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MEMORANDUM City of Tracy - 2 - 6 February 1979 an already non-compliance condition with NPDES limits, it was decided to operate the traveling bridge with one clarifier in service in an effort to meet effluent limns.. The return sludge pumps located on the traveling bridges have vari-speed motors. However, they have a total dynamic head of 15 feet. Mr. Baker stated he had ex- perimented with adjustments to the discharge valve to create a head for the centi- fugal pump and reduced motor speed settings. These experiments resulted in plugging the value and loss or near loss of the process. Mr. Baker decided to run the return sludge pump motors at full speed at all times. Another waste of energy and money. Effluent Quality At the time of the "C" level inspection, 24 hr. composite samples for industrial influent,domestic influent and combined industrial-domestic effluent were split with the City. The following determinatioins were made: BOD Sus. Solids Sample Date Lab (mg/1) (mg/1) Ind. Inf. 12/14/78 Bryte DWR >740* 708 Ind. Inf, same Tracy STP 1711 784 Dom. Inf. 12/14/78 Bryte DWR 80 298 Dom. Inf. same Tracy STP 101 250 Comb. Eff. 12/14/78 Bryte DWR 69 26 Comb. Eff. same Tracy STP 41 36 *dilution factor not great enough On 15 December 1978 three grab samples were collected of the final effluent for bacteriological testing, and taken to the Ray Beam Laboratory for total coliform determinations. All three samples showed 49 coliform/100 ml. Samples collected at the same time and location and determined by the Tracy laboratory personnel showed 460 coliform/100 ml. On 15 December 1978 determinations for settleable solids (0.1 ml/1) and chlorine residual (0.0 mg/1) were made on the final effluent. The only violation indicated on this inspection was the 69 mg/l BOD determined by the Bryte Laboratory on the combined effluent. However the Tracy Laboratory results do not indicate a violation. The daily maximum allowable in the NPDES permit is 50 mg/l BOD. A review of Tracy's waste facilities self monitoring report for the months of August, September, October, November, and December 1978, show the following violations: