SITE INFORMATION AND CORRESPONDENCE_FILE 1

Home Browse Search

i it AW M ENVIRONMENTAL HEALTH DEPARTMENT ;i Pp U I N SAN JOAQUIN COUNTY Unit Supervisors Donna K. Heran, R.E.H.S. Carl Borg man, R.E.H.S. 304 East Weber Avenue, Third Floor " v ` Director Mike Huggins, R.E.H.S., R.D.I. • Al Olsen, R.E.H.S. Stockton, California 95202-2708 Douglas W. Wilson, REES , • �q , �P Program Manager Telephone: (209) 468-3420 Margaret Lagorio, R.E.H. S . Fp a Laurie A. Cotulla, R.E.H.S. Robert McClellon, R.E.H.S. Program Manager Fax: (209) 464-0138 Mark Barcellos, R.E.H.S. PAUL ZUMBERGE O R TRANSPORT INC A C5 r MAR 18 2003 PHILADELPHIA 35 � 1 CHINO CA 917 13P 71 t I V' 03 RE: Frontier Transport, Inc. SITE CODE 2251 425 Larch Road RO : 252 Tracy, CA 95376 San Joaquin County Environmental Health Department (EHD) has reviewed the reports submitted for the 1996 through 2002 quarterly groundwater monitoring events; soil and groundwater analytical results; boring and monitoring well lithologies; cross-sections prepared in 1999, and the well receptor survey report prepared by Blakely Environmental Investigations, Inc . (BEII) for the above referenced site. Further site investigation is necessary to evaluate the lateral extent of impacted groundwater in the sand encountered at forty feet below surface grade (bsg) . EHD recommends a third monitoring well, in the deeper monitored interval near monitoring well MW- 1 to assess the vertical and lateral extent of impacted groundwater in that direction. A site conceptual model (SCM) should be prepared for this site. The SCM should include the following: 1 . Local and regional plan view maps showing location of sources, extent of contamination (i.e. , an interpretive drawing - not merely a plot of laboratory results), direction and rate of groundwater flow, and locations of receptors . "Receptors" include, but are not limited to, all supply wells within 2000 feet of the source area; 2 . Cross-sections showing the subsurface geologic framework of the site, depth of groundwater, man-made conduits, monitoring well construction, and an interpretive drawing of the vertical extent of soil contamination; 3 . Plots of key chemical concentrations vs. time (e.g. , plots should be shown for monitoring wells that demonstrate significant trends in contaminant concentrations); 4. Summary tables of chemical concentrations in the two media of concern;