FIELD DOCUMENTS AND WORK PLANS 2000-2003

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INFORMATION SHEET • • 8 WASTE DISCHARGE REQUIRMENTS ORDER NO. R5-2002-XXXX MARLEY COOLING TOWER COMPANY STOCKTON, SAN JOAQUIN COUNTY WATER UALITY BASED EFFLUENT LIMITATIONS Co er Total ENumber of Observations >20 Effluent Maximum 80.0 Dilution Credit 0 ECA a44 mg/L(ppm)hardness as CaCO3) 6.5PercObservations Below Detection >90% Coefficient of Variation(Default 0.6 Limiting LTA(acute)= ECA acute *Table 1 Acute Multiplier) 2.1 SaTphag Frequency n <4/mo AMEL LTA*Table 2 AMEL Multiplier) 3.3 /L b MDEL LTA*Table 2 MDEL Multiplier) 6.5 /L b New final average monthly(3.3 gg/L(ppb) @ 44 mg/L (ppm)hardness as CaCO3) and daily maximum (6.5 µg/L(ppb) @ 44 mg/L(ppm) hardness as CaCO3) effluent limitations for copper (total)have been established in this Order in accordance with Sections 1.3 and 1.4 of the SIP using the adjusted copper criteria. These limitations will be adjusted accordingly with results of corresponding receiving water monitoring for hardness. The Discharger operates treatment processes specific to the removal of copper. With proper operation of the existing treatment facilities, results of monitoring indicate the Discharger is capable of meeting the new daily maximum effluent limitation, therefore a time schedule for compliance with this limitation is not included in this new Order. However,results of monitoring are not sufficient to determine if the Discharger can meet the new monthly average effluent limitation for copper of 3.3 µg/L(ppb) @ 44 mg/L(ppm) hardness as CaCO3. Data submitted by the Discharger indicates that, when the facility is properly operated, effluent concentrations of copper are less than 5 gg/L(ppb). Historical data are not of sufficient quality to determine compliance with the monthly average limitation. Detection of copper to 0.5 µgll, (ppb) is feasible in accordance with the SIP. This Order includes a Provision which requires the Discharger to collect data sufficient to determine compliance with this new monthly average effluent limitation for copper. As provided in Section 2.1 of the SIP, a time schedule is included in this Order to allow the Discharger to achieve compliance with the new monthly average effluent limitation for copper. In accordance with the SIP, Sections 2.2, a numeric monthly average interim limitation for copper is established in this Order based upon current treatment facility performance. Since the treatment facilities can, when properly operated, produce and effluent with copper concentrations less than 5 µg/L(ppb), this Order includes a performance based interim average monthly effluent limitation for copper set at this historical limit of detection of 5 µg/L (ppb). This interim limitation shall be an enforceable limitation until the final monthly average effluent limitation becomes effective on 1 October 2007.