Laserfiche WebLink
d _ .� t} .s _ : meg _ <br /> e_ ', ° . IV • rt ". - s rg� yam- <br /> Mr. Kyle Christie <br /> Jul; 16, 1990 <br /> Page 3 <br /> Region, in May 1989 ARCO began monthly sampling and analysis of groundwater from the <br /> deeper monitoring well (W-213) for BETX. Groundwater samples from monitoring wells W-2, <br /> W-2A,W-213,W-3,W-4,W-5,W-6,and W-7 were collected for analyses on January 19 and 22, <br /> 1990. Monitoring W-1 was not sampled due to lack of water in the well. Monitoring well W-8 <br /> was not sampled as dissolved hydrocarbons have never been identified in groundwater samples <br /> from monitoring well W-8, and it is located some distance from any identified dissolved <br /> hydrocarbon occurrence. <br /> ]FIELD METHODS <br /> November and December 1989 Sampling of Monitoring Well W-2B <br /> For the months of November and December 1989, groundwater samples were collected for <br /> analyses from well W-2B. <br /> IPrior to purging well W-213,water-level measurements were taken. In November and December <br /> f 1989, depth to groundwater was 59.09 feet and 58.32 feet,respectively, below ground surface. <br /> Groundwater was purged from well W-2$ by Armour Petroleum Inc. (Armour) of Fairfield, <br /> �! California. Approximately three well volumes of groundwater (one well volume being the <br /> volume of water inside the casing plus 35 percent of the gravel packed annular space) were <br /> 1 evacuated. While purging well W-213, the pH and specific conductivity of the discharge water <br /> were monitored and recorded in the field notebook. The well was sampled with a teflon bailer <br /> equipped with a bottom-emptying valve. The sample was drained directly from the bottom valve <br /> into two 40-milliliter glass bottles with teflon-lined septums. The samples were stored on ice <br /> z from the time of collection through delivery to Eureka Laboratories, Inc., in Sacramento. All <br /> purging and sampling equipment was washed with laboratory-grade detergent and tap water,then <br /> r-.-ns--d with deionized water before each use. <br /> Dissolved BETX concentrations in groundwater samples collected from April 1987 through <br /> a January 1990 are summarized in Table 1. Complete Iaboratory reports of the November and <br /> December 1989 groundwater sample analyses of well W-213are enclosed as Exhibit A. Toluene <br /> [at a concentration of 0.8 parts per billion (ppb)] in November 1989 was the only BETX <br /> constituent detected in well W-2B during this 2-month period <br /> January 1990 Quarterly Sampling <br /> i <br /> In January 1990,_grou-ndwater samples were collected from monitorin wells W-2,W-2A,W-2B, T -- <br /> g <br /> 4 W-3, W-4, W-5,Wpb, and W-7. Monitoring W-1 was not sampled due to lack of water in the T TT <br /> well. Monitoring well W-8 was not sampled as dissolved t,;drocarbons have never been <br /> identified in groundwater samples from monitoring well W-8, and •. is located some distance <br /> from any identified dissolved hydrocarbon occurrence. <br /> Brown and Caldwell <br /> Consuuants <br /> mom <br /> 0 <br />