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Impact Area Review Team Meeting Minutes
Action Items:
Recommendations:
Future Agenda Items:
Handouts Distributed at Meeting:
Agenda Item #1. Welcome, Agenda Review, Approval of December 13, 2005 IART Minutes Mr. Murphy convened the meeting at 6:05 p.m. and reviewed the agenda, after which the Impact Area Review Team (IART) members as well as three prospective members at the table introduced themselves. Mr. Murphy asked if there were any changes or additions to the December 13, 2005 IART meeting minutes. Mr. Minior referred to the next to the last paragraph on page 3 and questioned the use of the word "clearage." Mr. Pinaud referred to the fifth paragraph on page 13 and said that he doesn't think that he had committed to the Massachusetts Department of Environmental Protection (MassDEP) sampling the road salt, but only to ask if the Massachusetts Highway Department could supply information about where the salt was purchased. The minutes were approved with these changes. Agenda Item #2. Late-Breaking News and Responses to Action Items Mr. Murphy confirmed that there was no late-breaking news to report at this time. He then asked if there were any comments on the Responses to Action Items from the December 13, 2005 IART meeting. Mr. Minior referred to Action Item #1 and suggested that "Wellhead Treatment vs. Aquifer Restoration" be addressed as a general topic (rather than as part of a range of alternatives for a specific feasibility study) so that team members could better understand, ahead of time, the pros and cons of the two approaches. Mr. Minior also referred to Action Item #3 and recommended that the "MDPH Update" item remain on the IART future agenda topics list so it will not be inadvertently forgotten. Mr. Schlesinger said that he agrees with Mr. Minior's comments regarding the "Wellhead Treatment vs. Aquifer Restoration" agenda item and thinks it might be useful to include the topic as part of an orientation/introduction session for the new IART members. Mr. Schlesinger also remarked that the response to Action Item #2 didn't answer his question about the sites other than the Massachusetts Military Reservation (MMR) where tungsten analysis is going to be conducted. Mr. Gonser clarified that the reason those sites couldn't be identified is because they have not yet been chosen; however, the IART will be informed when they are. Agenda Item #3. Community Involvement Issues and Future Agenda Items Mr. Minior announced that the February Plume Cleanup Team (PCT) meeting was cancelled due to a lack of agenda items. He also took this opportunity, on behalf of the Air Force, to thank and acknowledge Sue Walker, who will soon be moving away from the area, for "all her efforts and activities in support of the cleanup" over the years. Mr. Gonser informed the group that the Impact Area Groundwater Study Program (IAGWSP) has spoken with the Air Force Center for Environmental Excellence (AFCEE) Installation Restoration Program (IRP), and with MassDEP and the U.S. Environmental Protection Agency (EPA), about the possibility of combining the PCT and the IART. One benefit of such a merger is that it would allow for more people to comment on the aspects of the two cleanup programs. Also, given that the IAGWSP is in the process of moving into the actual cleanup phase of its work, it would be beneficial for the IART to draw upon the experience of the PCT, which has been dealing with the cleanup phase on the IRP side for a number of years. Mr. Gonser also said that merging the two teams could generate new interest on the part of PCT members, since the IRP's work is starting to wind down. In addition, combining the teams would provide a single forum for community members, the press, and other interested stakeholders to get "the whole picture." Also, a combined team might mean providing more consistent information to the public and minimizing the confusion over the two cleanup programs. Mr. Gonser noted that the PCT has been informed that the concept of a team merger is being considered. He also said that internal meetings with the regulators have included discussion about the idea of bringing in a contractor to conduct detailed interviews with citizen team members about the merger concept. Mr. Gonser further mentioned that the thought would be to divide meeting agendas appropriately according to the needs of each program. He concluded by stating that at this time the programs are making the teams and public aware that the merger concept is being discussed. Mr. Murphy welcomed initial reactions to the merger concept. Mr. Schlesinger stated that he is against a merger for a variety of reasons, including that the IART already has difficulty fitting into its monthly meetings all of the material that needs to be discussed. He also said that although he realizes that it's sometimes better to "have a lot of minds," sometimes having too many minds means that nothing gets accomplished. He further stated that he thinks that compared to the IRP and the PCT, the IAGWSP offers more opportunity for citizen input from the IART, and that input has a greater effect on the direction and progress of the investigation and cleanup. Mr. Schlesinger clarified that while he doesn't want to criticize anyone's efforts - especially those of Ms. Walker, who has done a great job in her activities with the IRP - he thinks it would be "ill-suited to mix the two programs." Mr. Minior reminded the group that the merger idea is still just a concept at this time. He also distributed to the IART members copies of a rough transcript of the PCT's discussion about the merger. Ms. Jennings clarified that the proposal to merge the two teams has not received regulatory approval, and in fact the regulators are still in the process of submitting official comments on the proposal. She mentioned that EPA was questioning whether it would be feasible to cover in one monthly meeting the amount