIONS AND RECOMMENDATIONS ............................................................... CLOSURE........................................................................... I ................ I... ............................... FIGURES Figure 1 — Site and Exploration Plan APPENDICES Appendix A — Subsurface Exploration Procedures and Logs Appendix B — Laboratory Testing Procedures and Results Appendix C — Subsurface Explorations Completed by Others RE Is U B JUN 23 2015 BUILDING DEPARk-MENT CITY OF EDMONDS Zipper Geo Associates, LLQ Geotechnical and Environmental Consulting Project Number 1482.01 June 3, 2015 Babbit Neuman Construction Company 215 Wilkes Street, Suite 103 Steilacoom, Washington 98288 Attention: Mr. Rick Neuman Subject: Geotechnical Engineering Report Neuman Residence Infiltration Study 390 Sunset Avenue North Edmonds, Washington Dear Mr. Neuman, In accordance with your request and written authorization, Zipper Geo Associates, LLC (ZGA) has completed the subsurface exploration and geotechnical engineering evaluation for the proposed Neuman single-family residence located at 390 Sunset Avenue North in Edmonds, Washington. This report presents the findings of the subsurface exploration and our geotechnical recommendations for stormwater infiltration. Our work was completed in general accordance with our Proposal for Geotechnical Engineering Services (Proposal No. P 15190) dated May 27, 2015. Written authorization to proceed was provided by Babbit Neuman Construction Company on May 28, 2015. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report, or if we may be of further service, please contact us. Sincerely, Zipper Geo Associates LLC as 0' co JAMES P. GEORGIS James P. Georgis, L.E.G. Principal Copies: Addressee (1) Thomas A. Jones, P.E. Principal 19023 36th Avenue West, Suite D Lynnwood, WA 98036 (425) 582-9928 VA -IF li May. 12,2015 Neuman SFR On -Site Storm Analysis GEOTECHNICAL ENGINEERING REPORT DATED JUNE 3,2015 BY ZIPPER GEO ASSOCIATES, LLC 18 '. 18:t z MA S24 , 41 Yee f`7. 177 �Alohll St A. _7- 47 ht UR 4F IVIM SC-310 TECHNICAL SPECIFICATION r90.7' (2304 mm) ACTUAL LENGTH -I A (251 mm) 1 15.6" (396 mm) 2L (146.9- 166 mm) NOMINAL CHAMBER SPECIFICATIONS SIZE (W X H X INSTALLED LENGTH) CHAMBER STORAGE MINIMUM INSTALLED STORAGE* WEIGHT NTS 85.4"(2169 mm) INSTALLED LENGTH <= BUILD ROW IN THIS DIRECTION START END OVERLAP NEXT CHAMBER HERE (OVER SMALL CORRUGATION) 16.0" (406 mm) --F 34.0" (864 mm) 34.0"X 16.0"X 85.4' (864 mm X 406 mm X 2169 mm) 14.7 CUBIC FEET (0.42 rri-) 31.0 CUBIC FEET (0.88 m-) 35.0 lbs. (16.8 kg) *ASSUMES 6" (152 mm) ABOVE, BELOW, AND BETWEEN CHAMBERS A B STUBS AT BOTTOM OF END CAP FOR PART NUMBERS ENDING WITH"B" STUBS AT TOP OF END CAP FOR PART NUMBERS ENDING WITH *T" A PART # STUB A B c SC310EPE06T I SC310EPE06TPC 6" (150 mm) 9.6" (244 mm) — 5.8" (147 mm) SC310EPE06B I SC310EPE06BPC 0.5" (13 mm) SC310EPE08T I SC310EPE08TPC 8"(200 mm) 11.9"(302 mm) 3.5"(89 mm) — SC310EPE08B / SC310EPE08BPC 0.6" (15 mm) SC310EPE1 OT / SC310EPE1 OTPC 10" (250 mm) 12.7" (323 mm) — 1 A"(36 mm) SC310EPEIOB / SC310EPEIOBPC 0.7" (18 mm) SC310EPE12B 12" (300 mm) 13.51' (343 mm) 0.9" (23 mm) ALL STUBS, EXCEPT FOR THE SC310EPE12B ARE PLACED AT BOTTOM OF END CAP SUCH THAT THE OUTSIDE DIAMETER OF THE STUB IS FLUSH WITH THE BOTTOM OF THE END CAP. FOR ADDITIONAL INFORMATION CONTACT STORMTECH AT 1-888-892-2694. * FOR THE SC310EPE12B THE 12" (300 mm) STUB LIES BELOW THE BOTTOM OF THE END CAP APPROXIMATELY 0.25"(6 mm). BACKFILL MATERIAL SHOULD BE REMOVED FROM BELOW THE N-12 STUB SO THAT THE FITTING SITS LEVEL. NOTE: ALL DIMENSIONS ARE NOMINAL 'r Subsurface Stormwater Managementro AASHTO/ASTM Standards StormTech chambers are designed in accordance with Section 12.12 of the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications. This document establishes requirements for design of profile wall thermoplastic structures for both live loads and permanent earth loads, Proper use of the AASHTO design method requires that load multipliers for impact and multiple presences are applied to the AASHTO design truck (HS20) live load. Additional factors are applied to the load and earth loads to provide the full safety factors for both live and earth loads. When installed in accordance with the minimum requirements specified in the StormTech installation instructions, StormTech chambers meet or exceed the AASHTO requirements for both live load and earth load design. StormTech chambers are also designed in accordance with ASTM F2787 "Standard Practice for Structural Design of Thermoplastic Corrugated Wall Stormwater Collection Chambers". This standard practice relates the AASHTO design methodology for thermoplastic pipe and