Impact Area Review Team

River River Drops of rain on a leaf

Impact Area Review Team
Falmouth Holiday Inn
December 7, 2004
6:00 p.m. - 9:00 p.m.

Meeting Minutes

Members: Organization: Attendees: Organization:
Hap Gonser IAGWSP John McDonagh IAGWSP
Ben Gregson IAGWSP Paul Nixon IAGWSP
Marty Aker AFCEE/MMR Kris Curley IAGWSP
Lynne Jennings US EPA Lori Boghdan IAGWSP
Bill Walsh-Rogalski US EPA Bill Gallagher IAGWSP
Margery Adams US EPA Mike Minior AFCEE/MMR
Len Pinaud MA DEP Bob Lim US EPA
Ellie Grillo MA DEP Jane Dolan US EPA
Mark Panni MA DEP Dave Williams MDPH
Kevin Hood UCONN/TOSC David Dow Sierra Club
Richard Hugus IART/Falmouth/ABC Amanda Lehmert Cape Cod Times
Peter Schlesinger IART/Sandwich Jay Clausen AMEC
Michael Butler IART/Bourne Rick Carr STL
Bob Mullennix IART/Bourne Jim Quinn Ellis Environmental
    Jennifer Washburn Portage Environmental
    Jane Moran Portage Environmental
Facilitator: Organization:    
Jim Murphy US EPA    

Action Items:

  1. Mr. Schlesinger asked if the two RDX detections in soil north of Wood Road are related to the Northwest Corner.
  2. Mr. Schlesinger asked the IAGWSP to consider installing an additional monitoring well at the toe of the Demo 1 plume downgradient of Pew Road, farther south than existing and planned wells.
  3. Mr. Pinaud agreed to forward to IART members the results of the DEP fireworks study conducted at UMass Dartmouth, when available.
  4. Mr. Schlesinger requested that depictions of RDX contamination be added to the perpendicular cross-sections of the Northwest Corner investigation area.

Handouts Distributed at Meeting:

  1. Responses to Action Items from the October 26, 2004 IART Meeting
  2. Groundwater Findings Map Massachusetts Military Reservation
  3. Presentation handout: Central Impact Area Update
  4. Presentation handout: Remediation & Investigation Update
  5. Maps/graphics to accompany Remediation & Investigation Update
  6. Data tables
  7. UXO Discoveries/Dispositions Since Last IART (Ending 11/30/04)
  8. News Releases, Neighborhood Notices, and Media Coverage (10/26/04 - 12/3/0

Agenda Item #1. Welcome, Agenda Review, Approval of October 26, 2004 IART Minutes

Mr. Murphy convened the meeting at 6:05 p.m. and announced that James Kinney is resigning from the Impact Area Review Team (IART). The IART members introduced themselves and Mr. Murphy reviewed the agenda. Mr. Schlesinger requested that two items be addressed under Open Discussion: the Forestdale information session and the base-wide plume map. Mr. Hugus noted he had requested that the contamination detected in the Peters Pond neighborhood of Sandwich be included on the agenda. Mr. Gonser replied that this topic would be discussed as part of the Southeast Ranges Delineation Efforts item.

Ms. Grillo reminded the group that the public comment period on the revised Massachusetts Contingency Plan (MCP) closes on December 10, 2004 at 5:00 pm.

Mr. Minior asked if his question regarding monitoring well 57 (MW-57) would be answered at tonight's meeting. Mr. Gregson replied that it would be addressed during the Investigation Update.

Mr. Murphy asked if there were any changes or additions to the October 26, 2004 IART meeting minutes. Mr. Hugus referred to page 5, paragraph 3, line 3, and noted that the word be should be inserted between "…was going to" and "a long-range water supply well…" The minutes were approved with this change.

Agenda Item #2. Late-Breaking News and Response to Action Items from the 10/26/04 IART Meeting

There were no late-breaking news items or further comments on the action items.

Agenda Item #3. Central Impact Area Update

Mr. Schlesinger questioned whether any Natural Resources personnel were attending the meeting. Mr. Gregson replied that they were unable to attend this meeting, but would be available at January's IART meeting when they could address any questions raised tonight. Mr. Murphy asked if those personnel would include staff from both the Impact Area Groundwater Study Program (IAGWSP) and the Environmental & Readiness Center (E&RC). Mr. Gregson replied that personnel from both offices would attend.

Mr. Gregson stated that the IAGWSP and the U.S. Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection (DEP) have been working diligently to evaluate data collected over the years at the Central Impact Area. Because of the complexities associated with the site, both short-term and long-term approaches to Central Impact Area soil are being developed. In the short term, which is over the next few months, an effort will be made to determine whether a relatively small source area exists at the Central Impact Area, where a source removal that provides a positive benefit to the underlying groundwater can be conducted. At the same time, the IAGWSP will continue with the long-term action of conducting the standard feasibility study process for the Central Impact Area soil operable unit and deciding on a final remedy.

Mr. Gregson showed a map depicting the Central Impact Area RDX and perchlorate plumes and noted that unlike other plumes being addressed by the IAGWSP, the RDX contamination has extended farther than the perchlorate contamination from the source area. He explained that RDX has been the main constituent for mortar and artillery firing since it was developed as an explosive in the latter part of World War II, while it's believed that the main source of perchlorate at the Central Impact Area is the spotting charge associated with Low-Intensity Training Rounds (LITR), which first came into use in the mid 1980s when high-explosive (HE) rounds were phased out. Mr. Gregson also reported that contaminant concentrations in the Central Impact Area plumes are typically about 10 parts per billion (ppb) for RDX or less, and less than 5 ppb for perchlorate - about an order of magnitude less than concentrations detected in the Demolition Area (Demo 1) and J-3 Range plumes.

Mr. Schlesinger remarked that the depiction of the Central Impact Area plumes on the base-wide plume map provided by the E&RC differs significantly from the map being shown at the meeting. Mr. Gregson said that he doesn't think that the plumes on the base-wide map are drawn to a nondetect contour. He also referred to the map being shown at the meeting and noted that the shades of pink represent perchlorate contours between nondetect and 1 ppb, between 1 ppb and 4 ppb, and greater than 4 ppb. Mr. Schlesinger asked if the two dark areas toward the end of the plume have to do with colors "bleeding through the background." Mr. Gregson replied that he thinks that those areas are the underlying RDX plume.

Mr. Schlesinger then questioned why no connection between the perchlorate at the Northwest Corner and at the Central Impact Area is shown on the map. He also said that if the perchlorate at the Northwest Corner is related to the Central Impact Area, then the perchlorate is out ahead of the RDX contamination. Mr. Gregson noted that there a couple of deep perchlorate detections in the Northwest Corner, but there are currently no data that indicate that those detections are connected to the Central Impact Area. He said that it is not a continuous plume, but is disconnected from the Central Impact Area. He also explained that the bulk of perchlorate contamination is behind the RDX part of the Central Impact Area plume; the detections that are farther out would be from earlier releases of perchlorate.

Mr. Walsh-Rogalski asked if it would be possible to produce two maps that show the RDX and perchlorate plumes separately as the overlay is difficult to understand. Mr. Gregson said that those maps could be provided. He also noted that he would look during the meeting break to see if he had such maps on his computer that he could show the team tonight.

Mr. Gregson then reported that other compounds detected at the Central Impact Area include HMX and TNT breakdown products such as 2A-DNT and 4A-DNT, which were detected much less frequently than RDX and perchlorate and were not as widely distributed. He also said that based on the overall plume shapes, it appears that a significant source area for the plumes exists somewhere in the vicinity of Turpentine Road and Tank Alley, although some detections in the plumes could be sourced from other spots within the Central Impact Area. Mr. Gregson explained that "because of this large area" the IAGWSP is looking at whether a short-term source removal remedy would be beneficial at this time. He also said that the IAGWSP believes that the extent of contamination in groundwater has been sufficiently defined in order to proceed with the feasibility study.