of material that needs to be covered. She also encouraged IART members to spend some time after the meeting to think about the merger idea and then e-mail their thoughts to her or Mr. Murphy. She noted that the PCT members had done this and provided some insightful input both pro and con. Ms. Jennings said that receiving similar input from IART members would be tremendously helpful in considering the merger idea. Mr. Hood noted that Ms. Conron, who was not able to attend this meeting, had asked him to convey her opinion, which is that the IART has too much information to cover at this time. However, she is in favor of a joint meeting farther down the road to begin to familiarize the two teams with each other. Ms. Walker, a member of the PCT and the former Public Information Team, said that she thinks that because of the IART's workload it would be premature to merge the two teams. She added that there's quite a bit before the PCT as well, including annual reports and the Interim Record of Decision (IROD) to Record of Decision (ROD) process. She also noted that she finds it a "complete mystery" as to why three of the last four PCT meetings were cancelled, and questions whether the cancellations were "a buildup" for the merger concept. Ms. Walker also said that it might be hard for the teams to adjust to the programs' "different cleanup standards," which would even make it difficult to show both programs' plumes on the same map. She added that she thinks the IART should be focusing on issues pertaining to the investigation phase of the IAGWSP's work, as the PCT is focusing on issues that are coming up during the "institutionalized phase" of the IRP's work. Ms. Walker then acknowledged the advantage of having more minds looking at the issues, but further noted that having to bring the two groups up to speed on each other's programs could tend to slow the process. She said that an orientation process of some kind would help alleviate that problem, should the teams be combined at some point in the future, at which time it would also be important to reach agreement on the process and how the teams are going to work. Mr. Murphy encouraged IART members to e-mail their thoughts on the proposed merger, as Ms. Jennings had recommended. Agenda Item #4. Remediation & Investigation Update Mr. Gregson stated that the IAGWSP is in the process of constructing remediation systems for the J-3 plume Rapid Response Action (RRA), the J-2 North plume RRA, and the Demolition Area 1 (Demo 1) comprehensive remedy. He said that the IART will be provided with status updates on those projects throughout the year. Mr. Gregson showed a map of the J-1 Range area and pointed out the base boundary, the Grand Oak/Little Acorn Lane neighborhood, Route 130, the Forestdale School, and monitoring wells downgradient of the J-1 Range and along the base boundary, depicted in red, where the explosive compound RDX was detected. He noted that the J-1 Range is an old contractor test range and training range near the base boundary and the Forestdale section of Sandwich. He also reported that the highest RDX detection was about 120 parts per billion (ppb), and that the IAGWSP has been furthering the investigation by drilling three monitoring wells on Little Acorn Lane and increasing the depth of an existing well at the Route 130 fire station, all of which tested nondetect for perchlorate and explosives. Mr. Gregson said that the IAGWSP is working with property owners to drill two more monitoring wells (on Wind Song Road) in an effort to define the downgradient extent of contamination. He also mentioned that the local residents would be informed about the drilling activities before they occur. Ms. Jennings asked Mr. Gregson to explain why the new wells aren't going to be located more to the northeast, as might be expected, given the location of RDX detections on base and along the base boundary. Mr. Gregson replied that based on the recent update of water table measurements, modeling indicates a more southerly track to groundwater flow in that area, which would push the potential contamination to the south. Based on the existing detections and the groundwater model, it seems most likely that the toe of the plume would be found at the two proposed locations, if it extends that far. Mr. Schlesinger asked if additional wells would be drilled farther north in the event that the currently proposed wells test nondetect. Mr. Gregson replied that that would be an option, but added that it's possible that the plume hasn't extended that far, and it's also quite likely that the currently proposed wells will end up having RDX detections. Mr. Dow inquired about the possibility of installing additional monitoring wells in the area between Wind Song Road and Little Acorn Lane, in the event that there are detections in the currently proposed wells. Mr. Gregson replied that doing so would be difficult and would require working with the homeowners in that area. Mr. Dow asked about any town-owned property there. Mr. Gregson mentioned Camp Good News and noted that the rest of the area is all private property, although some of the roads, like Little Acorn Lane, are town owned. However, Wind Song Road is a private road, so agreements with the property owners are needed before drilling can be done there. Mr. Gregson then reported that the effort to install some additional monitoring wells south of Snake Pond is ongoing. He showed a map of the area and pointed out Snake Pond, Weeks Pond, the J-3 Range plume, and the J-3 Range, which had also been a defense contractor operated range. Mr. Gregson pointed out the locations that were selected to ensure that the plume hasn't traveled underneath Snake Pond and said that the IAGWSP has received verbal agreement from the town and is now waiting for the temporary license agreement to be finalized before that drilling can occur. Agenda Item #5. Southeast Ranges Source Area Investigations Mr. Hill showed a map