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PES Environmental,Inc. Ms. Emily Cushman November 24, 2015 Page 2 In response to the fuel pipeline release in late September 2015, PES conducted a preliminary assessment on September 23, 2015 to expose the fuel pipeline and locate the pipeline failure as well as observe subsurface conditions. While the location of the pipeline failure was not identified, it was determined that the pipe leak was likely located beneath the adjacent paved parking area near the levee roadway. In early October 2015, further subsurface trenching was conducted during installation of a free product/groundwater collection trench. Observations made during this trenching identified first-encountered groundwater at least 8 feet below grade (at the elevation of the fueling pad) and that petroleum-affected soils were primarily present in unsaturated soils in the vicinity of the fueling pad. The likely location of the fuel line release was also better defined and appeared to be on the southern edge of the raised parking area on the east side of the levee (see Plate 2). Between October 27 and 30, 2015, PES conducted a focused soil excavation in the vicinity of the fuel release where petroleum hydrocarbons were observed in the vadose zone. Excavation was limited on all sides by site improvements including paved and curbed roadways and parking areas, an aboveground tank containment structure and in-use subsurface and overhead utilities. Approximately 200 cubic yards of clean over burden soil and 800 cubic yards of hydrocarbon-affected soil were excavated between the former fueling pad and southern parking lot (See Plate 2 for excavation perimeter). The clean overburden soil was temporarily stockpiled and will be used for on-site backfilling. The hydrocarbon-affected soil is also stockpiled on site for future treatment or off-site disposal. Prior to backfilling, the excavation was lined with a high density polyethylene membrane to maintain separation between the clean backfill materials and hydrocarbon-affected soils remaining in the excavation bottom and exposed sidewalls. Approximately 100 to 300 gallons of groundwater has been pumped from the free product/groundwater extraction trench on a daily basis. While hydrocarbon sheens were initially reported, groundwater recently extracted from beneath the excavation area does not exhibit evidence of free product. SCOPE OF WORK The scope of work for the investigation includes the following activities: (1) field preparation tasks; (2) collection and analysis of soil and groundwater samples; (3) submittal of samples for laboratory analysis; and (4) data evaluation and reporting. The proposed scope of work to be conducted is presented below. 148400101W003.doex