This Work Plan outlines the scope of work to be conducted to investigate the subsurface contaminant conditions at the property formerly leased by the Commodity Credit Corporation (CCC) in Powhattan, Kansas (Figure 1.1). Data obtained during this event will be used to (1) evaluate potential contaminant source areas on the property; (2) determine the vertical and horizontal extent of potential contamination; and (3) provide recommendations for future action, with the ultimate goal of assigning this site No Further Action status. The planned investigation includes groundwater monitoring requested by the Kansas Department of Health and Environment (KDHE), in accordance with Section V of the Intergovernmental Agreement between the KDHE and the Farm Service Agency of the U.S. Department of Agriculture (USDA). The work is being performed on behalf of the CCC/USDA by the Environmental Science Division of Argonne National Laboratory. A nonprofit, multidisciplinary research center operated by the University of Chicago for the U.S. Department of Energy, Argonne provides technical assistance to the CCC/USDA with environmental site characterization and remediation at former CCC/USDA grain storage facilities. Argonne issued a Master Work Plan (Argonne 2002) that has been approved by the KDHE. The Master Work Plan describes the general scope of all …

None

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) formerly operated a grain storage facility (during most of the interval 1949-1974) at Barnes, Kansas. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to investigate this contamination. In November 2007, the CCC/USDA began quarterly groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, in accord with the recommendations made in the report for the 2006-2007 targeted investigation (Argonne 2007). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. The sampling is presently conducted in a network of 28 individual monitoring wells at 19 distinct locations, 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation demonstrated the presence of carbon tetrachloride contamination at levels slightly exceeding the Kansas Department of Health and Environment (KDHE) Tier 2 risk-based screening level of 5.0 {micro}g/L for this compound, in a plume that appears to extend from the former CCC/USDA property northwestward, toward the Barnes public …

This Work Plan outlines the scope of work for targeted sampling at Webber, Kansas (Figure 1.1). This activity is being conducted at the request of the Kansas Department of Health and Environment (KDHE), in accordance with Section V of the Intergovernmental Agreement between the KDHE and the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). Data obtained in this sampling event will be used to (1) evaluate the current status of previously detected contamination at Webber and (2) determine whether the site requires further action. This work is being performed on behalf of the CCC/USDA by the Environmental Science 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. Argonne has 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 …

This document presents an Interim Measure Work Plan/Design for the short-term, field-scale pilot testing and subsequent implementation of a non-emergency Interim Measure (IM) at the site of the former grain storage facility operated by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) in Centralia, Kansas. The IM is recommended to mitigate both (1) localized carbon tetrachloride contamination in the vadose zone soils beneath the former facility and (2) present (and potentially future) carbon tetrachloride contamination identified in the shallow groundwater beneath and in the immediate vicinity of the former CCC/USDA facility. Investigations conducted on behalf of the CCC/USDA by Argonne National Laboratory have demonstrated that groundwater at the Centralia site is contaminated with carbon tetrachloride at levels that exceed the Kansas Tier 2 Risk-Based Screening Level (RBSL) and the U.S. Environmental Protection Agency's maximum contaminant level of 5.0 {micro}g/L for this compound. Groundwater sampling and analyses conducted by Argonne under a monitoring program approved by the Kansas Department of Health and Environment (KDHE) indicated that the carbon tetrachloride levels at several locations in the groundwater plume have increased since twice yearly monitoring of the site began in September 2005. The identified groundwater contamination currently poses no unacceptable …

Contamination in groundwater at Canada, Kansas, was discovered in 1997, during limited private well sampling near former grain storage facilities of the Commodity Credit Corporation, U.S. Department of Agriculture (CCC/USDA). Subsequent investigations by the Kansas Department of Health and Environment (KDHE) confirmed carbon tetrachloride and nitrate concentrations in groundwater above the respective maximum contaminant levels (MCLs) of 5.0 {micro}g/L and 10.0 mg/L. The KDHE investigations identified both the former CCC/USDA grain storage facility and a private grain storage facility as likely sources for the carbon tetrachloride contamination. The CCC/USDA funded extension of a rural water district line to provide a permanent alternate water supply, and the KDHE has conducted long-term monitoring under the State Water Plan. This document presents an analysis of the available information for the Canada site, acquired in previous investigations and the long-term KDHE monitoring. This analysis forms the technical justification for a request to reclassify the former CCC/USDA grain storage facility at Canada as a site requiring no further action under the Intergovernmental Agreement (IGA) between the KDHE and the USDA's Farm Service Agency. The KDHE's long-term water level monitoring results indicate a consistent groundwater flow direction to the east-southeast. Consequently, the wells with the highest …