Mr. Gregson then displayed a figure that showed the results of the airborne magnetometry (air mag) survey conducted at the Impact Area and pointed out the location of MW-1 at the intersection of Tank Alley and Turpentine Road. He pointed out the boundary of the Impact Area, which is 2,200 acres in size and centrally located within the northern 15,000 acres of the Massachusetts Military Reservation (MMR). He also noted that the Impact Area has been used as the main artillery and mortar target area since the early 1900s. HE artillery rounds were fired into the area until the mid-1980s, when the use of LITR rounds began in response to complaints about noise from the surrounding neighbors. Firing of HE mortars continued until 1997.

Mr. Gregson stated that the air mag survey results, which were first presented to the IART in 2001, show the large metal objects that were used as artillery targets along Turpentine Road and Tank Alley. He pointed out that the concentration of metal objects is roughly defined by a triangle shape, and the density of magnetic anomalies drops off with distance from the triangle. He also noted that targets were moved around over time as new ones were brought in. Mr. Gregson then explained that the gun positions did not have a direct view of the Central Impact Area, and so when rounds were shot a forward observer in the field would note where they landed and radio back to the gun position, which would adjust its fire until the target was struck. Consequently, the rounds were not that concentrated on the targets themselves.

Mr. Gregson stated that soil samples were collected in concentric rings around 39 of a total of 49 potential targets identified through aerial photographs, range use maps, field reconnaissance, and results of the air mag survey. The samples were analyzed for explosive compounds, and as the project progressed and perchlorate was identified as a potential contaminant of concern (COC), a subset of those targets was sampled again and analyzed for perchlorate. He referred to a map depicting RDX detections in soil and noted that of the 39 targets sampled, 25 had detections, 11 of which were detections greater than 1,000 ppb. He mentioned that DEP's proposed soil standard for RDX in the revised MCP is 1,000 ppb. He also pointed out the range of detections along Tank Alley - nondetect, less than 1,000 ppb, and greater than 1,000 ppb.

Mr. Gregson then noted that other findings in the target soil sampling program were detections of HMX, PETN, perchlorate, TNT, and TNT breakdown products. He also said that there were no detections at some targets and variable detections at others (using both discrete and composite samples) and explained that this could be due to the way the contaminant exists in the environment as small sized particles that are randomly distributed. He also mentioned the complicating factor of the soil being disturbed by explosions as artillery firing continued, thereby further spreading the contamination. Mr. Gregson noted that RDX detections in soil ranged up to about 35,000 ppb, while perchlorate was detected at relatively low concentrations, with a maximum detection of about 60 ppb.

Mr. Hugus referred to the air mag survey figure and noted that previous figures included the southeast corner as part of the Impact Area boundary. Mr. Gregson replied that much of that area is covered by the air mag surveys, ground surveys, soil sampling, and Rapid Response Actions (RRAs) conducted at the Southeast Ranges. He also noted, however, that it might be worthwhile to take a look at other areas in that "wedge."

Mr. Hugus asked if it's correct that DEP indicated that 1,000 ppb is a good cleanup level for RDX. Mr. Gregson confirmed that the revised MCP regulations that are currently out for public comment propose a 1,000-ppb "S1" soil cleanup standard for RDX. Mr. Pinaud added that that number was developed based on leaching potential to groundwater. He also said that backup information is available on DEP's web site. He further explained that while sites that have RDX contamination in soil where the groundwater is used for drinking water would be required to clean up to that level, there's also a requirement to evaluate the feasibility of cleaning up to background. And if it is feasible to clean up to background, that would be the expectation.

Mr. Hugus commented that some sort of mapping that shows concentrations throughout "that huge area" is needed. He said that he doesn't know how it's possible to go about addressing hotspots that could be contributing to groundwater when there isn't a comprehensive view of all the contamination. Mr. Gregson replied that this is an unusual situation in the environmental cleanup business in that there's a 330-acre source area, and source areas are usually less than one acre in size. He said that determining how to deal with it is going to be a major challenge both through the evaluation of further RRAs and through the feasibility study that will look at an ultimate remedy. Mr. Hugus reiterated that he thinks that "some kind of mapping" is needed in order to understand such a vast area.

Mr. Schlesinger asked for further clarification on the 1,000-ppb standard. Mr. Pinaud replied that the proposed standard for soil is 1,000 ppb and the proposed standard for groundwater is 0.8 ppb. Mr. Gregson noted that the groundwater cleanup at the Central Impact Area is a separate operable unit that will be evaluated in the feasibility study. Mr. Schlesinger questioned whether the IAGWSP plans to blanket the Central Impact Area with soil grids in order to come up with better information. He also noted that this points to the need for a Natural Resources officer, given past remarks about disturbing large numbers of acres of land that involve state-listed species. Mr. Gregson said that he had not completed his presentation, which does include additional data that might answer some questions.

Mr. Walsh-Rogalski said that the soil sampling method changed from Phase I to Phase II of the project, with samples taken farther away from the targets during Phase I. He then asked if the detections depicted in the figure were based on the same sampling grid. Mr. Gregson replied that he believes that the detections depicted on the figure were all based on a close-in sampling grid, with the closest sampling conducted at a 25-foot radius from the target. Mr. Walsh-Rogalski suggested that it might be useful to add that piece of information to the figure.

Ms. Jennings said that she thinks it's important for everyone to remember that there are a lot of data - groundwater data, air mag data, and chemical-specific data in soil - that are very complex, particularly the soil data. She also noted that she had asked Mr. Gregson for the same kind of map that was requested tonight and came to the realization "that it's not straightforward to do that." She explained that the soil detections are very sporadic, unlike a traditional source area where concentration contours can be identified that point to a location to excavate soil. She said that an effort is being made to look at the data and conclude what the real source is, as there's clearly a significant source, but one whose boundary is difficult to determine - which would be "kind of the short-term remedy."

Ms. Jennings then said that based on what she's seen, she doesn't necessarily think that the best approach would be to "pluck targets one at a time" in order to try to get a focused source area. She also said that Mr. Gregson's presentation will show that it's not obvious where to draw a boundary "for even just an RRA, versus a long-term source-control remedy." She further noted that she'd asked for the soil detections figure to see if certain targets had consistently elevated levels, and had mentioned the state standard (1,000 ppb) as the number, but not necessarily as the cleanup number, which she doesn't anticipate it will be. She then said that when she looks at the figure she sees that there are certain targets with many detections greater than 1,000 ppb right along the intersection of Tank Alley and Turpentine Road, and targets that are farther out that have detections less than 1,000 ppb and nondetects.

Ms. Jennings stated that looking at the figure she can't begin to conclude how the metal data and groundwater data correlate on a large scale with the chemical soil data, which do not correlate well on a small scale. She also said that over the next few months the technical people will be reviewing the data "layer by layer" to determine if there's an area that seems to be contributing most to groundwater contamination and warrants an RRA. Alternatives to deal with the larger Central Impact Area will be the topic of the feasibility study, which will take a couple years to complete.

Ms. Jennings requested that tonight the IART members just listen, look at the data, recognize the complexity of a soil remedy in the Central Impact Area, and understand that this is the first step toward trying to determine what the short-term action might be. She added that she doesn't think anyone is prepared to say what the cleanup level is and doesn't think that should be the focus of tonight's discussion. She also asked the team to recognize that an attempt is being made to tackle the Central Impact Area in both a short-term timeframe and a long-term timeframe.

Mr. Pinaud inquired about a theory as to why RDX wasn't detected at some of the targets. Mr. Gregson replied that it's possible that some of the targets weren't fired upon very often. For others it probably has to do with the heterogeneity of what was in the soil and that none of the small chunks of RDX ended up in the sample jar. Mr. Schlesinger suggested that perhaps the sampling wasn't sufficient. Mr. Gregson said that it may not have been designed in a way that all the RDX around a particular target could be detected.

