Impact Area Review Team

River River Drops of rain on a leaf

Impact Area Review Team
Bourne Best Western
February 24, 2004
6:00 - 9:00 p.m.

Meeting Minutes

Members: Organization: Telephone: E-Mail:
Hap Gonser IAGWSP 508-968-5107 Kent.gonser@ma.ngb.army.mil
Ben Gregson IAGWSP 508-968-5821 Ben.gregson@ma.ngb.army.mil
Marty Aker AFCEE/MMR 508-968-4670 Marty.aker@mmr.brooks.af.mil
Todd Borci US EPA 617-918-1358 Borci.todd@epa.gov
Bill Walsh-Rogalski US EPA 617-918-1035
Len Pinaud MA DEP 508-946-2871 Leonard.pinaud@state.ma.us
Mark Panni (sitting in for Ellie Grillo) MA DEP 508-946-2848 mark.panni@state.ma.us
Amine Dahmani UConn/TOSC 860-486-2781 adahmani@eri.uconn.edu
Jim Stahl TOSC 781-255-5537 stahl5@earthlink.net
Tom Cambareri IART/CCC 508-362-3828 tcambareri@capecodcommission.org
Evelyn Hayes IART/Barnstable 508-362-1785 truhayes@msn.com
Michael Butler IART/Bourne 508-564-6972 Michael.butler9@verizon.net
Bob Mullennix IART/Bourne 508-759-8319 Robert.mullennix@verizon.net
Judy Conron IART/Bourne 508-759-1559 Conron@gis.net
Dick Judge IART/At Large 508-212-5771 judges@capecod.net
 
Facilitator: Organization: Telephone: E-Mail:
Jim Murphy US EPA 617-918-1028 murphy.jim@epa.gov
 
Attendees: Organization: Telephone: E-Mail:
Robert Perry IAGWSP 508-968-5628 Robert.perry@ma.ngb.army.mil
John McDonagh IAGWSP 508-968-5636 John.mcdonagh@ma.ngb.army.mil
Kris Curley IAGWSP 508-968-5626 Kristina.curley@ma.ngb.army.mil
Tina Dolen IAGWSP 508-968-5629 tina.dolen@ma.ngb.army.mil
Lori Boghdan IAWGSP 508-968-5635 Lori.boghdan@ma.ngb.army.mil
Paul Nixon IAGWSP 508-968-5620
Bill Sullivan E&RC 508-968-5147
David Margolis USACE
Ian Osgerby USACE
Meghan Cassidy US EPA 617-918-1387 Cassidy.meghan@epa.gov
Jane Dolan US EPA
Dave Williams MDPH/EPHC 781-774-6612 dave.williams@state.ma.us
Kevin Hood UConn/TOSC 860-486-2546 khood@eri.uconn.edu
David Dow Sierra Club 508-540-7142
Mr. Racheotes Bourne resident
Matt Matlin Cape resident 508-274-8472 hossfeldt@yahoo.com
Martin Greene Bourne Firefighters Union 508-759-9178 Martyg7936@aol.com
Pat Skelly Citizen 508-524-3948
Chris Abate AMEC 978-692-9090
Katy Weeks AMEC 978-692-9090 Katherine.weeks@amec.com
Mark Applebee AMEC 978-692-9090 mark.appelbee@amec.com
Kim Harriz AMEC 978-692-9090 kim.harriz@amec.com
Mark Hutson Weston Solutions 303-729-6110 mark.hutson@westonsolutions.com
Rick Carr STL 781-455-0653 rcarr@stl-inc.com
Amanda Lehmert Cape Cod Times 508-548-9300 alehmert@capecodonline.com
Jane Moran Portage Environmental 508-759-9114 Jmoran@portageenv.com

Action Items:

  1. The Environmental & Readiness Center (E&RC) agreed to contact Mr. Judge and Ms. Hayes regarding the availability of base lease extension documents on the E&RC website, and regarding how to obtain copies of Governor Romney's comments on the lease extension.
  2. Mr. Judge requested that a discussion on Impact Area Review Team (IART) groundrules be included in the March IART meeting agenda.
  3. Mr. Cambareri requested that profile results from wells J2P-34 and J2P-35 be e-mailed to IART members when available.

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 January 27, 2004 IART Meeting
  2. Presentation handout: Thermal Desorption
  3. Presentation handout: Remediation & Investigation Update
  4. Data tables
  5. Presentation handout: Demo 1 Feasibility Study Modeling Update
  6. UXO Discoveries/Dispositions (ending 2/17/04)
  7. News Releases, Neighborhood Notices, and Media Coverage (1/24/04 - 2/20/04)

Agenda Item #1. Welcome, Review Agenda, Approval of January 27, 2004 IART Minutes

Mr. Murphy convened the meeting at 6:05 p.m., the IART members introduced themselves, and Mr. Murphy reviewed the agenda. Mr. Judge asked Mr. Murphy to add two topics to the "Open Discussion" portion of the agenda - the recent Cape Cod Times article and the Massachusetts Department of Environmental Protection (DEP) letter to water suppliers. Mr. Murphy noted that a copy of the newspaper article is included in the handout titled "News Releases, Neighborhood Notices, and Media Coverage (1/24/04 - 2/20/04)."

Mr. Murphy asked if there were any comments on January 27, 2004 IART meeting minutes. Mr. Pinaud referred to the first paragraph on page 5 and asked that the text be revised to include Mr. Schlesinger's inquiry as to whether both the Attorney General's office and DEP can enforce the Massachusetts Contingency Plan (MCP). No other comments were offered and the minutes were approved with the one change.

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

Mr. Murphy determined that there was no late-breaking news to report at this time. He then asked if there were any comments on the responses to action items from the January 27, 2004 IART meeting.

Mr. Judge said that he found the response to Action Item #1 (his request that the IART either be invited to the upcoming DEP/military meeting regarding Impact Area Groundwater Study Program (IAGWSP) compliance with the MCP, or be provided with the resulting meeting minutes) to be inadequate. He said that he thinks that DEP should issue a letter of noncompliance and make it available to the public. He also said that he doesn't think such a meeting should occur at all because the military is "either in compliance ornot," and "minor infringements" discussed behind closed doors could add up to "major problems." Mr. Judge noted that while he doesn't believe that such a meeting should even occur, he would want to be invited or at least receive the meeting minutes.

