Impact Area Review Team

River River Drops of rain on a leaf

Impact Area Review Team
Falmouth Holiday Inn
March 23, 2004
6:00 - 9:00 p.m.

Meeting Minutes

Members: Organization: Telephone: E-Mail:
Hap Gonser IAGWSP 508-968-5107
Ben Gregson IAGWSP 508-968-5821
Mike Minior (sitting in for Marty Aker) AFCEE/MMR 508-968-4670
Todd Borci US EPA 617-918-1358
Margery Adams US EPA 617-918-1733
Len Pinaud MA DEP 508-946-2871
Amine Dahmani UCONN/TOSC 860-486-2781
Bob Mullennix IART/Bourne 508-759-8319
Richard Hugus IART/ABC/Falmouth 508-540-6034
Peter Schlesinger IART/Sandwich 508-548-9375
Facilitator: Organization: Telephone: E-Mail:
Jim Murphy US EPA 617-918-1028
Attendees: Organization: Telephone: E-Mail:
Robert Perry IAGWSP 508-968-5628
John McDonagh IAGWSP 508-968-5636
Kris Curley IAGWSP 508-968-5626
Lori Boghdan IAWGSP 508-968-5635
Paul Nixon IAGWSP 508-968-5620
Bill Sullivan E&RC 508-968-5147
Doug Karson AFCEE/MMR 508-968-4670
Meghan Cassidy US EPA 617-918-1387
Jane Dolan US EPA
Dave Williams MDPH/EPHC 781-774-6612
Kevin Hood UConn/TOSC 860-486-2546
Matt Matlin Cape resident 508-274-8472
Martin Greene Bourne Firefighters Union 508-759-9178
Kim Harriz AMEC 978-692-9090
Jim Quin STL 720-963-9346
Amanda Lehmert Cape Cod Times 508-548-9300
Jane Moran Portage Environmental 508-759-9114

Action Items:

  1. Ms. Adams requested that the Environmental & Readiness Center (E&RC) add to its website two documents related to the lease extension: Supplemental Agreement #1, and the Memorandum of Understanding between the state, Army, and National Guard Bureau.
  2. The Impact Area Review Team (IART) asked to be provided with cross-section figures for contaminant plumes emanating from the J-1 and J-2 Ranges area. Also, Mr. Borci asked that the team be provided with forward particle tracks from monitoring well 310 (MW-310), MW-319, and MW-215.
  3. Mr. Schlesinger asked to be provided with cost breakdown figures for construction of each of several cleanup program monitoring wells.

Future Agenda Items:

  • TOSC Presentation on Ion Exchange
  • TOSC Presentation on Granular Activated Carbon
  • Summary Report on Northwest Corner Investigation
  • Massachusetts Department of Public Health Update
  • Zones of Contribution

Handouts Distributed at Meeting:

  1. Responses to Action Items from the February 24, 2004 IART Meeting
  2. IART Groundrules
  3. Presentation handout: Demolition Area 2 Rapid Response Action
  4. IAGWSP fact sheet: Demolition Area 2 Rapid Response Action
  5. Presentation handout: Remediation & Investigation Update
  6. Data tables
  7. Presentation handout: Northwest Corner Data Summary Report
  8. UXO Discoveries/Dispositions (ending 3/18/04)
  9. News Releases, Neighborhood Notices, and Media Coverage (2/21/04 - 3/19/04)

Agenda Item #1. Welcome, Review Agenda, Approval of February 24, 2004 IART Minutes

Mr. Murphy convened the meeting at 6:03 p.m., the IART members introduced themselves, and Mr. Murphy reviewed the agenda. He then asked if there were any changes to the February 24, 2004 IART meeting minutes. No changes were offered and the minutes were approved as written.

Agenda Item #2. Late-Breaking News and Responses to Action Items

Mr. Gregson reported that the IAGWSP issued a news release regarding the 5-ppb perchlorate detection at Jefferson Road, and also e-mailed this information to the IART.

Mr. Murphy stated that Mr. Judge had notified him to say that he was unable to attend the meeting. Mr. Murphy then asked if there were any comments on the responses to action items from the February 24, 2004 IART meeting.

Ms. Adams said that she believes that the E&RC website is missing two documents that pertain to the base lease extension. She asked that the E&RC add those documents, which are Supplemental Agreement #1 and the Memorandum of Understanding between Massachusetts, the U.S. Army, and the National Guard Bureau, both dated October 4, 2001. Mr. Murphy said that Mr. Judge also mentioned that he thought the website information was incomplete, and that observation has been passed along to Mr. Sullivan at the E&RC.

Agenda Item #3. IART Membership Discussion

Review of Groundrules

Mr. Murphy recommended postponing discussion of the IART groundrules until the next meeting, as Mr. Judge was the one who had requested that this item be added to the agenda.

Sandwich Membership Recruitment

Mr. Schlesinger inquired about the plan to recruit new IART members from Sandwich. Mr. Murphy explained that because the team currently has just one citizen member from Sandwich, the U.S. Environmental Protection Agency (EPA) issued a news release to invite interested Sandwich residents to apply for membership, attend an IART meeting, and then attend a subsequent IART meeting prepared to introduce themselves and answer questions. He noted that he has received only one résumé so far, has not yet contacted that person, and has received no applications to date. He also mentioned that applications are available on the EPA website and the IAGWSP website. Mr. Murphy added that another outreach effort probably would be made if there are no additional responses within the next couple weeks.

Mr. Murphy questioned whether the next item, "Rapid Response Action for Demolition Area 2," should be delayed, since the meeting was running ahead of schedule. Mr. Gregson said that because the official public comment period begins tonight, he would prefer to go forward with the Demolition Area 1 (Demo 1) update first and wait until the scheduled time to discuss Demo 2 in case anyone shows up at 6:30 p.m. to hear that particular presentation.

Agenda Item #4. Demolition Area 1 RRA Update

Mr. Nixon showed a series of photographs of the Demo 1 site and pointed out several features, including a large excavator, some standing ice in the kettle hole, and a stockpile being made. Mr. Schlesinger expressed concern about stockpiles of contaminated soil causing further contamination to the underlying soil. Mr. Nixon explained that the stockpiles are located within the limits of excavation so no new areas would be contaminated. Mr. Schlesinger inquired about the depth of excavation in the area beyond the stockpile shown in the photograph. Mr. Nixon replied that it's within the one-foot zone of excavation. He also noted that the contamination levels are fairly consistent throughout that area, and that the soil currently underneath the stockpile will be excavated last. Mr. Borci added that after the soil currently underneath the stockpile has been excavated, that area will be sampled to ensure that it's clean.

