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�,FKOFThq�y CITY ®F TRACY ■ Utilities Division 3900 Holly Drive Telephone: (209)836-1650 Tracy, CA 95376 Fax: (209)836-0932 SCO RPOlI� Date: July 19, 1995 Subject: Sampling Plan for Sludge Bed and Stockpiles. July, 1995 sampling prior to Fall land application. Background: Approximately 2700 metric tons of air dried sludge is present at the wastewater treatment plant. Approximately 1080 tons of this is stockpiled and 1630 tons of it is in our sludge drying beds. EPA requires that at least six representative samples of this be collected for the regulated metals and pathogens. The City's discharge permit also requires that one sample for PCBs be collected. Analyses are also needed for nutrients and other constituents related to the agronomic applications to our land application site. Procedure: Samples must be collected proportional to the mass of sludge present. Metals and Nutrients Since the beds contain 60 % of the material, four samples will be collected from them. The attached map shows that sludge will be removed from thirteen of the beds. Samples will be collected based on the estimated yards of sludge present in each bed. Sample# 1 will be collected from beds numbered 3, 4 and 5 South (663 yards). Sample# 2 will be collected from beds 6, 7 and 8 South and 1 North (699 yards). Sample#3 will be collected from beds 2, 3 and 4 North (685 yards). Sample#4 will be collected from beds 5, 6 and 7 North (822 yards). Each bed from each sample set will be divided into quadrants. A full depth sample will be collected from the middle of each quadrant with the auger. Each of these samples will be deposited into a stainless steel bucket and then onto a plastic sheet. Each composite of sludge will be shaped into a cone. The cone and quarter method will be used to divide the material into a size suitable for filling the sample containers provided by the contract laboratory.