of the base and pointed out the Southeast Ranges (the J-2, J-1, L, and J-3 Ranges), located at the top of the groundwater mound, from which groundwater radiates in all directions. He noted that during World War II and into the 1950s the Southeast Ranges were used primarily for military training. From the 1950s into the 1990s, the J Ranges were leased to a series of different defense contractors who conducted weapons testing and development activities that involved the disposal of various materials by burning and burial. The L Range, however, was used as a 40-mm grenade training range throughout most of its history. Mr. Hill stated that archive searches, any available range control records, witness interviews, and records provided by the defense contractors were used to help guide the Southeast Ranges investigation, which included a significant amount of drilling, with approximately 700 well screens at 170 locations and more than 4,500 soil samples. The investigation also involved a number of geophysical surveys used to assist in the identification and cleanup of source areas. Mr. Hill noted that one of the past geophysical survey methods used at the Southeast Ranges was aerial magnetometry (air mag), a helicopter-mounted magnetometer device that was flown in a series of parallel transects in that area. Due to the topography and varying heights of the vegetation growing on the ranges, however, the resulting signal maps were of limited use, as the air mag tool is best employed in a flat, relatively vegetation-free environment. Mr. Hill also spoke about the Munitions Survey Project (MSP), an investigation that employed a ground-based geophysical device called the EM-61, an electromagnetic instrument mounted on a small trailer that was towed in a series of parallel transects across the range area. He then showed a geophysical survey map and noted that the various colors identify subsurface magnetic anomalies, with the more significant ones being grouped together in what are known as polygons. Ms. Adams asked if it's correct that the purpose of the exercise was to find underground magnetic anomalies. Mr. Hill replied that the MSP was undertaken in response to the discovery of about 1,400 mortars buried near the entrance of the J-1 Range. He also noted that MSP activities occurred throughout Camp Edwards, including the Southeast Ranges, with the polygon investigation covering the entire J-2 Range and J-1 Range, and portions of the J-3 Range. Mr. Hill stated that two significant findings from the polygon investigation were: the J-2 Range Disposal Area 2, a burial pit, the apparent source of the J-2 North plume; and the J-1 Range Interberm Area, which is believed to be the source of the J-1 North plume, although the relationship there isn't as clear as that at J-2. Mr. Dow asked if both the shallow and deep layers of the J-1 North plume contamination are believed to be from the same area that Mr. Hill identified as the potential source. Mr. Hill replied that a number of distinct point sources are likely, and while the precise source or sources haven't been determined with certainty just yet, the investigation is very active at this time. Mr. Dow also asked if some of the polygons in that area have high concentrations of magnetic anomalies. Mr. Hill replied that munitions disposal has occurred in that area, although other polygons turned out to be rebar, steel plates, and other environmentally benign features. He said that about 25% to 40% turned out to be actual burials of one type of another. Mr. Schlesinger commented that the choice of colors to delineate the polygons "isn't very good." He also asked what the polygon map represented in terms of the amount of work that's been or is going to be done. Mr. Hill said that he would talk more about the how the investigations are evolving as he continues with his presentation. He also noted that the polygons depicted in red represent areas where there's evidence of disposal by burial, and those depicted in green represent generally environmentally benign materials. Mr. Hill then noted that as more groundwater and soil data became available and groundwater modeling capabilities improved, a grid-based approach was employed to help locate sources of groundwater contamination that were less obvious than some of the polygons were. He showed a grid map and noted that Priority 1 grids, selected for immediate investigation by excavation, are depicted in pink, and that eight of them were identified on the J-2 Range and 20 on the J-1 Range. Priority 2 and Priority 3 grids are depicted in blue and purple. Findings from the J-2 Range Priority 1 grid investigation, which was completed late last fall, included five burial pits where 68 of the 86 potentially explosive items identified in the investigation were found. The J-1 Range Priority 1 grid investigation findings also included five burial pits, within which all 209 potentially explosive items were found. Mr. Hill noted that after the Priority 1 grid investigations were completed, a statistical analysis of J-2 Range findings was undertaken (based on the apparent causal relationship between burial pits and plumes, and using all available EM-61 data for the J-2 Range) and the results were presented in a technical memo in December 2005. The memo identified geophysical signal strength/footprint criteria typical of burial pits, and the criteria were used to identify additional potential burial pits on the J-2 Range. EM-61 data from the J-1 range and J-3 Range also were evaluated. Mr Hill showed a figure depicting the J-2 Range results and noted that the "X"s represent locations where magnetic anomalies that meet the criteria for potential burial pits were identified. He noted that there were 36 of them at the J-2 Range, 24 of which actually fall outside the Priority 2 and 3 grids. At the J-1 Range, 41 potential burial pits were identified, 37 of which fall outside the Priority 2 and 3 grids. And seven potential