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Drainage report.pdfBlio BEYLER CONSULTING Issaquah Office Lakewood Office 455 Rainier Blvd N 7602 Bridgeport Way W Ste 3D Issaquah, WA 98027 Lakewood, WA 98499 (425) 392-8055 (253) 301-4157 1014 FOR IF (SMALL SITE, CATEGORY 2 PROJECT) 721 Edmonds Way Edmonds, WA 98020 Applicant: Thomas Chung 721 Edmonds Way Edmonds, WA 98020 Prepared by: Jeff Beckmann, P.E. Beyler Consulting 455 Rainier Blvd N Issaquah, WA 98027 425-392-8055 Job No. 16-089 July 2016 Plan. Manage & S � FURid, ENIMNEEIRING 11 LAIND SURVIlFfING ILA1140 P11 Atffffl4G FIRCIE10 MANAGHIEN 1' � PIEROUT EXPEII)ITTING � F1!A5111:ffl MV Category 2 Small Site Drainage Report Chung Short Plat June 2016 1. Project Description: The proposed project is a three lot short subdivision, per ECDC 20.75, on an existing 0.46 -acre parcel (#00745300000500). It is classified as a small site, category 2 project and is subject to RS -6 zoning requirements. 2. Existing Site Conditions: The subject site is a SW -facing, 20,155 sf lot located approximately one mile inland from Puget Sound in the Edmonds Way Direct Discharge Basin. It was created as lot 5 of the Pinestone Plat per Snohomish County records. There are two access points to the site via driveway drops on Edmonds Way (SR -104). There is a single home on the site along with a gravel driveway, a concrete loop driveway, concrete patio and walkway, rockeries, and landscaping consisting of lawn, shrubs, and trees. The existing impervious area on the site is 9,598 sf, or 48% of the parcel area. The site generally slopes from NE to SW at an average slope of 4%, with a total relief of 8 ft. The steepest portion of the site is a 35' stretch of gravel driveway that slopes toward the road at 8%. Site soils consist primarily of Everett very gravelly sandy loam, which is in hydrologic soils group A and highly conducive to infiltration. Runoff from the site that does not infiltrate drains as sheet flow or shallow, subsurface flow to an existing 48" storm drain in Edmonds Way. Site soils are described in an NRCS Custom Soil Resource Report attached at the end of this drainage report. 3. Developed Site Conditions: The proposed short plat will decrease the existing parcel area from 20,155 sf to 18,305 sf with a 10' right-of-way dedication along Edmonds Way and divide the remaining area into three new single family lots. The proposed new plus replaced impervious surface is 7,656 sf, a reduction of 1,942 sf of impervious area currently draining to the Edmonds Way Basin. Of the proposed impervious area, 1,922 sf is a 12' wide shared access driveway, within a 15' wide easement, serving lots 1 and 3. This is under the 5,000 sf threshold for runoff treatment for pollution -generating impervious surface (PGIS). The remaining 5,734 sf of impervious surface will be composed of roofs and other hard surfaces spread over the three lots, which averages 1,911 sf per lot. Runoff from the proposed impervious surface will be managed using onsite/LID techniques and infiltration as described in Chapter 5 of the City of Edmonds Stormwater Supplement. The shared access driveway will collect and control runoff in a series of catch basins connected by 8" perforated pipe, bedded in a 2' wide gravel trench. Given the nature of the site soils, driveway runoff will infiltrate easily, even in saturated conditions. The 8" pipe will provide excess storage capacity during high intensity storm events. Any overflow from the system will bubble up out of a catch basin with birdcage at the bottom of the driveway, and disperse slowly down a rock lined drainage path underlain by filter fabric to the existing conveyance system in Edmonds Way. Roof runoff from the three lots will be managed using dispersion BMPs in conjunction with compost amended soil on all pervious lot areas. Roof runoff from lots 1 and 2 will be collected by gutters and downspouts and discharged to splash blocks at the uphill end of each lot. From the splash block, runoff will disperse down a minimum 50' vegetated flowpath to the natural discharge point at the front of each lot. Every 700 sf of roof area will require a separate splash block. Roof runoff from lot 3 will be collected by gutters and downspouts and discharged to two dispersion trenches at the rear of the lot. Each trench is 2' wide by 10' long and can handle 700 sf of roof area. Downstream of each trench is a minimum 25' compost -amended, vegetated flowpath. n. ' arta Plan. i��.