Download or read book Anual Report of Groundwater Monitoring at Centralia Kansas in 2015 written by and published by . This book was released on 2016 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The KDHE (2012) agreed to annual sampling at all locations, beginning with the 2013 monitoring documented previously (Argonne 2014a). This present report documents the results of the annual sampling of the approved monitoring well network on September 27-30, 2015.

Download or read book Annual Report of Groundwater Monitoring at Centralia Kansas in 2014 written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Annual Report of Groundwater Monitoring at Centralia Kansas in 2011 written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Annual Report of Groundwater Monitoring at Centralia Kansas in 2013 written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This present report documents the results of the annual sampling of the approved monitoring well network on September 25-26, 2013.

Download or read book Annual Report of Groundwater Monitoring at Centralia Kansas in 2009 written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In September 2005, periodic sampling of groundwater was initiated by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Centralia, Kansas. The sampling at Centralia is being performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE). The objective is to monitor levels of carbon tetrachloride contamination identified in the groundwater at Centralia (Argonne 2003, 2004, 2005a). Under the KDHE-approved monitoring plan (Argonne 2005b), the groundwater was sampled twice yearly from September 2005 until September 2007 for analyses for volatile organic compounds (VOCs), as well as measurement of selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. The results from the two-year sampling program demonstrated the presence of carbon tetrachloride contamination at levels exceeding the KDHE Tier 2 risk-based screening level (RBSL) of 5 [mu]g/L for this compound in a localized groundwater plume that has shown little movement. The relative concentrations of chloroform, the primary degradation product of carbon tetrachloride, suggested that some degree of reductive dechlorination or natural biodegradation was taking place in situ at the former CCC/USDA facility on a localized scale. The CCC/USDA subsequently developed an Interim Measure Conceptual Design (Argonne 2007b), proposing a pilot test of the Adventus EHC technology for in situ chemical reduction (ISCR). The proposed interim measure (IM) was approved by the KDHE in November 2007 (KDHE 2007). Implementation of the pilot test occurred in November-December 2007. The objective was to create highly reducing conditions that would enhance both chemical and biological reductive dechlorination in the injection test area (Argonne 2009a). The KDHE (2008a) has requested that sitewide monitoring continue at Centralia until a final remedy has been selected (as part of a Corrective Action Study [CAS] evaluation) and implemented for this site. In response to this request, twice-yearly sampling of 10 monitoring wells and 6 piezometers (Figure 1.1) previously approved by the KDHE for monitoring of the groundwater at Centralia (KDHE 2005a, b) was continued in 2008. The sampling events under this extension of the two-year (2005-2007) monitoring program occurred in March and September 2008 (Argonne 2008b, 2009b). Additional piezometers specifically installed to evaluate the progress of the IM pilot test (PMP1-PMP9; Figure 1.2) were also sampled in 2008; the results of these analyses were reported and discussed separately (Argonne 2009a). On the basis of results of the 2005-2008 sitewide monitoring and the 2008 IM pilot test monitoring, the CCC/USDA recommended a revised sampling program to address both of the continuing monitoring objectives until a CAS for Centralia is developed (Section 4.2 in Argonne 2009b). The elements of this interim monitoring plan are as follows: (1) Annual sampling of twelve previously established (before the pilot test) monitoring points (locations identified in Figure 1.3) and the five outlying pilot test monitoring points (PMP4, PMP5, PMP6, PMP7, PMP9; Figure 1.4); and (2) Sampling twice yearly at the five pilot test monitoring points inside the injection area (PMP1-PMP3, PMP8, MW02; Figure 1.4). With the approval of the KDHE (2009), groundwater sampling for analyses of VOCs and selected other geochemical parameters was conducted at Centralia under the interim monitoring program outlined above in April and October 2009. This report documents the findings of the 2009 monitoring events.