Mr. Pinaud stated that DEP reviews many documents and issues comment letters (copies of which are provided to IART members) that outline where those documents don't meet MCP requirements. The letters also include a section about reservation of rights, which notes that DEP can choose to enforce the MCP and any other laws and regulations that it has the authority to enforce, at any time. Mr. Pinaud noted that while the MCP compliance issue is being worked, DEP's strategy is to try to move the program forward and reach cleanup decisions. He added that if the team desires, the issues that DEP makes clear in its comment letters can be reviewed at some point in the future.

Mr. Judge questioned why a stop-work order wasn't sent to the Guard for not complying. Mr. Pinaud replied that the goal is to achieve some cleanup while simultaneously working out the compliance issue. Mr. Judge said that by "stop work," he didn't mean in the area of cleanup. He also said that even Governor Romney said that the military would comply, and he (Mr. Judge) considered that promise to be the "lynch-pin" on which the decision to sign the lease extension agreement was based. He expressed great dissatisfaction with the IAGWSP's response to Action Item #1, which was to keep the team informed in the future. He said that the military is not in compliance right now and he wants to know what resulting actions will be taken.

Mr. Pinaud noted that today DEP Commissioner Golledge and U.S. Environmental Protection Agency (EPA) staff met with Ray Fatz, the Deputy Assistant Undersecretary of the Army, to discuss many Massachusetts Military Reservation (MMR) issues, including the noncompliance issue. A result of that discussion was an agreement to have a follow-on meeting at the technical level during the first week of March to talk about specific noncompliance issues.

Mr. Judge asked that DEP send a "letter of violation" to the Guard stating that what's needed is not a follow-on meeting but for the Guard to be in compliance. Mr. Murphy suggested that individual IART members could draft some type of letter. Mr. Judge said that he wouldn't want to misrepresent the team by speaking on its behalf, and he thinks that the appropriate individual action would be to contact the Attorney General's office, but he doesn't want to do that. He asked if DEP could issue a letter of noncompliance at this point. Mr. Pinaud replied that that will be DEP's - not the IART's - decision to make, based on the discussions that it has with the Army.

Mr. Judge remarked that just as a citizen isn't given the chance to arrange future meetings for discussion when issued a speeding ticket, he wants "the ticket issued now" to the Guard in order to prevent "the funny business of making a hundred thousand minor infringements in the future." Mr. Judge also reiterated that acceptance of the lease extension was based on the military's promise to comply.

Mr. Mullennix stated that unlike Mr. Judge, he is confident that the Army and DEP will work out the compliance issue, without any input from the IART at this time.

Mr. Walsh-Rogalski inquired about the context in which compliance with the MCP was promised. Mr. Judge replied that in both speech and print Governor Romney said that the lease renewal was based on the Guard's promise to comply with the MCP "and different things that were put in place." Mr. Walsh-Rogalski asked if this was part of the lease agreement itself. Mr. Judge replied that it was, and could be found in the "legal part" of the lease.

Ms. Hayes noted she agrees with Mr. Mullennix. She also said that she thinks it's important to have correct information and would like to know whether Mr. Judge's remarks about the lease extension are correct, and would like to see a copy of the lease. Mr. Judge asked Mr. Gonser to provide a copy of the lease to IART members, as well as a copy of Governor Romney's remarks regarding the lease. Mr. Gonser replied that he could pass this request on to the Massachusetts Guard, as his office doesn't have anything to do with the lease. He also said that his recollection is that the lease agreement contains no reference to the MCP. Mr. Murphy mentioned that the office to contact about the lease is the E&RC.

Mr. Judge then referred to Action Item #2, an inquiry about whether a news release was issued regarding perchlorate detections in the zone of contribution (ZOC) for an Upper Cape Water Cooperative supply well. He said that he'd like to be provided with copies of the August 28, 2003 Cape Cod Times and the August 29, 2003 Mashpee Enterprise, which the response notes addressed initial perchlorate detections in the ZOC. Mr. Murphy stated that copies of the articles were distributed to the team as part of a previous "News Releases, Neighborhood Notices, and Media Coverage" handout. Ms. Dolen then provided Mr. Judge with copies of the articles.

Mr. Cambareri questioned whether the IART was informed about the initial perchlorate detections at the time they occurred, or not until the January 2004 IART meeting. Mr. Gregson replied that he believes that the detections were discussed at an IART meeting at about the same time that they were reported in the newspapers. Mr. Borci clarified that additional perchlorate detections in the ZOC, which occurred in three downgradient monitoring wells located along Wood Road, were those discussed at the January meeting. He also noted that new data are available from two additional locations in the J-2 Range, and data from a farther downgradient monitoring well located on Jefferson Road is expected soon. He said that the project managers are trying to get a handle on what information should be released, and are waiting for the data from the Jefferson Road well. Mr. Judge asserted that the public has a right to be kept informed about hard data collected from monitoring wells in the ZOC - whether or not perchlorate is detected.

Mr. Cambareri asked whether IAGWSP news releases include contact information for IART members. Mr. Murphy said that he believes that this information is not included in news releases, but is available on the IAGWSP website. He also said that it's not the IAGWSP's job to direct the media to one team member or another; rather, the choice is left up to the media.

Mr. Judge questioned how many IART members were contacted by the Cape Cod Times for the recent article on perchlorate testing. Mr. Murphy asked Ms. Lehmert, the Cape Cod Times reporter in the audience, if she'd like to respond now, or later during the break. Ms. Lehmert noted that it's probably not appropriate for her to discuss how she does her reporting, but "to be fair," she noted that she contacted one IART member

Mr. Judge said that he considers this to be a problem because the story contained only one team member's opinion, which might vary from others' opinions. He mentioned the IART groundrules and said that this problem had occurred in the past. Mr. Murphy noted that from his reading of the article, it wasn't clear that Mr. Mullennix (the team member who was quoted) identified himself as an IART member. Mr. Judge described this comment as "being cute" and asked whether Mr. Murphy would want him to start writing articles and naming himself as a member of a citizen team that reviews Army cleanup at the base. Mr. Murphy asserted that it's a different situation when a publication decides to identify an individual in that way; it is beyond the individual's control. He noted that in previous groundrule discussions he was referring to a situation where an individual signed a letter to the editor as a member of the IART. Mr. Judge suggested that Mr. Murphy was "allowing cuteness" by distinguishing between an opinion given by someone identified as an IART member and someone identified as a member of "a citizen team that reviews Army cleanup" He added that he thinks this practice must be stopped.