burial pits were identified at the J-3 Range at a location north of a demolition area. Mr. Schlesinger referred to the potential burial pits identified outside the grids and asked what would be done in terms of magnetometry surveys there. Mr. Hill replied that right now the IAGWSP is acting on the statistical evaluation of existing data that were developed over the past five years, and the results are quite useful. He also said that the IAGWSP recently recommended to the regulators that priorities be shifted "away from the grid approach to areas where we appear to have potential disposal pits versus going to areas that do not." He added that the IAGWSP thinks its resources are best applied in going after those features that appear to be distinct causes of groundwater contamination. Mr. Schlesinger referred to the gridded area identified as M-20, said that "the plume shell goes beyond the grid," and suggested that it might make sense to look beyond the grid, out in the wooded area, which might not have been wooded at the time contaminants were being buried or released. Mr. Hill replied that historical aerial photographs were used as a reference when clearing that area in order to replicate the area that was cleared as of the 1970s. And while there's always some uncertainty associated with groundwater modeling, the trajectory of the plumes and where the source are implied to be located can be seen. Mr. Hill stated that a number of features were found that the IAGWSP thinks warrant a more focused investigation. Ms. Jennings said that she would provide a summary and the regulators' perspective. She stated that the EM-61 survey results led to the polygon investigation and the discovery of burial pits that were probably very significant source areas. However, once that investigation was completed, the question remained as to how to investigate the rest of that very large area that also shows metal underneath the ground surface. The answer was the grid approach, which looked at a number of lines of evidence (including magnetic data, soil concentration data, groundwater data, and records and interview information) and came up with a prioritization scheme. Ms. Jennings also said that the regulators' perspective is that all the grids should have been considered Priority 1 as they all deserve investigation. She went on to note, however, that only the eight Priority 1 grids were investigated, and that led to the discovery of four burial pits, as well as soil contamination, unexploded ordnance (UXO), and "lots of other things that cause groundwater contamination." Ms. Jennings stated that the regulators are not ready to abandon the grid approach, and have not yet bought into the proposed statistical approach. She said that she thinks that what's required to remedy the source areas is a thorough characterization, and she doesn't know how a full characterization could be achieved "without really looking over the whole site carefully." She also said that when first presented with the new information about two weeks ago it struck her that with the grid approach, four burial pits were found among eight grids, while with the statistical approach, only two burial pits were found after 12 targets were examined, and she believes that more should have been found. Ms. Jennings then noted that the IAGWSP has responded to that issue, but the regulators haven't accepted that response as true. Ms. Jennings further noted that she thinks that if the statistical approach works, it should be able to prove the positive and the negative. That is, it should be able to point not only to areas where burial pits or other significant source areas exist, but also to areas where there is nothing, and digging in both types of areas should bear that out. Ms. Jennings said that the Southeast Ranges source area investigation is a complicated one that the team is trying to tackle in a phased approach, and by using resources wisely. She also said that with respect to the regulators having had the opportunity to review information and form an opinion, in this situation, the regulators received the information only two weeks ago. EPA's contractor is still in the process of reviewing it and there will be a meeting with Sky Research (which conducted the statistical analysis) this week to examine the statistics more closely and perhaps propose some ways to prove or disprove that theory. Mr. Gregson reminded the group that when the EM-61 magnetometer survey was conducted, the range had been cleared and opened up to historical dimensions, based on historic aerial photos. And the survey was conducted not just in spots, but over 100% of that area, so there are now many existing data for potential locations of disposal pits or other sources of groundwater contamination. Mr. Gregson said that this is not to say that there are definitely no areas outside of there that might be a concern, but it's most likely that disposal areas would exist in open, rather than wooded, areas. He also stated that the IAGWSP is trying to use the data and tools it has to find the sites that are current or future threats to groundwater and take care of them "as quickly and as intelligently" as possible. Mr. Dow said that he thinks it would be useful to determine from the statistical analysis which areas predicted to contain disposal pits actually did, as well as to show "incorrect ones" where there were burial pits, but the statistical analysis didn't suggest there would be. He also recommended that the IAGWSP consider looking at the spectral signature of pine trees to identify areas of soil contamination. He explained that the microrize that attach to the trees' roots to transmit water and nutrients don't function as well where there's soil contamination or stress, and therefore the trees are not as healthy, and that can actually be detected out in space. Mr. Hill noted that the investigations have taken place in areas where the pine trees have been