applies it to buried stormwater chambers. Note that proper design for permanent earth loads, although often ignored by producers of other buried plastic structures, governs safe product design and is the basis for the service life of the system. StormTech's cutting edge materials research program and extensive product testing has established StormTech as the leader on thermoplastic chamber design for safe, long service life installations. StormTech chambers are produced to the requirements of the American Society of Testing Materials (ASTM) F2418 "Standard Specification for Polypropylene (PP) Corrugated Stormwater Collection Chambers" and ASTM F2922 "Standard Specification for Polyethylene (PE) Corrugated Stormwater Collection Chambers". ASTM standards play an important role in establishing strict product requirements that engineers and owners can rely upon for a high quality product on every project. StormTech's commitment to these two standards ensures consistent high quality products, safe structural design, and a service life in the 100-year range. JUN 2 3 2015 BUILDIMO DEPAF--7t1E13-,' DATE: 06/22/15 SOURCE: http://www.stormtech.com/resources/standards.htmi CITY OF EMIACNDS May. 12,2015 Neuman SFR On -Site Storm Analysis FIGURE 6: STORM TECH PRODUCT LOADING STATEMENT 16 14.0 StormTech Product Specifications 1.0 GENERAL 1.1 StormTech chambers are designed to control stormwater runoff. As a subsurface retention sys- tem, StormTech chambers retain and allow effective infiltration of water into the soil. As a subsurface detention system, StormTech chambers detain and allow for the metered flow of water to an outfall. 2.0 CHAMBER PARAMETERS 2.1 The Chamber shall be Injection molded of an impact modified polypropylene or polyethylene copolymer to maintain adequate stiffness through higher temperatures experienced during Installation and service. 2.2 The nominal chamber dimensions of the StormTech SC-740 and DC-780 shall be 30.0� (762 mm) tall, 51.0* (1295 mm) wide and 90.7' (2304 mm) long. The nominal chamber dimensions of the StormTech SC- 310 shall be 16.0'(406 mm) tall, 34.0'(864 mm) wide and 90Y (2304 mm) long. The installed length of a joined chamber shall be 85.4" (2169 mm). 2.3 The chamber shall have a continuously curved section profile. 2.4 The chamber shall be open -bottomed. 2.5 The chamber shall incorporate an overlapping corrugation joint system to allow chamber rows of almost any length to be created. The overlapping corrugation joint system shall be effective while allowing a chamber to be trimmed to shorten its overall length. 2.6 The nominal storage volume of all StormTech cham- bers includes the volume of the clean, crushed, angular stone with an assumed 40% porosity. The nominal storage volume of a joined StormTech SC-740 chamber shall be 74.9 ft' (2.1 ml) per chamber when installed per StormTech's typical details. This equates to a storage volume per unit area of bed of 2.2 ftl/ft2 (0.67 rr?/m2). The nominal storage volume of a joined StormTech DC-780 chamber shall be 78.4 ft' (2.2 M3) per chamber when installed per StormTech's typical details. This equates to a storage volume per unit area of bed of 2.3 f?/ft2 (0.70 m3/m2). The nominal storage volume of a joined StormTech SC-310 chamber shall be 31.0 ft' (0,88 ml) per chamber when installed per StormTech's typical details. This equates to a storage volume per unit area of bed of 1.3 ftl/ft' (0,40 m3/m2). 2.7 The SC-740 and SC-310 chambers shall have forty- eight orifices penetrating the sidewalls to allow for lateral conveyance of water. 2.8 The chamber shall have two orifices near its top to allow for equalization of air pressure between its interior and exterior. 2.9 The chamber shall have both of its ends open to allow for unimpeded hydraulic flows and visual inspections down a row's entire length. 2. 10 The chamber shall have 14 corrugations. 2.11 The chamber shall have a circular, indented, flat surface on the top of the chamber for an optional 4' (100 mm) diameter (maximum) Inspection port. 2.12 The chamber shall be analyzed and designed using AASHTO methods for thermoplastic culverts contained in the LRFD Bridge Design Specifications, 2nd Edition, including Interim Specifications through 2001. Design live load shall be the AASHTO design truck. Design shall consider earth and live loads as appropriate for the minimum to maximum specified depth of fill. 2.13 The chamber shall be manufactured In an ISO 9001:2000 certified facility. 3.0 END CAP PARAMETERS 3.1 The end cap shall be designed to fit into any corrugation of a chamber, which allows: capping a chamber that has its length trimmed; segmenting rows into storage basins of various lengths. 