SITE INFORMATION AND CORRESPONDENCE_1993-2003

Home Browse Search

• WASTE DISCHARGE REQUIREMENTS ORDER NO. R5-2002-XXXX 23 U.S. DEPARTMENT OF DEFENSE DEFENSE LOGISTICS AGENCY DEFENSE DISTRIBUTION DEPOT SAN JOAQUIN SHARPE GROUNDWATER REMEDIATION SYSTEM SAN JOAQUIN COUNTY 4. Mercury TMDL Reopener: This Order shall be reopened, as necessary,and final effluent limitations established for mercury based upon a waste load allocation derived from the , Delta waterways TMDL or a site-specific water quality objective. 5. Arsenic Dilution/Mixing Zone Study: Sufficient information regarding the quality and quantity of flows in the SSJID Canal and French Camp Slough is not available to adequately assess the location of drinking water intakes, the fate and transport of arsenic resulting from the effluent discharge, ambient dilution water, and mixing zone characteristics needed to assess alternative final effluent limitations for arsenic. Therefore, within six (6) months of adoption of this Order the Discharger shall complete and submit an Arsenic Dilution/Mixing Zone Study Workplan. The final Study shall be completed within thirty six (36) months from the date of adoption of this Order. The Discharger shall submit semi-annual progress reports on 15 January and 15 July each year until the Study is completed. Concurrently, the Discharger may provide information to the Regional Board to support a Basin Plan amendment to de-designate the municipal and domestic supply (MUN) beneficial use of the SSJID Canal based on the exceptions to S WRCB Resolution 88-63. Upon completion of the Study, this Order may be reopened to include alternative final effluent limitations for arsenic. 6. Chronic Toxicity Testing: The Discharger shall conduct the chronic toxicity testing specified in the Monitoring and Reporting Program. If the testing indicates that the discharge causes, has the reasonable potential to cause, or contributes to an in-stream excursion above the water quality objective for toxicity, the Discharger shall initiate a Toxicity Identification Evaluation(TIE) to identify the causes of toxicity. Upon completion of the TIE, the Discharger shall submit a workplan to conduct a Toxicity Reduction Evaluation (TRE) and, after Regional Board evaluation, conduct the TRE. This Order will be reopened and a chronic toxicity limitation included and/or a limitation for the specific toxicant identified in the TRE included. Additionally, if a chronic toxicity water quality objective is adopted by the SWRCB, this Order may be reopened and a limitation based on that objective included. 7. Bromacil Study: The pesticide Bromacil has been detected in the effluent of the three GWTPs at maximum concentrations of 5.2 µg/L (ppb) (North Balloon GWTP, 8/4/1998), 4.1 µg/L (ppb) (Central Area GWTP, 8/7/2001), and 7.6 µg/L (ppb) (South Balloon GWTP, 8/8/2000). No MCL has been established for Bromacil. The USEPA has published a drinking water health advisory, or Suggested No-Adverse Response Level (SNARL) of 90 µg/L (ppb). The Basin Plan does include an objective for Pesticides, stating in part: "Pesticide concentrations shall not exceed the lowest levels technically and economically achievable". The Discharger shall perform a study to determine the lowest effluent concentrations technically and economically feasible. Findings of this Bromacil Study will be used to evaluate whether additional treatment measures for Bromicil are necessary,feasible, and cost-effective. Within twenty four (24) months of adoption of