Laserfiche WebLink
INFORMATION SHEET <br /> MARLEY COOLING TOWER COMPANY <br /> SAN JOAQUIN COUNTY <br /> Past operational practices in the fabrication of cooling towers by the Marley <br /> Cooling Tower Company (MCTC) has caused soil and ground water contamination by <br /> copper, chromium and arsenic. In October 1987, MCTC initiated interim ground <br /> water remediation. This interim remedial action has been operating under Order <br /> No. 88-124 (NPDES No. CA0081787) . MCTC is presently permitted to discharge up <br /> to 0.37 mgd of treated stormwater and ground water to the Stockton Diverting <br /> Canal , tributary to the Calaveras River. <br /> MCTC submitted a Report of Waste Discharge (RWD) which requested an increase in <br /> the treated water flow from the treatment plant. MCTC proposed in the RWD an <br /> interim expansion of the on-site ground water treatment facility to control <br /> off-site contaminant movement. An electrochemical reduction and precipitation <br /> treatment plant will be constructed and used in parallel with the existing ion <br /> exchange treatment system. Flows have been proposed to be increased to 0.59 mgd. <br /> Ground water treatment will now consist of various combinations of the following <br /> unit processes: flow equalization, reduction, precipitation, settling, <br /> filtration, pH adjustment and ion exchange. <br /> MCTC submitted the Effluent Toxicity Program Report which demonstrated that the <br /> effluent does not have a reasonable potential to cause fathead minnow instream <br /> toxicity. However, this Report also indicated that the effluent may periodically <br /> cause acute invertebrate (Ceriodaphnia dubia) instream toxicity. More extensive <br /> invertebrate follow-up toxicity testing is needed to confirm this potential <br /> toxicity. <br /> During the first quarter of 1990, MCTC exceeded the effluent limitations in Order <br /> No. 88-124 for chromium, copper and total dissolved solids. The RWD was found <br /> to generally address the concerns associated with the permit violations. <br /> However, the RWD did not adequately address the operation and maintenance <br /> procedures to be taken during wet weather events and in the case of breakthrough. <br /> A revised Operation and Maintenance Manual for the treatment plant is needed to <br /> define those measures to be taken during these events. <br /> A Remedial Investigation/Feasibility Study has been conducted and in August 1990; <br /> the final Remedial Action Plan (RAP) was adopted by the DHS. The recommended <br /> ground water remedial action in the RAP included an increase of up to 0.72 mgd <br /> in the discharge of the treated ground water and/or storm water for an interim <br /> period, not to exceed 18 months. During this 18 month period, MCTC will be <br /> evaluating other discharge alternatives. Aquifer reinjection and reuse is <br /> considered a viable discharge alternative because it would minimize local <br /> dewatering of the aquifer due to overdraft and would restore the aquifer as a <br /> usable drinking water source due to recharge of the treated ground water and/or <br /> stormwater. <br /> A revised monitoring program has been prepared for the new interim plant startup <br /> and for the full scale operations. The adoption of the modified waste discharge <br /> requirements will expedite ground water cleanup by increasing flows and will <br /> implement a more stringent monitoring program. <br /> CKW:cw <br />