cleared. However, Mr. Dow asserted that it's possible that there are other areas that could have been contaminated in the past and are now covered by vegetation. Ms. Adams made a point of noting that there are other potential sources of groundwater contamination in addition to disposal pits and other magnetic materials beneath the ground surface. Those include areas, like at the J-3 Range, where defense contractors disposed of liquid wastewaters containing explosives; and the actual firing of munitions - at the firing point where propellant was released, and possibly at the landing point. Mr. Hill reminded the group of the RRA that was conducted at the J-2 Range in 2004, which involved cleaning up more than 8,000 tons of soil, including Disposal Area 2. He said that the RRA addressed the obvious sources of groundwater contamination, and now the statistical analysis that was done is suggesting that the "X's" shown on the map represent locations where subsurface potential sources of groundwater contamination currently reside at the Southeast Ranges. He also mentioned that in 2004 an RRA was conducted at the J-3 Range, where about 5,000 tons of contaminated soil was cleaned up. Mr. Schlesinger referred to Mr. Dow's recommendation about looking at the spectral signature of pine trees to identify areas of soil contamination, and Mr. Hill's comment about the clearing of the trees. He then suggested that a huge amount of satellite imagery of the Southeast Ranges exists, going back to 1972, so it might be possible to analyze older data and determine exactly where certain stressors exist, which might indeed lead to the discovery of more groundwater contamination. Ms. Jennings pointed out on the J-1 Range figure a grid that initially was not suspected to be a problem, but was recently categorized as Priority 1 because of the new groundwater plume recently found to be emanating from that area. She said that she thinks this validates the concern about the need to look elsewhere, and said "we'll consider that as we move forward." She also said that while she won't deny that soil contamination has been removed where it's been found, "if you don't look, you won't know if it's there to be removed." Ms. Jennings said that she thinks it's important to continue looking at all the data that point to areas on the Southeast Ranges that deserve further investigation, including the other potential sources of contamination that Ms. Adams mentioned. Mr. Lantery inquired about the dimensions of each grid block. Mr. Hill replied that each square is 100 feet by 100 feet in size. Agenda Item #6. Southeast Ranges Groundwater Monitoring Plan Mr. Goydas stated that his presentation pertains to the recently submitted groundwater monitoring plans for the five Southeast Range plumes: the J-1 North, J-2 North, J-2 East, L Range, and the J-3 plume. He noted that in 1999, early in the Impact Area investigation, a long-term groundwater monitoring program was initiated that involved more than 750 monitoring wells. The long-term monitoring plan involved sampling the wells, one to four times a year, for explosives and perchlorate, and some select wells for other potential groundwater contaminants too: volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), metals, and dyes. More than 50% of the monitoring wells continually tested nondetect, so it was learned not only where contamination existed in the aquifer, but also where it did not. This also meant, however, that a lot of data were being collected that did not further the investigation, and in 2004 the IAGWSP decided that the focus of the monitoring should be specific to the plumes. And the regulators provided similar comments around that same time. Mr. Goydas reported that a monitoring optimization effort was undertaken in order to ensure that the data being collected were as effective as possible. The effort involved clearly identifying data needs and determining how best to fill them in terms of spatial distribution of wells and sampling frequency required in order to understand contaminant fate and transport, and plume migration. Mr. Goydas also noted that the monitoring plan for each plume was considered with respect to where the plume was in the regulatory process. Mr. Goydas noted that the monitoring network optimization was accomplished through a two-step process. The first step was an intuitive/analytical assessment that involved looking at the relationship between wells, what the trend data indicate about what's happening within the plume, and the distance between wells. The assessment also involves migrating forward real data from previous years in order to identify high-density locations that might indicate data redundancy, as well as low-density areas. The second step was a far more rigorous quantitative analysis that included a spatial assessment and a temporal assessment. The spatial assessment determines which wells need to be sampled in order to map the plume in a consistent and reliable fashion, and involves assessing in three dimensions the importance of various wells and their physical proximity to one another. The temporal assessment looks at trend data over time in order to determine the needed sampling frequency of the monitoring wells. Mr. Goydas stated that in a general sense the monitoring optimization has been consistent with what's seen at other cleanups, including AFCEE's. He also said that overall semiannual sampling frequency is required for the purpose of assessing, tracking, and predicting changes within a plume, while an annual sampling frequency is sufficient for the purpose of re-mapping a plume. Mr. Goydas noted that there are two types of site-specific monitoring plans: a performance monitoring and evaluation plan (PME), for plumes where a remedial system is in place or is being installed, and an interim groundwater monitoring plan (IGM) for plumes still in the investigation phase. A PME plan includes treatment unit monitoring (to ensure