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FR-0H U H 0 CAL CERT-NUF T 05. 73. 19 il : i3 P. 2 <br /> ecology and environment, inc. <br /> 180 SPEAR STREET, SAN FRANCISCO, CALIFORNIA 84106, TEL, 415/777-2811 <br /> Intematbnai Spaclalhta In the Emylronment <br /> MEMORANDUM <br /> TO: Carolyn Douglas, U.S. EPA, SAM �y _ <br /> FROMI Paul Cort, Ecology and Environment, Inc. C <br /> DAM February 23, 1993 <br /> SUBJECT: Brea Agricultural Services #2 <br /> cc: Jim James, Ecology and Environment, Inc. <br /> Central File <br /> Ecology and Environment, Inc. .(E & E) has completed review of the <br /> Work Plan for Soil and Groundwater Invests ation (January 22, 1993) <br /> prepare by Condor EarthTechno ogles, Inc. (Condor) , for the <br /> PureGro/Brea facility in Stockton, California. The Work Plan was <br /> prepared in response to a request by the Central Valley Regional water <br /> Quality Control Board to investigate the source of 1,2-dichloropropane <br /> and nitrogen in the soils and groundwater at the site. The investigation <br /> at the PureGro/Brea facility is being overseen by Unocal. <br /> The purpose of E & E's review was to determine whether the Work Plan <br /> will meet EPA's objectives and to suggest possible changes to the Work <br /> Plan to facilitate a coordinated sampling effort between Unocal and EPA. <br /> To the extent that changes cannot be made to the Work Plan, separate <br /> sampling may need to be done to meet EPA needs. <br /> The current Work Plan includes installing three monitoring wells at <br /> the PureGro/Brea facility. During drilling of the boreholes, soil <br /> samples will be collected at 5-foot intervals using a split-spoon sampler <br /> fitted with three 6-inch-long brass liners. Condor will dispose the <br /> first (uppermost) liner, use the second for geological logging, and send <br /> the third to a laboratory for analysis. After the monitoring wells have <br /> been developed, Condor will collect groundwater samples for analysis and <br /> periodically measure groundwater depths to estimate the local groundwater <br /> gradient. <br /> E & E proposes the following modifications to the work Plan to <br /> achieve EPA's objectives: (1) move the proposed locations of the <br /> monitoring wells to target areas of known or suspected contamination and <br /> incorporate more of the facility and (2) provide EPA with two 3-inch <br /> brass liners of soil collected at 5-foot intervals. These changes are <br /> discussed in more detail below. E & E also proposes that EPA be allowed <br /> pc/brea2/memo <br /> rBC yCl1d p/n Bf <br />