ARCHIVED REPORTS_XR0012740 - Laserfiche WebLink

Home Browse Search

`a �_ sicer;vii a ' _ p ��1 h A v r 0 1 r 111r. Kyle Chri;,tic September 13, 1989 Page 4 Field Melhods--May and June 1989 Prior to sampic collection, groundwater was purged from well W-213 by bailing with a stainless steel bailer. The pH and specific conductance of the discharge water were monitored. Approximately three well volumes of groundwater(one well volume being the volume of water inside the well casing plus 35 percent of the gravel packed annular space) were evacuated. The well was sampled with 'a Teflon bailer equipped with a bottom-emptying valve. The sample was drained directly from the bottom valve into two 40-milliliter glass bottles with 'reflon-lined septums. The samples were stored on ice from the time of collection through delivery to Eureka Laboratories, Inc., in Sacramento. All purging and sampling equipment was washed with laboratory-grade detergent and tap water, then rinsed with deionizcd water before each use. IN Field and Analytical Results--May and June 1989 Groundwater levels were measured at approximately 49 feet below ground surface in April 1987, when the first three monitoring wells were installed. Water level measurements show that groundwater levels beneath the site rise somewhat;n the winter months but are declining overall. Depth to groundwater was approximately 55 feet in May 1989, and approximately i 57 feet in June 1989. In May 1989, groundwater flow direction was to the south-southwest. a In early June, groundwater flow direction was to the southwest-west. In mid-June, groundwater flow was to the west. This westerly shift in groundwater flow direction has been observed each summer/early fall since 1987. Dissolved BETX concentrations in groundwater.samples collected from April 1987 through E July 1989 are summarized in Table 1. Complete laboratory reports of the May and June 1989 groundwater sample analyses of well W-213 are enclosed as Exhibit A. BETX were not detected in groundwater in monitoring well W-21; in May 1989. In June 1989, xylene[ar a 1 concentration of 0.9 parts per billion (ppb)] was the only BETX constituent detected in well J W-2B. Monitoring well W-2B is tate deepest monitoring well on site and is accessible to groundwater in the 74- to 88-foot depth interval (see Figure 2). .� Field Methods--July 1989 Prior to sample collection, groundwater was purged by pumping from each monitoring well by Armour Petroleum, Inc., of Fairfield, California. The pH and specific conductance of the E discharged water were monitored. Three well volumes of groundwater were evacuated from monitoring wells W-2, W-2131, W-3, W-4, W-5, W-6, and W-7. The groundwater level in k: April 1989 (see Figure 2) made purging difficult in monitoring wells W-1 and W-2A. Due to slow recharge of groundwater into monitoring well W-I and W-2A, 0.18 and 1.1 well volumes, respectively, were evacuated from these wells. Sample collection, storage, and transportation. procedures, as well as sampleequipment a decontamination procedums, were the same as those used in May and June 1989. All groundwater produced during purging and sampling was disposed of by Armour Petroleum, Inc: BROWN AND CALDWELL 723SSTREET SALRAMENTQCAIIFORNIA95814-?GW-(9161444-0e23 - -