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•' 4. Screening of soil headspace in the field with an organic vapor analyzer (OVA) to x evaluate relative concentrations of organic vapors in the soil. Soil samples to be submitted for analysis will be selected based on OVA field readings; 5. Development of monitoring wells by mechanical surging and bailing; 6. Purging and sampling of monitoring wells. Samples from each well will be • submitted for laboratory analysis for TPH analytical method) and BTX&E (EPA 602 analytical method); bt+s ILL)Pr .r 7. Surveying of each monitoring well for exact location and exact elevation using the USGS ME-datum; 8. Measurement of water levels at well completion, before and after well developn. at,and before and after water sampling; 9. Detection of any possible free-product (LNAPL} on top of the water table, ;n measured at the completion of the well, and approximately 7 and 14 days after } completion; and z„ L10. Preparation of a written report summarizing field activities and analytical results. 3.2 Soil Boring/Monitoring Well Locations n � 7 Figure 3 is a site map depicting locations of the proposed soil boxings. Well locations were selected using the following priorities: Downgradient of tankfield,pump island,and waste oil tank; Upgxadiem of ta.nkfield,pump island, and waste oil tank; and - Distance between wells that allows establishment of a local groundwater flow direction. The proposed well locations are based on an approximate southwesterly groundwater flow direction,inferred from topography and surface water bodies in the area. The three proposed soil boring/monitoring well locations shown on Figure 3 are: - Immediately SW of Cie gasoline UST field; �t - Immediately SW of the waste-oil tank; and - In the NE part of the property,just S of driveway and S of the property line. The first two locations are designed to be immediately downgradient of the gasoline UST field and the waste-oil tank. The third location is to be an upgradient background monitoring location. 3.3 Drilling And Soil-Sampling Procedures Each soil boring will be installed using 12-inch hollow-stem augers. This will permit r 3 inches of annular space outside the well-casing, in the event that monitoring wells are installed. The total depth of each well will be dictated by the presence or absence of r groundwater and/or solid rock. If groundwater is encountered before a depth of 40 feet below ground surface, the boring will be drilled to a depth which will allow 10 feet of -6- x °' +► 172.3 .R1 318191