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Domestic Well Sampling Program Results Forward Landfill 1.0 INTRODUCTION On behalf of Forward Incorporated (Forward), this report presents the results from the domestic well sampling program as required by Condition 1(b) of Cleanup and Abatement Order (CAO) R5-2017-0703. Groundwater samples were collected from fifty-six (56) residences located in the vicinity of the Forward Landfill in accordance with the Domestic Well Sampling and Analysis Plan (dated June 13, 2017). The purpose of the sampling program was to identify those off-site wells that may have been impacted by volatile organic compounds (VOCs) associated with plume migration from the Forward Landfill. As shown on figure 1,the sampling program encompasses those wells identified within the area bounded by Highway 99 on the west, South Jack Tone Road to the east, 2500 feet north of Arch Road, and south to the south Fork of South Little John's Creek. The results from this initial sampling will provide a database of impacted wells to be included in a semiannual monitoring program, and identify those domestic wells where VOCs are measured that may be related to chlorinated hydrocarbons associated with the landfill. 1.1 Site Description The Forward Landfill is located at 9999 South Austin Road in Manteca, California (Figure 1). The current Forward Landfill is owned by Forward, Inc. and is a combination of the Forward Landfill (Forward Unit) and the Austin Road Unit (ARU). The combined site currently encompasses 567 acres, of which approximately 388 acres have been landfilled. The landfill property is located between two relatively minor drainages. The area surrounding the landfill is primarily used for agriculture although there are some nearby residences and the California Department of Corrections and Rehabilitation Facility (CDCRF), formerly the Northern California Youth Center, is situated along the northern border of the landfill (Figure 1). The CDCRF is a 77-acre, intermediate, medical and mental health care facility for inmate-patients of the California Department of Corrections and Rehabilitation prison system. 1.2 Groundwater Contamination Occurrence The San Joaquin Hydrologic Basin, including the area surrounding the landfill, is a major regional aquifer system and groundwater in the basin is used for industrial, domestic, and agricultural purposes. The first encountered groundwater in the area ranges from about 60 to 80 feet below the ground surface with water fluctuating by as much as 15 feet between wet and dry seasons. Additional productive groundwater occurs within deeper discontinuous coarser sand and gravel zones. Agricultural and water supply wells are typically constructed to depths on the order of 300 feet or more. Groundwater at the Forward Landfill is monitored by a series of groundwater monitoring wells, domestic wells, and piezometers (Figure 2). Quarterly groundwater monitoring data for the landfill indicate groundwater in the uppermost zone flows to the north-northeast at a hydraulic Project S017.1030 I Domestic Well Sampling Program Results.docx 1 November 2017