ARCHIVED REPORTS_XR0005235 - Laserfiche WebLink

Home Browse Search

HORIZON ENVIRONMENTAL INC. Specialists in Site Assessment,Remedial Testing,Design and Operation May 4, 2004 Mr. Joe Aldridge Ultramar Inc. 685 West Third Street MAl' 0 5 2004 Hanford, California 93230 ENVIRONMENT HEALTH PERMIT/SERVICES Subject: Quarterly Groundwater Monitoring Report First Quarter 2004 Former Beacon Station No. 12474 La 3440 East Main Street, Stockton, California Mr. Aldridge: Horizon Environmental Inc. (Horizon) has prepared this report which documents first quarter 2004 groundwater monitoring at the subject site located in San Joaquin County, as shown on Figure 1. There are currently 17 groundwater monitoring wells (MW-1 through MW-17), seven vapor extraction wells (VW-1 through VW-7), and one air-sparge well (AS-1) associated with this site. All of the wells are located on site, except for monitoring wells MW-4 and MW-5, which are located in the East Main Street and Broadway right-of- ways north of the site as shown on Figure 2. Monitoring wells MW-13 through MW-17 were installed in February 2004 but were not developed at the time of this quarterly monitoring event. Groundwater Monitoring Groundwater monitoring activities were conducted by Horizon on March 1, 2004 according to Horizon Field Methods and Procedures (Attachment A). Monitoring activities included measurement of static groundwater level, purging groundwater from the wells, collection of groundwater samples, and preparation and delivery of the samples to the analytical laboratory. The depth to groundwater was measured to the nearest 0.01 foot from the top-of-casing (TOC) in monitoring wells MW-1 through MW-12, vapor extraction wells VW-1 and VW- 4, and air-sparge well AS-1. Vapor extraction wells VW-2, VW-3 and VW-5 through VW-7 were dry. The physical parameters conductivity, pH and temperature were monitored with field instrumentation during the purging process. The visual characteristics of turbidity, the presence of free product or sheen, and the obvious olfactory characteristics of the groundwater were also noted during the purging process. Field groundwater monitoring well purge data were recorded on Horizon Monitoring Well Data sheets (Attachment B). Groundwater samples were collected from groundwater monitoring wells MW-I though MW-5, MW-7 though MW-12, VW-1 and VW-4. The samples were submitted under chain- 5011 Golden Foothill Parkway, Suite 7 • EI Dorado Hills, CA 95762 • (916) 939-2170 • FAX (916) 939-2172 P.O. Box 5283 * Bakersfield, CA 93388 • (661) 589-8389 • FAX (661) 589-1456