SITE INFORMATION AND CORRESPONDENCE

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Mr. Andrew Smith • - 2 - • 10 June 2004 PROJECT LOCATION AND DESCRIPTION The project is located at 15135 Eight Mile Road in an agricultural area next to Little Connection Slough in Stockton. The facility is an operating marina that provides petroleum products to customers along Little Connection Slough, which flows to the San Joaquin River. The point of discharge is an unnamed intermittent agricultural drainage ditch, which empties into an east-west trending island drainage canal. The canal is pumped up into the Little Connection Slough. The discharge location is between Assessor's Parcel Nos. 069-080-01 and 069-080-21at latitude N 37° 3' 37" and longitude W 121° 29' 57". The location map is included as Figure 1. Releases at the site have resulted in petroleum hydrocarbons in soil and groundwater. The most recent groundwater monitoring results show that the primary dissolved constituents include total petroleum hydrocarbons as gasoline [49,000 micrograms per liter(µg/1)], benzene (130 gg/1),toluene, (42 µg/1), ethylbenzene (I 10 µg/1), xylenes, (400 µg/1), methyl tertiary butyl ether(31,000 µg/1),tertiary butyl alcohol (820 µg/1), and tertiary amyl metyl ether (170 µg/1). In October 1991, five underground storage tanks were removed from the site (three with San Joaquin County oversight). One of the underground storage tanks had a hole in the bottom. Two investigations were conducted at the site to delineate the resulting pollution. Groundwater monitoring began at the site in 1997. Due to the presence of methyl tertiary butyl ether at the site and the location of the majority of the pollution near two aboveground storage tanks, Regional Board and San Joaquin County Environmental Health Department staff concluded a majority of the pollution was from the aboveground storage tanks. The highest concentrations are in monitoring well MW-2, which is east and downgradient of the aboveground storage tanks. The interim groundwater pump and treat remedial system will extract groundwater from the area with the highest petroleum hydrocarbon concentrations at about three gallons per minute and pipe it to a 750- gallon holding tank. From the holding tank, groundwater will be pumped through two 2,000-pound granular activated carbon(GAC) containers in series, then through a 2,000-pound container of SunSolve, and then through an additional 2,000-pound GAC container. Based on pollutant concentrations in groundwater at the site,breakthrough of the GAC and SunSolve is calculated to occur 133 days after initial startup. The treated water will then be piped to the agricultural drainage ditch. PUBLIC NOTIFICATION Pursuant to Section D of Attachment A of the General Order 5-00-119, the consultant for the Discharger published and sent a public notification letter to all recorded landowners within a 500-foot radius of the site and proposed discharge location. The letter was dated 25 March 2004 and requested written or verbal response within 14 days of the date of the letter. To date, neither Regional Board staff nor the Discharger's consultant have received a response. Certified mail receipts were received for the owners who were contacted. CONDITIONS OF APPLICABILITY The Discharger must submit a copy of the quarterly monitoring reports to Mr. Mike Negrete of the NPDES unit for his review. Mr. Negrete must receive a copy of all correspondence regarding the General Order. Reports required by the General Order must remain separate from other report submittals. The Discharger shall ensure that no groundwater, treated or untreated, is released over areas of rant tArl enil g�lg�tg.�. 1„ _ _f o . �re�t.. fhe._agrjsyl�y}i�] h, contain the treated water in a holding tank until results of the effluent sampling are received confirming