Mr. Murphy said that Mr. Judge's point is well taken; however, the team cannot control how the media identify individuals. Mr. Judge contended that the team can control how it responds to that. He said that he thinks the IART needs to be a cohesive group as often as possible, but when speaking as individuals, team members should make it clear they are not speaking on behalf of the team. He remarked that that is "too cute," he doesn't like it, and he thinks EPA shouldn't like it because the average reader might perceive that one person's opinion is that of the entire team. Mr. Murphy said that he understands Mr. Judge's point, but also noted that EPA certainly isn't in the business of "putting any kind of gag order on people." He said that he doesn't see going beyond the groundrule that members should not misrepresent their position as the position of the team, and while he thinks it makes sense, he doesn't see adding to the groundrules tonight Mr. Judge's suggestion that team members identify themselves as not speaking on behalf of the team.

Mr. Murphy also noted, however, that he thinks a future discussion on this issue is doable. Mr. Judge requested that that future agenda item pertain to instituting the use of a disclaimer whereby team members who speak to the media clarify that they are not speaking for the group - whether the group is identified in name, or whether the member "is cute" and identifies the group as "a citizen team that reviews Army cleanup." Mr. Murphy agreed to take this issue back as a discussion item for the groundrules. Mr. Judge asked when it would be an IART agenda item. Mr. Murphy replied that it could be discussed at the next meeting or two, depending on the agendas. Mr. Judge insisted that the topic be included as an agenda item at the March IART meeting. He said that he thinks this is a "serious" situation because in the Cape Cod Times article the team member used the term "inconsequential for health concerns" and he's afraid that the public might think that EPA, DEP, and other team members hold the same opinion. Mr. Murphy noted that he understands Mr. Judge's point. Mr. Judge added that he doesn't want "any member of the public to feel that they're inconsequential and that their health is inconsequential."

Ms. Hayes said that, with all due respect, she'd like to point out to the chair that he has a responsibility to control the length of time exercised on a subject. She also said that, with all due respect to her colleagues, on many occasions the opinions of two "rather prominent" IART members were included in articles published in the Cape Cod Times. She noted that those opinions were very different from her own, and she did not find that offensive. Ms. Hayes said, "That's what free press is." She also said that she doesn't expect team members to always agree, would think something was wrong if they did, and added, "Diversity is what we are looking for." Ms. Hayes further stated respectfully that whether or not it should, she doesn't think that the general public on Cape Cod recognizes the IART as "a very important body," although members of the public are concerned about their environment. She suggested that IART members shouldn't identify themselves "as being so important that everything that is stated in a news column is going to really rile the general population on the Cape" - because that doesn't happen. Ms. Hayes then asked the chair to keep the discussion at a level of intelligence appropriate for everyone. She also said that her respectful request of the chair is to table this discussion immediately and move on with the agenda. Mr. Judge remarked that he "respectfully and thoughtfully and very clearly disagrees."

Agenda Item #3. Technical Outreach Services for Communities (TOSC) Presentation on Thermal Desorption

Dr. Dahmani showed a schematic drawing of a thermal desorption system, and a photograph of an actual thermal desorption system. He noted that the system consists of a feed and screening unit, a rotary dryer, a cyclone, an oxidizer, a cooling chamber, a baghouse, and an emissions stack - each of which he would discuss in detail. He then showed another photograph of a thermal desorption system, shown through the viewpoint of the control room, as well as a photograph of a site in Ontario, Canada where thermal desorption technology is being used. Dr. Dahmani noted that this technology, which is going to be used to treat contaminated soil from the Demolition Area 1 (Demo 1) site on MMR, seems to be becoming increasingly popular because heat can be quite effective in destroying contaminants. He also mentioned, however, that the associated cost can be higher than that associated with other technologies.

Dr. Dahmani stated that the first step in the process is to excavate the contaminated soil, screen it to remove materials greater than two inches in size, and store it on a tarp before transporting it to the treatment unit. The soil will then be brought by truck to be placed on a lined asphalt pad built at the treatment area, where it will be allowed to air dry and/or drain to remove excess moisture. Water that drains from the soil will be sent to a wastewater treatment system. Clean treated water from that system will be used to cool and re-humidify the treated soil.

Ms. Hayes inquired about the cost of thermal desorption technology compared to other methods for addressing contaminated soil. Dr. Dahmani explained that it depends on the contaminants - the technology may be more costly for contaminants that are difficult to remove, but may be less costly when addressing contaminants that are more easily removed.

Dr. Dahmani then discussed problems that can be associated with thermal desorption technology. He noted that particle size of the material being handled can affect applicability or cost of thermal desorption technology, as can the moisture content of the soil, which is why dewatering is important. He also noted that a highly abrasive feed can cause problems with the mechanical equipment that the technology utilizes. Another potential problem is heavy metals in the feed, in which case the treated soil residue might have to be stabilized before being returned to the excavation site. Clay, silty soil, or clumpy soil also can be difficult to treat because heat has to contact the contaminants in order for the technology to be effective.

Dr. Dahmani then stated that dust control measures implemented at the site will include a spray called ConCover, tarps, and water trucks. He also noted that real-time monitoring for respirable dust will be conducted in order to ensure the safety of individuals working at the site. He further noted that soil with high clay content may require conditioning (usually a lime treatment) so that's it's easier to handle.