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility at the northeastern edge of the city of Hanover, Kansas, from 1950 until the early 1970s. During this time, commercial grain fumigants containing carbon tetrachloride were in common use by the grain storage industry to preserve grain in their facilities. In February 1998, trace to low levels of carbon tetrachloride (below the maximum contaminant level [MCL] of 5.0 {micro}g/L) were detected in two private wells near the former grain storage facility at Hanover, as part of a statewide USDA private well sampling program that was implemented by the Kansas Department of Health and Environment (KDHE) near former CCC/USDA facilities. In 2007, the CCC/USDA conducted near-surface soil sampling at 61 locations and also sampled indoor air at nine residences on or adjacent to its former Hanover facility to address the residents concerns regarding vapor intrusion. Low levels of carbon tetrachloride were detected at four of the nine homes. The results were submitted to the KDHE in October 2007 (Argonne 2007). On the basis of the results, the KDHE requested sub-slab sampling and/or indoor air sampling (KDHE 2007). This Work Plan describes, in …

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), to monitor levels of carbon tetrachloride contamination identified in the groundwater at this site (Argonne 2004, 2005a). This report provides results for the most recent monitoring event, in April 2008. Under the KDHE-approved monitoring plan (Argonne 2005b), groundwater was initially sampled twice yearly for a recommended 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. During the recommended two-year period, the originally approved scope of the monitoring was expanded to include vegetation sampling (initiated in October 2006) and surface water and stream bed sediment sampling (initiated in March 2007, after a …

On September 8-9, 2005, representatives of the Kansas Department of Health and Environment (KDHE), the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA), and Argonne National Laboratory met at the KDHE's offices in Topeka to review the status of the CCC/USDA's environmental activities in Kansas. A key CCC/USDA goal for this meeting was to obtain KDHE input on the selection of possible remedial approaches to be examined as part of the Corrective Action Study (CAS) for this site. As a result of the September meeting, the KDHE recommended several additional activities for the Everest site, to further assist in selecting and evaluating remedial alternatives for the CAS. The requested actions included the following: (1) Construction of several additional interpretive cross sections to improve the depiction of the hydrogeologic characteristics affecting groundwater and contaminant movement along the apparent main plume migration pathway to the north-northwest of the former CCC/USDA facility, and in the vicinity of the Nigh property. (2) Identification of potential locations for several additional monitoring wells, to better constrain the apparent western and northwestern margins of the existing groundwater plume. (3) Development of technical recommendations for a stepwise pumping study of the Everest aquifer unit in the …

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Barnes, Kansas, during most of the interval 1949-1974. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to characterize this contamination. Those results were reported previously (Argonne 2008a). In November 2007, the CCC/USDA began quarterly groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, in accord with the recommendations made in the report for the 2006-2007 targeted investigation (Argonne 2008a). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. The sampling is presently conducted in a network of 28 individual monitoring wells (at 19 distinct locations), 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation and the subsequent monitoring events in November 2007 (Argonne 2008b) and March 2008 (Argonne 2008c) demonstrated the presence of carbon tetrachloride contamination in groundwater at levels slightly exceeding the Kansas Department of Health and Environment (KDHE) Tier 2 risk-based screening level …

This document reports the results of groundwater monitoring in September 2005 and March 2006 at the grain storage facility formerly operated at Morrill, 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 monitoring network sampled in September 2005 consisted of 9 monitoring wells (MW1S-MW5S and MW1D [installed in the mid 1990s] and MW6S-MW8S [installed in 2004]), plus 3 private wells (Isch, Rillinger, and Stone). The groundwater samples collected in this first event were analyzed for volatile organic compounds (VOCs), dissolved hydrogen, and additional groundwater parameters to aid in evaluating the potential for reductive dechlorination processes. After the monitoring in September 2005, Argonne recommended expansion of the initial monitoring network. Previous sampling (August 2004) had already suggested that the initial network 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 3 additional monitoring wells (MW9S-MW11S). Details of the monitoring well installations are …

The 2006-2007 investigation of carbon tetrachloride and chloroform contamination at Barnes, Kansas, was conducted at the request of the Kansas Department of Health and Environment (KDHE). The Environmental Science Division of Argonne National Laboratory implemented the investigation on behalf of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The overall goal of the investigation was to establish criteria for monitoring leading to potential site reclassification. The investigation objectives were to (1) determine the hydraulic gradient near the former CCC/USDA facility, (2) delineate the downgradient carbon tetrachloride plume, and (3) design and implement an expanded monitoring network at Barnes (Argonne 2006a).

