Laserfiche WebLink
Site Characterization-Second Event Page 2 <br /> Former Karlson Trucking Facility <br /> Project No. 191.2 <br /> April 27, 2000 <br /> Upon reporting the hydrocarbon impact to the Regional Water Quality <br /> Control Board (RWQCB), the site was enrolled into the SLIC program and <br /> regulatory oversight of the site characterization began. In the period of <br /> January through April of 1999, initial site characterization work was <br /> completed at the site. This included the following work: <br /> • The completion of a soil gas survey as a reconnaissance tool to determine <br /> better identify the point of release, to determine the most effective <br /> locations for monitoring wells. <br /> • The installation of five monitoring wells. One well was to investigate <br /> suspected impact to groundwater from a drainage pit, and other four to <br /> investigate the dielectric/diesel oil impact to the subsurface. <br /> This work was completed with the a result that the lateral extent of the <br /> hydrocarbon contamination was bounded in the east, northeast and <br /> southwest direction. The direction of groundwater flow was measured to be <br /> to the northwest. Groundwater and soil gas data suggested that trace to non- <br /> detectable levels of BTEX petroleum hydrocarbons were present in the soil <br /> and groundwater at the site. Soil and groundwater samples from only one <br /> monitoring well, MW-4, contained detectable levels of total extractable <br /> petroleum hydrocarbons (TEPH). <br /> An additional round of groundwater sampling was completed in July of 1999 <br /> with groundwater gradient and contaminant data consistent with the initial <br /> monitoring event completed earlier in the year. <br /> The RWQCB directed that additional work be completed to determine the <br /> lateral and vertical extent of groundwater contamination. Pursuant to the <br /> this directive, Geo-Phase Environmental Inc. prepared a work plan to install <br /> five new Geo-Probe soil borings and two monitoring wells to more fully <br /> characterize the extent of hydrocarbon impact to the soil and groundwater. <br /> The work plan also proposed that one monitoring well, MW-5, be destroyed. <br /> 2.0 SOIL & GROUNDWATER INVESTIGATION <br /> 2.1 Soil Boring Installation <br /> This scope of work consisted of two parts: <br /> 1. The installation of 5 Geo-Probe soil borings, four completed to 20 feet <br /> below ground surface to more precisely define the lateral extent of <br /> 2937 Veneman Avenue,Suite B240 Geo-Phase Environmental Inc. Phone: (209)569-0293 <br /> Modesto, Ca 95356 Fax: (209)569-0295 <br />