Dr. Dahmani reported that the feed conveyance system involves a bar-type grizzly, which is equipment to remove anything that's too large to be fed into the rotary dryer. It also involves a scalping screen, which reduces the feed size, making it easier to treat. Before the soil reaches the rotary dryer it is weighed (tons per hour) so that it's known how much soil is entering the treatment unit.

Dr. Dahmani described the rotary dryer as "a big furnace" in which the soil tumbles and comes in contact with flame heat. The heat causes the contaminants to desorb from the soil, which then goes to a pugmill, a device where the treated soil is mixed with water and cooled. Dr. Dahmani noted that in the rotary dryer the contaminants actually volatilize from the soil, which travels the entire length of the dryer to reach the target temperature. The treated soil goes to the pugmill, and the organics (RDX, HMX, and TNT) and perchlorate go the air pollution control system.

Dr. Dahmani then noted the following advantages of thermal desorption technology: the heated purge gas (i.e., the hot flame) is introduced at the same end as the feed soil, therefore there's a longer residence time and the soil is heated faster; and mixing in the rotary dryer enhances heat transfer by convection, therefore the soil is heated faster. Dr. Dahmani also reviewed the following limitations of thermal desorption technology: the purge gas exit temperature is high; solids carryover of 20% or greater is not uncommon; soils that contain certain volatile gases (e.g., lead, arsenic, cadmium) can create emissions problems; some metals (e.g., lead, chromium) can be easily oxidized and become more leachable in the treated soils; and chlorinated aromatics in soils can produce dioxins and furans. Dr. Dahmani noted that it's his understanding that chlorinated aromatics and metals are not a problem for Demo 1 soils, but he thinks it might be prudent to conduct some sporadic testing on soils that have been treated.

Dr. Dahmani stated that Demo 1 contaminants of concern (COCs) RDX, HMX, and TNT can be removed from soil at a temperature of 550F. However, a treatability study at Hazen Research in Colorado showed that the other Demo 1 COC, perchlorate, requires a temperature of 775F for removal from soil. He noted that the higher temperature will make the operation a little more costly.

Dr. Dahmani showed a photograph of a pugmill, which he described as a "big blender" that mixes the hot treated soil and dust with cooling water to prepare it for future handling. He noted that less than 130F is the goal temperature when cooling the soil, and any steam generated in the pugmill is vented to the baghouse. From the pugmill the soil will be discharged to temporary stockpiles with a conveyor and radial stacker. Dust control measures will be implemented at the stockpiles, and individual grab samples of the treated soil will be collected (one for every 25 cubic yards) to verify remediation. Treated soil that meets treatment criteria will be used as clean backfill, and other soil will be reprocessed. Dr. Dahmani noted that some reconditioning of the treated soil probably will be required before it can be used on the base effectively.

Dr. Dahmani also stated that surface water runoff from the feed preparation area will be collected in a 20,000-gallon storage tank and sent to a wastewater treatment plant, after which one grab sample for every 10,000 gallons of water will be tested for explosives and perchlorate. The clean treated water will be used to cool and re-humidify the treated soils. Process water from dewatering activities will follow the same treatment.

Dr. Dahmani showed a schematic drawing of the cyclone, a very common and inexpensive technology. He explained that purge gas enters the cyclone and swirls around, causing remaining soil particles to fall out at an efficiency rate of about 70% to 90%. He noted that the thermal desorption system at MMR includes two cyclones to remove the soil particles from the gas. From there the gas goes to an oxidizer, where any remaining contaminants are burned at very high temperatures ranging from 1,200F to 2,000F. Residence time of the gas in the oxidizer is only a couple seconds.

Dr. Dahmani explained that off-gas from the oxidizer goes to an evaporative cooling chamber, where it's cooled to a temperature of 450F by air atomization water spray nozzles, before moving on to the baghouse. He noted that the baghouse, which is a series of filters, operates on the same principle as a vacuum cleaner, whereby the purge gas is pulled through and any remaining particulates or contaminants are retained by the filters. He also said that the baghouse is very efficient (98% or greater), can capture smaller particles than the cyclone can, and is more complex and more costly to operate than a cyclone. Also, the baghouse is extremely effective in controlling emission of metals and organic compounds that attach to fine particulates, and is a very important step in terms of controlling any remaining emissions. Dr. Dahmani also mentioned that the "cake" that forms in the baghouse is cleaned by pulses of air that physically shake it from the bags. He noted that fines from the baghouse are discharged to the pugmill, as are fines produced in the cyclone and in the oxidizer.

Dr. Dahmani stated that the last steps in the process are the induced draft fan, which draws air throughout the system and creates a negative pressure, thereby eliminating fugitive emissions, and the stack, through which the gases are emitted. He noted that stack gases are monitored with a continuous emissions monitoring system (CEMS).

Dr. Dahmani stated that under EPA regulations, a thermal treatment unit (that is an enclosed device using controlled flame combustion) is classified as an incinerator, and is subject to regulation as an incinerator if equipped with a fired afterburner or if the desorption chamber is directly fired, which is the case with the unit at MMR. He then showed a slide on which the following DEP emissions permitting statements were written: emissions limitations are created as part of the BACT (Best Available Control Technology) review; the applicant is obligated to accept the lowest achievable emission, taking into account cost, technological limitations, and environmental factors; the DEP permit approval establishes emissions limitations presented in various formats including tons per year, tons per month, pounds per hour, parts per million (volume), etc.; the emissions limits are for the various criteria pollutants (NOx, CO, SO2, VOC, particulate) and non-criteria pollutants of interest, in this case RDX, HMX, and perchlorate byproducts such as hydrogen chloride (HCl); and, ensure the operation of the equipment will not cause a localized exceedance of the National Ambient Air Quality Standards (NAAQS). Dr. Dahmani noted that the emissions screening modeling report produced by the contractor Environmental Chemical Corporation (ECC) shows that there are no exceedances of NAAQS. He further noted that DEP has provided conditional approval for operation of the thermal desorption unit; that is, DEP informed the Guard and ECC that they can operate the system under certain conditions, which have been put in place.

