Laserfiche WebLink
2. Planting beds must be mulched with 2 inches of organic material <br /> 3. Quality of compost and other materials used to meet the organic content <br /> requirements: <br /> a. The organic content for-pre-approved"amendment rates can be met only using compost that <br /> meets the definition of-composted materials" in WAC I73-350-220. This code is available <br /> online at: http://www.ecy.wa.gov/programs/swfa/facilities/350.html. <br /> Compost used in bioretention areas should be stable,mature and derived from yard debris,wood waste,or other <br /> organic materials that meet the intent of the organic soil amendment specification. Biosolids and manure <br /> composts can be higher in bio-available phosphorus than compost derived from yard or plant waste and therefore <br /> are not allowed in bioretention areas due to the possibility of exporting bio-available phosphorus in effluent. <br /> The compost must also have an organic matter content of 35%to 65%,and a carbon to nitrogen ratio below 25:I. <br /> The carbon to nitrogen ratio may be as high as 35:1 for plantings composed entirely of plants native to the Puget <br /> Sound Lowlands region. <br /> b. Calculated amendment rates may be met through use of composted materials as defined above; <br /> or other organic materials amended to meet the carbon to nitrogen ratio requirements, and <br /> meeting the contaminant standards of Grade A Compost. <br /> The resulting soil should be conducive to the type of vegetation to be established. <br /> • Implementation Options:The soil quality design guidelines listed above can be met by using one of the <br /> methods listed below. <br /> I. Leave undisturbed native vegetation and soil, and protect from compaction during construction. <br /> 2.Amend disturbed soil according to the following procedures: <br /> b. Scarify subsoil to a depth of one foot <br /> c. In planting beds,place three inches of compost and till in to an eight-inch depth. <br /> d. In turf areas, place two inches of compost and till in to an eight-inch depth. <br /> e. Apply two to four inches of arborist wood chip, coarse bark mulch, or compost mulch to <br /> planting beds after final planting. <br /> Alternatively,disturbed soil can be amended on a site-customized manner so that it meets the soil quality <br /> criteria set forth above, as determined by a licensed engineer, geologist, landscape architect, or other <br /> person as approved by the City of Everett. <br /> 3.Stockpile existing topsoil during grading, and replace it prior to planting. Stockpiled topsoil must be <br /> amended if needed to meet the organic matter and depth requirements by following the procedures in <br /> method (2) above). <br /> 4.Import topsoil mix of sufficient organic content and depth to meet the organic matter and depth <br /> requirements. <br /> 5.More than one method may be used on different portions of the same site. Soil that already meets the <br /> depth and organic matter quality standards, and is not compacted, does not need to be amended. <br /> Maintenance <br /> • Soil quality and depth should be established toward the end of construction and once established, <br /> should be protected from compaction, such as from large machinery use, and from erosion. <br /> • Soil should be planted and mulched after installation. <br /> • Plant debris or its equivalent should be left on the soil surface to replenish organic matter. <br /> Kymera 2-Lot SP Full Drainage Report <br /> Revised:April 21,2018 Page 13 <br />