Mr. Gregson then showed a figure depicting the Munitions Survey Project (MSP) sites at the Impact Area. He explained that the goals of the investigation of the High Use Target Areas (HUTAs) were: to characterize explosives contamination in soil and the physical distribution of unexploded ordnance (UXO) and munitions debris in a section of the Impact Area considered to be a source of explosives detected in groundwater, to characterize the distribution of UXO and munitions debris surrounding specific targets and look for any attenuation of UXO and munitions debris with increased distance from the targets, to evaluate the nature and extent of contamination around the targets, to quantify and catalog ordnance and explosives material by type; and to characterize contaminants on and below those items and look for evidence of leaking below them.

Mr. Gregson referred to the figure and pointed out the HUTAs in the Impact Area. He also pointed out the Sub-Caliber Aircraft Rocket (SCAR) site, and noted that SCAR rockets are small metal tubes containing 1.75 pounds of ballistic propellant. He reported that no evidence was found to indicate that the SCAR site contributed to contamination in the Impact Area any differently than other sites there. He also noted that two small disposal pits were discovered as part of that investigation and plans are being finalized to investigate them further. Mr. Gregson then pointed out the Eastern Test Site, located in the northern part of the Central Impact Area, and said that the exact use of the site was unknown, but a geophysical survey conducted there determined that it was not an ordnance disposal area.

Mr. Gregson then stated that the triangular Central Impact Area source area was defined based on multiple lines of evidence that include the geophysical data shown on the figure, chemical data, target sampling, range firing fans (the area where rounds from a gun position were most likely to land), backtracks from monitoring wells, and historical photographs that showed evidence of cratering, which indicates a concentration of UXO and RDX contamination.

Mr. Gregson noted that the IAGWSP is in the process of finishing the focused investigation at Target 23 (an old boiler located on the south side of Tank Alley) and Target 42 (an old tank located on the east side of Turpentine Road), the purpose of which was to try to measure contaminants leaching into the groundwater from soil around the targets and obtain data necessary to support future RRAs and future feasibility study actions. He noted that Targets 23 and 42 were selected because of the high concentration of contaminants and frequency of detections there and because they are relatively isolated, and therefore avoid interference from nearby targets that would prevent the acquisition of the best information on attenuation of contaminants and UXO with increased distance from the targets.

Mr. Gregson stated that the focused investigation included soil sampling that determined contaminant concentrations and the distance contamination extended from the targets, and munitions surveys to gauge the prevalence of low-order UXO or UXO that didn't explode completely and can expose the filler inside and to determine if there was a decrease in the density of UXO and low-order UXO with increased distance from the target. The investigation also included the installation of lysimeters, which are devices installed about 10 feet underground to collect water as it percolates through the soil so that contaminant concentrations can be measured. The lysimeters were installed prior to any excavation work to see contaminant concentrations in the deeper soil and then compare those results to surface soil samples, and to see if the analysis of deeper pore water at the Impact Area is a feasible technique for understanding how contaminants are migrating from the surface to the groundwater.

Mr. Gregson continued by displaying a figure that showed some Impact Area soil sampling results through November 2004. He pointed out Targets 42 and 23, noted that the green squares represent nondetects and the red squares represent RDX detections, and pointed out the 330-acre Central Impact Area operable unit boundary. He also noted that some of the soil samples were collected in transects in an effort to define the boundary of the operable unit. Mr. Gregson then reported that the munitions survey part of the investigation yielded three munitions identified as low order at Target 52 and no low order items at Target 23. He also pointed out on the figure where composite soil samples were collected from a depth of 0 to 3 inches in ten staggered grids along the transects away from the targets. He noted that explosives were detected in three samples at Target 42, but none were detected in the samples at Target 23.

Mr. Gregson stated that the IAGWSP recently issued a draft report of the focused investigation and is working with the regulatory agencies to review the results and determine what information can be gained from the data for the short-term phase of the project. He then showed another figure and reported that explosives were detected in 95% of the lysimeter samples at Target 42 and in 25% of the samples at Target 23 - although explosives were detected in only 5% of the soil samples collected at the two targets.

Mr. Gregson then noted that the soil around a specific target is a relatively small area when compared to the entire Central Impact Area. As part of the RRAs a 50-foot radius of soil was excavated around each target. He then showed a figure depicting the RDX detections and the nondetects near and around Target 42, and a similar figure for Target 23, and noted that samples along the transect leading away from Target 23 were all nondetect. Mr. Gregson remarked that even on such a fine scale (around an individual target), it's a complicated story. He also noted, however, that the focused investigation did lead to the conclusion that lysimeters can provide good information on characterizing explosives in pore water just below the surface soil. He said that the detections identified in the focused investigation will provide a baseline for future work in the study.

Mr. Hugus asked if lysimeters are a more efficient way of detecting contaminant concentrations in soil than soil sampling itself. Mr. Gregson replied that the surface soil contains un-dissolved particles of contaminant, some of which may end up in the sample jar. The lysimeters, however, collect pore water that contains dissolved contamination, which is probably a better representation of what's dissolving from the surface soil and working its way to the groundwater. Mr. Hugus asked if installing lysimeters is easy, as compared to conducting soil sampling. Mr. Gregson replied that it's more labor intensive to install lysimeters, which are basically miniature wells, as they are installed up to a depth of 10 feet, using hand augers. He said that he doesn't think it would be feasible to install lysimeters on a wide scale, but they can provide valuable information in other ways. Mr. Hugus said that if one lysimeter can provide as much data as perhaps 20 soil samples, and a truck were used to put the auger in the ground, it might be more efficient. Mr. Gregson replied that that type of approach would be considered, as it might be a better way of characterizing the soil at the Impact Area.

Mr. Panni asked if the lysimeters provided enough information to draw contaminant concentration contours. Mr. Gregson replied that he doesn't think there's enough data density at a particular location to do that. Mr. Panni then asked if it's correct that a lot of the lysimeters failed. Mr. Gallagher stated that the majority of them were very successful. However, the workplan noted that they would be installed to a depth of 10 feet, which, unfortunately, didn't work out in all cases, such that the best was about 7 feet. He then referred to Mr. Hugus's suggestion to install the lysimeters with a drill rig and said that that would be a good idea except for the UXO clearance issue in most areas of the Central Impact Area.

Mr. Panni questioned whether there would have been enough data density to draw contours if all the lysimeters had worked as planned. Mr. Gallagher replied that the lysimeters were set in pairs and within those pairs a sample was taken from each depth interval, such that no intervals were missed regardless of whether an individual lysimeter failed. Mr. Panni remarked, "But not enough to contour it," and explained that he was just interested in seeing the lysimeter information compared to the soil data. Mr. Gallagher indicated that more information is in the Focused Investigation report, and noted that from a preliminary evaluation of the data it seems there might not be a good correlation between detections in soil samples and detections in leachate in the lysimeters, which is probably a function of the heterogeneous distribution of the explosives in soil. He said that to a certain extent the lysimeters overcome that problem, but there are the issues of cost and installation time associated with the lysimeters.

Mr. Dow asked if the IAGWSP had explored the possibility of looking at perchlorate levels in vegetation such as pine trees (since perchlorate is taken up by plants) as a way to map it from the surface, rather than looking at the soil or lysimeters. Mr. Gregson replied that he does not know, but it seems worthwhile to take a look at that.

Mr. Schlesinger asked if the IART members were sent a copy of the report that Mr. Gallagher mentioned. Mr. Gregson replied that the Draft Focused Investigation Report for the Central Impact Area was sent out around November 16, 2004, and he would send another copy to Mr. Schlesinger if he didn't receive one.

Mr. Gregson resumed his presentation by noting that the RRA soil removal at Targets 23 and 42 began in June 2004. He explained that the 50-foot radius of excavation at each of these targets was determined based on previous excavation work done at Mortar Target 9 and at Target 25 (the armored personnel carrier). He also noted that UXO clearance was done in a 52-foot radius around each of the targets prior to excavation. This provided a detailed look at the ordnance there, which was catalogued, described, blown-in-place if necessary, or brought to the contained detonation chamber (CDC). He reported that 24 UXO items and 5 low-order/breeched items were found at Target 23, and 23 UXO items and 1 low-order item was found at Target 42. Mr. Gregson reminded the group that the air mag survey showed a general pattern of UXO distribution such that the higher density of UXO is right at the targets.

