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SSLAP – Lowell Snohomish River Road Agricultural Land <br />______________________________________________________________________________ <br />______________________________________________________________________________ <br />1 <br /> <br /> <br />Introduction <br />The City of Everett owns 165 acres of agricultural land within the limits of the City of Everett on Lowell- <br />Snohomish River Road called Marshland Site (Appendix A). About 124 acres of the land has been used for <br />biosolids beneficial use for many years. The site is managed for agricultural use by Sno-Valley Farms Inc. <br />based in Snohomish County. Sno-Valley Farms has farmed Marshland for over fifteen years and has been <br />farming in the area for forty-eight years. <br />This Site Specific Land Application Plan (SSLAP), submitted pursuant to the requirements of WAC 173- <br />308, provides a site description, overview of operations, and application rate calculation for 2021. In <br />future years, this SSLAP will be updated as needed, with current information on site-specific field <br />operations. The City’s Biosolids Program will track and record these activities in accordance with the <br />requirements of WAC 173-308, this SSLAP, and any permit conditions. <br />Biosolids Characteristics <br />Biosolids are the processed, stabilized product of municipal wastewater treatment. Biosolids have <br />undergone a Process to Significantly Reduce Pathogens (PSRP) or a Process to Further Reduce Pathogens <br />(PFRP). Biosolids contain numerous plant nutrients, soil conditioning organic matter, and are of such a <br />quality they can be safely and beneficially used. Generally, biosolids have a mild organic or ammonia <br />odor. Biosolids are considered a commodity under Title 70.95J.005 of the Revised Code of Washington. <br />To be beneficially applied at Marshland Site as a soil amendment, Everett’s biosolids are required to meet <br />Class B pathogen reduction requirements, vector attraction reduction requirements, and metal <br />concentrations that do not exceed Table 3 Pollutant Concentration Limits under WAC 173-308-160. A <br />summary of the biological and chemical analysis of biosolids applied will be available in the City of Everett <br />annual biosolids reports required under WAC 173-308 and 40 CFR part 503. <br />Nutrient Value <br />Biosolids contain numerous plant macro- and micronutrients essential for plant growth, including <br />nitrogen, phosphorous, potassium, sulfur, boron, manganese, and zinc. Biosolids generally have a <br />nitrogen content in the range between 1% and 6%. Most of this nitrogen is in organic form with a <br />small portion in mineral form (ammonia-nitrogen, nitrate-nitrogen). The mineral nitrogen is <br />rapidly available for plant use, much like commercial fertilizer. The remaining nitrogen is bound in <br />a complex of organic matter and is only available for plant use as it is metabolized by <br />microorganisms into mineral form. This process makes biosolids an excellent soil amendment as it <br />releases nutrients over a period at a rate that closely matches crop needs. This slow-release <br />process reduces the risk of nutrients leaching out of the root zone. <br />Biosolids application rates will be tailored to the soils, expected crops, and appropriate to the <br />season through a calculation known as the agronomic rate. The agronomic rate supplies nutrients <br />for specific crops while simultaneously protecting the surface and groundwater from excess <br />application that could leach nutrients into the water. See Appendix B for the Application Rate <br />Worksheet for the 2021 application on the East and West fields. Prior to future applications, <br />additional soil and biosolids sampling will be performed to adjust application rate calculations.