3.2 The end cap shall have saw guides to allow easy cutting for various diameters of pipe that may be used to Inlet the system. 3.3 The end cap shall have excess structural adequacies to allow cutting an orifice of any size at any invert elevation. 3.4 The primary face of an end cap shall be curved outward to resist horizontal loads generated near the edges of beds. 3.5 The end cap shall be manufactured in an ISO 9001:2000 certified facility. JUN 2 3 2015 29 Call StormTech at 860.629.8188 or 888.892.2694 or visit our Website at www.stormtech.com for technical and prod'gdnL'fffinjodoB'-PAF,,-ME.r�- CITY OF ED*VDNDS I .14 13.0 General Notes StormTdch- 1 StormTech ("StormTech") requires installing contrac- tors to use and understand StormTech's latest Installation Instructions prior to beginning system installation, 2. Our Technical Services Department offers installa- tion consultations to installing contractors. Contact our Technical Service Representatives at least 30 days prior to system installation to arrange a pre - installation consultation. Our representatives can then answer questions or address comments on the StormTech chamber system and inform - the Installing contractor of the minimum installation requirements before beginning the system's construction. Call 860-629-8188 to speak to a Technical Service Representative or visit www.stormtech.com to receive a copy of our Installation Instructions. 3. StormTech's requirements for systems with pavement design (asphalt, concrete pavers, etc.): Minimum cover for the SC-740, DC-780 and SC-31 0 chambers is 18" (457 mm) not including pavement; Maximum cover for the SC-740 and SC-310 chambers is 96" (2.4 m) including pavement design; Maximum cover for the DC-780 chamber is 12' (3.6 m) Including pavement design. For installations that do not include pavement, where rutting from vehicles may occur, minimum required cover is 24" (6 10 mm), maximum cover Is as stated above. 4. The contractor must report any discrepancies with the bearing capacity,of the chamber foundation materials to the design engineer, 5. AASHTO M288 Class 2 non -woven geotextile (filter fabric) must be used as indicated in the project plans. 6. Stone placement between chamber rows and around perimeter must follow instructions as Indicated in the most current version of StormTech's Installation Instructions. 7. Backtilling over the chambers must follow require- ments as indicated in the most current version of StormTech's Installation Instructions. 8. The contractor must refer to StormTech's Installation Instructions for a Table of Acceptable Vehicle Loads at various depths of cover. This information is also available at StormTech's website: www.stormtech.com. The contractor is responsible for preventing vehicles that exceed StormTech's requirements from traveling across or parking over the stormwater system. Temporary fencing, warning tape and appropriately located signs are commonly used to prevent unauthorized vehicles from entering sensitive construction areas. 9. The contractor must apply erosion and sediment con- trol measures to protect the stormwater system during all phases of site construction per local codes and design engineer's specifications. 10. STORMTECH PRODUCT WARRANTY IS LIMITED. Contact StormTech for warranty information. Call StormTech at 860.529.8188 or 888.892.2694 or visit our website at www.stormtech.com for technical and product Information. 28 12.0 Inspection & Maintenance STORMTECH ISOLATOR' ROW - STEP-BY-STEP MAINTENANCE PROCEDURES Step 1) Inspect Isolator Row for sediment A) Inspection ports (if present) i. Remove lid from floor box frame ii. Remove cap from inspection riser Ill. Using a flashlight and stadia rod, measure depth of sediment iv. If sediment Is at, or above, 3`7(76 mm) depth proceed to Step 2. If not proceed to Step 3. 13) All Isolator Rows i. Remove cover from manhole at upstream end of Isolator Row I[. Using a flashlight, inspect down Isolator Row through outlet pipe 1. Follow OSHA regulations for confined space entry if entering manhole 2. Mirrors on poles or cameras may be used to avoid a confined space entry Ill. If sediment is at or above the lower row of sidewall holes [approximately 3' (76 mm)] proceed to Step 2. It not proceed to Step 3. Step 2) Clean out Isolator Row using the JetVac process A) A fixed floor cleaning nozzle with rear facing nozzle spread of 45' (1143 mm) or more is preferable 13) Apply multiple passes of JetVac until back - flush water is clean C) Vacuum manhole sump as required during letting Step 3) Replace all caps, lids and covers Step 4) Inspect and clean catch basins and manholes upstream of the StormTech system following local guidelines. Figure 