Dr. Dahmani then asked when the proof of performance (POP) test is scheduled to occur. Mr. Nixon replied that the POP test will start on March 9, 2004, and initial "shakedown" testing of the system will begin tomorrow morning. Dr. Dahmani explained that the POP is a test to demonstrate that the system meets project-specified treatment criteria for soil, that the air emissions meet criteria established by DEP, and that the equipment can be safely operated in a controlled manner. He also reported that the treatment system is equipped with automatic waste feed shutoffs, which are enacted if any of the following occur: low oxidizer temperature, high temperature dryer discharge soil, high carbon monoxide concentration, or high dryer pressure.

Mr. Judge thanked Dr. Dahmani and said that he's looking forward to more educational presentations, which he thinks also should occur early in meetings.

Mr. Dow inquired about the use of pesticides (DDT) in the area, whether they would come out of the stack as dioxins and furans, and whether the emissions monitoring system would detect them. Dr. Dahmani replied that this is why the initial soil characterization is so important; knowledge of any halogenated compounds in the soil is essential because of the toxins Mr. Dow mentioned. He added that the whole process doesn't make sense if the soil isn't characterized properly. Mr. Dow asked if soil characterization is part of the POP process. Dr. Dahmani replied that it's not, and noted that soil characterization would occur before thermal desorption technology were even considered. Mr. Nixon noted that he's reviewed a great deal of data from Demo 1, and the soils have been tested for pesticides and herbicides. He said that he remembers only one or two cases where there might have been single-digit concentrations of those compounds, and all other samples tested nondetect. Dr. Stahl informed Mr. Dow that, unlike PCBs, DDT would not be expected to form dioxins and furans in the thermal desorption unit.

Dr. Stahl then inquired about the CEMS as it pertains to perchlorate. Dr. Dahmani replied that perchlorate is not part of the CEMS, but he believes that different sampling will be done for it. Mr. Nixon noted that the stack emissions will be tested for perchlorate during the POP test. Mr. Meyers of ECC explained that a source test contractor will come on site and take grab samples of the gases that go through the stack in order to test them for perchlorate.

Agenda Item #4. Demolition Area 1 Feasibility Study Modeling Update

Mr. Nixon noted that the Rapid Response Action (RRA) plan for Demo 1 groundwater is a temporary system scheduled for startup in September 2004. He also reported that the Demo 1 Feasibility Study (FS) process is under way and a comprehensive treatment system should be up and running in about three years, until which time the RRA system will continue to operate.

Mr. Nixon then reviewed the steps in the FS, as follows: conduct screening of alternatives; issue a draft FS document, to be followed by an informal public comment period; finalize the FS and produce a final document, to be followed a public comment period; release a remedy selection plan, also subject to public comment; and then formalize the plan in a decision document. Mr. Nixon also clarified that the FS doesn't actually select an alternative; rather, it prepares the information for evaluation by the IAGWSP, the regulatory agencies, and the public. He noted that once the decision document if finalized, engineers design the system, and construction and startup follow.

Mr. Nixon noted that the FS process used by the IAGWSP is dictated by an EPA Administrative Order (AO), which includes several required alternatives. One is a baseline alternative, which would be a no-action alternative if the RRA system wasn't going to be installed. However, at Demo 1, the baseline alternative is the RRA plan, as a no-action alternative wouldn't be relevant in this case. Another required alternative is the background alternative, designed to reduce contaminant concentrations to background concentrations in a reasonable amount of time, which is not specified. The 10-year alternative is meant to reach risk-based concentrations or regulatory standards within 10 years. The AO also allows for additional alternatives that attain site-specific remediation levels within different restoration timeframes, and the IAGWSP has developed such an alternative, known as "Risk-based A." Mr. Nixon then turned the presentation over to Dr. Chris Abate with AMEC, the IAGWSP's prime contractor for groundwater remediation and designs at Demo 1.

Dr. Abate stated that the model is based on a conceptual hydrogeologic model that was developed through ongoing field studies at Demo 1 and Cape-wide. The conceptual model is realized in the form of a numeric grid-based model called the regional groundwater flow model, for which a fairly coarse model grid is used. In order to do this design work, however, a sub-regional model with a much finer resolution is developed for the area of interest - in this case, Demo 1, for which the model grid cell size is 50 feet. The model simulates both the flow process and contaminant fate and transport, and is used for the various design scenario runs.

Dr. Abate noted that in the groundwater modeling process, multiple COCs are considered, each of which has a slightly different distribution, with the centers of mass in different locations. Hundreds of well locations are also considered; the power of computers permits the evaluation of every allowable combination of wells that is pre-specified and determines which combinations work best. In addition, pumping rates at the well locations are iteratively increased and decreased in order to achieve capture that meets a particular set of objectives. Dr. Abate further noted that the modeling approach not only meets concentration/time requirements set forth in the AO, but also evaluates the designs based on their mass removal effectiveness.

Dr. Abate then showed a figure of the Demo 1 sub-regional model and noted that it extends from Buzzards Bay to well upgradient of the plume's source area. He described the model as a simulation of the water table and groundwater flow, and pointed out the hydrologic head contours, or contours of the water table surface. He also explained that the model extends significantly beyond the plume in order to provide sufficient buffers, and further noted that the boundary conditions for the sub-regional model are derived from the regional model.

Dr. Abate noted that the well layout for the baseline alternative consists of the RRA system - one extraction well and two injection wells at Frank Perkins Road and one extraction well and one injection well at Pew Road. As originally designed, the extraction wells were to pump at 200 gallons per minute (gpm) and 100 gpm respectively, but was bumped up to a combined pumping rate of 320 gpm. Dr. Abate then showed a computer-generated 3-D animation of the modeled Demo 1 RDX plume baseline alternative. He described the plume depiction as a 3-D plume sliced down the axis in order to show the concentration distribution inside. He also pointed out the banded scale of concentration thresholds, two clay lenses believed to be fairly important in influencing the direction of plume migration, and the time indicator. Dr. Abate then ran the animation sequence forward in time and noted that while this alternative is quite effective at capturing the RDX plume in its entirety, it would take a fair amount of time to actually reach that objective. Mr. Judge inquired about the timeframe, and Dr. Abate replied that the animation sequence runs 50 years.