Mr. Nixon showed several more photographs of the site and pointed out the thermal treatment unit in the background; a piece of equipment that was used to thaw out the ground for excavation work during January; and the screener, which is used to screen out any rocks, roots, stumps, or remaining metallic debris from the stockpiled soil. He also pointed out the location of a strong magnet to remove from the soil any remaining pieces of ferrous metal, but noted that so far the unexploded ordnance (UXO) clearance work that preceded the excavation work seems to have accomplished that task fully. Mr. Nixon also showed a photograph of the thermal treatment unit and pointed out the emissions stack, the air emissions control equipment, and the soil handling and treatment equipment.

Mr. Hugus asked to see some kind of grid map that shows the relative progress of the excavation work. Mr. Nixon displayed a figure entitled "Demo 1 Site Map Excavation Progress" and pointed out the grids shown in white, which have not yet been excavated and include the deeper excavation work in the center; the green grids, which are nondetect; two areas where lead was detected in soil that was excavated and sent to a hazardous waste landfill; grids where excavation was done to a depth of two feet; and grids where an additional one foot of excavation is required. Mr. Hugus asked if the green grids represent areas that didn't need to be excavated. Mr. Nixon clarified that they represent areas that have been excavated and have tested clean. Mr. Schlesinger asked how many samples are tested from each 50' x 50' grid. Mr. Nixon explained that one sample is developed as a five-point composite that's made up of samples taken from locations arranged like the five dots on the "5" side of dice.

Mr. Schlesinger noted his concern about plant matter that's screened out of the contaminated soil and returned to the site, given the possibility that some plants (based on research done with lettuce) can uptake perchlorate. Mr. Nixon said that he's not aware of such studies having been conducted on the plant matter that exists at Demo 1, such as oak trees, pine trees, and blueberry bushes. Mr. Borci added that perchlorate concentrations at the site are low, while the uptake studies involved dosing plants with much higher concentrations. He also noted that most of the shrubs already were removed and chipped at the site, and so would be excavated along with the contaminated soil and subjected to thermal treatment. Mr. Nixon said that larger pieces, such a stump, would be returned to the site, but very little hasn't fit through the screener.

Mr. Nixon continued his presentation by noting that proof-of-performance (POP) testing of the treatment unit is scheduled to begin on March 31, 2004. Anomaly removal and excavation in the kettle hole, down to the natural grade (about 8 feet), will follow. While some soil treatment has been done as part of the shakedown testing, and more will be done as part of the POP tests, regular treatment activities are expected to begin in June 2004, once the Massachusetts Department of Environmental Protection (DEP) air permitting branch grants final approval. Backfilling at the site will occur as the process moves along.

Mr. Mullennix inquired about contaminant concentrations in soil used for testing of the treatment plant. Mr. Nixon replied that the soil used in testing is spiked to concentrations of 100 parts per million (ppm) and 1 ppm of perchlorate, HMX, and anthracene (a surrogate compound chemically similar to polychlorinated naphthalenes [PCNs], which exist at the J Ranges). Mr. Mullennix expressed concern that spiking the concentrations that high could cause "artificial" failure of the POP testing (since actual contaminant concentrations at Demo 1 are so significantly lower), which would cost both time and money. Mr. Nixon noted that some time and money already has been spent because of mixed results in recent testing, which led to trying some different conditions and laboratory analyses methods; however, the goal is "to do it right." Mr. Gregson added that higher perchlorate concentrations have been detected at other areas, such as the Southeast Ranges, and the Impact Area Groundwater Study Program (IAGWSP) wants to ensure that the shakedown and POP tests cover all possibilities in terms of contaminated soil that could be treated in the thermal treatment unit.

Dr. Dahmani told Mr. Mullennix that once the desired temperature is reached, he would expect the thermal treatment unit to effectively destroy 100-ppm concentrations as effectively as it would 1-ppm concentrations. He then asked if temperatures would be varied in the POP tests. Mr. Nixon replied that the shakedown tests involve a range of temperatures, but the plant will be at a set temperature for the POP test. Dr. Dahmani also inquired about the actual spiking method. Mr. Nixon replied that two methods have been used: mixing perchlorate (in its powder form) with water and adding it to the soil as it's run through the belt feeder, and adding some dry perchlorate powder mixed with soil to the soil that's being run through the belt feeder. Dr. Dahmani then asked about shakedown test results. Mr. Nixon replied that results available so far are for HMX, which was successfully treated from 100 ppm to down below the reporting limit, at 700°F, at 650°F, and at 600°F.

Mr. Schlesinger questioned whether soil spiked with perchlorate is representative of site soil conditions. Mr. Nixon said that soil that's been spiked with perchlorate mixed with water would be quite similar, but acknowledged that there are limitations with spiking. Mr. Schlesinger also asked how the appropriate temperature for the POP test would be determined. Mr. Nixon explained that shakedown tests are being run at decreasing temperatures until perchlorate treatment (at 100-ppm concentration) is unsuccessful; the lowest successful perchlorate treatment temperature would be used in the POP test. Mr. Schlesinger inquired about treatment temperatures for HMX and RDX. Mr. Nixon explained that the plant would operate at the required temperature for perchlorate, which is higher than temperatures required to treat HMX and RDX. He also mentioned that it would be possible to run the plant at a lower temperature to treat soils from other sites where there is no perchlorate, but a decision to do so hasn't been made.

Dr. Dahmani asked if spiking is being done for compounds other than perchlorate. Mr. Nixon replied that spiking includes perchlorate, anthracene, and HMX for the shakedown testing, but he doesn't think that anthracene will be included for the POP testing. He also noted that there's no need to spike for RDX. Dr. Dahmani then told Mr. Schlesinger that there's less concern about perchlorate spiking being representative of site conditions because it's soluble in water and doesn't adsorb that much to soil. However, in the case of HMX and PCN, which do adhere to organic matter or fine particles, spiking is less representative since the compounds would adhere more over time. Dr. Dahmani said that when high concentrations aren't found in the site soil, spiking is the only option, which, while not perfect, is an acceptable solution.

Agenda Item #5. Rapid Response Action (RRA) for Demo Area 2

Mr. Nixon showed a photograph of the east end of the Demo 2 site, and noted that it's somewhat similar to Demo 1, but was used for small charges, including TNT and C4, and shows no signs of open burn/open detonation (OB/OD) activities. He noted that Demo 1 is about the same size as Demo 2, but the contaminant concentrations are far lower. He also said that it's believed that the berm at Demo 2 was created some time in the past when soil in the area was "scraped up" and pushed over to one end of the site. He pointed out the berm, which he described as a discontinuous row of piles, and also pointed out the trees on and near the berm.

Mr. Nixon showed a plan view map of the site and pointed out the berm and an approximately 30-foot diameter area of RDX- and HMX-contaminated soil. He noted that no perchlorate has been detected at the site, and also mentioned that the investigation of a nearby groundwater plume is ongoing. Mr. Nixon stated that the Rapid Response Action (RRA) soil removal at Demo 2 involves excavating approximately 500 cubic yards of soil (the berm and the 30-foot area of contaminated soil), which is equal to about 825 tons or about 30 truckloads.