that the water that's being treated is clean when it leaves the treatment plant), and hydraulic monitoring and chemical monitoring (to assess the performance of a remedial system). The purpose of hydraulic monitoring is to understand how the aquifer is responding to pumping stress, while chemical monitoring allows for a longer term understanding of how the pumping stress is affecting the plume. An IGM plan is more basic in that it involves only the collection of chemical data to characterize the plume's nature and extent and to support remedial decision-making. Mr. Goydas displayed a table showing the status of monitoring plans for the various IAGWSP sites and noted that tonight he would review the plans for the five Southeast Ranges plumes, which were recently submitted to the regulators. Mr. Goydas then showed a J-3 plume map for perchlorate and noted that compared to the other plumes, J-3 has relatively elevated concentrations of perchlorate. He also noted that the plume migrates in a southerly direction toward Snake Pond, then showed the J-3 plume map for RDX and said that more than 230 monitoring wells lie within or immediately adjacent to the plume. Mr. Goydas also mentioned that known primary sources of the plume have been removed: the melt/pour building and the demolition area/artillery range. The IAGWSP is in the process of installing an RRA system for the J-3 plume that will include three extraction wells and treatment by a combination of ion exchange resin and granular activated carbon (GAC) housed at AFCEE's existing Fuel Spill 12 (FS-12) facility. The treated water will be returned to the aquifer via the existing wellfield that's part of the FS-12 system. Mr. Goydas stated that the PME plan for J-3 includes sampling of the treatment system (influent, mid-fluent, and effluent), hydraulic monitoring (approximately 50 wells that are evaluated prior to startup, during startup, and over the long term), and chemical monitoring. He then showed a figure depicting J-3 monitoring wells identified as semiannual and annual. He noted that the annual event includes a host of wells within the body of the plume, some near the source area, some at the boundary (both laterally and vertically), and some at the leading edge, the intent of which is to provide an understanding of how the geometry and internal heterogeneity of the plume are changing. He also noted that the purpose of the semiannual monitoring is to look for key changes in plume geometry, such as whether the plume is progressing in its leading edge extent, or if there are changes within the body of the plume that are important in understanding how the plume will migrate in the future. In response to a request from Ms. Jennings, Mr. Goydas pointed out on the map the leading edge wells, at the downgradient portion of the plume; the trailing edge wells, upgradient of the primary core of the plume; boundary wells, on the sides of the plume (and above or below the plume in cross-section); and the in-plume wells. He then showed cross-sections of the J-3 RDX plume and the perchlorate plume and noted that the tick marks represent where groundwater profile samples were collected and the boxes represent fixed permanent wells. He also explained that wells shown in green are sampled annually and those shown in blue are sampled semiannually. Mr. Cambareri remarked that the plume in the cross-section figures appears to be delineated based on profile data, yet he'd think it would make sense to show a cross-section "that's based upon the data that you're trying to compare to." Mr. Goydas replied that during the design phase those data will be used to represent what's believed to be a conservative representation of the plume. He also said that once the system is operating, the IAGWSP will use the same method AFCEE has, showing a design basis version of the plume side-by-side with plume depictions over subsequent years of system operation. Mr. Schlesinger said that he thinks that figures showing temporal changes in concentrations would be useful, as would a representation of existing knowledge about areas where there's clean water, or areas that haven't been sampled. He also said that it would be very useful to include arrows on plan view maps to indicate the direction in which the plume is traveling. Mr. Goydas said that time trend analysis figures are usually provided in annual assessment reports, given that there's generally not a wealth of information when going into the remedial investigation to show how the plume has changed. Mr. Dow inquired about the cross-hatching and stippled layers shown in the cross-section figures. Mr. Goydas referred to one of the cross-sections and pointed out the ground surface, the water table, the plume, bedrock, and the various fine-grain deposits: clay, silty clay, and silty sand, for example. Mr. Dow asked why some of the annual wells are found in low-conductivity layers. Mr. Goydas replied that a greater percentage of annual wells, rather than semiannual wells, are often deeper in the aquifer, where finer-grain deposits usually exist. The groundwater velocity is slower there, the contamination moves more slowly, and less change is anticipated. Ms. Jennings made a point of noting that oftentimes there are a number of well screens at one location; however, each well screen is counted as an individual well when describing monitoring plans. Therefore, while at first it may seem as though there are 26 monitoring wells in the core of the J-3 plume, they in fact exist at five locations, for example. Ms. Jennings said that she thinks it's important to clarify this, as well as the sampling frequencies, for members of the public so they can evaluate whether the monitoring plans seem sufficient. Mr. Goydas noted that there are some leading edge wells significantly downgradient of the plume, which are proposed for biennial sampling (every other year). He also pointed out some leading edge wells, in-plume wells, and