SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

ENVIRONMENTAL H ALTH tIEPARTMENT SAN JOAQU N COUNTY W: r �i Donna K. Heran, 'R.E.H.S. Program Coordinators .� Director 304 East WeberAv nue Third Floor Carl $orgman, R.E.H.S. Q Laurie A. Cotulla, R.E.H.S. Stockton, California 95202-2708 Mike Huggins,R.E.H.S., R.DT Assistant Director Telephone: (2 9)468-3420 Margaretaret La orio, R.E.H.S. Robert Mccllon, R.E.H.S. Fax: {209) 64-013$ .teff Carruesco, R.E.H.S. Website:www.s.jgov.org/ehd/ Kasey Foley, R.E.H.S. S 6f HELEN HIGGINS 5815 MORGAN PLACE #16 'NAV 4 Z � STOCKTON CA 95219 RE: Vogue Cleaners SITE CODE: 231032 2315 N. California St. RO#: 607 Stockton, CA 95204 SWRCB-CUF#: 011775 The San Joaquin County Environmental Health Dep rtment (SJCEHD) has reviewed Report of Findings from CPT#3, #4, & #5 (the Report) as s bmitted to Geotracker and Work Plan for MW-7S&D and MW-8S&D (the Plan) and has the oliowing comments. Originally, the SJCEHD had approved the o-phase investigative approach by correspondence dated May 10, 2006. The Report detailed the Phase 1 field activities (CPT placements) conducted in August 2006, the results of which were to have been submitted to the SJCEHD in the format of an updated Site Conceptual Model (SCM) so that an evaluation could be made as to the number and locations of th monitoring wells required in Phase 2. Unfortunately, the Plan, for installation of MW-7 & 8 (S&D), not in the context of an SCM, was prepared and submitted before the SJCEHD had opportunity to complete its review and evaluation of the Report and comment on the Report. The SJCEHD is concerned that the only ground water grab sample collected in CPT-3 was from a stiff fine grain layer (97 to 104 feet below ground surface ['bgs]) where the CPT log indicated elevated pore pressures with thin streaks of lower pore pressure are present. The approved work plan had specified that the grab groundwater samples would be collected from "the most apparent permeable water-bearing u if'. Just above the sampled interval, at 87 to 97' bgs, and below the interval at 110 to 114' bgs, the CPT log recorded significantly lower pore pressure, indicating zones of probable higher permeability. It is possible that the non-defect laboratory analytical result for the sample from the higher pore pressure depths may not adequately evaluate the potential migratory p thways for the primary contaminant of concern, 1,2-DCA. The SJCEHD feels a ground watE r sample from the lower pore pressure interval would have better indicated the plume's r resence or absence at this location approximately 100 feet from a source (the former UST). Without a grab groundwater sample from one of these potentially more permeable interval 3, the SJCEHD is unable to definitively accept the ground water sample result from CPT-3 as delineating the vertical extent of the petroleum contamination (1,2-DCA) present near MW 3D. That being said, the SJCEHD does note that the deeper MW-3 monitoring well yields groundwater samples with relatively low concentratio s of 1,2-DCA, while the deeper MW-5 monitoring well yields groundwater samples impacted by relatively high 1,2-DCA concentrations. The grab groundwater samples fro both CPT3-103-108' bgs (with the concern noted above) and CPT5-97-104' bgs contained less than detectable concentrations of 1,2-DCA, as did the sample from CPT4-102-107 bgs. This data is supported by the