Laserfiche WebLink
S Kiggo're�ioad,Suite 100 <br /> INTERNATIONAL Rancho Cordova,CA 95670 <br /> S E C O R INCORPORATED 916-861-0400 TEL <br /> 916-861-0430 FAX <br /> December 9, 2002. u MED <br /> DEC 1 1 2002 <br /> Ms. Margaret Lagorio ENVIRONMENT HEALTH <br /> San Joaquin County Public Health Services PERMIT/SERVICES <br /> Environmental Health Division <br /> 304 East Weber Avenue, Third Floor <br /> Stockton, California 95202 <br /> RE: Work Plan for Well Destruction and UST Removal <br /> Chevron Service Station 9-0557 <br /> 139 South Center Street <br /> Stockton, California <br /> SECOR Project No.: 77.CH.90557.01 <br /> Dear Ms. Lagorio: <br /> SECOR International Incorporated (SECOR), on behalf of Chevron Environmental Management <br /> Company (Chevron), has prepared this work plan for the destruction of all onsite groundwater <br /> monitoring wells and ozone sparge wells at the above-referenced site (Figure 1). Chevron Products <br /> Company has scheduled demolition of the station beginning in January 2003, including removal of <br /> existing underground storage tank (UST) facilities, piping, and fuel dispensers (Figure 2). There are <br /> nine onsite groundwater monitoring wells (MW-1, MW-2, MW-4, MW-9, MW-9A, MW-9S, and MW-10 <br /> through MW-12) and four onsite ozone sparge well pairs (OS-1 S/1 D, OS-2S/2D, OS-3S/3D, and 0S- <br /> 4S/4D) located at the site. Due to limited space on the site and the extent of station abandonment <br /> activities, the possibility of jeopardizing the integrity of the onsite wells exists. Therefore, SECOR. <br /> proposes to properly destroy the groundwater monitoring and ozone sparge wells before site <br /> demolition occurs. <br /> PROPOSED SCOPE OF WORK <br /> Well Destruction <br /> Nine groundwater monitoring wells and four ozone sparge well pairs will be destroyed in accordance <br /> with San Joaquin County requirements and with Bulletin 74-90: California Well Standards, California <br /> Department of Water Resources, June 1991. The wells will be destroyed by drilling out and <br /> removing all material within the original borehole including the well casing, screen, filter pack, and <br /> annular seal to the total depth of the well or well pair. The boreholes will then be pressure grouted <br /> using a tremie pipe and appropriate sealing material from the bottom of the borehole to surface. The <br /> wells will then be completed to grade with a material matching the existing surface. <br /> UST Removal and Sampling Activities <br /> SECOR will oversee the removal of the USTs, fuel piping, and fuel dispensers, including the <br /> collection of all required soil and groundwater samples in accordance with the California Regional <br /> Water Quality Control Board's Tri-Regional Board Staff Recommendations for Preliminary <br /> Investigation and Evaluation of Underground Tank Sites, dated August 10, 1990. In addition to the <br /> removal of all underground fuel facilities, SECOR will direct the excavation contractor to remove <br /> observed significantly impacted soil to the extent practicable. SECOR will collect sidewall and <br /> bottom soil samples from the final excavation area in order to define the remaining impacts, if any, at <br /> the site. Field and laboratory procedures for the proposed activities are presented in Attachment 1. <br /> I:\Chevron\90557\REP0RTS\We11 destruction wp 2002.doc <br />