WA ST Dept of Ecology Biosolids 9/8/2022

SSLAP – Lowell Snohomish River Road Agricultural Land ___________________________________________________________________________________ ______________________________________________________________________________________ 1 Introduction The City of Everett owns 166 acres of agricultural land within the limits of the City of Everett on Lowell- Snohomish River Road (Appendix A). About 124 acres of the land has been used for agricultural purposes for many years. The site is managed for agricultural use by Sno-Valley Farms, a local farming outfit based in Snohomish County. Sno-Valley Farms, Inc. has had a license to farm the land for the last ten plus years and has been farming in the area for forty-eight years. This Site Specific Land Application Plan (SSLAP), submitted pursuant to the requirements of WAC 173- 308, provides a site description, overview of operations, and application rate calculation for 2021. In future years, this SSLAP will be updated as needed, with current information on site-specific field operations. The City’s Biosolids Program will track and record these activities pursuant to the requirements of WAC 173-308, this SSLAP, and any permit conditions. Biosolids Characteristics Biosolids are the processed, stabilized product of municipal wastewater treatment. Biosolids have undergone a Process to Significantly Reduce Pathogens (PSRP) or a Process to Further Reduce Pathogens (PFRP). Biosolids contain numerous plant nutrients, soil conditioning organic matter, and are of such a quality they can be safely and beneficially recycled on land. Generally, biosolids have a mild organic or ammonia odor. Biosolids are considered a commodity under Title 70.95J.005 of the Revised Code of Washington. At a minimum, all biosolids will be required to meet Class B pathogen and vector reduction requirements, as well as metal concentrations that do not exceed Ceiling Concentration Limits. A summary of the biological and chemical analysis of biosolids applied will be available in the City of Everett annual biosolids reports required under WAC 173-308 and 40 CFR part 503. • Nutrient Value Biosolids contain numerous plant macro- and micronutrients essential for plant growth, including nitrogen, phosphorous, potassium, sulfur, boron, manganese, and zinc. Biosolids generally have a nitrogen content in the range between 1% and 6%. Most of this nitrogen is in organic form with a small portion in mineral form (ammonia-nitrogen, nitrate-nitrogen). The mineral nitrogen is rapidly available for plant use, much like commercial fertilizer. The remaining nitrogen is bound in a complex of organic matter and is only available for plant use as it is metabolized by microorganisms into mineral form. This process makes biosolids an excellent soil amendment as it releases nutrients over a period at a rate that closely matches crop needs. This slow-release process reduces the risk of nutrients leaching out of the root zone. Biosolids application rates will be tailored to the soils, expected crops, and appropriate to the season through a calculation known as the agronomic rate. The agronomic rate supplies nutrients for specific crops while simultaneously protecting the surface and groundwater from excess