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Cleanup and Abatement Order R5-2008-0714 Forward Landfill San Joaquin County from the entrance to Austin Road Landfill. There are also two residences on Lynch Road, approximately 0.5 miles southeast of the site. 4. The Austin Road Landfill was filled by the City of Stockton using the trench method. Trenches were excavated to an approximate depth of 20 feet below ground surface. There is no liner or leachate collection and removal system in the trenches to prevent the downward migration of landfill leachate or gas from the unit to the underlying groundwater. 5. The landfill is on the floor of the northern San Joaquin Valley. Surface drainage is toward the west to Littlejohns Creek in the Duck-Littlejohns Hydrologic Area (31.40) of the San Joaquin River Basin. 6. The Water Quality Control Plan, Fourth Edition, for the Sacramento River Basin and the San Joaquin River Basin (hereafter Basin Plan), designates beneficial uses, establishes water quality objectives, and contains implementation plans and policies for all waters of the Basin. The designated beneficial uses of Littlejohns Creek, as specified in the Basin Plan, are agricultural supply, industrial service and process AML supply water, contact and non -contact water, recreation, warm fresh water habitat, oppreservation of rare, threatened and endangered species, and groundwater recharge. 7. The direction of groundwater flow is to the north-northeast. The measured hydraulic conductivity of the uppermost aquifer underlying the landfill ranges between 2 x 10-2 and 2 x 10-3 cm/sec. The groundwater gradients, based on the Discharger's fourth quarter 2007 groundwater monitoring report measurements, range from 0.0010 to 0.0020 ft/ft. The average groundwater velocity is 195 feet per year (Order No. R5- 2003-0049, Finding 26 at p. 6). 8. The first encountered groundwater is about 60 to 80 feet below the native ground surface. Groundwater elevations range from -20 feet mean sea level (MSL) to -30 feet MSL. The groundwater is unconfined. The depth to groundwater fluctuates seasonally by as much as 10 feet. 9. There are an estimated 35 domestic, industrial, or agricultural groundwater supply wells within one mile of the site. 10. The designated beneficial uses of the groundwater, as specified in the Basin Plan, are domestic and municipal supply, agricultural supply, industrial service supply, and industrial process supply. 11