Laserfiche WebLink
419 Main St., Manteca <br /> Page 2 <br /> in the area of the three.10,000 gallon underground storage tanks (UST) adjacent to the <br /> dispenser, as well as other on-site sources (if any) must first be performed. <br /> The work which took place on October 5, 1998 failed to follow the "Underground <br /> Storage Tank Preliminary Investigation Work Plan" dated May 22, 1998 prepared by <br /> WHF, Inc., which expressively called for advancing the borings to a depth of 30.0 feet <br /> bgl. The WHF field consultant and the driller (Fisch Environmental) at the site failed <br /> to follow the verbal recommendation of PHS/EHD staff on site to continue to <br /> advance the borings to beyond 30 feet bgl to obtain vertical delineation with at least <br /> two consecutive 5-foot intervals of clean soil based on photo-ionization detector-(PID) <br /> readings and field observations. The PID reading of SB-1 at 1446 feet bgl was 9.1 ppm. <br /> The WHF field consultant and the driller also failed to comply with the San Joaquin <br /> County Well Standards Section 13.12.6 which states cement-bentonite grout shall not <br /> contain more than 3 to 5.% bentonite. After discussion with the WHF consultant, it <br /> was decided that 10% or more bentonite was used in the grout mixture. This is also in <br /> contrast to the work plan which called for 3% bentonite in the cement-bentonite mix. <br /> Submit a work plan to PHS/EHD by February 20, 1999 that will investigate site <br /> sources of contamination and delineate the vertical and horizontal extent of the <br /> contamination. This includes soil sampling below groundwater. <br /> Donna Heran, REHS, Director <br /> Environmental Health Division <br /> Jeffrey Wong , REHS Margare�'Lagorio, REHS <br /> LOP/Site Mitigation Unit IV Supervisor <br /> c: RWQCB, Central Valley Region-Mark List <br /> C: WHF, Inc. -Bill Fox <br /> c: Fisch Environmental -David Fisch <br />