Mr. Nixon noted that the RRA is intended to remove the bulk of contamination, but not necessarily to serve as the final remedy there. He said that the 15-day public comment period on the Demo 2 RRA Workplan begins this evening and runs through Wednesday, April 7, 2004. Copies of the plan are available on the IAGWSP website,, and at the public libraries in Bourne, Falmouth, Mashpee, and Sandwich.

Mr. Schlesinger asked why the berm exists. Mr. Borci said that during a site walk conducted after soil samples collected across the area came up nondetect for explosives (despite RDX detected in groundwater) some C4 pieces were found at the area in the middle of the site, near MW-16. Also, the decision was made to look at the berm, on the assumption that perhaps at one time the site was cleaned off and the surface soil pushed aside, and in fact explosives were detected in the berm. Mr. Borci also clarified that Demo 2 had been used as an OB/OD area one time in 1999, but the surrounding soil was removed soon after that activity. Mr. Nixon noted that it would have been more accurate if he'd said that no burn pits, like those at Demo 1, were found at Demo 2.

Mr. Schlesinger asked if C4 is 100% RDX. Mr. Nixon replied that he's not sure, but knows that it's mostly RDX. Mr. Schlesinger then asked if the C4 found at the site was from training activities or disposal activities. Mr. Borci said that he believes that the C4 was classified as disposal because beneath the several pieces found on the surface were other pieces deeper in the ground as well as some coiled fuse.

Mr. Hugus said that a former IART member, Paul Zanis, recalled that the Demo 2 area was scraped up about four or five years ago, after EPA issued its administrative order, which he believes occurred about seven years ago. Mr. Hugus noted that it appears to him that the area was scraped without EPA's oversight. Mr. Nixon said that the size of the trees growing out of the berm indicates that the scraping occurred longer ago than four or seven years. Mr. Hugus asked when the berm was made. Mr. Nixon replied that he doesn't know, but noted again that growth in the area indicates that it was more than seven years ago.

Mr. Borci said that historic aerial photographs and the report could be examined, but he doesn't think it could ever be determined with certainty when the area was scraped. He also said that while he's not sure whether the scraping occurred after 1997, as far as he knows it's been more than 10 years since any (military) activity occurred there. Mr. Gallagher of the IAGWSP noted that he's been with the cleanup program since 1997 and has done work at the Demo 2 site. He said that it wasn't known that the berm existed until about six months ago, and what Mr. Zanis probably saw was some bulldozing to grade an area for a drill pad. Mr. Gallagher noted that this work was unrelated to the mounds that make up the berm, "which certainly predated 1997."

Mr. Mullennix noted that with respect to when the berm was created, he's comfortable with Mr. Nixon's comments about the trees at the site, Mr. Gallagher's knowledge of the site, and Mr. Borci's statement that to the best of his knowledge the scraping did not occur after 1997. He added that he thinks it would waste the team's time "to chase some phantom hearsay." Mr. Schlesinger said that he disagrees and thinks it's important to know the age of the berm in order to determine whether that contamination has reached groundwater, and if so, how far it could have traveled. Mr. Nixon noted that contamination already has entered the groundwater and monitoring wells are currently being installed. Mr. Schlesinger also noted that the Demo 2 fact sheet states that the site was used in the 1970s and 1980s as a demolition area. He proposed that the berm would be quite a bit older than that if the trees on top of it are any indication of age. Mr. Nixon replied that, as with Demo 1 where the soil was reworked as part of regular training missions, he would expect that some sort of earth work also occurred at Demo 2.

Mr. Nixon stated that the IAGWSP hopes to have the Demo 2 RRA Workplan approved in April and then start doing site clearance. Excavation would occur in May, and the idea would be to treat the contaminated soil at the thermal treatment unit in May or June. He said that comments on the workplan could be e-mailed to Kris Curley at the IAGWSP.

Ms. Adams asked the IAGWSP to be mindful of Resource Conservation and Recovery Act (RCRA) implications, which are the same at Demo 2 as at Demo 1. Mr. Nixon stated that as yet nothing has been found that trips RCRA hazardous waste requirements. He also noted that to fill a data gap, additional sampling was done recently for total metals, which should "close the loop" on that.

Mr. Schlesinger said that he thinks that additional resources should be put into finding out about the history of the Demo 2 site. Mr. Nixon noted that the workplan contains a more detailed site description and site history explanation than he was able to provide in tonight's brief presentation. He said that if Mr. Schlesinger finds that he needs more information than that, the IAGWSP could try to look it up.

Agenda Item #6. Remediation and Investigation Update

J-1 and J-2 Ranges Recent Unvalidated Detections

Mr. Gregson displayed a map that showed the J-1 and J-2 Ranges and the zones of contribution (ZOCs) for Upper Cape Water Cooperative supply wells 1, 2, and 3. He referred to the interberm area at the center of the J-1 Range, a source area of perchlorate and explosives contamination in groundwater that's migrating to the north/northwest up into the Impact Area. He reported that RDX was recently detected in MW-315 at 0.54 ppb. Screens were set at that depth and at depths that correspond to other detections in the plume. Mr. Gregson also noted that MW-315 is one of nine wells drilled in that vicinity to better define contamination from the interberm area.

Mr. Gregson then referred to Disposal Area 2 on the J-2 Range, an apparent OB/OD site that probably was used before Demo 1. He noted that investigation of the Disposal Area 2 plume was kicked off with the discovery of a 370-ppb perchlorate detection in an MW-289 profile sample, which was followed by an actual well sample there that tested at 140 ppb for perchlorate. Since that time, eight monitoring wells have been drilled to define the extent of that contamination, including wells on Wood Road where the highest perchlorate detection was about 89 ppb. MW-296, to the north, tested nondetect for perchlorate and explosives. Mr. Gregson then pointed out the monitoring well where perchlorate was detected recently at 5 ppb, and MW-318, to the east, which tested nondetect for perchlorate and RDX. He also reported that today drilling was completed at well location J2P-36 on Wood Road as "an eastern step out." He said that information from the wells, including MW-296, would be plugged into the model in order to determine the best location to drill downgradient of the 5-ppb detection. Mr. Gregson also noted that the Upper Cape Water Cooperative (the "Co-op") has agreed to allow the IAGWSP to conduct sampling of its chemical monitoring wells. Past sampling conducted by the Co-op has shown those wells to be nondetect for perchlorate. He said that with information from additional downgradient wells and from the Co-op's wells, the IAGWSP hope to define the toe of the plume fairly soon.

Mr. Gregson then referred to detections at MW-310 (perchlorate up to about 5 ppb and RDX at 0.5 ppb) and MW-319 (perchlorate at slightly higher than 5 ppb), and noted that they seem to track back to a source area or multiple source areas in the eastern part of the J-2 Range. He said that a number of wells are yet to be drilled to investigate this area of contamination that would migrate off to the east.

