Laserfiche WebLink
1 <br /> ATTACHMENT 1: <br /> ASSESSMENT ACTIVITIES <br /> WESTERN GEOLOGIC RESOURCES, 1989 <br /> ' WGR performed a soil-vapor survey in 1989 Twelve temporary soil-vapor sampling points were <br /> installed at the site Vapor samples were collected from each location at 5 and 15 feet bgs The highest <br /> concentration of total volatile hydrocarbons (TVH) found at 5 feet bgs was 2,500 ppm (VP-11) <br /> Vapor Points VP-1 and VP-12 also contained elevated concentrations of TVH at 5 feet bgs (680 ppm <br /> and 390 ppm, respectively) Soil-vapor samples collected from 15 feet bgs contained concentrations <br /> ' as high as 91,000 ppm TVH (VP-11) Concentrations of TVH in excess of 50,000 ppm were found <br /> in Vapor Points VP-1 and VP-12 at 15 feet bgs Volatile hydrocarbons were also found in Vapor <br /> Points VP-2, VP-3, VP-4, VP-9, and VP-10, but at lower concentrations (3,100 ppm, 410 ppm, 15 <br /> ppm, 220 ppm, and 1,800 ppm, respectively) The highest concentrations were in the vicinity of the <br /> former tank pit <br /> ' Following the soil-vapor survey,WGR installed five monitoring wells Five borings were drilled <br /> on the site and completed as Monitoring Wells MW-1 through MW-5 in February and March 1989 <br /> ' Groundwater sampling confirmed that the highest concentrations were in the vicinity of the former <br /> tank pit <br /> EARTH TECHNOLOGY NOLOGY COR PORATEON, 1991 <br />' In 1991, Earth conducted cone penetrometer tests (CPT) and groundwater sampling at the site <br /> The CPT data provide general hthologic descriptions as well as the ability to collect discrete ground- <br /> water samples (Earth,November 1991) This work further confirmed that the highest concentrations <br />' were in the vicinity of the former tank pit <br /> GROUNDWATER TECHNOLOGY, INC., 1992 <br />' In March 1992, GTI installed Morutonng Wells MW-6 and MW-7 as well as Vapor Well VW-1 at <br />' the locations shown in Figure 2 Well MW-6 was installed across Plymouth Road, down-gradient <br /> from the site,to determine the extent of the plume Well MW-7 was installed upgradient of the known <br /> extent of contamination to further delineate the plume Well VW-1 was completed in the vadose zone, <br />' to be used as a vapor-extraction well in the future <br />' Monitonng Well MW-8 was installed in December 1993 to further define the downgradient hmits <br /> of the plume extending from the property <br /> In June 1994, GTI installed Monitoring Well MW-9 and Soil Borings SB-1 through SB-4 The <br /> locations of Well MW-9 and Soil Borings SB-1 through SB-4 are shown in Figure 2 of the main <br />' report <br /> GM-NCHMONRROXACHFVRON CHFV N ZW Wl"CORK-lCrAnchl doe <br />' GERAGHTY& MILLER,INC ���@ <br />