Laserfiche WebLink
{ <br /> GEOLOGICAL AND HYDROGEOLOGICAL OVERVIEW <br /> According to information contained within the September <br /> 1991 Waterwork assessment , the Reeve ' s site is located on <br /> Teves terrain underlain by flood plain deposits of <br /> Pleistocene and Holocene age that are composed of sediments <br /> similar to and probably conformable on , underlying <br /> deposits of alluvium and Tulare formation The flood plain <br /> deposits are light to dark-brown and grey clay , silty sand , <br /> and organic materials with locally high concentrations of <br /> salt and alkali Stream channel deposits of sand and <br /> gravel are also included <br /> Groundwater within the shallow water bearing zone occurs <br /> less than ten feet below grade at the site as well as over <br /> most of the Tracy area General groundwater gradient is to <br /> the north The flood plain deposits of the shallow water <br /> bearing zone have well developed soil profiles and , <br /> consequently exhibit poor permeability The base of the <br /> shallow zone is poorly defined and probably is from five to <br /> twenty feet below ground surface <br /> RECENT ENVIRONMENTAL COMPLIANCE ACTIVITIES <br /> . In accordance with recommendations made in its September , <br /> 1991 report WaterWork installed three , 4-inch diameter <br /> groundwater monitoring wells (designated MW-1 , MW-2 , and <br /> MW-3 ) and a series of soil borings at the locations shown <br /> on Figure 2 The monitoring wells have been developed and <br /> sampled most recently by EPM Technologies , Inc on <br /> August 16-18 , 1993 and again on December 2 , 1993 EPM has <br /> also prepared and submitted a workplan for further <br /> characterization of the extent of soil and shallow <br /> groundwater contamination to PHS/EHD and requested an <br /> encroachment permit for the hand angering of soil borings <br /> along Grant Line Road from the City of Tracy Copies of <br /> this workplan have been submitted to the City of Tracy (as <br /> part of the encroachment permit application process ) and <br /> the Central Valley Regional Water Quality Control Board <br /> (RWQCB ) <br /> WELL SAMPLING METHODOLOGY USED BY EPM <br /> Sampling of the three on-site 4-inch inside-diameter <br /> groundwater monitoring wells (MW-1 , MW-2 , and MW-3 ) was <br /> performed on December 2 , 1993 with the approval of Mr <br /> Michael infurna of San Joaquin County Public Health <br /> Services , Environmental Health Division ( PHS/EHD) <br /> Depth to water and total depth of each of the wells were <br /> measured using an electric tape and the volume of water <br /> witnin each well casing was computed Each well was then <br /> Page 2 <br />