Mr. Schlesinger asked Mr. Gregson to discuss Figure 4: J-2 Range Plume and Proposed Locations. Mr. Gregson explained that the figure shows some updated plume contours based on information collected from wells at Wood Road, and also shows the ZOC for permitted pumping of water supply well #2 (about 1 million gallons per day) and the ZOC for that well that's based on historic and projected pumping rates. Mr. Schlesinger observed that the plume contours shown on the figure don't include a recent perchlorate/RDX detection. Mr. Gregson agreed and said that when the figure is updated again, the contour will be extended and "will wrap around that location." He also noted that drilling is going to be done downgradient of that location to define the toe of the plume.

Mr. Schlesinger said that the plume migrating to the east could potentially affect the Sandwich ZOC. He inquired about plans to assess that plume, and whether the Town of Sandwich has been informed about it. Mr. Gregson replied that the IAGWSP has been keeping the Sandwich Water District and the Co-op updated on the investigation. He said that it's important for the IAGWSP to understand the extent of the plume as quickly as possible because of its potential effect on the Sandwich water supply wells ZOC and the Co-op's water supply well #1 ZOC.

Mr. Schlesinger also inquired about plume shells or cross-sections for the J Range plumes. Mr. Gregson replied that there's not enough information yet on the contamination that's migrating to the east to develop a plume shell. He did, however, display cross-section B-B', which shows the plume from Disposal Area 2 and runs down the axis of the ZOC for water supply well #1. He pointed out MW-63, a far-field well; the sections at Jefferson Road, Wood Road, and the source area; and the ZOC for the current pumping rate and for the permitted pumping rate. He also acknowledged that the cross-section figure needs to be updated to include the most recent downgradient detection.

Mr. Schlesinger then asked what is known about how the pumping well affects the rate of flow at different depths in the aquifer. Mr. Gregson replied that much depends on the geology right at the well screen. In general, however, the geology gets finer-grained with increased depth, making flow in the deeper sections more restricted, with the expectation being that flow to the well would be from shallower zones in the aquifer. Mr. Schlesinger asked if the supply well is going to be shut down. Mr. Gregson said that the IAGWSP is providing the information to the water suppliers who will make decisions about which wells to pump and at which rates.

Mr. Borci recommended that the IAGWSP update the cross-section figure for the Disposal Area 2 plume for the next IART meeting. He also noted that the plume exists in both the permitted ZOC and the actual ZOC for water supply well #2. He further noted that it's thought that because of different conditions in the aquifer, this plume won't extend as far downgradient from the 5-ppb detection as the Demo 1 plume does, and additional monitoring wells are being installed to ensure that that's the case. Mr. Gregson agreed to see that the figure is updated for the next meeting.

Mr. Schlesinger said that the screens in MW-63 don't appear to be at the proper depths to catch the plume. Mr. Borci noted that that well was installed before the Co-op water supply wells were installed. He also said that this gets to what Mr. Gregson had mentioned earlier, that the IAGWSP has received approval from the Co-op to sample its sentinel wells, which are not depicted on the figure. Mr. Gregson noted that based on the requirements, in order for the Co-op to obtain its permit those screens have to extend across the vertical section of the ZOC, which should provide fairly good coverage. He also agreed to see that the sentinel well screens are added to the updated figure.

Mr. Borci referred to MW-310, MW-319, and MW-215 near the Sandwich ZOC, and said that the depths of the detections there "are similar but they don't appear to match up perfectly." He said that providing the team with a cross-section figure for this area would be helpful, as would information on forward particle tracking. He said that the forward particle track from MW-310 goes up to the northeast, and the forward particle track from MW-319 essentially goes to the east. Taking that information into account, and the fact that MW-57 (a far-field well with five screens at a depth where contamination might be expected) has been clean, it seems that there might be at least two plumes in that area - one headed northeast, and one headed east. Mr. Borci said that additional investigation is going to be done under those hypotheses, and a couple of new figures for the next meeting might help clarify that.

Mr. Schlesinger inquired about MW-307. Mr. Borci replied that the model indicates that the contaminant detected there is headed toward well location J2P-26, and could be yet another area of contamination. Mr. Gregson added that the J-2 Range involves many burial/disposal type source areas, which, theoretically, each could have a small plume associated with it. This is further complicated because the area is at the top of the mound so the plumes travel in various directions.

Mr. Schlesinger asked if all the residents in the area are connected to town water. Mr. Gregson replied that the IAGWSP has been looking into that. He pointed out a neighborhood where all the homes are believed to be on town water, and another area, near Quaker Meetinghouse Road, where the IAGWSP is continuing to check for any private wells.

Mr. Hugus asked why the contamination near the ZOC for water supply #3 doesn't appear to be following the logical line that the ZOC would suggest. Mr. Gregson replied this is difficult to explain, other than to say that the ZOC was based on one set of models and a certain position for the top of the mound, while the plume that's drawn is not based on modeling, but on actual field data. He said that he tends to trust the latter as a more accurate depiction of what the groundwater is doing over a long period of time and how it's influencing the migration of contaminants. Mr. Hugus expressed his concern that this might imply that contamination in the water supply well #2 ZOC might actually travel north/northwest into the water supply well #3 ZOC. Mr. Gregson said that given the available field data and groundwater flow over time, it seems pretty clear that that contamination would be heading directly to the north.

Mr. Hugus also inquired about the future of water supply well #2, asked why there isn't discussion about stopping the plume, and asked where the next well would be located to define the toe of the plume. Mr. Gregson said that the row of Co-op sentinel wells that the IAGWSP is going to sample is about five years' travel time upgradient of the supply well. More time is available depending on how far the contamination has traveled, and there are possible drilling locations on Gibbs Road, Barlow Road, and another road where wells could be installed with minimal impacts and as quickly as possible. Mr. Gregson said that the next well location to define the toe of the plume is still being discussed with the regulators. He noted that data that could indicate the width of the plume are expected by the end of the week. The information will be reviewed with the regulators and downgradient locations will be chosen. Mr. Hugus urged the IAGWSP to make plans to remedy this situation right away as it involves a very important water supply area.

Mr. Mullennix asked when the source of contamination at the J-2 Range began. Mr. Gregson replied that records indicate that that area was used before Demo 1, probably sometime in the 1960s and 1970s. He said that he thinks operations ceased there about 10 to 15 or more years ago. He also said that the source is relatively old, but because it's near the top of the mound, the contamination first moves vertically before flattening out and migrating, which does buy some time.

Dr. Dahmani asked if the IAGWSP has an RRA for groundwater to address this plume. Mr. Gregson replied that that possibility is being discussed, but the first step is to find the toe of the plume. Dr. Dahmani inquired about source removal. Mr. Gregson replied that a source removal RRA at Disposal Area 2 is planned for this summer. Dr. Dahmani also asked if the IAGWSP is looking at ways to expedite plume characterization. Mr. Gregson replied that in fact that process is happening much faster with this plume, for two reasons: reliance on an updated sub-regional groundwater flow model that's continually updated and used in choosing drilling locations, and the method of moving the drill rig to a next location that's based on profile data, without first setting well screens, but coming back later to do so.