Dr. Abate then showed the animation sequence for the modeled Demo 1 perchlorate plume baseline alternative and pointed out that the perchlorate plume is considerably larger than the RDX plume. He noted that the RRA system is quite effective at containing the highest concentration portions of the plume, while the downgradient part of the plume disappears through dilution and dispersion to below detection limit concentrations before it ever migrates off base. Mr. Pinaud clarified that this is only what the model predicts. He noted that modeling is a tool, not reality. Dr. Abate replied that that is a good point, and thanked Mr. Pinaud for mentioning it. Mr. Judge suggested that the dilution and dispersion process can be reversed through bioaccumulation in certain animals that inhabit Cape Cod.

Dr. Abate noted that the well layout for the background alternative consists of four extraction wells - the two RRA wells, another upgradient of Frank Perkins Road, and another downgradient of the present-interpreted toe of the plume. It also includes the three RRA injection wells and an additional injection well along Pew Road. The combined pumping rate for the extraction wells is 472 gpm, and the assumed "reasonable timeframe" is on the order of 30 years.

Mr. Dow asked if the animations assume that the contaminants get trapped in the clay layers. Dr. Abate replied that the clay is simulated in the model as a permeable deposit through which water and contaminants flow. The model predicts that the contaminants move very slowly when they enter the clay deposits and then bleed out over time.

Mr. Hood inquired about the margin of error associated with the model, and how it compares to known actual performance. Dr. Abate replied that there are not yet any Demo 1 performance data to validate the model, but when the RRA system becomes operational, data will be fed back into the model to prove the predictions. Mr. Hood asked Dr. Abate to identify the margin of error to the best of his knowledge. Dr. Abate replied that it's very difficult to quantify. However, there is a percentage of uncertainty associated with all the input parameters and the predictions, and sensitivity analysis is conducted to try to quantify that. Mr. Hood asked what number Dr. Abate would quote if he had to. Dr. Abate replied, "out of the hat at this point, 10%, or less."

Dr. Dahmani asked how the clay layers were identified. Dr. Abate replied that in addition to RRA wells, there are probably about 100 monitoring wells screened throughout that region, including a line of wells along Pew Road where clay was repeatedly encountered during drilling. He said that it's a laterally continuous clay layer, and added that the upgradient and downgradient extents had to be assumed where there aren't real boundaries for it. He also noted that this feature was actually verified through geophysical logging; a distinct low-permeability or fine-grained unit corresponds to the intervals in the drilling logs. Mr. Nixon added that a sample of the clay was collected when the Pew Road extraction well was drilled, and it was also seen at other locations. Dr. Dahmani inquired about the calculation of permeability. Dr. Abate replied that it was modeled on a permeability of 0.5 feet per day in the horizontal and 0.05 feet per day in the vertical. He also noted that pots could be made from the clay, and characterized it as "really gooey stuff" that "fits that lithologic description most accurately."

Mr. Cambareri asked Dr. Abate to point out the contact of the outwash and the moraine. Dr. Abate replied that the boundary is Frank Perkins Road, and the clay lens is interpreted to exist only within the moraine zone, as mapped by the U.S. Geological Survey.

Dr. Abate then showed the animation sequence for the modeled Demo 1 perchlorate plume background alternative and noted that the objective was to achieve cleanup within 30 years. He also explained that in each simulation it's assumed that the RRA system will operate for four years, with the FS system becoming operational in 2008. He noted that the model predicts that the background alternative would almost completely clean up the plume after about 20 years of operation that begins in 2008.

Mr. Judge said that he understands that Dr. Abate "went out on a limb" to give the team the 10% number to work with, and so he wouldn't hold him to it. He further stated, however, that in the future he wants "confidence levels of everything that we see" so that it's known how useful a model really is. He also remarked that the 3-D animations are excellent.

Mr. Cambareri said that while this is the first time the IART's been shown such enhanced modeling, pump-and-treat containment systems are not new. The idea of such systems' reliability can be illuminated by the effectiveness and reliability of the Installation Restoration Program's pump-and-treat systems, which use the same tools, science, and physics to do containment elsewhere on MMR. Mr. Cambareri said that he considers containment to be a proven technology, which involves "setting up a flow field and sucking in the contamination." Dr. Abate added that to his knowledge, most of the systems have actually outperformed expectations, largely because of conservatism in engineering design and in model predictions. He said that it's important to understand that uncertainty is taken into account upfront in model development. Mr. Judge stated that he'd like future modeling presentations to identify the level of conservatism - very, medium, and so forth.

Dr. Abate then continued with his presentation by noting that the 10-year alternative is designed to achieve risk-based concentration levels within 10 years, for both perchlorate and RDX. However, this alternative involves a combined pumping rate of 1,400 gpm, with one well exceeding 500 gpm. He noted that the 10-year alternative includes five extraction wells, but without one at the toe location because concentrations downgradient from Pew Road are actually below risk-based levels already. Dr. Abate showed the animation sequence for the 10-year alternative and noted that by 2018, with the exception of a small amount of residual mass in the clay, aquifer concentrations are fully reduced to below the target level.

Dr. Abate stated that the additional alternative, referred to as risk-based A, consists of the same five well locations as the 10-year alternative, but with a combined pumping rate of 900 gpm. It meets the objectives in just a few more years than the 10-year alternative, but with an approximately 50% reduction in the pumping rate. Dr. Abate showed the animation sequence and noted that the same level of cleanup achieved by 2018 with the 10-year alternative is achieved by 2022 with the risk-based A alternative. He also mentioned that in reality it's not expected that contaminants will permeate the clay lenses; however, it's good modeling practice not to simulate things as impermeable.

Dr. Abate then displayed a line graph and pie chart that illustrated RDX mass removal efficiencies for each of the four alternatives. He noted that at a minimum all of the alternatives achieve in excess of 90% capture within a 30-year timeframe. The 10-year alternative achieves nearly 100% capture in 10 years. However, there's virtually no difference in the cumulative percentage at 10 years for risk-based A alternative, at a 50% lower pumping rate, making it the most efficient design in the case of RDX.

