GROUNDWATER MONITORING REPORT FOR CHITTENDEN MILLS BEVERAGE JERICHO, VERMONT (VTDEC Site # 94-1594) July 2007 Prepared for: Champlain Oil Company 45 San Remo Drive South Burlington, VT 05407-2126 Prepared by: 368 Avenue D, Suite 15 P.O. Box 787 Williston, Vermont 05495 Phone: (802) 383-0486 Fax: (802) 383-0490 [email protected] KAS Project# 410040018 Groundwater Monitoring Report Chittenden Mills Beverage, Jericho, VT Table of Contents 1. INTRODUCTION..............................................................................................................1 2. GROUNDWATER MONITORING ................................................................................1 2.1. GROUNDWATER FLOW DIRECTION AND GRADIENT ...........................................................................................1 2.2. GROUNDWATER QUALITY................................................................................................................................1 2.3. QUALITY ASSURANCE AND CONTROL..............................................................................................................2 3. CONCLUSIONS & RECOMMENDATIONS................................................................2 APPENDICES Appendix A Maps • Site Location Map • Site Map • Groundwater Elevation Map • Contaminant Concentration Map Appendix B Liquid Level Monitoring Data Appendix C Groundwater Quality Data and LNAPL Recovery Summary Appendix D Analytical Laboratory Reports July 2007 i KAS # 410040018 VTDEC Site # 94-1594 Groundwater Monitoring Report Chittenden Mills Beverage, Jericho, VT 1. INTRODUCTION This report is a summary of the groundwater monitoring program at the Chittenden Mills Beverage Site, located on Route 15 in Jericho, Vermont, conducted on June 11, 2007. A Site location map is included in Appendix A. This investigation was conducted by KAS, Inc (KAS), for Champlain Oil Company (COCO) of South Burlington, Vermont. This work is being performed according to the recommendations outlined in the LNAPL Recovery Report dated May 21, 2007. Free product had not been observed for three consecutive quarterly monitoring events, and was last measured at the Site in September 2006. Therefore, KAS recommended that groundwater samples be obtained from monitoring wells MW-1 and MW-2 in June 2007. These recommendations were approved by Mr. Richard Spiese of the Vermont Department of Environmental Conservation (VTDEC). 2. GROUNDWATER MONITORING Liquid level measurements were obtained for MW-1 and MW-2, and MW-1 was sampled on June 11, 2007. A Site map indicating the location of the monitoring wells is presented in Appendix A. 2.1. Groundwater flow direction and gradient The monitoring wells were gauged with a KeckTm interface probe to collect the depth to groundwater measurements, and also to detect the presence of free product. Free product was detected in MW-2, at a thickness of 0.03 feet. Liquid level measurements, both present and historic, are located in Appendix B. The relative water table elevations were obtained by subtracting the depth to water from the top of casing elevation. The groundwater elevations obtained from the June 11, 2007 sampling event were plotted and a Groundwater Elevation Map is included in Appendix A. The groundwater flow direction and gradient could not be established for this Site, since only two monitoring wells exist at the Site. However, the topography of the Site and the location of surface waters imply that groundwater flow is most likely directed to the east. 2.2. Groundwater Quality A groundwater sample was collected from MW-1. MW-2 was not sampled due to the presence of free product. The groundwater sample was analyzed by Endyne, Inc (Williston, VT) for major petroleum volatile organic compounds (VOCs) using EPA Method 8021B. Analytical results of the groundwater samples to date are presented in Appendix C. The laboratory analytical report is located in Appendix D. The laboratory data indicated the presence of dissolved hydrocarbons at concentrations higher than the Vermont Groundwater Enforcement Standard (VGES) in the sample collected from monitoring well MW-1. The total targeted VOCs have exhibited a decrease in this monitoring July 2007 1 KAS # 410040018 VTDEC Site # 94-1594 Groundwater Monitoring Report Chittenden Mills Beverage, Jericho, VT well since a spike was reported in 2002. However, contaminant concentrations are still fairly high in this monitoring well. Free product has been measured at this Site since 2003. Approximately 14.8 gallons of product have been removed from the on-Site monitoring wells since free product recovery began in October 2003. Monitoring well MW-1 has not contained free product since August of 2004, while monitoring well MW-2 continues to exhibit small amounts of free product. The analytical results from the June 11, 2007 sampling event were plotted to identify the contamination concentration (see the Contamination Map in Appendix A). The relationship