FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

CONESTOGA-ROVERS Ms. Victoria McCartney &ASSOCIATES October 1, 2007 2001 Geoprobe Soil and Groundwater Sampling Activities: On July 26, 2001, SECOR supervised Gregg Drilling and Testing, Inc. of Martinez, California (Gregg) advance Geoprobe soil borings GP-1 through GP-3 to approximately 40 fbg, along the southwest edge of the property. Two soil samples and one grab-groundwater sample were collected from each boring and submitted for chemical analysis. The grab-groundwater samples were collected between 36 and)�S-fbg. MTBE was detected in one soil sample (GP-2 at 32 fbg) at 0.19 mg/kg. No other hydrocarbons were detected in soil. The grab-groundwater sample collected from boring GP-1 at 36 fbg contained 79 micrograms per liter (pg/L) MTBE and 6.3 µg/L tertiary-amyl methyl ether (TAME). The grab- groundwater sample collected from GP-2 at 37 fbg contained 0.85 gg/L benzene, 0.51 pg/L xylenes, 890 pg/L MTBE, and 52 pg/L TAME. The grab-groundwater sample collected from GP-3 at 39 fbg contained 0.51 µg/L benzene, 0.91 pg/L xylenes, 76 µg/L MTBE, and 5.3 µg/L TAME. -- 2002 Monitoring Well Installation: On January 7 through 9, 2002, SECOR supervised V&W Drilling, Inc. of Isleton, California install shallow monitoring wells MW-5S and MW-6S and deep wells MW-5D, MW-6D, and MW-7D. No hydrocarbons were detected in soil, with the exception of 0.002 mg/kg MTBE in one sample(MW- 5D at 51 fbg). P&O 14 ulu 100rl-j- i Yt a U Edi- w,-nr1,a cno, !I'll "5 a, ,} 7Z - 2003 Cone Penetration Test and Well Installation: On February 4 and 5, 2003, SECOR supervised Gregg advance cone penetration borings CPT-1 and CPT-2 to assess soil strati ra�phy and collected discrete grab- groundwater samples. Each boring was advanced to approximately 120 fbg.') Three depth-discrete grab- groundwater samples were collected at each of the CPT boring locations. MTBE was detected in all six samples at concentrations ranging from 2 µg/L to 22 µg/L; TAME was detected in two of the samples at concentrations ranging from 0.9 gg/L to 0.5 µg/L. f 2003 Monitoring Well Installation: On February 12, 2003, SECOR supervised Spectrum Drilling and Exploration of Stockton, California install one 6-inch diameter groundwater monitoring well (MW-8) to a total depth of approximately 40 fbg. No samples were collected from this well due to its close proximity to CPT-2. 2004 to 2005 Remedial Action - Batch Groundwater Extraction: From August 2004 to June 2005, SECOR performed batch groundwater extraction events on wells MW-6S and MW-8. Integrated Wastestream Management (IWM), under the supervision of SECOR, extracted approximately 114,450 gallons of groundwater. During this time, the MTBE concentration declined from approximately 20,000 pg/L to approximately 300 µg/L, and eventually below reporting limits. Approximately 3.8 pounds of MTBE was removed from the groundwater system. 3 Worldwide Engineering,Environmental,Construction,and IT Services