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 is being sampled twice yearly (for a recommended period of two years) 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 sampling is presently conducted in a network of 10 monitoring wells and 6 piezometers (Figure 1.1), at locations approved by the KDHE (Argonne 2006a). The results of groundwater sampling and VOCs analyses in September-October 2005, March 2006, September 2006, March 2007, and September 2007 were documented previously (Argonne 2006a,b, 2007a, 2008). The results have demonstrated the presence …

This Interim Measure Work Plan/Design (IMWP/D) is supplemental to the Argonne document Interim Measure Conceptual Design for Remediation of Source Area Contamination at Agra, Kansas. The IMWP/D includes information required by Kansas Department of Health and Environment (KDHE) Policy BER-RS-029, Policy and Scope of Work for Interim Measures. Specific to Policy BER-RS-029 is the requirement for several documents that will ensure that an adequate amount and type of data are collected for implementation of the IMWP/D and that data quality and safe conditions are prevailed. Such information is included in the IMWP/D as follows: Appendix A: Data Acquisition Plan--Design Testing Requirements; Appendix B: Basis of Design; Appendix C: Permits; Appendix D: Quality Assurance Project Plan; Appendix E: Health and Safety Plan; and Appendix F: Operations, Maintenance, and Monitoring Schedule. The proposed remedial technology for this project is the installation of five large-diameter boreholes (LDBs) in a source area that has been identified on the property formerly used for grain storage by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The goal of the LDB technology is the remediation of the source area by removal of mass quantities of contaminated soil from the vadose zone and treatment of …

On September 8-9, 2005, representatives of the Kansas Department of Health and Environment (KDHE), the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA), and Argonne National Laboratory met at the KDHE's offices in Topeka to review the status of the CCC/USDA's environmental activities in Kansas. As a result of this meeting, the KDHE recommended several additional activities to augment the CCC/USDA's investigations at Everest, Kansas, and assist in the selection of remedial approaches to be evaluated as part of a Corrective Action Study (CAS) for this site. The requested actions included the following: (1) Construction of several additional interpretive cross sections illustrating the hydrogeologic setting along the apparent main plume migration pathway to the north-northwest of the former CCC/USDA facility, as well as in the vicinity of the Nigh property. (2) Installation of additional permanent monitoring wells, to better constrain the apparent western, northern, and northwestern margins of the existing groundwater plume. (3) Development of technical recommendations for a phased pumping study of the Everest aquifer unit in the area near and to the north of the Nigh property.

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility in Hilton, Kansas, in 1954-1965. In 1992, carbon tetrachloride was first identified, at a concentration of 910 {micro}g/L, in groundwater from well GW01 at Hilton. This discovery occurred in association with the sale of the private grain storage facility on which well GW01 is located to the current owner, the Mid-Kansas Cooperative Association. The Kansas Department of Health and Environment conducted investigations at Hilton in 1992-1994. In 1996-1997, Argonne National Laboratory conducted Phase I and Phase II investigations on behalf of the CCC/USDA to characterize the distribution of the carbon tetrachloride contamination identified in well GW01, the stratigraphic units potentially hosting contaminant migration, and local hydrogeology in the Hilton area. The 2007 targeted investigation reported here focused specifically on the former CCC/USDA property at Hilton, west of the railroad tracks. (Until a property record search in 2005, the location of the CCC/USDA's former facility at Hilton was not known with certainty.) The objectives of the investigation, as implemented, were to (1) investigate for carbon tetrachloride contamination in the shallower soil and shallow aquifer units below the former CCC/USDA property and (2) …

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Barnes, Kansas, during most of the interval 1949-1974. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to characterize this contamination. Those results were reported previously (Argonne 2007). In November 2007, the CCC/USDA began quarterly groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, in accord with the recommendations made in the report for the 2006-2007 targeted investigation (Argonne 2007). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. The sampling is presently conducted in a network of 28 individual monitoring wells (at 19 distinct locations), 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation (Argonne 2007) and the initial monitoring in November 2007 (Argonne 2008) demonstrated the presence of carbon tetrachloride contamination in groundwater at levels slightly exceeding the Kansas Department of Health and Environment (KDHE) Tier 2 risk-based screening level (RBSL) of 5.0 {micro}g/L …

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), operated a grain storage facility at the northeastern edge of the city of Hanover, Kansas, from 1950 until the early 1970s. During this time, commercial grain fumigants containing carbon tetrachloride were in common use by the grain storage industry to preserve grain in their facilities. In February 1998, trace to low levels of carbon tetrachloride (below the maximum contaminant level [MCL] of 5.0 {micro}g/L) were detected in two private wells near the former grain storage facility at Hanover, as part of a statewide USDA private well sampling program that was implemented by the Kansas Department of Health and Environment (KDHE) near former CCC/USDA facilities. In April 2007, the CCC/USDA collected near-surface soil samples at 1.8-2 ft BGL (below ground level) at 61 locations across the former CCC/USDA facility. All soil samples were analyzed by the rigorous gas chromatograph-mass spectrometer analytical method (purge-and-trap method). No contamination was found in soil samples above the reporting limit of 10 {micro}g/kg. In July 2007, the CCC/USDA sampled indoor air at nine residences on or adjacent to its former facility to address the residents concerns regarding vapor intrusion. Low levels of …

