Laserfiche WebLink
/��r <br /> STATE OF CALIFORNIA-Environmental Protectikency PTE WILSON, Governor <br /> CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD <br /> CENTRAL VALLEY REGION j-1}1 g�" <br /> 3443 Routier Road,suite A -- <br /> Sacramento,CA 95827-3098 <br /> PHONE:(916)255-3000 ' = 1'C� j j ,7 <br /> FAX:(916)255-3015rds' <br /> 18 October 1996 <br /> Mr. Verrill Norwood <br /> Pioneer Chlor Alkali Company, Inc. <br /> 116 Sunburst Lane, NW <br /> Cleveland, TN 37312 <br /> CLOSURE WORK PLAN FOR SURFACE IMPOUNDMENTS, ALL PURE CHEMICAL <br /> COMPANY, TRACY, SAN JOAQUIN COUNTY <br /> I have reviewed the 9 September 1996 Revised Closure Work Plan - Surface Impoundments submitted <br /> by Helmick and Lerner Inc. for the All Pure Chemical Company (All Pure) facility in Tracy. The <br /> work plan was submitted in response to our 6 August 1996 letter commenting on All Pure's 24 June <br /> 1996 Closure Work Plan. All Pure may proceed with closure of the ponds if the following comments <br /> are addressed. The comments are in reference to the noted sections of the report. <br /> Small Wastewater Pond <br /> All Pure's proposal to collect soil samples from within the backfill soil and from the base of the <br /> former small wastewater pond may determine the vertical extent of soil contamination if the depth of <br /> ground water is no more five feet below ground surface (bgs). If ground water is more than five feet <br /> bgs, the vertical extent of soil contamination needs to determined by collecting soil samples at a <br /> minimum of every five feet and at changes in lithology down to ground water. As I discussed with <br /> your consultant, Mr. Noel Lerner, a phased approach which includes collection and analysis of deeper <br /> samples if contaminants are detected in the initial shallow sample is acceptable. <br /> SCOPE OF WORK <br /> Task 3 - Soil Sampling <br /> The proposal for soil sampling within the existing ponds may not determine the vertical extent of soil <br /> contamination. All Pure proposes to sample only within the ponds at depths of two to three feet bgs. As <br /> stated above, soil samples need to be collected at a minimum of every five feet and at changes in <br /> lithology down to ground water. If the depth to ground water extends more than five feet below the <br /> bottoms of the ponds, deeper soil samples must be collected for analyses. The same phased approach to <br /> be used at the former small wastewater pond is acceptable for sampling the existing ponds. <br /> All Pure has not agreed to collect soil gas samples other than by field measurements with an organic <br /> vapor analyzer (OVA). The OVA does not differentiate between different volatile organic compounds <br /> (VOCs) and does not accurately quantify concentrations of VOCs in soil gas. Both are necessary to <br /> determine the potential threat to ground water quality and the cleanup goals. A minimum of one soil <br /> gas sample needs to be collected from the bottom of each of the four ponds to be closed and the <br /> former small wastewater pond. All Pure must submit, and obtain approval for, a proposal for soil gas <br /> sampling at least two weeks before sampling takes place. The proposal should include details of the <br /> sampling equipment, analytical methods, detection limits to be achieved, sampling locations, and <br /> other pertinent information. <br />