perimeter wells, and noted that because many of the J-3 wells have been sampled 10 times or more, and because of AFCEE's hydraulic data to the east, and modeling, the J-3 plume flow trajectory is quite well understood. Mr. Goydas also referred to Ms. Jennings' point about several wells existing in the same profile and said that the intent is to determine which of them are most critical to understanding the fate of the plume. He noted when the assessment was done for the J-3 RRA, for example, it was determined that some of wells "top and bottom" would have relatively no effect on the state of the plume because the plume is "driven by the significant mass that's the engine behind it." For a very diffuse plume that lacks a well defined core, however, it may be necessary to sample a greater number of wells. Ms. Jennings requested that figures used in future monitoring plan presentations identify sampling frequencies for each well. Mr. Schlesinger added that he'd like a legend to be included on the figures noting that wells represented by green dots are sampled annually, and those represented by blue dots are sampled semiannually. Mr. Goydas continued with his presentation by showing a map of the J-2 North plume and noting that the plume's source area, Disposal Area 2, was addressed through a soil removal RRA. He also reported that the J-2 North plume, which is approximately 8,000 feet long and 2,000 feet wide, is composed primarily of perchlorate and RDX and is migrating north toward an existing water supply well. He noted that an extraction well is currently being installed and the water will be treated using GAC and ion exchange resin and then returned to the aquifer via four reinjection trenches along the sides of the plume. Mr. Goydas stated that the PME plan for J-2 North is similar to that for the J-3 plume. However, approximately 16 new monitoring wells and piezometers are being installed for the J-2 North plume (primarily for the hydraulic evaluation), as it lacks the well density found at J-3, which has undergone more investigation. He noted that for J-2 North 38 wells will be sampled for explosives and 42 for perchlorate annually, with less amounts sampled semiannually and biennially. Mr. Goydas then displayed plan view and cross-section figures showing the general distribution of wells. He also explained that there are more annual wells than semiannual wells for J-2 North because most of the RDX plume is significantly upgradient of the treatment system, and therefore no significant changes are expected to be seen any time soon - also because the maximum RDX concentration is only about 10 ppb. The semiannual wells are more focused on the perchlorate plume, towards the leading edge, where more dramatic and rapid changes are expected. Mr. Cambareri inquired about the "very large" well screens shown in the cross-section figures. Mr. Goydas replied that those are the three extraction wells, which will be sampled semiannually for the influent treatment plant monitoring. Mr. Lantery inquired about the depth to groundwater and any monitoring being done at the source. Mr. Goydas replied that depth to groundwater is generally between 90 to 130 feet below ground surface (depending on the elevation of the ground surface). The elevation of the water table at the source is about 66 feet mean sea level and goes down to about 55 feet mean sea level at the leading edge of the plume. He also said that Disposal Area 2, which was believed to be the primary source of the J-2 North plume, has been addressed as part of an RRA. In addition, some significant decreasing concentrations have been observed at the trailing edge wells, near the source. Ms. Jennings remarked that it would be helpful to note which wells are annual and which are semiannual in plan view as well as cross-section. Mr. Schlesinger asked if it's correct that MW-337 and MW-327, which are semiannual wells, are supposed to act as sentry wells and determine if the extraction well "has suitably picked up the plume." Mr. Goydas replied that capture is really assessed through hydraulic monitoring, although chemical monitoring also will provide that information, but in a long-term and subjective manner. He said that sentry wells may be the wrong term; rather, the wells that Mr. Schlesinger mentioned would be described as leading edge downgradient monitoring wells to provide information about the timing and levels of concentrations arriving there. Mr. Schlesinger expressed concern about the water supply well. Mr. Goydas replied that there are at least 15 years of travel time between the identified leading edge of the plume and the intake to the supply well. Mr. Schlesinger noted that predicted travel time for the Demo 1 plume had turned out to be inaccurate. Mr. Goydas acknowledged that there's always some uncertainty associated with plume delineations; however, based on what is known, the sampling frequency of semiannual for those downgradient wells "is more than appropriate" relative to the predicted travel time to the supply well. Mr. Goydas stated that the remaining Southeast Ranges plumes have IGM plans. He also said that there's no specific guidance associated with IGM plans; instead, the idea is to collect data while furthering the investigation to support the risk assessment, remedial investigation, and feasibility study. Mr. Goydas showed a perchlorate map of the J-2 East plume and noted that likely sources are Disposal Area 1, several polygons (14, 15, and 16), and some soil contamination at the southeast end of the range. He also noted that the plume is migrating in a north/northeast direction, then showed the RDX plume map and pointed out a location where an additional well is in the process of being installed. The next step for the J-2 East plume is a remedial investigation, to be followed by a feasibility study, which is planned to be combined with the J-2 North feasibility study. The IGM plan for the J-2 East plume will allow