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2.7.3 LOCAL WELLS Wells within one mile of the project site are used primarily to supply water for agricultural and domestic purposes. Of the facilities in the surrounding area, the detention and correctional facilities north of the FL both have wells that are used to supply domestic water. The water used for dust control, compaction, and irrigation on FL is primarily supplied by a well at the entrance. The well was drilled to a depth of approximately 135 feet and groundwater occurs at a depth of approximately 70 feet. The well was likely installed before the opening of the landfill, having been previously used for agricultural purposes. It is pumped at a rate of approximately 1,500 gallons per minute at a maximum frequency of approximately eight times per hour. Forward drilled a water supply well in the northwest corner of the site to irrigate plants used to establish the riparian habitat created adjacent to the realigned North Creek. There are additional wells present on the Brochini property, which are currently used for irrigation. All water supply wells are shown on Figure A. Information on ownership and use of these wells is also presented in the JTD. Well information presented was obtained from well log files from the Department of Water Resources in Sacramento, California. 2.7.4 GROUNDWATER FLOW DIRECTION AND GRADIENT The groundwater surface and gradient are measured at the FL in a network of groundwater monitoring wells. The monitoring network for the Forward Unit of the FL currently includes 19 groundwater monitoring wells The monitoring network for the Austin Unit currently includes 14 groundwater monitoring wells and two domestic wells. The location of the wells and other monitoring points at the Forward Landfill are depicted on Figure B. Data from on-site monitoring wells indicates that the groundwater flow direction is generally to the north at gradients ranging from 0.001 to 0.005 ft/ft. 2.7.5 HYDRAULIC CONDUCTIVITY AND GROUNDWATER VELOCITY ESTIMATES To assess the insitu hydraulic conductivity of the uppermost aquifer underlying the ® Forward Unit of the FL, slug tests were performed in four wells during 1991 by Kleinfelder as part of the RCRA Facility Investigation for the closed Class I area. Forward Landfill-Project Description 2-11 BRYAN A.STIRRAT A ASSOCIATES J:\Allied\Forward\2007.0018 Lateral Expansion\Reports\Prof Descrip\021308 Final Proj Des\Sec 2.doc:2/13/2008)