9909 2ND AVE W 2018-08-01 - Laserfiche WebLink

Soils Information The following soils information is copied from a scanned version of the text of the original Soil Survey report of Snohomish County Area, Washington issued July 1983. This information is available from the NRCS Washington state web site www.wa.nrcs.usda.gov/index.html 5-Alderwood-Urban land complex,2 to 8 The Alderwood soil in this unit is used mainly percent slopes.This map unit is on till plains. for parks, building sites, lawns,gardens, and Areas are irregular in shape and are 100 to 1,000 woodland. acres in size.The native vegetation is mainly The main limitations of the Alderwood soil for conifers. Elevation is 50 to 550 feet.The average homesites and septic tank absorption fields are the annual precipitation is about 40 inches,the depth to the hardpan and the seasonal perched average annual air temperature is about 50 water table. Onsite waste disposal systems often degrees F,and the average frost-free season is fail or do not function properly during periods of 170 to 190 days. high rainfall. Drainage is needed if buildings with This unit is about 60 percent Alderwood basements and crawl spaces are constructed. gravelly sandy loam and about 25 percent urban Topsoil needs to be stockpiled during site land.The components of this unit are so intricately preparation and subsequently used to cover the intermingled that it was not practical to map them exposed material. Additions of fertilizer and peat separately at the scale used. are desirable prior to seeding grass for lawns. Included in this unit are small areas of This map unit is in capability subclass IVe. McKenna and Norma soils and Terric Medisaprists in depressional areas and drainageways on plains. 32-McKenna gravelly silt loam,0 to 8 percent Also included are small areas of soils that are very slopes.This moderately deep, poorly drained soil shallow over a hardpan;small areas of Everett, is in depressional areas and drainageways on till Indianola, and Ragnar soils on terraces and plains. It formed in glacial till.The native vegetation outwash plains;and soils that have a stony and is mainly conifers. Elevation is 100 to 800 feet.The bouldery surface layer. Included areas make up average annual precipitation is about 45 inches, about 15 percent of the total acreage. the average annual air temperature is about 50 The Alderwood soil is moderately deep over a degrees F, and the average frost-free season is hardpan and is moderately well drained. It formed 150 to 180 days. in glacial till. Typically,the surface layer is very Typically,the surface layer is very dark grayish dark grayish brown gravelly sandy loam about 7 brown gravelly silt loam about 8 inches thick.The inches thick.The upper part of the subsoil is dark subsoil is brown and light olive brown gravelly silt yellowish brown and dark brown very gravelly loam about 25 inches thick. sandy loam about 23 inches thick.The lower part is Olive,compact glacial till is at a depth of 33 inches. olive brown very gravelly sandy loam about 5 Depth to glacial till ranges from 20 to 40 inches. inches thick. A weakly cemented hardpan is at a Included in this unit are small areas of soils depth of about 35 inches. Depth to the hardpan that have slopes of more than 8 percent.Also ranges from 20 to 40 inches. included are Alderwood and Tokul soils on till Permeability of the Alderwood soil is plains, Everett soils on terraces and outwash moderately rapid above the hardpan and very slow plains,and Norma soils and Terric edisaprists in through it.Available water capacity is low. Effective depressional areas and on outwash plains and till rooting depth is 20 to 40 inches. Runoff is slow, plains. Included areas make up about 15 percent and the hazard of water erosion is slight. A of the total acreage. seasonal perched water table is at a depth of 18 Permeability of this McKenna soil is slow.Available to 36 inches from January to March. water capacity is moderate. Effective rooting depth Urban land is areas that are covered by is 20 to 40 inches. Runoff is slow, and the hazard streets, buildings, parking lots, and other structures of erosion is slight.A that obscure or alter the soils so that identification seasonal perched water table is at a depth of 0 to is not possible. about 6 inches. Ponding occurs from November to April.The effect of the layer of dense glacial till on use and management is