Dr. Abate also displayed a line graph and pie chart that illustrated perchlorate mass removal efficiencies for each of the four alternatives. He noted that for perchlorate, peak percentages aren't captured because of mass within the clay or mass that's diluted and dispersed to below threshold concentrations. He also pointed out that, again, the most aggressive design is the 10-year alternative, but risk-based A is just effective at the 10-year point and appears to be more effective through the end of the particular simulation run that concluded at 20 years. Dr. Abate suggested that this might be because higher pumping rates would cause increased stagnation between the wells where mass can't be removed easily.

Mr. Mullennix asked if it's correct that any of the alternatives would remove or dissipate the COCs before they migrate off the base boundary, assuming that the model predictions are accurate. Dr. Abate replied that it is. Mr. Mullennix said that he is then confident that as the model is validated, the correct decision will be made in terms of benefit and cost.

Mr. Walsh-Rogalski inquired about the assumed risk levels. Dr. Abate replied that the risk-based concentration number for TNT is 2.0 parts per billion (ppb), for RDX 0.6 ppb, and for perchlorate 1.0 ppb. Mr. Walsh-Rogalski asked if the cumulative risk of the three contaminants at those concentrations has been calculated. Mr. Nixon replied that he's not aware of any synergistic effect between the three, and added that as far as he knows that calculation hasn't been done. Mr. Walsh-Rogalski asked if Mr. Nixon is aware that there is no synergistic effect. Mr. Nixon replied that he isn't. Mr. Walsh-Rogalski said that he would hope that this issue is considered when looking at risk-based concentrations.

Mr. Walsh-Rogalski also requested clarification regarding the number of years to final remedy startup. Dr. Abate explained that before a three-year timeframe for the RRA system was determined, a timeframe had to be assumed for the purposes of modeling, and that timeframe was four years. Therefore, in the models the RRA system startup date is 2004 and the FS system startup date is 2008. Mr. Nixon added that based on the timeframes in the AO, the process would normally take about four to five years, but the IAGWSP is fairly confident that the time can be kept to about three years. Mr. Walsh-Rogalski inquired about the time interval between remedy selection and system startup. Mr. Nixon replied that that would be about two years, and would include construction. Mr. Walsh-Rogalski asked whether that assumes use of off-the-shelf technology or some type of customized technology. Mr. Nixon replied that off-the-shelf technologies could be used, and noted that while tonight's presentation focused on modeling, part of the FS will be to evaluate different treatment technologies. He also mentioned the familiar treatment media - fluidized bed reactors and ion exchange for perchlorate, and granular activated carbon (GAC) for the explosives.

Dr. Dahmani asked if the modeling shown tonight assumes that the Demo 1 source area will be removed. He also inquired about contaminants in the vadose zone. Dr. Abate replied that the modeling doesn't include any kind of prediction of contaminants that might be en route, but does assume full source removal. Dr. Dahmani inquired about any vadose zone data. Mr. Nixon stated that post-excavation sampling results from the one-foot-depth excavation area at Demo 1 showed detectable RDX concentrations in only three of the twenty-five 50' x 50' quadrants. He also mentioned that some past investigations that were done down to depth showed very sporadic concentrations that generally weren't very high, but those concentrations change over time as they are transported with the percolating rainfall and snow. Mr. Nixon further noted that the RRA plan contains all those data. Mr. Borci clarified that vadose zone contamination is not included in the model, and it's unknown how long it will take to flush out everything that isn't excavated.

Dr. Dahmani then asked if it's accurate to say that most of the flow will occur in the moraine. Dr. Abate replied that about half of the perchlorate plume already is within an area that's mapped as moraine. Dr. Dahmani asked how well hydraulic conductivities are characterized vertically in the moraine, and how reliable that will be in the prediction. Dr. Abate replied that hydraulic conductivities in the model are based on extensive slug testing conducted at Demo 1 monitoring wells. He also noted that in the past slug tests weren't considered very reliable in high-permeability aquifers, but pneumatic slug tests, the new slug test technology implemented at Demo 1, have been shown to be very reliable. Dr. Dahmani noted that slug tests still represent only a very small portion of the soil. Dr. Abate agreed.

Dr. Dahmani then asked about sensitivity analysis. Dr. Abate replied that sensitivity analysis that looks at varying hydraulic conductivities, recharge, and some other parameters, has been done. Dr. Dahmani questioned whether there are any high-hydraulic-conductivity layers in the moraine that could affect the model drastically. Dr. Abate replied that the Demo 1 monitoring wells are screened where contaminant was detected and where water is observed to be actively moving through the system. Therefore, sampling probably already is being conducted in the highest permeability zones within the aquifer, and the slug tests would reflect those high permeability values. He said that geophysical logging has shown a fair amount of heterogeneity in the moraine, definitely more heterogeneity than exists in the outwash. He also said, "it's just sand and gravel, with a little more clay someplace."

Dr. Dahmani also asked when the model would be calibrated. Dr. Abate replied that it has been calibrated and predictions on the performance of the different alternatives have been made. He also noted that RRA performance data would be used to validate those predictions. Mr. Nixon added that it will be "an iterative process through the entire duration that the plant is operating." The model will continually be updated with new data from the plume and from the RRA system, and the various parameters that go into the model will help refine and improve it. He also noted that the regulators and everyone would be kept informed of any significant changes that occur in the model.

Mr. Judge remarked that he has a challenge with the word iterative because he wants to "avoid iteration later on by making the best decision" right up front. He also asked if it's correct that pumping in the model simulations starts in 2008. Dr. Abate clarified that the simulations show the RRA system operating for four years, beginning in 2004, and the additional FS wells operating for the balance of the time, beginning in 2008. Mr. Nixon noted that startup of the RRA system is expected to occur in about six months. Mr. Cambareri asked for clarification on the time periods represented in the pie chart. Dr. Abate replied that the time objectives there are based on when the FS alternative is implemented. Mr. Judge remarked that as a citizen he's interested in real time, that is when the wells start pumping and when they finish pumping.

Mr. Nixon stated that the draft FS is scheduled to be submitted in the next couple months. However, the IAGWSP is waiting to hear whether the regulators want to seen additional modeled alternatives, which could delay that submittal. He also mentioned again that the RRA system should begin operating this September and run for about three years, until the comprehensive system in place and operating.