Mr. Gregson stated that 1,700 tons of soil has been excavated from the two 50-foot radii around the targets, which translates to about 1/6 of an acre. He noted that post-excavation samples at Target 23 collected after the first two feet of soil were removed showed a 260-ppb RDX detection. An additional foot of soil was removed and confirmation test results for that location are pending. Post-excavation samples at Target 42 showed four RDX detections ranging from 170 ppb to 640 ppb, and TNT at 7,200 ppb. The proposal is to remove an additional foot of soil, bringing that excavation to a total depth of three feet.

Mr. Gregson then reported that based on the available data, some conclusions are being reached. Low-order detonations and cracked open UXO with exposed HE filler can act as a point source of groundwater contamination, which also is being found at other bases around the country. High-order detonations are also believed to be a source, but their relative contribution is thought to be low. Mr. Gregson explained that when a round explodes as intended, the particles are very small and dissolve more readily than some of the larger particles in low-order rounds. He also noted that it was concluded that the majority of UXO in the Central Impact Area are located within the top one meter of soil, the highest frequency of detections of explosive compounds in soil appear to be in surface soil less than one foot deep, and the distribution of explosives is extremely heterogeneous and hard to characterize using existing soil sampling methodologies.

Mr. Gregson then reviewed the next steps associated with the Central Impact Area soil investigation, as follows: to issue a completion report for the RRAs conducted at Targets 23 and 42, to evaluate additional lysimeter data and complete the Focused Investigation report, to respond to regulator and citizen comments on the draft Focused Investigation report, to identify other areas with contamination where RRAs could be successful, to conduct an innovative technology evaluation of in situ treatment technology options (alkaline hydrolysis and bioremediation), to complete the remedial investigation report, and to prepare the feasibility study for the Central Impact Area soil remedy. He also reported that the feasibility study for Central Impact Area groundwater is currently scheduled to be completed in late 2005, but the IAGWSP and the regulators are considering whether the feasibility study for soil and the feasibility study for groundwater should be brought back together on a parallel schedule so that information gained from one can inform the remedy for the other.

Mr. Walsh-Rogalski asked if the UXO found near the targets were all HE rounds. Mr. Gallagher replied that he believes that the bulk of them were. Mr. Walsh-Rogalski noted that reference had been made to rounds that were broken open and to low-order rounds. He said that it's his understanding that there can be rounds that are broken open that aren't necessarily low order and he asked if that distinction had been made with respect to items discussed during the presentation. Mr. Gallagher explained that the IAGWSP uses the term "low order/breeched" to describe items that had become cracked open and had exposed fillers, either because they were partially detonated, didn't function as designed, or were hit by another round. Since it couldn't be determined exactly what had occurred, the combined term "low order/breeched" is used.

Mr. Walsh-Rogalski asked if RRAs for additional target areas and the feasibility study for soil would address UXO in the areas they address. Mr. Gregson replied yes, for the areas being addressed, but also noted that the longer-term issue of UXO as a contaminant source is on a different track than the feasibility study and the RRAs. Mr. Walsh-Rogalski said that it's his understanding that the agreement is to deal with UXO in soil at each area that's addressed. Mr. Gregson confirmed that that is correct.

Mr. Mullennix noted that the Central Impact Area plume extends in the direction of the Northwest Corner investigation area. He then asked if there are any existing or planned water supply wells downgradient of the Central Impact Area plume. Mr. Gregson replied that there are currently no public water supply wells downgradient of the plume; however, there are a couple of private wells near the Bourne Bridge and a couple of irrigation wells at the technical school in the Northwest Corner area.

Mr. Mullennix then said that given the very real possibility that it won't be achievable to clean up all the widespread Impact Area contamination, he wonders if it would be possible to put together a model to determine the amount of mass of contamination and its fate and transport as it reaches the groundwater plume. Mr. Gregson said that that is one reason the IAGWSP is interested in merging the feasibility studies for soil and groundwater. He noted that the IAGWSP plans to look at mass loading in the soil, how it's affecting the groundwater, and how it informs the cleanup decision for both soil and groundwater. Mr. Mullennix suggested that one scenario to consider would be what happens to the plume if there's no soil cleanup. Mr. Gregson agreed that one of the alternatives for groundwater is to look at what the remedy would be if there was no further soil cleanup. Mr. Mullennix inquired about the timeframe for conducting the modeling. Mr. Gregson replied that the IAGWSP is currently working on the groundwater modeling for the feasibility study and will be getting some results back between now and a year from now, when the feasibility study report is expected to be completed.

Ms. Adams questioned whether there are other sources of perchlorate in the Central Impact Area, in addition to LITR rounds. Mr. Gregson noted that he had mentioned that other munitions that contain perchlorate were found there. Ms. Adams said that she thinks that items, such as smokes, might also contain perchlorate and she wouldn't want to lose sight of those as potential sources. Mr. Gregson replied that he believes that smokes and flares are probably more relevant outside of the Impact Area; however, some other rounds used in the Impact Area did contain perchlorate and he could check on that and provide that information.

Mr. Dow said that he recalls that there were some wells near the base boundary being considered for use as public water supply wells, which he thinks might be in the path of the Central Impact Area plume. Mr. Gregson said that those wells, which are located in the Northwest Corner investigation area, would be in the path of the Central Impact Area plume. Mr. Gonser added that a number of years ago the Bourne Water District was considering using those wells, which are identified as 95-15 and 95-6, as part of the Air Force Center for Environmental Excellence (AFCEE) proposal to replace Bourne wells #2 and #5. However, it is instead now looking at well site #4, an old well installed under the water supply program, which is closer and more accessible to the Bourne Water District's pipelines.

Mr. Schlesinger remarked that he doesn't think nearly enough information is available yet to be concluding that there's too much contamination in the Impact Area to be cleaned up. Mr. Gregson noted that that would be part of the feasibility study. Mr. Schlesinger then inquired about any plans to seek clean water in the "extreme north northwest corner." Mr. Gonser said that he'd looked at that area during the water supply program project and the problem there is the confluence of both moraines, one going north/south and one going east/west, which makes it very difficult to find a good well site. He also noted that it would be necessary to drill very deep, that the area is quite a distance from any of the towns' distribution systems, and that one well was drilled there but came up dry. He concluded that from a water supplier's standpoint, that is probably the least desirable of all the areas on MMR to look for water.

Mr. Schlesinger inquired about efforts to survey the source area associated with the J-2 Range plume. Mr. Gregson replied that the J-2 Range has its own history of intense investigation, including air and ground magnetometry. He also said that at a future meeting the IAGWSP could give a presentation on the Southeast Ranges, similar to tonight's Central Impact Area presentation. Mr. Schlesinger said that the IART certainly will need to discuss source removal there. Mr. Gregson clarified that source removal work for the J-2 Range plume has been done, but there is more work to do at the Southeast Ranges.

Mr. Hugus asked if it's known whether the Central Impact Area plume affected the wells in the Monument Beach wellfield in Bourne. Mr. Gregson replied that the source of those perchlorate detections is not thought to be part of the Impact Area. He then pointed out on the plume map the area where that source, which is currently unknown, is believed to be located. Mr. Hugus remarked that he would hate to see that area written off "as a place of no risk" and the conclusion drawn that it's not worthwhile to clean up the soil or groundwater. He said that the base-wide plume map, "as faulty as it might be," shows that there is no area in the northern part of Upper Cape Cod that should be considered of no concern since it might very well be that future water supplies will have to come from that area.