Download or read book Annual Report of Groundwater Monitoring at Centralia Kansas in 2010 written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In September 2005, periodic sampling of groundwater was initiated by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Centralia, Kansas. The sampling at Centralia is performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE). The objective is to monitor levels of carbon tetrachloride contamination identified in the groundwater at Centralia (Argonne 2003, 2004, 2005a). Under the KDHE-approved monitoring plan (Argonne 2005b), the groundwater was sampled twice yearly from September 2005 until September 2007 for analyses for volatile organic compounds (VOCs), as well as measurement of selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation processes (reductive dechlorination) in the subsurface environment (Argonne 2006, 2007a, 2008a). The results from the two-year sampling program demonstrated the presence of carbon tetrachloride contamination at levels exceeding the KDHE Tier 2 risk-based screening level (RBSL) of 5 [mu]g/L for this compound, in a localized groundwater plume that has shown little movement. The relative concentrations of chloroform, the primary degradation product of carbon tetrachloride, suggested that some degree of reductive dechlorination or natural biodegradation was talking place in situ at the former CCC/USDA facility on a localized scale. The CCC/USDA subsequently developed an Interim Measure Conceptual Design (Argonne 2007b), proposing a pilot test of the Adventus EHC technology for in situ chemical reduction (ISCR). The proposed interim measure (IM) was approved by the KDHE in November 2007 (KDHE 2007). Implementation of the pilot test occurred in November-December 2007. The objective was to create highly reducing conditions that would enhance both chemical and biological reductive dechlorination in the injection test area (Argonne 2009a). The KDHE (2008a) requested that sitewide monitoring continue until a final remedy is selected (as part of a Corrective Action Study [CAS] evaluation) and implemented. In response to this request, the established sampling across the site and additional sampling in the IM pilot test area continued in 2008 (Argonne 2008b, 2009a, b). On the basis of results of the 2005-2008 sitewide monitoring and the 2008 IM pilot test monitoring, the CCC/USDA recommended a revised sampling program for both the wider site and the IM pilot test area (Section 4.2 in Argonne 2009b). The elements of this interim monitoring plan are as follows: (1) Annual sampling of twelve monitoring points across the site (Figure 1.1) and five outlying IM pilot test monitoring points (PMP4, PMP5, PMP6, PMP7, PMP9; Figure 1.2); and (2) Twice yearly sampling of five IM pilot test monitoring points inside the injection area (PMP1-PMP3, PMP8, MW02; Figure 1.2). With the approval of the KDHE (2009), the initial groundwater sampling for VOCs and geochemical analyses under the interim monitoring plan outlined above was conducted in 2009 (Argonne 2010). The present report documents the findings of the 2010 monitoring events, conducted on April 5 and September 19-21, 2010.

Download or read book Annual Report of Groundwater Monitoring at Centralia Kansas in 2012 written by and published by . This book was released on 2013 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Periodic sampling is performed at Centralia, Kansas, on behalf of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) by Argonne National Laboratory. The sampling is currently (2009-2012) conducted in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE 2009). The objective is to monitor levels of carbon tetrachloride contamination identified in the groundwater sitewide (Argonne 2003, 2004, 2005a), as well as the response to the interim measure (IM) pilot test that is in progress (Argonne 2007b). This report provides a summary of the findings for groundwater inspection in Centralia.