�,m.wi�. CIV 1[ 11 & S.OI'1PRA1 V 11V(;UNIf hI11RING I I- AI'llf) SURVIFYIING I LAND PILAJININING PIcM I Tl MANAGIFmnIFU p u1II:I MF1 Ir xu>IF 1")M G y Ir F A<.II13FL11Y Category 2 Small Site Drainage Report Chung Short Plat June 2016 4. Small Site Minimum Requirements (SSMRs) Per City of Edmonds Stormwater Supplement Chapter 5 SSMR #1 — Preparation of Stormwater Site Plan This report combined with the Site Development Plans addresses this requirement. SSMR #2 — Construction Stormwater Pollution Prevention Plan The Site Development Plans include information and methods addressing this requirement. SSMR #3 — Source Control of Pollution Specific source controls are not required for single family residential sites. SSMR #4 — Preservation of Natural Drainage Systems and Outfalls The proposed development preserves the natural drainage system and outfall to the Edmonds Way direct discharge basin. It also reduces the amount of impervious area draining to the existing system by 1,942 sf. SSMR #5 — Onsite Stormwater Management Onsite Stormwater Management requirement is met by utilizing onsite/LID techniques and infiltration as described in Chapter 5 of the City of Edmonds Stormwater Supplement. All pervious areas on site will use compost amended soil per City of Edmonds Handout #E72 C. SSMR #6 — Runoff Treatment Proposed PGIS is less than the 5,000 sf threshold required for treatment. SSMR #7 — Flow Control Flow control requirement is met by utilizing onsite/LID techniques and infiltration as described in Chapter 5 of the City of Edmonds Stormwater Supplement. All pervious areas on site will use compost amended soil per City of Edmonds Handout #E72 C. SSMR #8 — Wetland Protection No known wetlands are located within 1/4 mile of the subject site. SSMR #9 — Operation and Maintenance Operation and Maintenance of all installed BMPs will be performed by the homeowners in accordance with the provisions in Chapter 7 of the City of Edmonds Stormwater Supplement. M an. Df.�sigzi� Manage Q:AV111 & S"I W4' 1 p.,9RM IVIG1N1F1l IR1 NG � Il LAND "r;14UP0n:Y111 (-, � 11 AIT-) P11 ANNi(Oh G PR, llll C II° IMNl'JAG IIILAI T � II"II.I1M111 II }« "II:1'N VNG � V V 6`16:4.111 F1Y 2 Category 2 Small Site Drainage Report Chung Short Plat June 2016 SSMR #10 — Offsite Analysis and Mitigation The existing downstream conveyance system was examined during the design process and appears to be functioning properly. The project reduces the amount of impervious surface draining to the existing system by 1,942 sf, so there are no adverse impacts anticipated. SSMR #11 — Financial Liability Necessary performance bonds will be placed by the developer prior to construction. S. Attachments • VICINITY MAPS • PROJECT CLASSIFICATION DRAINAGE BASIN MAP 0 NRCS SOILS REPORT Plan Design. Manage Q IVIIII1 & ."°b']"'FU➢G;P.➢IIRAI III A1411D f:iv4➢RV1f:1(llh'"G I O.AIIVIIID PAM"CING �:�ll c o tl� ,V ��ntl 111 utl'V p IP1:::1 MF11I a P lEA R ING, p tl EAS111IIM IfY 3 Category 2 Small Site Drainage Report Chung Short Plat June 2016 VICINITY MAPS NTS Plan. Design. Manage CIVIII & SHIZUKTUIUMI EINIGHNIIIFREING, III MITI) SUIRVEYTIN(I IL.AIIIIIID N AITIVIAG PW) I ECT uAAIIIla,E11411::W 11 p u1u.F,1A1u a::1FIFINTUNG p uFEASIlBUI ffY 4 Wh� WA� P.W im Z Co, 4 PROJECT SITE 721 EDMONDS WAY"�"' J Plan. Design. Manage CIVIII & SHIZUKTUIUMI EINIGHNIIIFREING, III MITI) SUIRVEYTIN(I IL.AIIIIIID N AITIVIAG PW) I ECT uAAIIIla,E11411::W 11 p u1u.F,1A1u a::1FIFINTUNG p uFEASIlBUI ffY 4 Category 2 Small Site Drainage Report Chung Short Plat June 2016 PROJECT CLASSIFICATION Per City of Edmonds Handout #E72 If you have determined that the Stormwater U na etncnt Code llalia _((!..Your tr i l i t I igurr .j. follow .1 ..Blue boxes in the chart below to determine the Classification„ofyour project, 1 Does the protect involve 1- Yes 10 acre or more of land - disturbing aclilyll„i'' Large Site Project: IT � No[ See. Stormwater Supplement Yk's Chapter 4 for specific Is the prof"A t part of a larger requirements, conunon plan oj'development or sale where the total disturbed area_,,,,__, for the entire plan will total I -acre Does that: proj: ct civaite or add 5,00) square lett c,ir or, u; osv of land -disturbing activity? o'itoare of new regulated re lat`of impervious .surface or new, plus No regulated replaced ln,ipervious surface? Does the Project involve one or more of the OR following: Convert 4 