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03 OF TRA <br />CFO <br />M N <br />m Q <br />t�CORPOgP� <br />Utilities Division <br />3900 Holly Drive <br />Tracy, CA 95376 <br />Telephone: (209) 836-1650 <br />Fax: (209) 836-0932 <br />A composite sample from our sludge drying beds was collected on July 20, 1993, before <br />the fall application. Each bed was divided into four quadrants and a 250 ml plastic beaker <br />used to collect samples from the center of each of the quadrants. Aliquots were <br />combined, well mixed and analyzed for the EPA 503 metals. <br />Samples of air dried and stockpiled sludge were collected on October 18, 1993, just <br />before a fall application. Samples were collected from specific locations, combined, mixed <br />and analyzed for the EPA pathogens. Samples were refrigerated, treated and shipped in <br />containers specified by the contract laboratory. <br />Diagrams of sample locations are included. <br />Analytical Results <br />The attached table shows analytical results obtained on samples collected in 1993. Results <br />met or exceeded the compliance limits for metals and the Class A requirements for <br />pathogens. <br />Vector Attraction Reduction <br />Digested sludge is allowed to dry in our air drying beds for at least three months at <br />temperatures over 0 degrees centigrade on a daily basis. Sludge applied in the fall of 1993 <br />was over 90 percent solids. <br />Our land applied sludge meets the vector attraction reduction requirements because it is <br />air dried, digested sludge that is applied at over 75 % solids. <br />The attached schematic shows the sludge handling process. <br />1994 Monitoring <br />Samples in the past have been collected from our stockpiled sludge before application. <br />The California Regional Water Quality Control Board has suggested that we collect our <br />metals samples directly from the sludge wasting stream as the sludge is being wasted from <br />the digestors to the drying beds. This may give us data that is more representative of <br />seasonal variations that may occur in the sludge quality. We will be doing this. <br />Pathogen samples will continue to be collected from the stockpiles when the sludge is <br />applied. <br />N <br />