Download or read book Final Report written by L. M. LaFreniere and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This document reports the results of groundwater sampling in September-October 2005 and March 2006 at the grain storage facility formerly operated at Centralia, Kansas, by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). These activities were the first and second twice yearly sampling events of the two-year monitoring program approved by the CCC/USDA and Kansas Department of Health and Environment (KDHE) project managers. The initial monitoring network sampled in September and October 2005 consisted of six monitoring wells (MW1-MW6) installed in 2004, plus five groundwater piezometers (SB01, SB04, SB05, SB08, SB09) installed in 2002. The combined September-October 2005 sampling was the first monitoring event in the planned two-year program for Centralia. The groundwater samples collected in both September and October were analyzed for volatile organic compounds (VOCs), and samples collected in September were analyzed for dissolved hydrogen and additional groundwater parameters to aid in evaluating the potential for reductive dechlorination processes. After the monitoring in September-October 2005, Argonne recommended expansion of the initial monitoring network. Previous sampling (August 2004) had already suggested that this network of six monitoring wells and five piezometers was inadequate to delineate the extent of the carbon tetrachloride plume. With the approval of the CCC/USDA and KDHE project managers, the monitoring network was expanded in January 2006 through the installation of four additional monitoring wells (MW7-MW10) and one new piezometer (SB07R) to replace a damaged piezometer (the former SB07). Details of the monitoring well and piezometer installations are reported in this document. The expanded monitoring network of ten monitoring wells (MW01-MW10) and six piezometers (SB01, SB04, SB05, SB07R, SB08, and SB09) was sampled in March 2006. This March 2006 sampling was the second monitoring event in the planned two-year program. Results of analyses for VOCs showed further increases in contaminant levels and expansion of the carbon tetrachloride plume toward the south and west from the former CCC/USDA facility. The groundwater samples collected in March 2006 were also analyzed for additional groundwater parameters to aid in the evaluation of the potential for reductive dechlorination processes. Preliminary screening of groundwater parameters provided limited evidence that reductive dechlorination of carbon tetrachloride is taking place at some locations on the former CCC/USDA facility. Groundwater levels measured manually in September 2005, March 2006, and June 2006 were used to map the potentiometric surface at Centralia. Overall, these results were consistent with each other and with previous measurements, generally indicating a groundwater flow direction toward the south-southwest from the former CCC/USDA facility. Data recorders installed in wells MW01-MW06 in August 2004 are gathering long-term data on the groundwater elevation and gradient. Data downloaded in March 2005, September 2005, and June 2006 indicate that two wells north and west of the former CCC/USDA facility boundary show distinct, transient and seasonal water level variations. In contrast, two different wells southwest and south of the former facility boundary show virtually no response to the same events. The first two monitoring events of the planned two-year monitoring program for Centralia have demonstrated increased carbon tetrachloride concentrations and lateral expansion of the contaminated zone. Argonne recommends that the CCC/USDA and KDHE project managers consider development and approval of a work plan to expedite the selection and implementation of an active remedial alternative addressing the concentrated areas of groundwater contamination before the end of the two-year monitoring program in 2007.

Download or read book Final Work Plan written by L. M. LaFreniere and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This Work Plan outlines the scope of work for a program of twice yearly groundwater monitoring at the site of a former grain storage facility at Centralia, Kansas (Figure 1.1). The purposes of this monitoring program are to follow changes in plume dynamics and to collect data necessary to evaluate the suitability of monitored natural attenuation as a remedial option, under the requirements of Kansas Department of Health and Environment (KDHE) Policy No. BER-RS-042. This monitoring program is planned for a minimum of 2 yr. The planned monitoring activity is part of an investigation at Centralia being performed on behalf of the Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), by the Environmental Research Division of Argonne National Laboratory. Argonne is a nonprofit, multidisciplinary research center operated by the University of Chicago for the U.S. Department of Energy (DOE). The CCC/USDA has entered into an interagency agreement with DOE, under which Argonne provides technical assistance to the CCC/USDA with environmental site characterization and remediation at its former grain storage facilities. Details and background for this Work Plan were presented previously (Argonne 2004, 2005). Argonne has also issued a Master Work Plan (Argonne 2002) that describes the general scope of and guidance for all investigations at former CCC/USDA facilities in Kansas. The Master Work Plan (approved by the KDHE) contains the materials common to investigations at all locations in Kansas. These documents must be consulted for the complete details of plans for this work associated with the former CCC/USDA facility at Centralia.