between the total targeted VOCs and time for these wells, as well as free product recovery to date, is presented in graphical form in Appendix C. 2.3. Quality Assurance and Control The groundwater samples obtained during this study were collected in accordance with KAS’ groundwater sampling protocol. VOCs were not detected in the Trip Blank sampled prepared on June 11, 2007. A duplicate sample was obtained at monitoring well MW-1. The relative percent difference (RPD) values are low, and indicate that adequate quality and assurance and control were maintained during sampling, transporting, and analysis. The RPD is defined as 100 times the difference between the actual and duplicate sample, divided by the mean of the two samples. A low RPD indicates a good correlation between the two samples, while a high RPD indicates a poor correlation. The absolute RPD values range from a low of 0.4% for MTBE to a high of 6.4% for xylenes. This data is presented in Appendix C. 3. CONCLUSIONS & RECOMMENDATIONS Based on the groundwater sampling event conducted on June 11, 2007, and historical data at the Chittenden Mills Beverage facility, the following conclusions are presented: 1. Free product was detected in monitoring well MW-2 during the sampling event, and no sample was collected from this monitoring well; and, 2. Petroleum constituents exceeding their applicable VGES continue to be reported in the groundwater sample collected from monitoring well MW-1. The groundwater concentrations in this monitoring well have decreased since a spike was reported in 2002, but the concentrations remain fairly high. Based on these conclusions, KAS recommends quarterly free product recovery Site visits continue at this Site. If no product is measured for three consecutive quarterly visits, the monitoring wells should be re-sampled. During the next sampling groundwater sampling event, samples should be analyzed for 8021 B and Lead Scavengers per the VTDEC memo dated May 3, 2007. Also, pursuant to an email request from Richard Spiese of the VTDEC on June 13, 2007, KAS recommends collecting a sample of the free product and submitting it for analysis of July 2007 2 KAS # 410040018 VTDEC Site # 94-1594 Groundwater Monitoring Report Chittenden Mills Beverage, Jericho, VT Fuel ID during the next quarterly Site visit. The next quarterly free product recovery event will be scheduled for September 2007. July 2007 3 KAS # 410040018 VTDEC Site # 94-1594 SITE North KAS Job Number: 410040018 Source: www.maptech.com Chittenden Mills 39 Vermont Route 15 Jericho, Vermont Site Location Map Date: 11/08/05Drawing No. 1 Scale: NTS By: AR Liquid Level Monitoring Data KAS, Inc. Chittenden Mills Beverage Jericho, Vermont Monitoring Date: 6/11/07 Top of Depth To Depth To Specific Corrected Corrected Well I.D. Well Depth Casing Product Water Product Gravity Water Depth Water Table btoc Elevation btoc btoc Thickness Of Product Equivalent To Water Elevation MW-1 10.03 100.00 - 6.15 - - - - 93.85 MW-2 10.10 99.86 6.01 6.04 0.03 0.76 0.02 6.02 93.84 . All Values Reported in Feet btoc - Below Top of Casing Elevations determined relative to the top of the monitoring well MW-1, which was arbitrarily set at 100' KAS Project # 410040018 VTDEC Site # 94-1594 KAS, Inc. Chittenden Mills Beverage Jericho, Vermont Historic Liquid Level Data Chittenden Mills Beverage Route 15 Jericho, VT Well I.D. Sample Date: 9/8/1994 4/6/1995 10/13/1995 4/25/1996 10/15/1996 4/2/1997 10/3/1997 10/2/1998 3/14/2000 10/19/2000 12/14/2001 MW-1 99.91 91.80 90.51 93.56 91.19 92.26 90.71 92.19 92.12 90.55 89.97 MW-2 99.92 91.82 90.53 93.57 91.20 92.29 90.71 92.19 92.11 90.55 89.76 Well I.D. Sample Date: 10/1/2002 10/14/2003 10/4/2004 10/11/2004 10/18/2004 11/8/2004 12/7/2004 1/3/2005 11/14/2005 12/19/2005 1/4/2006 MW-1 91.49 92.07 94.35 94.07 93.84 93.37 93.36 93.91 94.16 NM 94.00 MW-2 91.48 92.07 94.33 94.03 93.82 93.36 93.35 92.90 94.16 94.13 94.00 Well I.D. Sample Date: 1/16/2006 3/2/2006 3/29/2006 5/11/2006 6/5/2006 7/14/2006 9/13/2006 11/16/2006 2/16/2007 5/20/2007 6/11/2007 MW-1 NM NM NM NM NM NM NM NM NM NM 93.85 MW-2 94.30 93.86 NM 94.06 94.62 94.75 93.65 94.81 93.59 94.40 93.84 Notes: All Values Reported in Feet btoc - Below Top of Casing Elevations determined relative to the top of the monitoring well MW-1, which was arbitrarily set at 100' KAS Project # 410040018 VTDEC Site # 94-1594 Groundwater Quality Data LNAPL Recovery Summary KAS, Inc. Chittenden Mills Beverage Jericho, Vermont MW-1 EPA METHOD 602 Date of Sample Collection Enforcement PARAMETER 9/8/1994 4/6/1995 10/13/1995 4/25/1996 10/15/1996 4/2/1997 10/3/1997 10/2/1998 Standard Benzene 1,240. 264. 518. 186. 615. 75.1 489. 199. 5.0* Chlorobenzene ND>500 ND>50 ND>100 ND>20 ND>100 ND>20 ND>100 ND>50 100* 1,2-DCB ND>500 ND>50 ND>100 ND>20 ND>100 ND>20 ND>100 ND>50 600* 1,3-DCB ND>500 ND>50 ND>100 ND>20 ND>100 ND>20 ND>100 ND>50 600** 1,4-DCB ND>500 ND>50 ND>100 ND>20 ND>100 ND>20 ND>100 ND>50 75* Ethylbenzene ND>500 102.