Laserfiche WebLink
& EMORANDUM <br /> CALIFORNIA REGIONAL WATER QUALITY CONTROLBOARD - CENTRAL VALLETREGION <br /> 3443 Routier Road,Suite Phone 916) 361-5600 <br /> Sacramento, CA 95827-3098 ATSS Phrne 8-495-5600. <br /> TO Antonia Vorsten' FROM. Richard McHenry <br /> Senior Engineer Area Engineer <br /> DATE: 8 March 1990 SIGNATURE: <br /> SUBJECT: LINCOLN VILLAGE PHASE II SAILING PLAN, STOCICTON SAN JGtApf/I/I L17UNTY <br /> (CASE #3002) <br /> A revised Phase II work plan for. site assessment at Lincoln Village Center. dated <br /> 13 February 1990 was reviewed for conformance with our 21 December 1989 Tetter.' My <br /> comments are as follows: <br /> 1. Monthly water level contour maps were not submitted. Ground water elevation data <br /> was submitted which appears to agree with a general ground water northeast <br /> direction of flow, however, contour maps should be developed. The piaceoent and <br /> screening of the proposed monitoring wells should be supported by tF s data. <br /> 2. Laboratory data sheets and chain-of-custody forms should be submit'ted as an <br /> appendage to all reports. Water samples shall be analyzed for EPA 601 compounds. <br /> Page 6 of the work plan states that all samples will be analyzed for PCE only. <br /> 3. The rationale for placement and screening of the proposed monitoring wells, <br /> shallow and deep, were not submitted with the work plan. San Joaquin County has <br /> a standard requirement for a *foot sanitary seal on wells and a minimum distance <br /> requirements from sewer lines which could adversely effect proper site assessment. <br /> 4. The monitoring well installation technique appears adequate, 2 wells are hollow <br /> stem continuous core, 5 wells are hollow stem with split spoon samplirg at 5 foot <br /> intervals. <br /> 5. Evaluation of LVMD Well Nos. 1, 2 and 6 have not been fully addressed- Two deep <br /> (150 ft. ) wells are proposed to determine pollution levels in the deeps- aquifer. <br /> It must be determined if the LVMD wells are a conduit for pollution to the deeper <br /> aquifer, also, these wells should be pumped to determine the relationmip of the <br /> shallow and deeper aquifers. If the LVMD wells are the source of deeler aquifer <br /> pollution, either by inadequate well structure or pumping rates causira downward <br /> migration, remedial action must be taken. A schedule for regularmortoring of <br /> the LVMD wells for EPA 601 compounds should be developed unless it is shown that <br /> these wells are the cause of pollution within the deeper aquifer. <br /> FILE <br />