Mr. Schlesinger asked if the IAGWSP is investigating a connection between the contamination at the Northwest Corner and at the Central Impact Area, working back from the Northwest Corner. Mr. Gregson replied that he believes that the IAGWSP is working from both ends to try to answer the question of whether the two areas of contamination are connected. Mr. Schlesinger then inquired about the two detections of RDX in soil north of Wood Road, which don't seem to coincide with the detections in groundwater shown on the base-wide plume map. Mr. Gregson said that he would look into the reason why those detections aren't included in the Central Impact Area plume boundary. Mr. Gonser made a point of noting that those detections were in soil, and the groundwater plume might not exist there. Mr. Gallagher added that he believes that those were TNT detections, although the map legend indicates that they were RDX.

Following a short break in the meeting, Mr. Gregson showed the team two maps, one depicting perchlorate contamination in the Impact Area, the other depicting RDX contamination. He also pointed out the concentration contours on each of the maps and said that copies would be provided to IART members. Mr. Schlesinger remarked that the base-wide plume map makes more sense to him now, except for a discrepancy in the depiction of the small plume finger, which appears as two areas on the base-wide map. Mr. Minior explained that that area of contamination is the CS-19 plume, and the base-wide map shows it as depicted by AFCEE.

Agenda Item #4. Remediation & Investigation Update

Demolition Area 1 Groundwater RRA

Mr. Nixon reported that to date 36.5 million gallons of water have been treated by the two systems in place at the Demolition Area 1 (Demo 1) plume. He noted that during the month of November the systems operated 97.7% of the available time, with one brief interruption to upgrade some computer software. Startup sampling and testing of the systems' operations showed that they are working as planned, and hydraulic monitoring that involved a planned shutdown and restart of the systems to measure the rebound of the aquifer and the drawdown with or without pumping showed that the systems are capturing the plume as intended and as presented in the RRA plan.

Mr. Gregson stated that initial sampling was completed at the two systems. He also noted that on November 16, 2004, breakthrough of perchlorate was detected for the first time in the initial granular activated carbon (GAC) vessels in the treatment containers at the Frank Perkins Road system. This occurred as expected and does not require an immediate carbon exchange as the perchlorate is being removed by the ion exchange vessels and the existing carbon continues to remove the RDX coming into the system. Mr. Gregson reported that perchlorate concentrations at the Frank Perkins Road system are 30 ppb to 40 ppb, and at the Pew Road system are about 10 ppb. RDX concentrations at Frank Perkins Road are 4 ppb to 5 ppb, and less than 1 ppb at Pew Road. Contaminant concentrations at Pew Road are increasing slightly and effluent samples from both systems continue to be nondetect for all parameters.

Soil Rapid Response Actions

Mr. Nixon stated that soil RRAs are being completed at the J-3 Range, the J-2 Range, the Central Impact Area, and Demo 1. The thermal treatment plant, which is currently operating, is expected to complete treatment of the current lot of soil on December 21, 2004, including soil excavated from the CS-19 source area under the AFCEE cleanup program. Mr. Gregson noted that about 900 tons of soil was excavated from the Demo 2 site, and based on post-excavation sampling results, an additional 334 tons of soil was excavated from the J-3 Range site. He also said that next week the IAGWSP plans to begin removing about 750 tons of soil from Gun Position 6 (GP-6); that soil also will be treated at the thermal treatment unit.

Mr. Dow asked if any of the treated soil had been replaced or if it all remains in stockpiles. Mr. Nixon replied that the treated soil is stockpiled on the outer fringes of the Demo 1 site and probably will remain there into the winter as final EM-61 surveys have to be conducted. He also noted that the last section of the site to be excavated will be the soil beneath the existing stockpiles. Once that has been completed, the treated soil will start to be moved in to the hole at Demo 1.

Demo Area 1 Recent Results

Mr. Nixon reported that groundwater samples from the three well screens at MW-352 and the three at MW-353 tested nondetect for perchlorate and explosives. He also noted that in follow-up to a question raised at the last IART meeting, it's been confirmed that the Rod & Gun Club, which is situated in that area, does not have a private well and uses town water. It was also confirmed that none of the homes in that area have private wells and are all hooked up to the Bourne Water District system.

Mr. Schlesinger mentioned the proposed monitoring wells shown on the map. Mr. Nixon noted that those are intended to be sentinel wells, but won't be installed unless there's a detection in MW-352 or MW-353. Mr. Schlesinger noted that he's interested in the proposed well that's located above the label for MW-352. Mr. Nixon apologized for not having noticed it before and explained that it is just a "stray," which shouldn't be there. Mr. Schlesinger also inquired about the color of the dot depicting MW-252. Mr. Nixon replied that it is yellow, which means that the detection there was less than 1 ppb, and noted that the new plume delineation includes that well. Mr. Schlesinger then asked whether a monitoring well could be installed at the location of the "stray." Mr. Nixon replied that the IAGWSP could take a look at that. Mr. Schlesinger said that if there's a detection at the nearby MW-252, the end of the plume has not been determined.

Demolition Area 1 Feasibility Study Update

Mr. Nixon stated that the Demo 1 feasibility study was based on data through May 2003; however, newer data indicate that the plume migrated a bit farther. He noted that the revised plume delineations will be used in supplemental evaluations to determine the fate and transport of contaminant past Pew Road. He then showed the revised RDX plume map, noted that it shows the RDX plume extending about 200 feet past Pew Road, and said that based on an EPA comment, the plume outline will be extended a bit wider to encompass the area around MW-341, which was installed in August 2004. He also showed the revised perchlorate plume map, pointed out MW-252 where detections have been hovering around the detection limit (0.35 ppb), and noted that the revised plume outline extends an additional couple hundred feet, but at very low concentrations.

Mr. Nixon then showed cross-section figure of the Demo 1 plume and pointed out the Pew Road and Frank Perkins Road extraction wells. Mr. Murphy questioned whether the figure was included in the presentation handout and Mr. Nixon confirmed that it was not. He then showed another cross section (E-E') and pointed out MW-341. He also pointed out that the plume seems to be riding on top of a confining (clay/silt) layer in that area (Pew Road), which is fortuitous because it causes the extraction well to stay focused on the contaminated portion of the aquifer.

Mr. Walsh-Rogalski requested that the team be provided with copies of such graphics during future presentations, particularly those that pertain to issues such as the downgradient extent of the Demo 1 plume.

Ms. Adams said that she didn't understand which transect the E-E' cross-section figure is showing. Mr. Nixon referred to the plan view map and replied that the view is looking downgradient at Pew Road, with south on the left and north on the right.

Mr. Schlesinger remarked that the bulk of the plume mass is located in the southern portion of the cross-section. Mr. Nixon pointed out a monitoring well, installed after the extraction well, which led to the belief that the center of plume mass was more to the south than originally thought. Mr. Schlesinger said that for years IART members have been arguing that more investigation is needed toward the south and he questioned why even today the focus of investigation is to the north. Mr. Nixon suggested that the monitoring well installed in August addresses that concern. Mr. Schlesinger disagreed and said that it seems to him that the "bulk going to the south" needs to be addressed, "from MW-252 and beyond." Mr. Nixon replied that he thinks this is a valid concern past Pew Road; he also noted, however, that what the graphic doesn't even try to show is how the extraction well draws in the upgradient contamination.

Ms. Jennings questioned whether the Pew Road extraction well's capture zone includes the full width of the plume. Mr. Nixon replied that he doesn't yet have a graphic that shows the capture zone. He did, however, point out the general area of the capture zone and two small areas that are not being captured, but where the contaminant concentrations are barely above the detection limit. He added that it does capture just about the entire width of the plume and noted that in the future he'll have a graphic to show that more clearly.