Mr. Schlesinger said that he'd like the IAGWSP to update the ZOCs for the Co-op supply wells in order to provide better information on which to base decisions and set priorities. He also noted that Mr. Gregson had said that a groundwater RRA was possible after the toe of the plume has been identified, yet the toe of the Demo 1 plume still hasn't been defined and an RRA is ongoing at that site. Mr. Gregson explained that this plume is a somewhat different case in that the objective of an RRA would be to cut off the contamination before it reaches the water supply well. Because of that objective, it's very important to place an extraction well at the toe of the plume. He also mentioned that the possibility of using a containerized treatment system, like the one at Pew Road, would cut down on design time.

Mr. Schlesinger also inquired about plans to investigate the plume that's headed northwest. Mr. Gregson replied that he thinks that three wells are currently planned for that area. He said that modeling indicates that the plume would continue through the Impact Area, across the base, and eventually discharge to the canal. He also noted that it's important that the investigation answers the question of whether the plume, which is at the very tip of a ZOC, would affect that water supply well. He further noted, however, that 40 years of travel time exists between those two points. Mr. Schlesinger asked Mr. Gregson to provide cross-sections at the next meeting for each of the plumes: heading northwest, north, and east. Mr. Gregson agreed to do so.

Mr. Borci pointed out to Mr. Schlesinger that perchlorate was detected in MW-222 (on the far left of the map) and it's being investigated whether that might be an extension of the westernmost area of contamination. Mr. Borci also noted that if one were to ask several individuals to develop a ZOC for a particular well, the end result would be several different ZOCs. He explained that he wants to caution Mr. Schlesinger not to throw out the ZOCs depicted on the map as they are believed to be relatively accurate for the purpose of the investigation. He further noted that a close look at the tail end of the ZOC for supply well #3 shows that it's starting to "pinch off" and "matches fine" with the direction of the plume. Mr. Borci also mentioned the problem of looking at contamination as it spreads away from a radial source (the top of the mound). He further noted that a drawback of the expedited process to characterize contamination in this area is having to wait for actual groundwater data from the set screens, and now the program is trying to catch up to produce revised figures.

Wester Boundary Unvalidated Detections

Mr. Gregson showed a map of the Western Boundary area and pointed out the base boundary, Route 28, and the Bourne Water District's Monument Beach wellfield. He referred to well CPB-3, which was installed to help determine the eastern extent of perchlorate contamination, and reported that perchlorate was recently detected there in four intervals, from 0.48 ppb to about 4 ppb - a slightly higher level than other detections in that area, which generates interest in seeing what the actual well results will be. Mr. Gregson also reported that drilling was recently completed at well location CBP-9, which tested nondetect for explosives and perchlorate in profile sampling, and may have defined the upgradient extent of the contamination.

Northwest Corner Recent Unvalidated Detections

Mr. Gregson reported that at MW-314, which is located on the road that parallels the canal, perchlorate was detected in three intervals, at 4 to 24 feet below water table (bwt), at concentrations between 0.43 ppb and 0.82 ppb. Profile sampling results at MW-320 showed perchlorate in four intervals from the water table to 30 feet bwt, at concentrations between 2 ppb at the water table and 0.88 ppb at the deepest interval. Groundwater sampling results from the shallow (water table) screen at MW-298 showed a low-level detection of perchlorate at 0.57 ppb. The slightly deeper screens at MW-298 were nondetect. Groundwater sampling results from MW-301 showed perchlorate at about 2.8 ppb. Also, at existing water table wells on the nearby skating rink property, perchlorate was detected at 1.5 ppb in one well and at 1.12 ppb in the other.

Mr. Gregson noted that the next location to be drilled is NWP-8A, to try to determine the southern extent of the contamination. Also, the IAGWSP is continuing its effort to enter into an easement agreement with the landowner in order to obtain access to drill a well at NWP-13. Mr. Gregson also mentioned that tomorrow the IAGWSP would conduct a field visit with the regulators to look at other potential well locations for the investigation.

Mr. Schlesinger inquired about the depth of the screens at MW-298. While Mr. Gregson was looking up the answer to this question, Mr. Schlesinger asked about plans for upgradient wells in the area. He then said that the team has always been told that monitoring wells cost $100,000 a piece, and he's concerned that this is "perhaps not the truth," but is being used as "an excuse" for not moving this investigation along more quickly. Mr. Schlesinger requested that the IAGWSP provide an itemized cost breakdown of the $100,000 figure, including use of the drill rig, overhead costs, contractor costs, and so forth. Mr. Murphy said that this could be made an action item, and then announced a 10-minute break.

The meeting reconvened after the break and Mr. Schlesinger said that he wanted to amend his action item so that the request includes cost breakdowns for several wells, not just one. He also said, "Some information we're getting is that these wells don't cost $100,000," and he wants the IAGWSP to show him that they do in fact add up to that figure.

Regarding Mr. Schlesinger's previous question about MW-298, Mr. Gregson informed him that it was drilled and profiled to bedrock. Three screens were set in the well - one at the water table, one at the depth of the deepest perchlorate detection (about 111 feet bwt in the profile, which has since had nondetect results), and one at the approximate depth of the reverse particle track from MW-284 here (which also had nondetect results). Mr. Gregson also stated that most of the wells drilled as part of this investigation over the past year have been deep wells, profiled to bedrock, to provide a picture of the entire aquifer.

Agenda Item #7. Northwest Corner Data Summary Report

Mr. Gregson stated that the Northwest Corner Data Summary Report, an interim report issued at the end of January, provided an update of investigation results to date and some interpretation of those results. He showed a map of the investigation area and pointed out several features, including the Cape Cod Canal, the Bourne Bridge, the base boundary, two training areas on base (B9 and B11), and former gun positions GP-14, GP-16, GP-12, and GP-19. He noted that past military use of pyrotechnics (smoke grenades, signals, artillery simulators, and other items) that contain perchlorate has been documented in the area, but that kind of activity ceased in 1997 with the Administrative Order issued by EPA. Mr. Gregson also noted that commercial fireworks, which contain perchlorate, have been launched annually from the tech school property located in the investigation area.

Mr. Gregson stated that the investigation began when 6.1 ppb of perchlorate was detected in a well at the skating rink near the canal and RDX was detected at a level below the health advisory in a community supply well at a nearby condominium complex. Since those two detections occurred (and through the January 1, 2004 data cutoff date for the report), 21 monitoring wells at nine locations were installed and sampled. Since that time, 10 additional wells at five locations have been installed. Mr. Gregson also noted that as of January 1, 2004, groundwater was sampled from 30 existing wells, and 108 soil samples at 52 locations were collected and analyzed. In addition, the IAGWSP collected suspected fireworks debris from along Canal View Road and had it analyzed for perchlorate.

