ARCHIVED REPORTS XR0004147 - Laserfiche WebLink

Home Browse Search

e � til 3330 Data Drive Delta Suite 100 IR& Cofl Cordova,CA 95670 En��ronmental 9161636/63 8 2085 nsultants,Inc. FAX 9161638 8385 February 18, 1992 yf a. 7—d w FEB 2 7 1992 ENVIRQNMLN;AL Hr_ Al TH Mr Kenneth Earnest PERMIT/SE��VICES Ultramar Inc. 525 West Third Street Hanford, California 93230 Subject Quarterly Monitoring Letter Report, Fourth Quarter 1991 Beacon Station No 696 2448 West Kettleman Lane, Lodi, California Delta Project No 40-90-839 Dear Mr. Earnest Delta Environmental Consultants, Inc (Delta), has been authorized by Ultramar Inc (Ultramar), to conduct quarterly ground water monitoring at Beacon Station No 696 located at 2448 West Kettleman Lane, Lodi, California The location of the site is shown in Figure 1. This letter report contains results of the most recent quarterly ground water monitoring performed at the site Ground water levels were measured and ground water samples were collected for analysis on December 30, 1991 Work conducted at the site by Delta was performed in accordance with the field methods and procedures described in Enclosure A A total of 24 monitoring wells are present at and adjacent to the site as shown in Figure 2 Twenty of these monitoring wells are currently dry and four wells contain measurable ground water Ground water level data collected from monitoring wells MW-20, MW-34, MW-35, and MW-36, on December 30, 1991, are presented in Table 1 with ground water level data collected since February 1991 Ground water was present at the site between approximately 52 and 53 feet below the surface on December 30, 1991, and has risen approximately 1 foot since the previous quarterly monitoring event in September 1991 A ground water elevation contour map constructed from the ground water levels measured on December 30, 1991, is shown in Figure 3 The apparent ground water flow direction across the site was toward the northwest Previous ground water level data collected in February, April, and June 1991 indicated the ground water flow direction at the site was toward the south Ground water level measurements recorded during the previous quarterly sampling event in September 1991 indicated that the ground water flow direction at the site was toward the southeast A soil vapor recovery system has been in operation at the site since August 1991 Because the inferred ground water flow direction is based on measurements of depth to the ground water surface, the apparent shifts in the ground water flow direction may be caused by the soil vapor recovery system The system applies a vacuum to vadose wells MW-2, MW-5, MW-7, MW-10, MW-19, MW-20, and MW-28, and monitoring wells MW-34 and MW-35 Variations in the vacuum applied to the wells, or temporary system shut-downs, could cause slight fluctuations in the ground water levels of some monitoring wells Because of the relatively low hydraulic gradient at the site, minor fluctuations of ground water levels could cause the apparent shifts in the ground water flow direction It is anticipated that the actual ground water flow direction is toward the south as determined by previous monitoring events Delta Delivers Solutions