WORK PLANS - Laserfiche WebLink

Home Browse Search

i � � rE►r►cr+tErrEr Mr. Roy Knight 24 October 1997 Page 3 These laboratory results are consistent with the belief that the oily material discovered in the drain inlets most likely originated from the Lube Shop and derived from oils and fuels used in that area. Based on this presumption, the proposed investigation will focus on the drain inlets located on the storm drain line that begins at the north end of the Lube Shop and terminates at the manholes located near the Tire Shop (see Figure 1). PHASE I— SOIL INVESTIGATION The investigation will focus on the five drain inlets that receive runoff from the area around the Lube Shop (refer to Figure 1). These inlets are of particular concern because they do not have concrete bottoms. There are three additional manholes downstream from the five drain inlets, but because they have concrete bottoms, they do not present the same concern with direct discharges to native soil that are posed by the open bottomed drain inlets. Prior to conducting any drilling, liquid present in the drain inlets will be transferred into drums for disposal at a facility permitted for this waste. We estimate that one or two drums (50 to 100 gallons) will be filled, and samples will be collected to profile the waste for disposal purposes. After the drain inlets are emptied, soil samples will be collected from underneath the drain inlets by the Geoprobe coring method to evaluate the vertical extent of contamination. The coring will continue to a depth of 10 feet, or until field screening indicates that hydrocarbons are no longer present. This screening will consist of visual inspections for staining and monitoring for the presence of petroleum odors and hydrocarbon vapors with a field organic vapor analyzer. Two additional corings will be driven next to each storm drain to evaluate the lateral extent of contamination. These corings will continue to a depth of 5 feet, or until field screening indicates . that hydrocarbons are no longer present. Two samples will be selected from each coring to evaluate chemicals present and estimate the extent of excavation that will be required to remove the contaminated material. These soil samples will be analyzed for the following constituents: • Benzene, Toluene,Ethylbenzene,Total Xylenes and Methyl Tertiary Butyl Ether (MTBE)using EPA Method 8020 • Total Petroleum Hydrocarbons as Gasoline TPH-G and Total Petroleum Hydrocarbons as Diesel(TPH-D)using EPA Method 8015 modified • Total Oil and Grease using EPA Method 5520B