Mr. Dow questioned whether the confining layer that Mr. Nixon mentioned is responsible for the asymmetry that occurs in the plume between north and south. Mr. Nixon replied that that is possible, and noted that the hydraulic gradient there under ambient conditions is slightly upwards. Once the system is turned on, however, that goes away and everything is drawn toward the well. Mr. Dow also asked, if the confining layer affects the plume's asymmetry, whether there is any horizontal flux that would tend to take it outside of the capture zone. Mr. Nixon suggested that Mr. Dow is referring to some sort of blockage around which everything is diverted. Mr. Dow confirmed that he is. Mr. Nixon said that based on data from the monitoring wells there (which he acknowledged are spaced hundreds of feet apart), there is no indication of that. He also noted, however, that cross-section G-G' does show a case where that might be happening.

Mr. Schlesinger remarked that cross-section F-F' further proves his point "that there's more on the south than on the north." Mr. Nixon explained that because there isn't another monitoring well there to indicate exactly how far out to draw the contamination, it was defined very conservatively, based on a 0.71-ppb detection, which he pointed out on cross-section F-F'. He noted that the concentrations in that area are very low, with a maximum of about 2.1 ppb. He also said that there may be a remnant of the confining layer in that area. Ms. Adams asked if the 2.1-ppb detection is within the capture zone of the Pew Road extraction well. Mr. Nixon replied that it is not. He also noted that the point of the additional modeling is to determine what happens to the contamination not captured by that system. He explained that a code in the model will represent 25-foot spaces, and the concentration in each space will be fed into the model for each one of those bits of code.

Mr. Nixon then showed cross-section G-G' and pointed out the area where it appears that there could be lower hydraulic conductivity and consequently some diversion. He said that this might explain why the monitoring well that appears to be in the middle of the path of the plume has never had a perchlorate detection. He also pointed out that the screens in that well are set at the correct elevation to detect the plume. Mr. Nixon then said that the concentrations in that area are very low and it appears that it would take a higher concentration to drive forward and be detected at that well; whether that will happen some day is unknown. He also pointed out the beginning of the finger of the plume that extends toward North Pond.

Mr. Panni questioned whether the model would account for effects of the pond on the western edge of the plume. Mr. Nixon replied that the pond would be included in the model; however, it's not very big and is only about 5 feet deep and is not expected to have too much influence. He noted that the plume is about 30 or 40 feet below the bottom of the pond.

Mr. Nixon stated that next steps are to reach agreement on the revised plume shape; input new data into the model; run the model and determine what happens to the contamination, particularly past Pew Road; and do the remedy selection plan, using information from the model to decide whether a sixth extraction well is needed. He noted that a conceptual draft remedy selection plan has been done already. Mr. Nixon further noted that there will be a public comment period on the remedy selection plan, after which a decision document will be written, and system design, part of which is already done because of the RRA, will move forward and be followed by construction and operation of the full-scale system, probably in the first half of 2006. He also mentioned that the Frank Perkins Road part of the system will probably be an approximately 12,000 square foot treatment building housing ion exchange and carbon vessels.

Ms. Grillo asked for the general timeframes associated with the schedule. Mr. Nixon replied that system startup should occur in 2006, with system construction beginning in 2005, depending on factors such as the Textron issue. System design, which is ongoing, should be completed in the first half of 2005, and the decision document should be issued just before the final design. The remedy selection plan is scheduled for the first quarter of 2005.

Mr. Schlesinger remarked that he takes such long-term plans with a grain of salt, given that he's read newspaper articles that the White House is "about to start dismantling 30 years of environmental protection." He then asked if there are any plans to dismantle the Safe Drinking Water Act (SDWA) such that it would disturb the plans to clean up MMR. Mr. Walsh-Rogalski replied that legislation put forward previously has affected the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Resource Conservation and Recovery Act (RCRA), but not the SDWA. He also said that he thinks part of the reason for that is that the SDWA is a public health statute.

Mr. Hugus asked for clarification on Textron's role in the schedule. Mr. Nixon replied that while the schedule depends on the entire process, including the modeling, the public comment period, and so on, Textron is on board for construction of the treatment plant, at least conceptually. Mr. Walsh-Rogalski added that a final settlement with Textron has not yet been reached, but a meeting is scheduled for later this week. Mr. Hugus suggested that the IAGWSP must have money for the project, aside from what Textron might pay in a settlement. Mr. Walsh-Rogalski confirmed that it does, but also explained that if Textron were to build the treatment system, it would happen more quickly, since Textron wouldn't have to go through all the funding hoops that the Department of Army would. Mr. Hugus asked if Textron is now in the business of building cleanup systems. Mr. Walsh-Rogalski clarified that Textron would hire a cleanup contractor to do the construction under government supervision. Mr. Nixon added that in the meantime the RRA system is containing that portion of the plume.

Northwest Corner Update

Mr. Gregson showed a map of the Northwest Corner and noted that the investigation there continues, focusing on the boundaries of the perchlorate plume and trying to identify the source of RDX detections in MW-323. He reported that recent groundwater results showed 0.59-ppb and 0.72-ppb perchlorate detections in MW-344 and a 0.5-ppb perchlorate detection in MW-350. He also noted that a new monitoring well is planned at GP-19 to find the upgradient extent of RDX detected at MW-323. He said it was hoped that results from MW-350 would answer that question; however, it tested nondetect for RDX. Mr. Gregson said that this means either that there's a detached plume, that that's the end of the RDX contamination, or that the RDX is coming from a slightly different direction.

Mr. Gregson then showed cross-section A-A', which he noted looks down the direction of groundwater flow, toward the Cape Cod Canal. He pointed out the perchlorate concentration contours (nondetect to 1 ppb, 1 ppb to 4 ppb, and 4 ppb to 18 ppb) and noted that RDX was detected at only one well in the figure (MW-284).

Mr. Schlesinger said that he's interested in seeing cross-sections that are on base, from GP-19 across the 35-foot groundwater elevation line, for example, which he believes would define "how much of this area is coming from up above and how much is coming from below." Mr. Gregson showed cross-section D-D', which runs near the base boundary and includes a perchlorate detection near the water table. He also noted that a cross-section in the area Mr. Schlesinger mentioned would show a sliver of perchlorate up at the water table.

Mr. Schlesinger then asked if the purpose of the planned air modeling is to determine whether the dispersion of fireworks smoke or debris would explain the perchlorate contamination south of the G-G' cross-section line. Mr. Gregson replied that the air modeling will to try to validate the conceptual model of fireworks displays as a potential source of perchlorate contamination in that part of the plume, and conversely, whether there's some other explanation for those perchlorate detections. Mr. Schlesinger questioned why Mr. Gregson didn't say that the alternative explanation would be military training. Mr. Gregson said that if the model indicates that fireworks debris is a contaminant source but only extends "this far," the question of a second source will have to be answered.

Mr. Walsh-Rogalski asked if the modeling would account for smoke-pots that were used for training along Canal View Road. Mr. Gregson replied that while the IAGWSP will look at the whole picture, including information on training records, detections at gun positions, content of munitions debris, and so forth, the air modeling is designed to determine if it's feasible that fireworks launched at the fireworks display site caused perchlorate contamination in soil "up in that area." Mr. Walsh-Rogalski remarked that he doesn't understand how that piece of information could be useful if there are other sources of perchlorate being introduced into the environment in that area, such as smoke-pots along Canal View Road. Mr. Gregson explained that the IAGWSP is trying to come up with a conceptual model that answers the question of why there is such widespread low-level perchlorate contamination in the Northwest Corner, whether fireworks is a contributor, and if not, what the contributors are. Mr. Walsh-Rogalski said that he's not trying to diminish the fact that fireworks are a potential source, but he thinks it might be worthwhile to look into modeling other potential sources, such as smoke-pot contamination. He added that it doesn't seem to him that getting the answer that the IAGWSP is seeking will provide a lot of information, given that there are other sources.

Mr. Minior noted that information about wind speed and direction during past fireworks displays would be available through the people at the Otis air base. Mr. Gregson said that the IAGWSP has obtained those data to plug into the model. Mr. Minior then requested that, as they become available, the DEP provide the IART with results of the pre- and post-fireworks study it conducted at the University of Massachusetts, Dartmouth. Mr. Murphy said that this request would be noted as an action item. Mr. Mullennix noted that the gentleman in charge of that study informed him that the results would be ready this month. He also said that he thinks the study is important enough that IART members should receive the results as soon as possible.

