Laserfiche WebLink
ENVIRONMENTAL HEALTH DEPARTMENT <br /> PQ�'N SAN JOAQUIN COUNTY <br /> Unit Supervisors <br /> a .?A Donna K.Heran,R.E.H.S. Carl Borgn an,R.E.H.S. <br /> Director 304 East Weber Avenue, Third Floor Mike Huggins,R.E.H.S.,R.D.I. <br /> Al Olsen,R.E.H.S. Stockton, California 95202-2708 Douglas W.Wilson,R.E.H.S. <br /> 'c• Program Manager Telephone: (209) 468-3420 Margaret Lagorio,R.E.H.S. <br /> Cglipo Laurie A.Corolla,R.E.H.S. RobertMcClellon,R.E.H.S. <br /> Program Manager Fax: (209) 464-0138 Mark Barcellos,R.E.H.S. <br /> KEN GILLIES SEP 3 0 2004 <br /> GILLIES TRUCKING <br /> P O BOX 8303 <br /> STOCKTON CA 95208 <br /> RE: Gillies Trucking SITE CODE: 1703 <br /> 3931 Newton Road RO: 0264 <br /> Stockton, CA 95205 <br /> The San Joaquin County Environmental Health Department (EHD) has received <br /> and reviewed Workplan for Delineation of Groundwater Contamination in the <br /> Riverbank Aquifer (WP), dated 28 July 2004, prepared by your consultant <br /> Upgradient Environmental Consultants (UEC) in response to the EHD directive <br /> letter of 17 June 2004. The EHD comments as follows: <br /> Through modeling the findings from past site investigations, UEC has <br /> constructed a site model for potential migration of impacted ground water <br /> consisting of one sand unit in the Modesto Formation and three successively <br /> deeper sand units in the Riverbank Formation. The three Riverbank Formation <br /> aquifer sand units are referred to as the First Riverbank Aquifer (151 RBA), <br /> generally 10 feet thick or thinner and laying between 50ndand 75 feet below <br /> surface grade (bsg); the Second Riverbank Aquifer (2 RBA), varying in <br /> thickness from 5 to 25 feet and generally occurring between 75 and 100 feet bsg; <br /> and the Third Riverbank Aquifer (3rd RBA), of unknown thickness and generally <br /> occurring between 110 and 120 feet bsg. Impacted groundwater has been <br /> encountered in all four sand units, although the Modesto Aquifer is currently 'dry' <br /> due to the falling groundwater elevation. It is necessary to fully characterize each <br /> of the aquifer units and the impacted groundwater in them to adequately consider <br /> site remediation and/or monitoring requirements or suitability for closure <br /> consideration. <br /> The geometry and trend of the 3rd RBA is least understood, that of the 151 RBA is <br /> best understood. All of the sand bodies are inferred to be river channel sands <br /> that are thicker in the former channel centers (axes) and thinner toward the <br /> former channel margins. <br />