Mr. Gregson referred to the map that shows perchlorate detections and noted that groundwater flow direction is to the northwest, toward the canal where the groundwater discharges. He noted that the perchlorate plume is shallow in the aquifer, with detections at the water table in the area near Canal View Road, and slightly deeper to the west. The overall size of this plume as depicted is about 315 acres, and the maximum perchlorate concentration is 19 ppb, which was detected in MW-278. Mr. Gregson also mentioned MW-270, where perchlorate was detected from the water table all the way to bedrock in both profile samples and monitoring well results. He said that the reason for this type of distribution is still not well understood, and it hasn't been seen at any other locations. Mr. Gregson also noted that the IAGWSP has sampled the three private drinking water wells and the irrigation well within the plume area, and the two private wells to the south near the Bourne Bridge. The private well designated RSNW03 has had consistent detections of perchlorate at about 1.9 ppb.

Mr. Gregson referred to the map that shows RDX detections (all of which have been less than 1 ppb) and reported that the contaminant was detected in a couple of screens at MW-284, in the irrigation well known as RSNW06, and in the community supply well at the condominium complex. All the other locations sampled for RDX, including all the wells on base, have been nondetect.

Mr. Gregson then displayed a figure that showed soil sampling results from May 2002 and from September/October 2003. He noted that the 2002 sampling at GP-16, which was part of a base-wide investigation of gun positions, showed several perchlorate detections ranging from about 1 ppb to about 5.5 ppb. Samples from September 2003 (collected at GP-19, up Canal View Road, and in a former cleared area identified on aerial photographs) showed perchlorate detections from surface down to about two feet, at concentrations that ranged up to 64 ppb, with the highest detection at a grid along Canal View Road.

Mr. Gregson also displayed a figure that showed soil and fireworks debris sampling results from July 2003. He noted that this sampling was not done as part of a written workplan approved by the agencies, but the same procedures were used to collect the samples and the same laboratory was used to conduct the analysis. He said that the July 2, 2003 sampling event showed just two perchlorate detections (3.8 ppb and 4.2 ppb) while the remaining samples were nondetect. Sampling conducted on July 7, 2003, after the fireworks display, showed detections up to 7,650 ppb at a location on Canal View Road. Mr. Gregson pointed out that the figure shows distribution of suspected fireworks debris observed along Canal View Road. The debris was collected and analyzed, with perchlorate results ranging from 302 ppb to 34,200 ppb.

Mr. Gregson continued his presentation by showing cross-section F-F', which runs from the canal up through the base boundary and on to the base. He pointed out the canal; MW-284; the well at the skating rink where perchlorate was detected; the particle track from the shallower detection at that well and where it reaches the water table; and the particle track from the deeper detection at that well, which would reach the water table at a farther distance, off the figure. Mr. Gregson also pointed out MW-298 on the base boundary and noted that it has relatively high detections in the shallow groundwater and no deep detections. In addition, Mr. Gregson pointed out the community supply well at the condominium complex and residential well RSNW06, where RDX was detected. He noted that the exact depths of those particular well screens are unknown, so their locations on the figure are basically a guess.

Mr. Gregson then displayed a figure that showed an outline of the potential source area. He explained that the source area outline was based on particle backtracking from wells with perchlorate detections back to the water table. He noted that the figure also shows the grids where perchlorate was detected in soil. Mr. Gregson said that the potential source area is more than 300 acres in size, and the distribution of contamination would fit a conceptual site model of aerial deposition of perchlorate either from fireworks or from military pyrotechnics. He said that there's no record of disposal areas in that vicinity, and the size of the plume itself supports a more widespread source area.

Mr. Gregson stated that based on the work done to date there are two potential sources of contamination, and one is military pyrotechnics. He noted that historical information exists that the area had been used for some level of training, which could have involved military munitions that contained perchlorate. He also said that when exposed to the environment perchlorate is expected to migrate rapidly to the water table. However, an unknown variable is how long it would take for an intact or recently broken open munition or pyrotechnic device to deteriorate and expose that filler to the environment. Mr. Gregson stated that the other potential perchlorate source is the fireworks displays at the tech school property, which have been conducted there annually since 1996. He noted that suspected fireworks debris was observed along Canal View Road and that perchlorate was measured in that debris.

Mr. Gregson stated that the Northwest Corner investigation is continuing. Archival information is being examined to determine what else can be learned about military training activities in the vicinity and the extent to which those activities would explain the source of perchlorate contamination. The IAGWSP is in the process of drilling wells at NWP-8A and at NWP-13 on the condominium complex property, and will join the regulators in the field tomorrow to look at additional soil sampling locations and a couple more well locations to complete the definition of the extent of contamination. Mr. Gregson noted that the purpose of the soil and groundwater sampling is to get a better understanding of the relative contributions of both fireworks and military use of pyrotechnics to the contamination being seen in the Northwest Corner. He concluded his presentation by saying that cleanup options would be assessed once the investigation has been completed.

Mr. Borci said that EPA made the comment that for what was supposed to be an interim report in the middle of an investigation, it was not as objective as it should have been. Also, EPA had tried to point out specific examples where it thought "that there were either conflicting or other data points." He said that EPA's comments were fairly extensive, and as thorough as possible, because the agency wants to see specific data needs filled as the investigation progresses. He asked if the IAGWSP agrees that additional data are needed in this area, and Mr. Gregson did agree.

Mr. Pinaud stated that DEP thinks that to date the IAGWSP has done a good job of implementing the scope of work for the investigation, and has been very accommodating in terms of back-and-forth discussions about installing wells and conducting soil sampling. However, DEP was surprised to see "such a definitive statement in an interim document," considering that the investigation hasn't been completed. Mr. Pinaud said that DEP doesn't think that the assertion that fireworks displays are the primary cause of the perchlorate groundwater plume is adequately supported by the interim document. He added that he thinks DEP made many good comments regarding data gaps to be filled and additional work to do if the IAGWSP wanted to prove that aerial deposition is a primary source.

Mr. Murphy asked team members to limit their initial round of questions to one or two per person.

Mr. Schlesinger said that DEP's comment letter dated March 18, 2003 indicated that there's a need for more information regarding the travel time of perchlorate. He said that he agrees and would like to see information on both the travel time from the surface to the water table and the travel time within groundwater. Mr. Schlesinger said that he's not discounting the issue of the fireworks, but is interested in knowing whether it would have been possible for perchlorate in the outlined potential source area to have traveled to those downgradient locations where it's been detected "within that timeframe." Mr. Gregson noted that about a week ago the IAGWSP completed a new sub-regional model that will provide detailed information on groundwater flow rates in that area and so expects to be able to start doing a better job of answering questions relating to groundwater flow.

