ARCHIVED REPORTS XR0003073 - Laserfiche WebLink

Home Browse Search

Chevron Products Company 9 Former Chevron Service Stanon 95775, 301 West Kettleman Cane, Lodt, California March 30, 2000 • AQUIFER PARAMETER ANALYSIS AND RESULTS • Aquifer Parameter Analysis The computer program AgtesolvTM was used to assist with the aquifer parameter analysis This program combines statistical parameter estimation methods with interactive curve - matching capabilities Based on the available lithology, drawdown data from the constant - rate pumping test were analyzed using the Theis unconfined curve -matching method (Theis, 1935) Results of the parameter analysts for the constant rate pumping tests are summarized in Table 2 Also, the AgtesolvTM analysis was performed using the assumption that the pumping wells were partially penetrating, and the saturated thickness of the aquifer was 445 feet The saturated thickness of the aquifer is based on Well 12 construction details provided by the city of Lodi Effects of pumping from Well 12 are also evaluated by performing AgtesolvTM analysis with and without accounting for operation of the Well 12 during the pump test A brief discussion of the results from the constant -rate pumping test is presented in the following sections Test Results Pumping Test During the constant -rate pumping test, significant drawdown effects were observed in shallow screened observation wells MW -1 and MW-14/EX-2, and MW -5A All these wells are located within 60 feet of extraction well EX -3 However, no appreciable drawdown was observed in either of the deeper screened observation wells MW -5B and MW -8B, which are located approximately 42 and 177 feet, respectively, from the extraction well EX -3 Furthermore, no appreciable drawdown was observed in the shallow screened observation well MW -8A, located approximately 171 feet from extraction well EX -3 Any changes in water levels in well MW -8A could be attributed to changes in barometric pressure Drawdown observed in well MW -8B could be attributed to pumping from Well 12 During the constant -rate pumping test, the water level in pumping well EX -3 decreased approximately 8 50 feet in response to pumping The water levels in observation wells MW - 1, MW-14/EX-2, and MW -5A (located 6, 51, and 57 feet, respectively from EX -3) decreased by approximately 0 82, 0 24, and 0 40 feet, respectively Aquifer parameter analysis was conducted on drawdown using the Theis unconfined curve - matching method Estimates of T and S for the aquifer are summarized on Table 2 Based on results of the Theis solution, both corrections for barometric pressure and pumping from the Well 12 affected results of the analysis Transmissivity and storativity values ranged from 1Chevron1957751Aqutfer testlRevtsed195775Aqutfertestrevtsed doe