Mr. Dow asked if the IAGWSP plans to make a computation of where the dry and wet deposition comes down, in addition to looking at where the wind might carry the material that emanates from the fireworks site. Mr. Gregson replied that the model will use the wind speed and direction information pertaining to the fireworks events (which are of relatively short duration, about a one-hour Fourth of July celebration) and provide the extent of fallout of debris and smoke particulate and the relative loading onto the ground, based on those events. Information that's not available to put into the model, however, is the mass of resultant perchlorate after the fireworks detonation. Nevertheless, it's believed that knowing the extent and relative density of deposition will be helpful. Mr. Dow said that it seems to him that in order to make any meaningful predictions, it's important to know if the fireworks material travels from the atmosphere down to the ground via wet or dry deposition, which are quite different processes. Mr. Gregson replied that dry deposition would be the most likely process since fireworks events are short in duration and do not usually occur when it's raining. He added that just like artillery rounds going off at the base, the fireworks go off, particulates of various size are released, and due to gravity and the density of particles, they fall to the ground.

Mr. Dow noted that it's his understanding that industrial smokestacks are built such that the pollution travels a good distance and doesn't fall to the ground nearby and create a problem for the plant's neighbors. Therefore, it seems to him that if the fireworks are shot up into the atmosphere, they would be transported quite a distance and wouldn't land as close by as the plume outline location. Mr. Gregson replied that one important difference is that smokestacks emit very small particles, whereas fireworks particles vary from smoke size all the way up to chunks of the fireworks items themselves. And based on their size and weight, they fall out at different locations.

Mr. Dow said that he would recommend validating the air modeling with some on-the-ground data (perhaps some kind of "randomized circles" that could be sampled); otherwise he thinks the modeling would be of no use at all. Mr. Gregson replied that that concept has been considered, and the IAGWSP does have the soil data that show detections in the area. One problem with dealing with those results, however, is that perchlorate detections in soil drop off rapidly with time as the contaminant dissolves and goes into the subsurface.

Mr. Gallagher clarified that the CALPUFF model, which will be used for the air modeling, addresses mostly the smoke size particles, and not the larger particles as Mr. Gregson may have indicated. He also noted that it's known from technical reconnaissance approximately where the larger particulates landed.

Mr. Hugus said that he doesn't understand why the IAGWSP is devoting so much of its resources to the fireworks hypothesis. He then questioned whether the IAGWSP is claiming that the RDX that's also been detected in the Northwest Corner came from fireworks as well. Mr. Gregson showed cross-section I-I' and pointed out that the RDX is a much narrower plume. He noted that the RDX source (probably farther up on the base) appears to be different from the source of much of the perchlorate contamination in the Northwest Corner. He also acknowledged that some locations have deeper detections of perchlorate, and the source of those is likely farther up on the base as well.

Mr. Hugus asked why the IAGWSP is concerned about proving that fireworks was the source of the perchlorate contamination when it's responsible for the RDX contamination and will have to clean up both plumes anyway. Mr. Gregson replied that the goal of the air modeling is to validate the conceptual model and obtain an understanding of the potential extent of perchlorate deposition to the surface soil. He also said that at this point he doesn't know when it will be determined "what caused what and what extraction system is going to extract what." Mr. Hugus said that he thinks this is a question of liability, and therefore the IAGWSP is trying to prove that fireworks caused the contamination, yet is not following up by taking actions such as installing monitoring wells across the canal to see if perchlorate from fireworks was distributed there.

Mr. Gregson explained that at this point there's no reason to investigate that area because the prevailing winds are from the southwest during fireworks displays and do not blow in that direction. Mr. Hugus remarked that the whole investigation "drops dead" at the canal. Mr. Gregson explained that this is because the plume is discharging into the canal. Mr. Gonser further explained that the contamination near the canal reached that area via the groundwater after having been carried by the wind and then deposited "basically on the right side of the plume." He also said that the reason for the air modeling is not to get into liability, but to identify a source. Once the source or multiple sources have been identified, the best remedy to address the contamination can be determined.

Mr. Hugus said that he doesn't see the same level of effort to explain other potential source areas, such as GP-14. Mr. Gregson replied that the IAGWSP has done extensive investigation of potential military sources on the base, including sampling and complete UXO surveys at gun positions, and sampling at various sites in the woods (identified by the IAGWSP and the regulators) where former military actions took place. He said that the IAGWSP is trying to track down any potential sources of contamination, which are all part of the puzzle. Mr. Hugus asked if there's a plan to conduct air modeling pertaining to propellant bag burning that occurred at GP-14 and GP-16. Mr. Gregson noted that bag burning resulted in 2,4-DNT contamination, which has not been detected in that area.

Mr. Pinaud referred to cross-section E-E' and inquired about a theory to explain the very deep perchlorate contamination at MW-270, near the canal. Mr. Gregson replied that, as mentioned at previous IART meetings, detections in MW-270 are very unusual in that both profile samples and groundwater samples showed perchlorate from the surface to the bottom. He said that it's still unknown what is happening at that well; however, one potential theory is that for some reason the contamination is dropping down at that area near the canal. Mr. Pinaud asked if it's unknown then whether that perchlorate is traveling similar to how the RDX is traveling (from an upgradient source), or if it has something to do with the geology or the groundwater flow near the canal. Mr. Gregson said that he thinks it might have to do with the geology at that location and the influence of the canal on groundwater flow. He also noted that perchlorate detections from water table to bedrock have not been seen in any other monitoring well.

Mr. Pinaud also inquired about next steps for the Northwest Corner. Mr. Gregson replied that the next steps are to complete the modeling and to revise the report that was issued in January 2004 or issue a new report based on the recent data. Mr. Pinaud asked if that would be considered a remedial investigation report. Mr. Gregson replied that if it answers the questions that need to be answered, such as nature and extent of the contamination, then it would be a remedial investigation report, and the next step would be a feasibility study.

Mr. Schlesinger said that he's very thankful for having been provided with so many cross-section figures, which help quite a bit in understanding the Northwest Corner investigation area. He also requested, however, that depictions of RDX contamination be added to the perpendicular cross-sections for future presentations. Mr. Gregson replied that this could be done.

Mr. Mullennix, in response to the concern about the IAGWSP spending too much time trying to identify the source of contamination in the Northwest Corner, noted that the draft report that was issued in January 2004, which concluded that fireworks were the primary source of perchlorate contamination in the Northwest Corner, was rejected by EPA, DEP, and a member of the IART. Therefore, the IAGWSP was asked to gather more information, conduct some modeling, and make additional determinations as to what the source might be, and he thinks that that is exactly what the IAGWSP is doing.

Mr. Mullennix also expressed concern that the CALPUFF model (to be used for the air modeling) would provide a flawed representation of what occurs from fireworks displays, given that it accounts for only the small particulate matter, and not the larger material, such as shell casings, which fall to the ground. Mr. Gregson clarified that deposition of those materials would be taken into account in the conceptual model.

Central Impact Area Recent Results

Mr. Gregson reported that a recent 0.6-ppb perchlorate detection at MW-89 will result in extending the perchlorate concentration contour downgradient to encompass that well. He noted that this was expected, based on the groundwater model and the understanding of how the plume will migrate. He also said that historically MW-89 had had detections of RDX and HMX.

J-2 Range Recent Results

Mr. Gregson stated that several small plumes of RDX and perchlorate are emanating from the eastern end of the J-2 Range. He then reported that profile samples from MW-355 (located in the driveway to the Forestdale School in Sandwich) tested nondetect for explosives and perchlorate, as did MW-357 (located on the base boundary). Profile samples from MW-358 (located adjacent to the Town of Sandwich cemetery along Route 130) also tested nondetect for explosives and perchlorate, but did show detections of PCE in 11 intervals, from 19 to 119 feet below the water table, at concentrations between 0.36 and 2.0 ppb. Mr. Gregson then noted that MW-57, the well about which Mr. Minior had inquired, has also had PCE detections. He said that the source of the PCE in the two wells is not certain, and added that the base boundary runs to the west of them.

