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<br /> <br />1 of 8 <br /> <br />Standard Operating Procedure <br />WPCF Operations <br />In-situ Biosolids Sampling and Monitoring Procedure <br />Revised: 2/21/2025 <br />A. Overview <br />The City of Everett stores residual solids from wastewater treatment in its wastewater lagoons. <br />These lagoon solids are dredged regularly to maintain treatment capacity of the lagoons. Biosolids <br />are the dewatered solids removed from the lagoons and are a beneficial resource that can be used <br />as a soil improvement provided that regulatory requirements are met as stated by the Statewide <br />General Permit for Biosolids Management and Chapter 173-308 WAC. <br /> <br />The purpose of this SOP is to standardize the sampling method of in-situ solids and ensure that <br />analyses are done in a repeatable and representative manner. Sampling methods must meet the <br />guidelines within the Statewide General Permit for Biosolids Management and Chapter 173-308 <br />WAC. <br /> <br />This SOP also describes the methods used to collect sludge blanket and lagoon liner data. <br /> <br />B. Hazards & Safety Precautions <br />1. A personal floatation device is required at all times when working on watercraft. <br />2. A minimum of two crew members are required any time a vessel is offshore. <br />3. The boat deck can become extremely slippery; ensure proper footing as to not fall overboard. <br />4. Do not operate or board the barge or bio boat in freezing conditions. <br />5. Sustained winds over 5 mph affect the maneuverability of the barge and make sample <br />collection difficult. Under these conditions, postpone sample collection, if possible. Sustained <br />winds over 10 mph disable the maneuverability of the barge and make barge operation unsafe. <br />Do not operate the barge with sustained winds over 10 mph. <br />6. The driver of the boat must have a working radio at all times. <br />C. Definitions <br />1. Lagoon Monitoring Sections: The distinct areas in each lagoon as defined by the Lagoon <br />Monitoring Map. <br />2. Representative Sampling Areas: The area determined by the Biosolids Manager which each <br />analyzed sample is representative of. A predetermined sampling area may be as small as a <br />single lagoon monitoring section or may be as large as the entire lagoon. <br />