Mr. Schlesinger also referred to well 4036011 shown on cross-section F-F', for which the screen depth is unknown, and suggested that that point could have a large effect on the position of the upgradient outline of the potential source area. Mr. Schlesinger also inquired about source areas for RDX. Mr. Gregson explained that because the screen depth of well 4036011 was unknown, it was not used in creating the outline of the potential source area. He also noted that RDX is a component of military munitions, but to the best of his knowledge, is not contained in fireworks. He said that the suspected source of the RDX is unknown but is likely to be someplace farther up on the base.

Mr. Schlesinger said that as he interprets the cross-sections, perchlorate has been detected at the same depths as the RDX detections, so he would assume that that perchlorate is not from fireworks, but from a military source. Mr. Gregson noted that RDX was detected in only a few locations, and the screen depths in two of them are unknown. He also mentioned the complicating factor of the possible effect on distribution of contaminants from the mixing zone at the canal. He said that all he can tell Mr. Schlesinger is that the RDX probably is from a military source, in which case the source is likely farther up on the base, perhaps as far back as the Impact Area. Mr. Murphy asked Mr. Schlesinger to hold any follow-up response until after other team members have had a chance to ask questions.

Mr. Hugus remarked that he's disturbed by the amount of time and resources being spent on this study because he thinks there's a political motive for conducting it - that is, he believes that the military is trying to escape liability for perchlorate in private wells of homeowners in this area. He noted that one gentleman who attended past IART meetings (Mr. Racheotes) told the team that he'd been asking for eight months for funds for a water hookup because there's perchlorate in his well. Mr. Hugus said that he believes that "the Guard's refusing to provide the hookup because they're not acknowledging their responsibility for it," and is trying to make the case that the Town of Bourne is responsible because of its fireworks displays. Mr. Hugus said that he'd prefer to see resources spent on investigating the contamination that's threatening water supply well #2. He also asked Mr. Gregson to explain how aerial deposition could have caused the plume.

Mr. Gregson noted that it's known that fireworks contain perchlorate. He then pointed out the launch area on the map and noted that the prevailing wind direction in the summer is from the southwest, as was the case during last summer's fireworks display, at about 10 miles per hour. He explained that the fireworks explode in the air, and the debris gets blown off to the northeast and lands on the ground, after which rainfall infiltrates the ground and perchlorate gets into the water table. Mr. Hugus inquired about the height the fireworks reach. Mr. Gregson replied that he doesn't have that answer, but knows that they reach high enough that likely fireworks debris was observed along Canal View Road. Mr. Hugus inquired about the area "way up to the northeast." Mr. Gregson explained that it's a dispersion pattern - as distance from the source increases, concentrations drop off to the northeast.

Mr. Hugus remarked that it seems more logical to him that this plume comes from the gun positions. He said that the aerial deposition theory seems like a stretch, and isn't the explanation for any other plume on the base. Mr. Gregson noted the exception of the Central Impact Area plume, which has a combination source that includes aerial deposition. Mr. Hugus said that if the fireworks explode 1,000 feet up in the air, the wind is blowing at 10 miles per hour, and the aerial deposition hypothesis is correct, he'd expect to see deposition much farther to the northeast than what's being shown. Mr. Gregson reminded Mr. Hugus that the report was an interim report and that further data needs have to be filled in order to answer the question on the relative contribution of fireworks to the perchlorate contamination.

Mr. Murphy noted that Mr. Schlesinger came over to him to say that he felt he was denied the opportunity to ask all of his questions and engage in a discussion. Mr. Murphy said that he told Mr. Schlesinger that this issue could be addressed at the next meeting during the discussion on groundrules. He also explained that his intent was to give everyone at the table a chance to ask questions in sequence, and then go back to those who had further questions.

Dr. Dahmani said that EPA and DEP positions on this study are unclear to him. Mr. Borci stated that EPA comments indicated that it does not buy into any conclusions at this point, and thinks that there appear to be multiple sources. He also said that he thinks Mr. Gregson is presenting one side of the story, but when one steps back and looks at the situation, there's no single easy answer and more work must be done before coming even near to a conclusion, including what would be a primary or secondary source.

Mr. Pinaud stated that DEP agrees that it's premature to be so definitive at this point, as the investigation hasn't been completed and the report was supposed to have been a data report with a minimal amount of interpretation. He also noted that DEP outlined some areas where it believes that there are data gaps and put forth some suggestions, such as air dispersion modeling, that the IAGWSP could do if it wants to pursue multiple source areas. He said that DEP would review the responses to comments and try to work through a scope of work to finish the investigation.

Dr. Dahmani asked if it's correct that there's going to be another study with input from the regulators, which could be accepted by everyone. Mr. Pinaud clarified that there isn't going to be another study, just a continuation of the investigation. Dr. Dahmani said that he assumes the approach will be different, with some modeling and a different sampling plan. Mr. Gregson said that he wants to make it clear that the one aspect of the study that wasn't done under a written approved workplan was the soil sampling before and after the fireworks and the analysis of the three samples of fireworks debris. The IAGWSP worked closely with the regulators on all other aspects of the investigation, including the additional soil sampling and the installation and sampling of all the monitoring wells. At this point the data are being reviewed, thought is being given to conceptual site models, and it's being determined what additional investigation needs to be done to fill the data gaps.

Dr. Dahmani asked if the IAGWSP's intent is to talk about percentages in terms of contribution to the perchlorate plume. Mr. Gregson replied that he doesn't know if it's possible to answer the question of percentages. He explained that while there's information on training use and on the perchlorate content of munitions that could have been used in the area, it's unknown how many of those munitions might have been used or what residue would remain in the environment after their use. For the fireworks component, it's known that they were shot off annually for eight years, and the mass of perchlorate contained in the displays could probably be calculated fairly easily. However, it's unknown how much perchlorate was consumed during the displays and how much ended up on the ground. Mr. Gregson also said that he thinks the investigation should focus not so much on the relative percentages, since the activities that contributed to the contamination have ceased, but on understanding how much is left in the environment and whether that residue is at such concentrations that a cleanup action should be taken. Dr. Dahmani asked if it's a possibility that it might be a waste of time and money trying to investigate the answer to the question of percentages. Mr. Gregson replied that that's a possibility.

Dr. Dahmani also said that in the Bourne fire chief's letter about the report he was adamant about not being responsible for this. Dr. Dahmani questioned whether the fire chief or his consultant would play a role in determining next steps in terms of the investigation. Mr. Pinaud said that he hadn't seen a letter from the fire chief, but did see a comment letter from the Town of Bourne. Mr. Greene, a Bourne firefighter, noted that the firefighters' union sponsors the fireworks displays, which are handled by a private fireworks company. He also clarified that Brent Goins, the solid waste manager of Bourne's landfill, was asked by the town to review the Northwest Corner report and provide comments in writing. Mr. Greene said that he thinks this is the letter Dr. Dahmani mentioned. He also noted that as of yet the firefighters' union hasn't sought its own consultant to review the report. Dr. Dahmani said that he thinks it's important to involve all the various players who are interested in this issue in order to come up with a plan that's acceptable to everyone, and everyone can agree on the conclusions.

