REMOVAL_2008 CLOSURE IN PLACE - Laserfiche WebLink

Home Browse Search

KLElNFELDER Soil Sampling Observations and Activities ,. A total of eight soil samples were collected between December 4 and 5, 2007 from four test pits TP1/TP2, TP3, TP4 and TP5, advanced in proximity to the five 20,000 gallon asphalt USTs (see Plate 3). A concrete apron was noted on the east side of the easternmost 30,000 gallon AST and asphalt was noted west of the western 30,000 gallon AST. Test Pit TP1/TP2 was advanced between UST Nos. 1 and 2 and between externally exposed tanks lids for these same tanks noted at the ground surface. Small .. diameter (<5 feet) asphalt spill/s were noted in proximity to these two tanks lids at the surface north of UST Nos. 1 and 2. Potential evidence of infiltration (soil discoloration/odors) of asphaltic material in the near surface was not noted in Test Pit v TP1/TP2 located in proximity to noted spills. Surface spill of asphaltic material was not noted in the immediate vicinity of the remaining three test pits although secondary surface containment units and a dispenser area were noted at the south end of the two ►w ASTs and near the exposed ends of UST Nos. 4 and 5. Two soil samples were collected at approximately 8 and 15 feet bgs at each of the four test pit locations. At the base of each test pit a hand auger was used to remove slough and obtain soil samples at the desired depth intervals. A backhoe and operator supplied by Granite Construction was present to remove overburden material prior to collection of soil samples. No unusual odors or soil discoloration was noted in the test pits. It has been Kleinfelder's experience that heavier hydrocarbons, such as asphaltic oils will leave a dark brown to gray discoloration in impacted soil. Soil in general was noted to be primarily light brown silty sands and sandy silts, fine to medium grained from near surface to approximately 12 feet bgs underlain by olive brown silty clays from approximately 12 feet bgs to the total explored depth near 15 feet bgs. The southern ends of UST Nos. 4 and 5 were exposed during the test pit advancement and soil sampling activities. No groundwater was encountered during the test pit excavations or soil sampling activities. Overburden material was placed near the respective test pits. Due to the specific location of Test Pit Nos. 3 and 5, collection of the deeper soil samples (approximately 15 feet bgs) were collected from a hand auger advanced at an ` approximate 45 degree angle from the base of the test pit in an attempt to collect a soil sample nearer the base on the nearby UST Nos. 3 and 5. In general, the remaining test pits were closer to the base of the nearby tanks. Soil samples were collected either into ` the sidewalls or the bottom of the test pits nearest to the respective UST. A pre-cleaned stainless steel hand auger was used to remove slough and to collect the ` soil samples. The stainless steel auger was cleaned between sample locations and just prior to sample collection at the desired depths. The soil in the bottom of the hand auger from the desired sample interval was transferred into laboratory supplied glass jars or stainless steel tubes by hand with new nitrile gloves. 90163.T03/ST07R1061 January 3,2008 ®2007 Kleinfelder Page 3 of 7