ARCHIVED REPORTS_NOTICE OF INTENT FOR INSTALLATION, OPERATION AND MAINTENANCE OF AN OZONE INJECTION GROUNDWATER REMEDIATION SYSTEM

Home Browse Search

' AIR-SPARGE AND OZONE-SPARGE PILOT TEST REPORT ' 1.0 BACKGROUND 1.1 Site Information ' The Site consists of a vacant, irregularly shaped parcel, located in downtown Stockton. A former remediation compound is located in the central portion of the Site. The perimeter of the Site is enclosed by chain link fence. The Site location is depicted on the Vicinity Map, Figure 1. The Site is bounded to the west by North American Street as well as private residences, to the north by East ' Lindsay Street, to the east by commercial businesses including A-One Auto Repair and Stockton Clutch and Brake, and to the south by East Miner Avenue. The general layout of the Site and associated monitoring wells are depicted on the Site Plan,Figure 2. ' hi March 1992, a soil and groundwater investigation conducted at the Site by Earth Systems ' Environmental, Inc. (ESE) included the installation of groundwater monitoring wells MW-1 through MW-3. Gasoline-impacted soil and groundwater were reported in each of the borings, and free-product ' was observed in each of the three groundwater monitoring wells. hi May 1993, ESE removed three underground storage tanks (USTs) (two 10,000-gallon unleaded ' gasoline and one 5,000-gallon leaded gasoline) from the Site. The USTs and associated piping were reported to be in good condition with the exception of the northernmost UST (10,000-gallon unleaded ' gasoline), which contained a 7/8-inch hole in its bottom. The property owner estimated that approximately 3,200 gallons of gasoline had been released from the UST. ' Several phases of subsurface investigations have been performed at the Site since 1993 resulting in the installation of groundwater monitoring wells MW-1 through MW-13, soil vapor extraction (SVE) ' wells SVE-1 through SVE-12 and VX-1, air-sparge (AS) wells AS-1 through AS-5, removal of free- product, and installation and operation of a SVE and AS system. Approximately 32 gallons of free- product was reported to have been removed during free-product recovery, and free-product has not been reported at the Site since 1994 (MW-2). The onsite SVE/AS system operated from August 3, 2001, through October 13, 2005. Shaw Environmental, Inc. estimated that approximately 333 pounds of ' gasoline and 3 pounds of benzene were removed by the onsite SVE system. The approximate locations of the Site SVE and AS wells are shown on Figure 3. The site investigations have resulted in definition ' of the lateral and vertical extent of the gasoline impacts, with the greatest dissolved total petroleum hydrocarbons as gasoline (TPHg) groundwater impacts (>1,000 micrograms per liter [µg/1]) in the vicinity of the former USTs (wells MW-1, MW-3 and GWX-1). Historical groundwater elevation and ' analytical data are presented in Table 1 and Table 2. Project No.59183-06-02 - 1 - July 2,2009 1