Laserfiche WebLink
PUBLIC HtALTH SERVICES <br /> SAN JOAQUIN COUNTY Z. <br /> c: Za <br /> ENVIRONMENTAL HEALTH DIVISION ". <br /> Karen Furst, M.D., M.P.H., Health Officer <br /> 304 East Weber Avenue, Third Floor • Stockton, CA 95202 `'FORS <br /> 209/468-3420 <br /> TINA MAYHEW FILE COPY <br /> WEST CLAY PROPERTIES <br /> PO BOX 6152 OCT 13 1999 <br /> STOCKTON CA 95206 <br /> RE: West Clay Properties Site Code: 1065 <br /> 639 West Clay Street <br /> Stockton, California <br /> This letter chronicles the changes made to the Work Plan Addendum -May 1999 and <br /> Work Plan Addendum - September 1999 prepared by Advanced Geo-Environmental, <br /> Inc. (AGE) between October 5 and October 8, 1999, due to information obtained <br /> during implementation of the work plan. <br /> A soil boring (B-9) was advanced at the north end of the former underground storage <br /> tank (UST) cluster at the above referenced site on October 5, 1999. Groundwater <br /> appeared to have been impacted based on field observation (odor) and photo-ionization <br /> detector (PID) results. San Joaquin County Public Health Services, Environmental <br /> Health Division (PHS/EHD) and AGE agreed that the second proposed soil boring, <br /> north of B-9, should be converted to a monitoring well in order to assess the level of <br /> contamination in the groundwater. PHS/EHD, AGE, and the C-57 licensed <br /> contractor agreed to install the monitoring well the week of October 19, 1999. <br /> Based on field observations and PID results, contamination appeared to exist in both <br /> the soil and groundwater samples taken from B-10 and B-11 in the former UST over- <br /> excavation area, beneath 60 feet below surface grade (bsg). PHS/EHD recommended <br /> both B-10 and B-11 be advanced below the proposed 60 feet bsg and until the vertical <br /> extent of the contamination was defined. Due to a highly porous sand layer discovered <br /> between approximately 70 feet bsg and 90 feet bsg at the area, PHS/EHD further <br /> recommended a soil sample be taken from B-12 and B-13 at about 80 feet bsg in order <br /> to assess the lateral limit of the contamination. Due to time constraints, two of the soil <br /> borings proposed in the work plan were not drilled. PHS/EHD, AGE, and the <br /> contractor agreed that these two soil borings would be completed the week of October <br /> 19, 1999. <br /> Based on field observations, the area of the former over-excavation appears to contain <br /> many different stratas of sand. In a discussion with AGE staff, PHS/EHD <br /> recommended that soil physical characteristics be analyzed to evaluate the feasibility <br /> A Division of San Joaquin County Health Care Services <br />