Download or read book Annual Report of Monitoring at Everest Kansas in 2015 written by and published by . This book was released on 2016 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: In March 2009, the CCC/USDA developed a plan for annual monitoring of the groundwater and surface water (Argonne 2009). Under this plan, approved by the KDHE (2009), monitoring wells are sampled by using the low-flow procedure (Puls and Barcelona 1996; Yeskis and Zavala 2002), and surface water samples are collected at five locations along the intermittent creek. Vegetation sampling is conducted as a secondary indicator of plume migration. As of 2015, the frequency of surface water sampling has been decreased to once yearly, per the approval of the KDHE (2015).

Download or read book Annual Report of Groundwater Monitoring at Everest Kansas in 2010 written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) began its environmental investigations at Everest, Kansas, in 2000. The work at Everest is implemented on behalf of the CCC/USDA by Argonne National Laboratory, under the oversight of the Kansas Department of Health and Environment (KDHE). The results of the environmental investigations have been reported in detail (Argonne 2001, 2003, 2006a, b). The lateral extent of the carbon tetrachloride in groundwater over the years of investigation has been interpreted as shown in Figure 1.1 (2001-2002 data), Figure 1.2 (2006 data), Figure 1.3 (2008 data), and Figure 1.4 (2009 data). The pattern of groundwater flow and inferred contaminant migration has consistently been to the north-northwest from the former CCC/USDA facility toward the Nigh property, and then west-southwest from the Nigh property (e.g., Figure 1.5 [2008 data] and Figure 1.6 [2009 data]). Both the monitoring data for carbon tetrachloride and the low groundwater flow rates estimated for the Everest aquifer unit (Argonne 2003, 2006a, b, 2008) indicate slow contaminant migration. On the basis of the accumulated findings, in March 2009 the CCC/USDA developed a plan for annual monitoring of the groundwater and surface water. This current monitoring plan (Appendix A in the report of monitoring in 2009 [Argonne 2010]) was approved by the KDHE (2009a). Under this plan, the monitoring wells are sampled by the low-flow procedure, and sample preservation, shipping, and analysis activities are consistent with previous work at Everest. The annual sampling will continue until identified conditions at the site indicate a technical justification for a change. The first annual sampling event under the new monitoring plan took place in April 2009. The results of analyses for volatile organic compounds (VOCs) and water level measurements were consistent with previous observations (Figures 1.1-1.4). No carbon tetrachloride was detected in surface water of the intermittent creek or in tree branch samples collected at 18 locations along the creek banks. The complete results were reported previously (Argonne 2010). This report presents the results of the second annual sampling events, conducted in 2010. Included in the 2010 monitoring were the following: (1) Continued automatic and manual monitoring of groundwater levels. (2) Groundwater sampling on April 8-9, 2010. (3) Surface water sampling on April 8, 2010. (4) Vegetation sampling on July 28, 2010. (5) Indoor air sampling at selected residences on August 11-12, 2010. The activities are described in Section 2, and the results are discussed in Section 3. Conclusions and recommendations are presented in Section 4.

Download or read book Annual Reporting of Monitoring at Morrill Kansas in 2015 written by and published by . This book was released on 2016 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: In September 2005, the CCC/USDA initiated periodic sampling of groundwater, in accord with a program (Argonne 2005b) approved by the KDHE (2005), to monitor carbon tetrachloride concentrations in the groundwater. Under the KDHE-approved monitoring plan (Argonne 2005b), groundwater was sampled twice yearly for VOCs analyses through 2011. During the initial two years of monitoring, analysis for selected geochemical parameters was also conducted to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. Consistently low levels of dissolved oxygen (DO) and oxidation-reduction potential (ORP) at monitoring well MW1D (in the deepest portion of the contaminated aquifer) and the presence of chloroform (the primary degradation product of carbon tetrachloride) suggested that some degree of reductive dechlorination was occurring.

