SITE INFORMATION AND CORRESPONDENCE FILE 2

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Nov • 24. 2008 4: 54PM Wright Environmental 832 5152 No -H21 P . 4 U . U I I 2.2 Additional Groundwater Monitoring Well Sampling Wright will schedule another round of groundwater monitoring well sampling for the existing wells as requested by EHD. The chemical data will be sent directly to EHD and a separate report for this monitoring event will not be prepared, only the raw data will be submitted. The wells will be sampled using the existing contractor well sampler. 2.3 Up-Gradient Source Review Wright has presented the groundwater information in quarterly monitoring reports where MW-6, positioned up gradient of the known underground tank site, has consistently shown low levels of TPHG. The mapped ground water flow direction has been consistently to the north from MW-6 and MW-7 toward the former underground pit and existing wells beyond. A geophysical survey in January 16, 2001 by Noreal Geophysical did not reveal any potential additional sources between MW-6 and"the known tank pit Since the EHD has desired additional information regarding support for an off-site source Wright proposes the following: • Wright will review historic information sources including aerial photographs for possible up-gradient sources across 11" Street (south) of the site. A summary discussion of the historic potential site sources will be prepared. • Wright will review the historic groundwater monitoring data from MW-6 and MW-7 to compare to the monitoring wells data downgradient of the former underground storage tank location and comment upon possible trends or differences. • A second GeoProbe boring will be advanced to sample groundwater at depths 12-16 feet (about the existing well screen interval), 20-24 feet and 26-30 feet to profile groundwater to ascertain if dissolved contaminants are flowing on site. Groundwater samples will be collected using the procedure discussed in Section 2.1 above. 3.0 Chemical Analysis Up to four groundwater HydroPunch samples, two soil samples and nine groundwater monitoring well samples will be analyzed at a certified analytical laboratory. Samples will be tested for'the following;Total Petroleum Hydrocarbons as Gasoline(TPHG)and Diesel (TPHD), and Volatile Organic Compounds (VOC), Benzene (B), Toluene (T), Ethylbenzene (E), Xylene (X) Methyl-tert-butyl-ether (MTBE), and fuel oxygenates tert-Amyl-Methyl-Ether, Ethyl-tert- Butyl-Etder, Di-Isopropyl Ether and tert-Butyl Alcohol, and 1,2-DiChloroethane and Ethylene Dibromide using EPA Methods 8015m,8260B. The laboratory will be instructed to analyze the samples on.a"normal" turnaround basis. - Page 3 of 4