Laserfiche WebLink
3 \ameVr GEORGE DEUKMEJIAN,Governor <br /> 'VTA?E 0OWLIFORNIA <br /> CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD— <br /> CENTRAL VALLEY REGION <br /> 3443 ROUTIER ROAD <br /> SACRAMENTO,CA 95827-3098 <br /> 17 April 1989 <br /> Mr. D. M. Noe ' <br /> Mobil Oil Corporation <br /> 3800 West Alamenda Avenue, Suite 700 R 11989 <br /> Burbank, CA 91505 µ <br /> PROPOSED WORK PLAN FOR MOBIL BULK PLANT, 500 EAST GRANS <br /> SAN JOAQUIN COUNTY <br /> Thank you for submitting the 22 February 1989 work plan for investigation work <br /> at your site for our review. We have reviewed the work plan and case file, <br /> and have the following comments: <br /> 1 . The proposed work is limited in extent, since it does not address the <br /> need to further define the extent of soil contamination. Total <br /> petroleum hydrocarbon (TPH) as diesel was reported at levels as high as <br /> 2,900 ppm in soil samples from borings drilled on 21 November 1988 along <br /> the northern portion of the site. The work proposed in this work plan <br /> will not adequately define the extent of soil contamination at this <br /> site. <br /> 2. The plan does not propose the installation of a downgradient monitoring <br /> well within ten feet of the tank pit area. If no hydrocarbons are <br /> detected in the four proposed monitoring wells, you will be required to <br /> have a monitoring well installed at this location in order to show that <br /> ground water has not been impacted at this site. <br /> 3. Kaprealian Engineering, Inc. (KEI) needs to supply more details on their <br /> well purging procedures. The proposed work plan states that <br /> approximately four casing volumes of water will be purged from each well <br /> prior to sampling. We recommend, if a well yields sufficient quantities <br /> of water, that the following well parameters, EC, pH, and temperature, <br /> be monitored and allowed to stabilized prior to sampling. At a minimum, <br /> EC, pH, and temperature should be measured as every 2.5 gallons of water <br /> (approximately one casing volume) are purged from the proposed 2-inch <br /> diameter wells. Once the parameters have stabilized (relatively <br /> unchanged for three consecutive readings) ground water samples should be <br /> collected. If a well goes dry during purging, the time of recovery <br /> prior to collecting the water sample is to be recorded, as well as the <br /> water level at the time the sample is collected. This information is to <br /> be reported in the technical report. <br /> 4. We request that water samples be collected from monitoring wells E-1, <br /> E-2 and E-3 (referred to in the 8 September 1986 Report on Remedial <br /> Action) if they still exist, to be analyzed for BTX&E, TPH as gasoline <br /> and diesel , ECB, and ECD, when the proposed work is conducted at this <br /> site. Water level measurements are also to be made at this time. <br /> These issues are to be addressed in a revised work plan and submitted to us <br /> and the San Joaquin Local Health District (SJLHD) by 8 May 1989. <br />