Download or read book Annual Report of Groundwater Monitoring at Everest Kansas in 2013 written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the results of the annual sampling event conducted in 2013.

Download or read book Annual Report of Groundwater Monitoring at Everest Kansas in 2011 written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Everest, Kansas, is a small rural community (population approximately 300) located in the southeast corner of Brown County, in the northeastern corner of Kansas. Carbon tetrachloride and chloroform contamination in groundwater at Everest was initially identified in 1997 as a result of testing performed under the Commodity Credit Corporation/U.S. Department of Agriculture (CCC/USDA) private well sampling program conducted by the Kansas Department of Health and Environment (KDHE). The KDHE collected samples from seven private wells in and near Everest. Carbon tetrachloride and chloroform were found in only one of the wells, the Donnie Nigh domestic well (owned at that time by Tim Gale), approximately 3/8 mi northwest of the former Everest CCC/USDA facility. Carbon tetrachloride and chloroform were detected at 121?g/L and 4?g/L, respectively. Nitrate was found at 12.62 mg/L. The USDA subsequently connected the Nigh residence to the Everest public water supply system. The findings of the 2011 monitoring at Everest support the following conclusions: (1) Measurements of groundwater levels obtained manually during annual monitoring in 2009-2011 (and through the use of automatic recorders in 2002-2010) have consistently indicated an initial direction of groundwater flow from the former CCC/USDA facility to the north-northwest and toward the Nigh property, then west-southwest from the Nigh property toward the intermittent creek that lies west of the former CCC/USDA facility and the Nigh property. (2) At most of the monitored locations, carbon tetrachloride concentrations decreased in April 2011 relative to 2010 results. Noteworthy decreases of> 50% occurred at locations MW4, MW60, and MW88, in the most concentrated part of the plume. (3) Comparison of accumulated data demonstrates that the area of the carbon tetrachloride plume with concentrations> 200?g/L has decreased markedly over time and suggests a generally decreasing trend in contaminant levels. (4) The trace increases in carbon tetrachloride concentrations observed in 2010 at locations SB63 and SB64 were notable because of the locations proximity to the downgradient intermittent creek. However, these increases were not confirmed in sampling in 2011. (5) The results of the April 2011 monitoring event continue to support the interpretation, made during the 9-yr observation period from 2001 to 2010, that the migration rate for contamination in groundwater toward the intermittent creek is very slow. (6) No carbon tetrachloride was detected in five samples of surface water collected from the intermittent creek west of the former CCC/USDA facility and the Nigh property, or in tree branch tissue samples collected at locations along the banks of the creek. These observations indicate that the carbon tetrachloride contamination identified at Everest has, to date, not impacted the surface waters of the intermittent creek.

Download or read book Groundwater Monitoring Report Semi annual Second Half 2015 written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Annual Report of Groundwater Monitoring at Everest Kansas in 2012 written by and published by . This book was released on 2013 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: In March 2009, the CCC/USDA developed a plan for annual monitoring of the groundwater and surface water (Argonne 2009). Under this plan, approved by the KDHE (2009), monitoring wells are sampled by using the low-flow procedure, and surface water samples are collected at five locations along the intermittent creek. Vegetation sampling is conducted as a secondary indicator of plume migration. Results of annual sampling in 2009-2011 for volatile organic compounds (VOCs) and water level measurements (Argonne 2010a, 2011a, b) were consistent with previous observations (Argonne 2003, 2006a, d, 2008). No carbon tetrachloride was detected in surface water of the intermittent creek or in tree branch samples collected at locations along the creek banks. This report presents the results of the fourth annual sampling event, conducted in 2012.