for periodic check-ins to ensure that the conceptual model that's being used in developing the remedial investigation is holding up with time. Mr. Goydas stated that the J-2 East IGM plan includes explosives and perchlorate sampling, both annual and semiannual. There is less semiannual sampling than with the PME plans, however, because the aquifer is not being stressed and rapid changes aren't expected. He then displayed a plan view figure that showed the distribution of wells to be sampled and said that although the figures he's showing tonight are exactly the same as those originally proposed to the regulators, some changes have been made through the comment resolution process. For example, in this case MW-57 was added to the monitoring network. Mr. Goydas also showed J-2 East cross-section figures and pointed out the semiannual and annual monitoring wells. Mr. Goydas then showed a J-1 North map and noted that the plume, which is approximately 5,000 feet long and 1,300 feet wide, migrates out of the interberm area in a north/northwest direction, and contains primarily RDX and perchlorate, and some HMX. He noted that ongoing investigations at the J-1 Range are expected to further define the likely sources there and help in understanding the relationship between groundwater and soil contamination. He also said that, as with J-2 East, the J-1 North IGM plan involves a greater number of annual wells and a fair number of semiannual wells too. Mr. Goydas then showed a cross-section figure of the plume and pointed out that it's quite deep because the source is very close to the top of the mound where groundwater tends to drive very deeply into the aquifer. At this time Mr. Goydas mentioned that the one area of contamination in the Southeast Ranges that's not being discussed at this meeting is J-1 Southeast, as it's too early in the investigative phase to do so. Mr. Goydas then showed a map of the L Range area and pointed out the FS-12 extraction system, the J-3 plume to the west, and the L Range plume, an area of low-level, decreasing RDX and perchlorate contaminant concentrations. He noted that the remedial investigation report on this plume was recently published and the next step is the upcoming feasibility study, which will be combined with the adjacent J-3 plume. Mr. Goydas stated that the L Range IGM plan, which includes sampling for both explosives and perchlorate, is the only one that involves annual monitoring only. This is because the plume is very stable, concentrations are decreasing, and it has essentially reached a steady state, plus there's a safety net in terms of the downgradient extraction system. Mr. Goydas also showed cross-section figures of this plume. Ms. Adams asked if Mr. Goydas was referring to the FS-12 extraction system when he mentioned a safety net. Mr. Goydas replied that he was, but added that in reality there's no indication that the plume is going to migrate any distance anyway. Mr. Schlesinger requested that future presentations show L Range figures that include IRP wells associated with the FS-12 plume. Also, that figures depicting groundwater contamination include scale bars, as well as arrows to indicate groundwater flow direction. Mr. Dow questioned whether annual wells located in low-conductivity sediments would have to be sampled longer than semiannual wells, given that the contamination there might be expected to bleed out at low levels over a long period of time. Mr. Goydas first noted that cross-sections attempt to compress all three-dimensional space into one line, so in reality the plume might not penetrate a silt unit as fully as it appears to. However, there are points where a plume does migrate into low-conductivity deposits. In order to determine that a monitoring network will work down the road, the transport model, which includes all the low-conductivity deposits, is used to migrate the plume a year or two into the future to ensure that the expected dynamics are accurately captured in the monitoring network. Mr. Lantery requested that in addition to noting scale on the figures themselves, presenters also make verbal mention of scale when discussing plume figures. Agenda Item #7. Open Discussion Mr. Schlesinger stated that validated detections of SVOCs and VOCs were noted in the Monthly Progress Report, as were four locations where BEHP has been detected consistently, and a statement that it can't be ruled out that military activities may be the cause of that BEHP. He then asked if these compounds are being ignored for the time being while the IAGWSP deals with higher priorities. Mr. Gregson replied the IAGWSP is not ignoring these compounds, which is why the detections are noted in the Monthly Progress Report. However, they are a lower priority than the plume contaminants that the program is in the midst of addressing. As time goes on, the IAGWSP will take a look at those sporadic detections (of SVOCs, VOCs, and BEHP) to see if they can be linked to a source that's actionable or if there are actions that need to be taken to address them. Mr. Schlesinger noted, for example, that the report mentioned a detection of naphthalene, which is a fuel, not something commonly found in the ground. Ms. Jennings assured Mr. Schlesinger that these other compounds are not going to be forgotten. She explained that as part of the risk assessment all compounds detected at a site are evaluated in terms of frequency of detection, maximum concentrations, and any standards that exist. Although a risk management decision may be made to monitor a compound, it is not just forgotten, but will come up in the remedial investigation report and be evaluated during the risk assessment. Agenda Item #8. Adjourn Mr. Murphy noted that the IART would meet next on February 28, 2006 at Oakcrest Cove Lodge in the Forestdale neighborhood of Sandwich. He then adjourned the meeting at 8:50 p.m. |
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| Administrative Notice |