acre or mole of ntitive vegetation etati'on tan, 2,0(X) square feet (s1} or more of new Yes lawn or landscaped area iruperiious surface, regulated re)llrreed OR impervious surface or new plus regulated Through a combination of creating eftective replaced impervious surface? irtilw'rvious surface and converted pervious OR sut„fkes, causes an increase of 0.1 cubic feet per 7,0W sf or more of laud -disturbing actirzty? second in the 100 -year flow frequency from a OR threshold discharge area as estimated Lasing an 50 cubic yards or more of either grading fill, or approved model? excavation as defined in Chapter 19, 40. ECDC? Nlinor Site ProJecl: See Stormwater Supplement requirements Plan.: U' �d�:��.��si��;�i�xi, Manage "A"tIIV n `>1III� V+ I�IJI'U)'111 1�9ONI I hlN( -IiI IL"�I�VI) UP' 1 )(1N( L�V14I) II II1M,NINIIIN(; V' 1 0' I �' ,l I1v1 V �� I V 1 t:= I'�d VI P,` II' 0 IVU I V �� P F ID l l I l' :'a [ r I 'y' , HM I a I Category I Small Site Project: Category Z Small Site PI'o,ll'l'E: See Stormwater Supplement � See Stormwater Supplement Chapter 6 for specific Chapter 5 or specific Chapter 5 for specific rf'.'quln..nSE',ntti FegLlll'enlellt5 5 Category 2 Small Site Drainage Report Chung Short Plat June 2016 DRAINAGE BASIN MAP City of Edmonds GIS NTS a fMIlvfl0 FAM G¢ ,,o w`«�m MSN 0N'G �1 A� M"luta NNNa9: 4/dqmu7� low f Wu 14 nvf N , y .., rz. MM rw g Y "U' t % 6 9th+t afxa+�, �rvr4a„ka•�NP � "omoNulswoy ii PROJEC T *,'AEM�4S '.WA � � q^' p��.�a G b tl M"nb �� r p N uzr r � k IIIa Plan. 'I )esign. Manage CII:TgII., & STUUUG°'Q”"4,.URAII II AND ";;;'nVVR"4v'llXTING°u � 11 A11411) II°'N II..,PaN NllllNiG I A NUUNNG uEIII1II::IINUU IIaEIIAM^ II "IINII':!'',IIUII:TTNG a ill ASUIIUlfll U"U"'"N' 6 Category 2 Small Site Drainage Report MRCS SOILS REPORT Plax,%,. Design. Manage CIVIL & SURUCTUIRAIL EINGIINIEERTING I LAND SURVEYING I JAINID PLANNING PROJECTMANAGEIM16mI PERMIT EXPEIDIT-11ING I FEASIBILITY Chung Short Plat June 2016 USDA United States Department of Agriculture MRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Snohomish Count Area, Washington I June 16, 2016 Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nres.usda.gov/wps/portal/ nres/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices. sc.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 SoilMap................................................................................................a,,....,..........7 SoilMap................................................................................................................8 Legend..................................................................................................................9 MapUnit Legend................................................................................................10 Map Unit Descriptions........................................................................................10 Snohomish County Area, Washington............................................................12 17—Everett very gravelly sandy loam, 0 to 8 percent slopes.....................12 References.............................................................................................................14 4 � Are ,w 1V "" Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil -vegetation -landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil scientists classified and named the soils in the survey area, they compared the Custom Soil Resource Report individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil - landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil -landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field -observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 11 The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 7 M,£T,ZZ oZZT M „BT ,ZZ oZZT Z V a "£S 06SE6ZS 09SE6ZS OLS£6ZS 09S£6ZS OSS£6ZS Z V V ObS£6ZS ug M „£T ,ZZ ozu n pzp z nj M F yF v a v 8 co 3 z �oo O A m Ln O F O � Q VVQQ k C .1 O H � L ` pa O I.: ? p z O n �' M „BT ,ZZ oZZT V- 0 Q N N U 7 O N O (C C O N 7 U �!A �p _.........................._. ...................... c wo rn 0 (n ca . 0 coIT N N N` N O 0) O N O C ' I 3 C; N U O C U O) p L N p p Vl y 7 O 0) U N (Cz U Nw m E -O (n N d N f7 N� E a) C @ U 0 N C E -Y N D)CL m•� o 3r u m n wQ o O 0) d f0 N `� O C 00 ma m N O V) U) >� > LO E 7 0) O N L) 922-80 L Cl)•L.