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), formerly operated grain storage facilities at two different locations at Everest, Kansas (Figure 1.1). One facility (referred to in this report as the Everest facility) was at the western edge of the city. The second facility (referred to in this report as Everest East) was about 0.5 mi northeast of the town. The CCC/USDA operated these facilities from the early 1950s until the early 1970s, at a time when commercial fumigants containing carbon tetrachloride were in common use by the CCC/USDA and private industry for the preservation of grain in storage. In 1997 the Kansas Department of Health and Environment (KDHE) sampled several domestic drinking water and non-drinking water wells in the Everest area as part of the CCC/USDA Private Well Sampling Program. All of the sampled wells were outside the Everest city limits. Carbon tetrachloride contamination was identified at a single domestic drinking water well (the Nigh well, DW06; Figure 1.1) approximately 3/8 mi northwest of the former Everest CCC/USDA grain storage facility. Subsequent KDHE investigations suggested that the contamination in DW06 could be linked to the former use of grain fumigants at the CCC/USDA …

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 …

The 2007 investigation of carbon tetrachloride and chloroform contamination at Powhattan, Kansas, was conducted at the request of the Kansas Department of Health and Environment (KDHE 2006a). The Environmental Science Division of Argonne National Laboratory implemented the investigation on behalf of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The primary purposes of the investigation were to evaluate potential contaminant source areas on the former CCC/USDA property, determine the horizontal and vertical extent of potential contamination, conduct groundwater monitoring, and provide recommendations for future action.

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 is being sampled twice yearly (for a recommended period of two years) 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 sampling is presently conducted in a network of 10 monitoring wells and 6 piezometers (Figure 1.1), at locations approved by the KDHE (Argonne 2006a). The results of groundwater sampling and VOCs analyses in September-October 2005, March 2006, September 2006, and March 2007 were documented previously (Argonne 2006a,b, 2007a). The results have demonstrated the presence of carbon tetrachloride …

The Commodity Credit Corporation (CCC), an agency of the U.S. Department of Agriculture (USDA), formerly operated a grain storage facility in Courtland, Kansas. Prior to 1986, commercial grain fumigants containing carbon tetrachloride were commonly used by the CCC/USDA and the grain industry to preserve stored grain. In 1999, the Kansas Department of Health and Environment (KDHE) identified the former CCC/USDA operation as the likely source of carbon tetrachloride found in groundwater east of the former CCC/USDA facility in Courtland. Sampling by the KDHE in April 1998 had found carbon tetrachloride in the Garman residence lawn and garden well at a concentration of 2.1 {micro}g/L and in the Hoard residence lawn and garden well at a concentration of 0.5 {micro}g/L. Subsequent soil and groundwater sampling by the KDHE at the former CCC/USDA facility found no indication of a continuing source, and subsequent sampling of the affected wells showed generally declining contaminant levels. At the request of the KDHE and the CCC/USDA, Argonne National Laboratory prepared a Work Plan for Groundwater Sampling for Potential Site Reclassification, Courtland, Kansas (Argonne 2004). The objective of the proposed work was to conduct a single groundwater monitoring event and collect information necessary to update the status …

On September 7, 2005, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) presented a Scoping Memo (Argonne 2005) for preliminary consideration by the Kansas Department of Health and Environment (KDHE), suggesting possible remedial options for the carbon tetrachloride contamination in groundwater at Everest, Kansas. The suggested approaches were discussed by representatives of the KDHE, the CCC/USDA, and Argonne at the KDHE office in Topeka on September 8-9, 2005, along with other technical and logistic issues related to the Everest site. In response to these discussions, the KDHE recommended (KDHE 2005) evaluation of several remedial processes, either alone or in combination, as part of a Corrective Action Study (CAS) for Everest. The primary remedial processes suggested by the KDHE were the following: Hydraulic control by groundwater extraction with aboveground treatment; Air sparging (AS) coupled with soil vapor extraction (SVE) in large-diameter boreholes (LDBs); and Phytoremediation. As a further outcome of the 2005 meeting and as a precursor to development of a possible CAS, the CCC/USDA completed the following supplemental investigations at Everest to address several specific technical concerns discussed with the KDHE: (1) Construction of interpretive cross sections at strategic locations selected by the KDHE along the main …