Laserfiche WebLink
Mr Kyle Christie Project 0805-144 02 <br /> • July 28, 1995 <br /> Page 2 <br /> data to evaluate dissolved gasoline hydrocarbon concentrations and the flow direction and <br /> groundwater gradient <br /> On May 15, 1995, a technician from EMCON took water level measurements and <br /> collected groundwater samples from monitoring wells MWA through MW-4 for <br /> subjective and laboratory analyses The technician did not observe floating product or <br /> product sheen on samples collected from the wells (see Table 1) Sampling and analysis <br /> procedures are presented in Attachment A <br /> The surveyed elevations of the top of casing and the depth-to-groundwater measurements <br /> (see Table 1) were used to evaluate the potentfometric surface beneath the site On <br /> May 15, 1995, the direction of groundwater flow was toward the northwest with a <br /> gradient of approximately 0 01 (see Figure 3) The direction of groundwa erer flow is <br /> consistent with previous sampling events Groundwater elevation decreased approximately <br /> 0 17 foot from the previous sampling event (February 1995) <br /> Groundwater samples from each well were analyzed for total petroleum hydrocarbons as <br /> gasoline (TPHG), and benzene, toluene, ethylbenzene, and total xylenes (BTEX) using <br /> Environmental Protection Agency Methods Modified 5015 and 5030/8020, respectively <br /> The samples were analyzed at Columbia Analytical Services, Inc , in San Jose, California <br /> The results of analyses are summarized in Table 1 Copies of the chain-of-custody records <br /> and laboratory analysis reports are presented in Attachment B Results of analyses <br /> indicated TPHG and BTEX concentrations were below laboratory detection limits in <br /> groundwater samples collected from wells MW-1 through MW-4 <br /> ACTIVITIES PERFORMED DURING THE SECOND QUARTER <br /> • EMCON performed quarterly groundwater sampling <br /> • EMCON compiled and evaluated groundwater monitoring data <br /> ANTICIPATED WORK <br /> • ARCO will continue to perform quarterly groundwater monitoring The next <br /> sampling event is tentatively scheduled for August 1995 <br /> CONCLUSIONS <br /> • The groundwater flow direction was to the northwest, which is consistent with previous <br /> sampling events Gasoline hydrocarbons were not detected in groundwater samples <br /> collected from monitoring wells MW-1 through MW-4 Gasoline hydrocarbons have not <br /> SAL-Npj ft80"8051440 2b1-951fc 2 <br />