COMPLIANCE INFO_1970-2012 - Laserfiche WebLink

Home Browse Search

Arcady ,Oil Company -2- 30 August 1989 landward gradient. M-6 and M-7 are on the eastern perimeter of the site. M-5 and M-8 are across the road to the east of the site. M-5, M-6, M-7, and M-8 are downgradient of the drilling mud. The following table shows water levels taken during this inspection (datum is mean sea level , units are feet) . WELL NO. ELEV. DEPTH TO ELEV OF DEPTH TO WELL WATER WATER BOTTOM M-3 8.00 9.5 -1.5 18.5 M-4 7.85 7.75 0.10 18.75 M-5 6.59 13.9 -7.3 17.95 M-6 8.90 16.6 -7.7 18.25 M-7 9.38 dry dry not measured M-8 4.99 13.5 -8.51 18.2 CURRENT SAMPLING EVENT Samples were collected from M-3, M-4, M-5, and M-8. Well M-7 was dry. Well M-6 had too little water to purge with the hand pump. The water in OH-2 was covered with film (iron bacteria?) , and the steel casing was extremely rusted. Since metals were the primary constituent of concern, we decided not to sample OH-2. Sampled wells were purged of about three well volumes of water using a portable hand pump. Wells M-5 and M-8 were purged until the water ran clear. Purged water was discharged to the ground. Samples were then taken with a bailer. Filtered and unfiltered samples were collected for analysis for metals. Samples were also collected for general minerals analyses and analysis by EPA methods 601 and 602. For further information regarding the sampling methodology see the memorandum from the Toxics Unit which is in the files. RESULTS OF CHEMICAL ANALYSES ON GROUND WATER SAMPLES Results of the analyses for Halogenated Volatile Organics (EPA Method 601) were all non-detectable except for 1,1,2-Trichloro-2,2,1-trifluoroethane which was found in samples from the two wells for which samples were submitted, M-6 and M-8, and the blanks. A footnote on the lab report notes, "analytical results should not be considered reliable for this common lab contaminant unless the sample result exceeds 5 times the reporting limit or 10 times the blank result. " The constituent was found as follows: M-6 1.1 ug/l M-8 1.2 travel blank 1.4 method blank 1.6 reporting limit 1.0 Results of the analyses for Aromatic Volatile Organics (EPA Method 602) were non- detectable on the submitted samples which were from M-6 and M-8. The results of the general minerals analyses showed that ground water is generally high in dissolved solids. Table I summarizes these results, as well as general minerals analyses on samples from four nearby supply wells. Samples from the monitoring wells contained from 612 to 2300 mg/L of total dissolved solids (TDS) . The highest level of TDS was found in M-4, a well upgradient of the drilling mud. The lowest level of TDS was found in M-5, a downgradient well . TDS levels in samples collected from four nearby supply wells on 21 October 1987 ranged from 515 to 2480 mg/L. The locations of these four wells is shown on figure 2.