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�! Groundwater samples were collected on October 22, 1996 from wells MW3 and MW6. No lf> groundwater samples were collected from MW4 due to the presence of free product. Prior to sample collection, each sampled well was purged of a minimum of three well casing volumes of water. Purged water was contained in labeled 55 gallon drums (DOT H), and stored on-site. Groundwater samples were collected after physical parameters (pH, temperature, and conductivity) were monitored and had stabilized. Dedicated disposable bailers with bottom- emptying devices were used to collect samples from the wells. All field activities were performed in accordance with the Field Methods included in Attachment 1. Field purge logs are presented in Attachment 2. LABORATORY ANALYSES Collected groundwater samples were analyzed for benzene, toluene, ethylbenzene, xylenes (BTEX) and total petroleum hydrocarbons as diesel (TPHd) by Sequoia Analytical, a State- certified laboratory, utilizing EPA methods 8020 and modified 8015, respectively. Analytical results are summarized in Table 3. Laboratory data sheets and chain-of-custody documentation are included in Attachment 3. Laboratory results indicate that BTEX was not detected above method detection limits in collected groundwater samples. Weathered TPHd was detected in the sample collected from well MW3 at a .concentration of 350 parts per billion (ppb). TPHd was detected in the sample collected from well MW6 at a concentration of 130 ppb, but was reported by the laboratory as a non-diesel mix. WORK IN PROGRESS The next groundwater monitoring episode is scheduled to be performed in January 1997 and will include sample collection from monitoring wells MW-1 through MW6, including MW4 (if free of petroleum product sheen). S l w:1943691quarllyl4gmr1996.dac 2 I I • SMTH