+ N C� O L N o 'O w Q N D E f0 @ N o cmc I/) N d m N Z N N w w L E u7i L o C Q S in 'f0E m E 0 11 LU� =— N d 6 O — OO . m Q N OU O UL La L p q 70- OU)N N CN O Q O i of 3 °) u 70 O �" g `° t� n o E>+m LL O 3 IaO)a O� 0) Zo E O N E Z N � f -- L U)fn O C U) a o, m = EEp O O O C C co L d U) N N E- — Z o p -O L m O •N °c N m o a) a ) IL a JD�v°O a°'i L 5 0)ami °) 3 Q U N M> E u! .F y CL CL a)f6 L fa J Z U) U) CO L Q O N_ f/) ) f0 N L N C .. p O r m O O f0 a) E m E U Q a� H C v m� w m > �L o o v «N a �T �� t m oz w L �� Q w E _ ov%, m Zo c m 7o O f0 w 3 m uoi Zi m = a cn c u a`T) E ococoa E c m'0 -o v.� Q oa . 0 rn0 Ew N N u� N � w� a`m � 44)) a E rn N L Oaw o E m 7 °� m m 7L o a.�:° (D v u) — Z — a� E m L >f0 C .N N '0 W E d tq 0) N d E p N p (on � U (6 O M L � O_ V Q U L � O 7 (n fn O fn O O O � N L O E � U .- o O_ y af0i LL h m N gg L L m C/) N O) N O `l Q CL CO y p J o N E N ° o O O L o .d C ° N U) V L d 0) N V C N 0_' f0 N U) O (0 l0 U W QD €' ` t H, c C 7 3 m W J aa a,� = o: a N °° o a NCL w E C c c ` > > a m n 3 ; w n) O C7 E °a CL o w` a ° O Q o m m m m LL 0_ > —'' _ ° L > E p �. p ° Q (n LL <n w 'p 3 O m m T y U L) C'J 0) (7 J J N U N Y LL W C_ U U) U) 0) N in O) (n m - E O `- I 0 OC 0 0 + X �q 4,eg p0 N ) Q N �!A Custom Soil Resource Report Map Unit Legend Snohomish County Area, Washington (WA661) Map Unit Symbol Map UnitName Acres In AN Percent of AOI 17 Everett very gravelly sandy 0.4 100.0% loam, 0 to 8 percent slopes Totals for Area of Interest 0.4 100.0% Maps Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. 10 Custom Soil Resource Report An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha - Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. 11 Custom Soil Resource Report Snohomish County Area, Washington 17—Everett very gravelly sandy loam, 0 to 8 percent slopes Map Unit Setting National map unit symbol: 2t629 Elevation: 30 to 900 feet Mean annual precipitation: 35 to 91 inches Mean annual air temperature: 48 to 52 degrees F Frost -free period: 180 to 240 days Farmland classification: Farmland of statewide importance Map Unit Composition Everett and similar soils: 80 percent Minor components: 20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Everett Setting Landform: Eskers, kames, moraines Landform position (two-dimensional): Shoulder, summit Landform position (three-dimensional): Crest, interfluve Down-slope shape: Convex Across -slope shape: Convex Parent material: Sandy and gravelly glacial outwash Typical profile Oi - 0 to 1 inches: slightly decomposed plant material A - 1 to 3 inches: very gravelly sandy loam Bw - 3 to 24 inches: very gravelly sandy loam C1 - 24 to 35 inches: very gravelly loamy sand C2 - 35 to 60 inches: extremely cobbly coarse sand Properties and qualities Slope: 0 to 8 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Capacity of the most limiting layer to transmit water (Ksat): High (1.98 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 3.2 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4s Hydrologic Soil Group: A Other vegetative classification: Droughty Soils (G002XS401 WA), Droughty Soils (G002XF403WA), Droughty Soils (G002XN402WA) Minor Components Alderwood Percent of map unit: 10 percent Landform: Ridges, hills 12 Custom Soil Resource Report Landform position (two-dimensional): Summit Landform position (three-dimensional): Crest, talf Down-slope shape: Linear, convex Across -slope shape: Convex Indianola Percent of map unit: 10 percent Landform: Eskers, kames, terraces Landform position (three-dimensional): Tread Down-slope shape: Linear Across -slope shape: Linear 13 In - American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep -water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/nres/ detail/national/soils/?cid=nres142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nres.usda.gov/wps/portal/ nres/detail/national/soils/?cid=nres142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nres.usda.gov/wps/ portal/nres/detail/national/soils/?cid=nres142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nres.usda.gov/wps/portal/nres/detail/soils/ home/?cid=nres142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 14 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 43041. http://www.nres.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=nres142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www. nres. usda.gov/wps/portal/nres/detail/national/soils/? cid=nres142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nres.usda.gov/Internet/FSE_DOCUMENTS/nresl42p2_052290.pdf 15