Download or read book Annual Report of Monitoring at Morrill Kansas in 2009 written by and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In September 2005, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) initiated periodic sampling of groundwater in the vicinity of a grain storage facility formerly operated by the CCC/USDA at Morrill, Kansas. The sampling at Morrill is being performed on behalf of the CCC/USDA by Argonne National Laboratory, in accord with a monitoring program approved by the Kansas Department of Health and Environment (KDHE 2005), to monitor levels of carbon tetrachloride contamination identified in the groundwater at this site (Argonne 2004, 2005a). This report provides results for monitoring events in April and September 2009. Under the KDHE-approved monitoring plan (Argonne 2005b), groundwater was initially sampled twice yearly for a period of two years (in fall 2005, in spring and fall 2006, and in spring and fall 2007). The samples were analyzed for volatile organic compounds (VOCs), as well as for selected geochemical parameters to aid in the evaluation of possible natural contaminant degradation (reductive dechlorination) processes in the subsurface environment. The analytical results for groundwater sampling events at Morrill from September 2005 to October 2008 were documented previously (Argonne 2006a, b, 2007, 2008a, b, 2009). Those results consistently demonstrated the presence of carbon tetrachloride contamination, at levels exceeding the KDHE Tier 2 risk-based screening level of 5.0?g/L for this compound, in a groundwater plume extending generally south-southeastward from the former CCC/USDA facility, toward Terrapin Creek at the south edge of the town. Low levels (d"1.3?g/L) of carbon tetrachloride were persistently detected at monitoring well MW8S, on the bank of an intermittent tributary to Terrapin Creek. This observation suggested a possible risk of contamination of the surface waters of the creek. That concern is the regulatory driver for ongoing monitoring. In light of the early findings, in 2006 the CCC/USDA recommended expansion of the approved monitoring program to include the collection and analysis of surface water samples along Terrapin Creek (Argonne 2006a). At the request of the KDHE (2007a), locations for both surface water and shallow sediment sampling were discussed with the KDHE in January 2007. An addendum to the existing monitoring plan (Appendix A) and a standard operating procedure (SOP AGEM-15; Appendix B) for sediment sampling were submitted to the KDHE on the basis of these discussions and were subsequently approved (KDHE 2008b). Results of sediment sampling prior to 2009 were reported previously (Argonne 2008a, b; 2009). To supplement the original scope of the monitoring, Argonne also sampled natural vegetation along Terrapin Creek in October 2006, April 2007, and July 2007 for analyses for VOCs. The results of these plant tissue analyses were reported previously (Argonne 2008a, 2009). The April and September 2009 sampling events reported here represent a continuation of the two-year monitoring program, as requested by the KDHE (2007b). The groundwater sampling is presently conducted, in accord with the monitoring plan (Argonne 2005b) and the addendum to that plan (Appendix A in this report), in a network of 12 monitoring wells and 3 private wells (Figure 1.1), at locations approved by the KDHE (2008b). The findings of the April and September 2009 monitoring events at Morrill support the following conclusions: (1) Groundwater flow during the early spring and the later part of this review period was predominantly to the south-southeast, from the vicinity of the former CCC/USDA facility toward Terrapin Creek. In late spring, a slight shift occurred toward more southerly groundwater flow (possibly southwesterly in the immediate vicinity of the intermittent tributary that flows into Terrapin Creek). This shift in the late spring reflected transient seasonal precipitation and recharge that resulted in higher groundwater levels at this time. (2) No significant changes were observed in the levels or distribution of carbon tetrachloride in the groundwater at Morrill during the current review period, or in comparison to the results of the spring and fall 2008 monitoring events. A maximum carbon tetrachloride concentration of 28-30?g/L was identified in groundwater - at well MW3S - during both the April and September 2009 sampling events. (3) No carbon tetrachloride contamination was detected in surface waters or shallow streambed sediments sampled at five locations along Terrapin Creek, downgradient from the former CCC/USDA facility. (4) Sampling of tree branch tissues from existing trees for VOCs analyses can be an indicator of shallow subsurface groundwater contamination. Detections of carbon tetrachloride in vegetation at the Morrill site to date have been generally consistent with the documented location of the groundwater plume.