ARCHIVED REPORTS_XR0002282 - Laserfiche WebLink

Home Browse Search

V , March 19, 1992 - Hm-ding Lawson Associates �. 19060, 025 . 03 Mr. Bud Good The Southland Corporation Page 2 +� In March 1989, the underground tanks and fuel dispensing facilities were removed from the site. During these activities MW-A and MW-7 (formerly MW-B) , near the tank backfill, were .. destroyed. The remaining 14 HLA wells were left intact. GROUNDWATER SAMPLING On December 301 1991, HLA collected groundwater samples from all 14 monitoring wells. Before sampling, we purged at least three +• casing volumes from each well while monitoring temperature, pH, and conductivity. After those parameters stabilized, groundwater samples were collected with a clean stainless steel .. bailer, and decanted directly into laboratory-prepared volatile organic analysis (VOA) vials and sterilized fecal coliform sample containers. The samples were labeled and placed into an ice-chilled cooler for transportation, under chain-of-custody, to a state-certified chemical testing laboratory. Between wells, all purging and sampling equipment was cleaned with an Alconox solution and rinsed with deionized water. CHEMICAL TESTING Samples were sent to Superior Analytical Laboratories in Martinez, California, and analyzed for total petroleum hydrocarbons (TPH) as gasoline, using EPA Test Method 8015; and for benzene, toluene, ethylbenzene, and xylenes (BTEX) , using EPA Test Method 8020. Samples for fecal coliform were submitted to BC Analytical in Emeryville, California. The results of - chemical analyses are presented in Table 1, along with groundwater data from preceding phases of site investigation and characterization. Laboratory data sheets and chain of custody are included in the Appendix. GROUNDWATER GRADIENT Water level measurements were obtained using a chalked steel tape accurate to 0. 01 feet. Well survey and water level data are presented in Table 2 . The water levels in each of the wells have declined relative to previous periodic measurements. Our V