Mr. Gregson also reported that continued sampling of residential wells on Peters Pond Road has yielded no additional detections except at the one well where perchlorate was detected initially. That well has been sampled seven times, with the average detection being 1.12 ppb, and the most recent being 1.8 ppb.

Mr. Schlesinger said that he's read about perchlorate problems related to blasting in other parts of the state. He then asked if any blasting activities have occurred at the P.A. Landers pit area. Mr. Gregson replied that the P.A. Landers site is a sandpit, not a rock quarry, and although he has no information that blasting has occurred there, it has not been ruled out as a potential candidate, even though it would be a "bit off" in terms of groundwater flow. Mr. Pinaud inquired about the non-potable well at that sandpit. Mr. Gregson replied that that well was sampled and tested nondetect for perchlorate.

J-3 Range Recent Results

Mr. Gregson showed a map of the J-3 Range perchlorate plume and pointed out the base boundary and Snake Pond. He also pointed out MW-359 and MW-356, which were installed to help define the western boundary of the plume and to provide information about any contamination emanating from the Hillside area, a former target area next to the J-3 Range. He reported that profile samples from MW-359 showed perchlorate at 0.6 ppb and 0.61 ppb in two intervals, and profile samples from MW-356 showed perchlorate between 0.45 ppb and 1.4 ppb, and a low-level detection of HMX (0.73 ppb) in one profile sample. He noted that screens are being set in the wells.

Ms. Adams inquired about the source of perchlorate at the J-3 Range. Mr. Gregson replied that the likely source is the disposal area in the center of the J-3 Range, where open burn/open detonation activities took place. Ms Adams inquired about the specific items that contained perchlorate, and whether there might be any ties to Textron or other contractors that used the J-3 Range. Mr. Gregson replied that he would have to check on that, as he's not sure what specific items might have been disposed there.

Mr. Walsh-Rogalski asked if the Minuteman missile test area had been ruled out. Mr. Gregson said that he doesn't think so, and he believes that some additional investigation is being done there. Mr. Walsh-Rogalski also asked if Mr. Gregson is referring to the target wall when he speaks of the disposal area. Mr. Gregson clarified that he's referring to that general portion of the range, which includes a target wall, a disposal pit, a burn box, and the Minuteman test area.

Mr. Schlesinger inquired about the J-3 Range RDX plume. Mr. Gregson did not have with him a figure that depicts the RDX plume, but noted that it is essentially co-located with the perchlorate plume. He also said that the IAGWSP is currently working with the regulators on the wellfield design for an RRA that utilizes the Fuel Spill 12 (FS-12) plume treatment plant to address the J-3 Range plume. Mr. Schlesinger suggested that this plan would only work well if the plume didn't move farther to the west. Mr. Gregson pointed out particular monitoring wells whose data provide an understanding of the extent of the plume. He also noted that the RRA will be designed conservatively designed to account for some uncertainties along the western edge of the plume. He further noted that the RRA is not necessarily the final action to be taken on the plume, and adjustments would be made in the future, if needed.

Agenda Item #5. Open Discussion

Mr. Hugus asked if anyone from the E&RC was present at the meeting to hear the team's comments on the base-wide plume map it produced. Mr. Murphy confirmed that no one from the E&RC was in attendance. Mr. Hugus said that he thinks that the map is missing some important information, including any indication that Bourne's Monument Beach wells were ever affected by contamination from the base. He also remarked that the FS-12 plume is depicted in a "pond color," such that looks like a pond rather than a plume, and that the mild pastel colors that are used overall have the effect of minimizing the importance of the plumes. He further noted that the map is lacking depictions of known J Range plumes. Mr. Hugus suggested that the solution is to update the map, include plume contours up to nondetect so that the impact of base contamination in places like the Monument Beach wellfield can be understood, and change the colors to better distinguish between plumes and bodies of water. He also said that he would appreciate it if the E&RC provided IART members with an opportunity to review and comment on the updated map before it's released to the public, which was not the case with the current map.

Ms. Grillo noted that after the last IART meeting she followed up with Lynda Wadsworth at the E&RC and told her that everyone was a bit surprised that they weren't given an opportunity to review the map and that the request for a base-wide plume map had come from the advisory teams. She also said that Ms. Wadsworth plans to meet with her and Mr. Murphy. Ms. Grillo then advised those individuals at AFCEE and the IAGWSP who were given the opportunity to review the map to include the IART and the regulators in future reviews, should the E&RC forget to do so.

Mr. Mullennix noted that the map, which he found to be fairly accurate and quite informative, did draw the plumes down to low detections (1 ppb for perchlorate). He also said that he thinks its incumbent on "this group" and the IART not to create needless fear and worry by producing a map that appears to show gross contamination where in fact it does not exist. Mr. Mullennix said that he thinks that a little bit of judgment and circumspection is required when drawing such a map in order to prevent inflaming fears of people who are not particularly knowledgeable about the levels of contamination that the cleanup programs are addressing.

Mr. Schlesinger remarked that it seems to him that the person who oversaw the making of the base-wide plume map read the book "How to Lie with Maps" by Mark Monmonier. He also noted that information about the contamination heading toward the Peters Pond neighborhood was known prior to the map's release, and yet it was not included. He said that opposite to Mr. Mullennix, he believes that maps are being made to specifically misinform the public. He stressed that he is not making things up, and that this type of map preparation has been going for years. He added that if there were true concern about supplying the public with information it can use to make good decisions and get involved with the process, it would be provided with "information rather than falsehoods." Mr. Schlesinger further noted that he echoes all of Mr. Hugus's comments about the maps. He also expressed displeasure that the map was distributed at the Forestdale information session, without depictions of the very plumes that affect that neighborhood.

Mr. Schlesinger then noted that some individuals who attended the Forestdale information session told him that the IAGWSP offered the owners of the nine properties of interest only $2,000 for a period of 25 years of access, which they found to be inadequate, considering the length of time and the inconvenience of a well installation and sampling. Mr. Schlesinger then asked if that is the standard proposal or if the amount is negotiable. Mr. Gregson said that he believes that is the standard amount that's been offered to everyone the IAGWSP has contacted regarding gaining access to their property to help with the investigation. He also noted that one particular commercial property turned down the offer and so the IAGWSP went across the street to property owned by the Massachusetts Division of Fisheries & Wildlife and a town right-of-way to install a well there to answer the same data objective. Mr. Gregson further noted that two of the nine homeowners were agreeable to the proposal, and the IAGWSP is pursuing one of those locations for a well installation. He also said that the IAGWSP thinks that the offer for the easement and annual sampling of the wells is reasonable, is consistent within the program, and is consistent with how AFCEE deals with access issues in its cleanup program.

Mr. Schlesinger then said that the individuals who spoke to him said that they were a bit miffed at the IAGWSP's attitude, in that they were told that it didn't matter if the private citizens didn't grant access because the military could simply close down a road and install a well in the middle of it. Mr. Gregson confirmed that one option being considered in the event that the IAGWSP can't obtain access to any of the private properties in that area to answer the data needs of the project is to install a well in the road. Mr. Walsh-Rogalski asked if a manhole would be put in the road in that case. Mr. Gregson replied that while this is not the preferred option because of the risk of damage, a well installed in the pavement would be covered with small flush-mounted well box cover about eight inches in size. Mr. Walsh-Rogalski noted that it would not then affect traffic. Mr. Gregson agreed that it wouldn't. Mr. Gonser added that an installation in a road often means installation in the road right-of-way, not in the actual road itself.

Agenda Item #6. Adjourn

Mr. Murphy noted that the IART would meet next on January 25, 2005 at a location to be determined. He then adjourned the meeting at 9:25 p.m.

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