20 — StormTech Isolator Row (not to scale) 12.3 ECCENTRIC PIPE HEADER INSPECTION Theses guidelines do not supercede a pipe manufac- turer's recommended I&M procedures. Consult with the manufacturer of the pipe header system for specific I&M procedures, Inspection of the header system should be carried out quarterly. On sites which generate higher levels of sediment more frequent inspections may be necessary. Headers may be accessed through risers, access ports or manholes. Measurement of sediment may be taken with a stadia rod or similar device. Clean - out of sediment should occur when the sediment volume has reduced the storage area by 25% or the depth of sediment has reached approximately 25% of the diameter of the structure. 12.4 ECCENTRIC PIPE MANIFOLD MAINTENANCE Cleanout of accumulated material should be accom- plished by vacuum pumping the material from the head- er. Cleanout should be accomplished during dry weath- er. Care should be taken to avoid flushing sediments out through the outlet pipes and into the chamber rows. Eccentric Header Step -by -Step Maintenance Procedures 1 . Locate manholes connected to the manifold system 2. Remove grates or covers 3. Using a stadia rod, measure the depth of sediment 4. If sediment is at a depth of about 25% pipe volume or 25% pipe diameter proceed to step 5. If not proceed to step 6. 5. Vacuum pump the sediment. Do not flush sediment out inlet pipes. 6. Replace grates and covers 7. Record depth and date and schedule next inspection Figure 21 — Eccentric Manifold Maintenance 3.4,5 Please contact StormTech's Technical Services Department at 888-892-2894 for a spreadsheet to estimate cleaning intervals. It Irl 0 n .1015 27 Call StormTech at 660.529.8188 or 888.892.2694 or visit our webslte at www.stormtech.com for technical and procludcYlInhi'MaYok BUILDING DEPAFiWIEM7 CITY OF ED.VDM0S 12.0 Inspection and Maintenance 12.1 ISOLATOR ROW INSPECTION Regular inspection and maintenance are essential to assure a properly functioning stormwater system. Inspection is easily accomplished through the manhole or optional inspection parts of an Isolator Row. Please follow local and OSHA rules for a confined space entry. Inspection ports -can allow inspection to be accomplished completely from the surface without the need for a con- fined space entr)6 Inspection ports provide visual access to the system with the use of a flashlight. A stadia rod may be inserted to determine the depth otsediment. If upon visual inspection it is found that sediment has accumulated to an average depth exceeding 3" (76 mm), cleanout is required. A StormTech Isolator Row should initially be inspected immediately after completion of the site's construction. While every effort should be made to prevent sediment from entering the system during construction, it is during this time that excess amounts of sediments are most likely to enter any stormwater system. Inspection and maintenance, if necessary, should be performed prior to passing responsibility over to the site's owner. Once in normal service, a StormTech Isolator Row should be inspected bi-annually until an understanding of the sites characteristics is developed. The site's maintenance manager can then revise the inspection schedule based on experience or local requirements. 12.2 ISOLATOR ROW MAINTENANCE JetVac maintenance is recommended if sediment has been collected to an average depth of 3' (76 mm) inside the Isolator Row. More frequent maintenance may be required to maintain minimum flow rates through the Isolator Row. The JetVac process utilizes a high pressure water nozzle to propel itself down the Isolator Row while scouring and suspending sediments. As the nozzle is retrieved, a wave of suspended sediments is flushed back into the manhole for vacuuming. Most sewer and pipe maintenance companies have vacuum/ JetVac combi- nation vehicles. Fixed nozzles designed for culverts or large diameter pipe cleaning are preferable. Rear facing jets with an effective spread of at least 45' (1143 mm) are best. The JetVac process shall only be performed on StormTech Rows that have AASHTO class 1 woven geotextile over the foundation stone (ADS 315ST or equal). 6 Stor megch- Looking down the Isolator Row. A typical JetVac truck. (7his Is not a Storm7ech product.) Examples of culvert cleaning nozzles appropriate for Isolator Row maintenance. (These are not Storm Toch products.) 'Call StormTech at 860.529.8188 or 888.892.2694 or visit our website, at www.stormtech.com for technical and product Information. Zb May. 12,2015 Neuman SFR on -Site Storm Analysis FIGURE 5: STORM TECH SPECIAL MAINTENANCE PROCEDURES L HIESUM F JUN 2 3 2015 BUILDING D'=0AF7ViE'�'T arf OF Awbmbs