Mr. Mullennix noted that EPA's March 2, 2004 19-page comment letter on the report included the statement that the National Guard Bureau must correct the deficiencies and resubmit the plan by March 19, 2004, or else it would be in violation of EPA's administrative orders. Mr. Mullennix inquired about the status of this situation. Mr. Borci stated that at the Guard's request EPA agreed to a time extension, and he believes the new deadline is March 30, 2004. He also said that EPA is typically flexible on such dates, and now that both agencies' comments are in, EPA wants to sit down and resolve the problems.

Mr. Mullennix then said that based on the data presented by Mr. Gregson, he thinks it's very evident that aerial deposition of fireworks is the likely source of perchlorate contamination, especially given that what he believes are the highest perchlorate levels seen in any plume investigation were found right after the fireworks. He also said that he understands that the Bourne firefighters union has elected to be prudent by not having a fireworks display this Fourth of July, and certainly the Guard hasn't used any perchlorate-laden pyrotechnics or flares since 1997. Because of this, in terms of detection work "the trail is getting colder by the day."

Mr. Mullennix then said that perchlorate is a national issue, and has always been perceived as a military issue. Now, however, there's some indication that in fact it might be broader, that fireworks are a cause of perchlorate contamination. He also said that it's common knowledge that the number of fireworks displays around the country has grown significantly over the last 10 years.

Mr. Mullennix then told the group that last year he and a couple of other citizens did some sampling in downwind areas before and after some fireworks on Cape Cod, had the samples analyzed by the same laboratory that the IAGWSP uses, and presented the results to DEP. He said that he believes those results support the aerial deposition theory, as no perchlorate was detected before the fireworks, but samples taken after the fireworks showed perchlorate at about 125 ppb. Mr. Mullennix said that there are numerous upcoming opportunities for DEP and EPA to definitively determine whether or not perchlorate contamination is coming from aerial fireworks displays, and he is asking them to consider working together to develop a workplan for such a study. He also said that if money is a problem, he would suggest that because this is such a large issue to the military, it could help support the funding in order find out with certainty whether aerial deposition from fireworks causes perchlorate contamination.

Mr. Hugus said that he's disturbed that the regulators were not involved in last summer's soil sampling and doesn't "trust the data that the Guard puts out unilaterally." He also noted that he thinks that the co-location of RDX with perchlorate argues against fireworks being the cause of the plume. Mr. Hugus then responded to Mr. Mullennix's comments by saying that he (Mr. Hugus) thinks it is well known that defense contractors all across the country have been notorious polluters, producing rocket fuel for the Pentagon. He also suggested that the reason nobody's taking responsibility for this contamination is because the issue just continues to be discussed repeatedly. He said that if the contamination source can't be clearly determined, there will never be a point when Mr. Racheotes will get justice, and he thinks that's a travesty. Mr. Hugus further remarked that he thinks it's "very small-minded" of the Guard to pursue this "really remote hypothesis" and he distrusts the Guard's motive in doing it.

Mr. Schlesinger inquired about the correlation between perchlorate detections in soil and in underlying groundwater. Mr. Gregson replied that the highest perchlorate concentration in groundwater in this area, 19 ppb, was detected at MW-278. Mr. Schlesinger asked if the correlation of perchlorate findings in groundwater and in soil elsewhere on the base could be examined. Mr. Gregson replied that this is a complicated issue because perchlorate dissolves readily in the environment. He mentioned that the highest perchlorate detections on the base, up to 300 ppb, are at Demo 1 (which has 20- to 30-years worth of source area), and the number of perchlorate detections in soil there are limited, with the highest being about 27 ppb. Mr. Gregson said that there isn't very much information on the correlation between a recent perchlorate source and resulting groundwater contamination, but it might be possible to try to do some modeling in this regard.

Mr. Schlesinger again inquired about likely sources of the RDX detected in the Northwest Corner investigation. Mr. Gregson replied that because the depths of those detections are unknown, it's difficult to determine the potential source area, but it could go as far back as the Impact Area. He noted again that RDX is a component of certain military munitions and so likely has a military source. Mr. Schlesinger noted that cross-section F-F' shows RDX almost co-located at the same depth as perchlorate, yet it seems the assumption being made is that the RDX is from a distant source and perchlorate is from a more nearby source.

Mr. Borci said that this gets to the point about an objective evaluation of the data. He said that he thinks the report causes confusion because it concludes that because of the shallow detections, perchlorate is coming from the Canal View Road, but is less conclusive about RDX seen in a well near the canal where perchlorate also was detected. Mr. Borci said that there's a need to collect additional data points in order to make sense of the data that are available now and clear up the confusion.

Mr. Gregson showed cross-section F-F' and Mr. Schlesinger inquired about well 403611. Mr. Gregson noted that one estimated perchlorate detection occurred at that location, and RDX was detected there as well. He said that if one were to "take the leap" that they were both detected at that well screen, a couple things could be happening. If the well screen is shallow, perchlorate could be co-located with RDX at the base boundary; if it is deeper, the source could include both perchlorate and RDX from a source farther back on the base. Mr. Gregson also said that that particular well screen is just one part of the entire picture; there are plenty of other wells where RDX was not detected, but perchlorate was detected in shallower screens.

Mr. Borci informed the team that the IAGWSP and the regulators plan to meet this Thursday to discuss additional data needs at the Northwest Corner and "jumpstart" the recommendations made in EPA's and DEP's comments. He explained that in this way the investigation will move forward as quickly as possible, without waiting to "battle out over" comments and responses to comments.

Agenda Item #8. Open Discussion

Mr. Schlesinger remarked that he finds it difficult to read the labels on the figure in the Demo 2 RRA fact sheet. He said that he thinks it's important for graphics to be read easily, especially because fact sheets are intended for public distribution.

Mr. Hugus inquired about the status of water hookups in the Northwest Corner area. Mr. Gonser replied that there have been several meetings with EPA, DEP, and the Army to develop strategies on how to go about providing water hookups for the residence where perchlorate was detected in the private well and for the other two residences with private wells on that road. He said that he thinks everyone agrees that this is something that needs to be done and various funding sources and mechanisms to accomplish that are being examined. He also said that he expects to have more definitive information on this issue by the next IART meeting. Mr. Gonser also said that the condominium complex had a town water hookup plan in place, and he's not sure whether that contract has been let, but expects to have more information at the next meeting as well. Mr. Hugus stated for the record that "nothing's happened" for Mr. Racheotes and his neighbors in the 11 months since perchlorate was detected in Mr. Racheotes's private well.

Agenda Item #9. Adjourn

Mr. Murphy announced that the IART would meet next on Tuesday, April 27, 2004 at the Quashnet Valley Country Club in Mashpee. He then adjourned the meeting at 9:10 p.m.

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