Washington State Dept. of Ecology 3/27/2025

Page 1 of 8 Marshland Site Sampling and Analysis Plan (SAP) WPCF Operations Marshland Soil Nutrients Sampling and Groundwater Monitoring Revised 2/21/25 A. Overview Biosolids dredged from the WPCF may be land applied to the City of Everett Marshland Site on Lowell- Snohomish River Road. The East and West fields of the Marshland Site are separated by the Marshland Canal (Appendix A). The City collects soil samples from the fields to determine nutrient levels and agronomic application rates for each field prior to biosolids application and to monitor plant nutrient uptake after crop cutting. Samples are collected below the organic layer and composited for analysis. Groundwater monitoring is also conducted for this site prior to biosolids application. Minor modifications to the implementation of the SAP will be made to ensure representative samples are collected. B. Access Requirements Gates are locked with chain to prevent public access. The code for the combination lock is . Do not drive on fields if too muddy (tire ruts make cause complications for farming equipment) or if the field has been planted. Make sure vehicle has 4WD. C. Hazards & Safety Precautions Personal protective equipment (PPE) is required when handling biosolids sampling equipment, including steel-toed boots and gloves. Rainboots may be required after rain events. Due to wet conditions on the fields, only drive and park vehicles in the areas indicated on the map in Appendix A. D. Analytes 1) pH (soil) 2) Total Kjeldahl Nitrogen (TKN) 3) Ammonia 4) Nitrate 5) Nitrite E. Equipment and Supplies 1) Shovel, post-hole digger or core sampler 2) Cordless drill/driver with bucket mixer attachment. 3) Socket wrench kit for opening monitoring well covers. 4) Two 5-gallon buckets. 5) Map of East and West Fields with sample location markers (Appendix A). 6) 6 sample jars per field (250 mL clear glass wide-mouth jars with Teflon-lined lid). 7) Sample container labels. 8) Chain of custody form (COC) and pen.