Mr. Judge again expressed high praise for the 3-D animation and said that he would welcome more because it so clearly shows what's happening, or what's predicted to happen.

Agenda Item #5. Remediation and Investigation Update

Demo 1 Soil Remediation Update

Mr. Nixon stated that a system shakedown test of the thermal desorption treatment unit is scheduled to begin tomorrow at 6:00 a.m. Results from the POP test, which is scheduled to begin on March 9, 2004 and run for four to five days, will be sent to DEP's air permitting branch. Shortly after DEP approval is received, full-scale treatment of Demo 1 soils will begin. Anomaly removal has been completed, and soil excavation is ongoing, as is soil screening. Weather conditions are improving and the frost that caused excavation activities to cease temporarily in January is finally starting to melt. Mr. Nixon also referred to earlier comments about restoring treated soil so it can support life, and noted that the IAGWSP's plan is to cover the treated soil that's returned to Demo 1 with at least six inches of topsoil from areas on or near the base so it will support the same flora and fauna.

Demo 1 Groundwater Remediation Update

Mr. Nixon stated that the Innovative Technology Evaluation (ITE) system at Pew Road, which is a side-by-side evaluation of three filter media (two different types of ion exchange resin and an amended carbon), has been operating since mid January, with no breakthrough thus far. Once the ITE is completed, which is expected to be sometime in July, a modular system will be installed and the pumping rate will be boosted to 100 gpm for full-scale operation of that part of the RRA system. Mr. Nixon also reported that installation of the Frank Perkins Road wells and piping is nearly completed, the RRA plan approval is pending, and system startup of the RRA system is scheduled for September. The extraction well at Frank Perkins Road will be pumped at 220 gpm until the FS system is chosen, designed, and constructed.

Mr. Nixon showed a process flow diagram of the Frank Perkins Road RRA treatment system and noted that the IAGWSP and the regulators have reached conceptual agreement on the form it will take. He explained that the black outlines in the diagram represent three 40' x 10' containers. Influent perchlorate concentrations are expected to range from 10 to 20 ppb, and influent RDX concentrations are expected to be in the high single digits. Flow from the extraction well will be split among the three containers where it will go through an initial particulate filter, then GAC vessels to remove the explosives compounds, then ion exchange vessels to remove the perchlorate, and then GAC vessels again, a polishing step to ensure removal of all contaminants. Each container also includes a tank that holds water to backwash the filters as needed. Treated water exiting the containers will be recombined and transported to two injection wells, one to the north and one to the south of the plume.

Mr. Nixon pointed out that this system, which will operate until the comprehensive system begins, is substantially changed from the one in the original RRA plan, which involved a large building and a fluidized bed reactor, sand filtration, and GAC to address the contaminants. He also noted that the comprehensive system will involve a full-sized building. The actual treatment train for the comprehensive system hasn't been determined, but the FS will provide all the information necessary to do an evaluation and make that determination.

Dr. Stahl said that he wants to be certain that the soil that goes into the thermal treatment unit during the POP test contains COCs so that sampling of the treated soil is meaningful. Mr. Nixon replied that the stockpiled soil for the POP test is from the most contaminated grids at Demo 1. Two samples of this soil were tested - one came back essentially nondetect for explosives and nondetect for perchlorate, and the other showed fairly low levels of explosives and also tested nondetect for perchlorate. Mr. Nixon said that contaminant levels at Demo 1 are extremely low and the IAGWSP is working on getting concurrence from DEP on a plan to spike those soils with some higher-concentration contaminants for testing before and after treatment.

Dr. Stahl then noted that the groundwater treatment system that Mr. Nixon showed involves two GAC units in parallel, two ion exchange units in parallel, and another two GAC units in parallel. He said that he remembers discussion about having those units in series so if the first one became plugged, it would be possible to take it off line and replace it. Mr. Nixon replied, "On the bigger scale, that's exactly right," and explained that with this system if a unit within a container becomes plugged or breakthrough occurs, the overall flow rate would be decreased temporarily by approximately one third, and flow would be routed through the other two containers.

Dr. Dahmani said that he thinks it's important in the POP to use soil that's representative of the area, which could mean having to take a number of samples from various locations at the Demo 1 site. He also expressed concern about spiking the soil because it wouldn't represent the actual situation. He noted RDX that's been present for a while would have had time to adsorb to the soil, whereas spiked contaminant on top of the soil wouldn't have time to adsorb into the matrix. Dr. Dahmani stated that he would be more comfortable with samples that are representative of the site, whether or not they contain contaminants.

Mr. Nixon replied that that was the original plan, when it was thought that higher concentrations existed in Demo 1 soils. Mr. Gonser said that he thinks Dr. Dahmani has a good point, and added that he doesn't see why both types of soil couldn't be sampled. Mr. Borci remarked that he would place greater emphasis on the characterization when the soils were in place, and added that there were good characterization data going in. Mr. Nixon noted that the cleanup is based on the in situ sampling that was done in the past.

J-1 and J-2 Ranges Recent Unvalidated Detections

Mr. Gregson stated that a major drilling program at the Southeast Ranges is ongoing, with about 30 monitoring wells in the process of being installed. He then referred to monitoring well 306 (MW-306), which was installed to delineate the perchlorate and RDX plume emanating from the interberm area on the J-1 Range. He noted that profile sampling in that well showed perchlorate detections in eight intervals at concentrations up to 3.4 ppb, HMX in five intervals up to 1.08 ppb, RDX in six intervals up to 21.9 ppb, and 2,6-DNT in one interval, but with some interference associated with both the 2,6-DNT and RDX detections.

Mr. Gregson stated that monitoring wells are being installed in an effort to understand the extent of contamination from the J-2 Range. He reported that profile sampling at MW-307 showed RDX at 0.27 ppb and, more significantly, perchlorate in six intervals up to a concentration of 18 ppb. Profile sampling in MW-310 showed perchlorate in four intervals up to 20 ppb and RDX in one interval at 1.4 ppb. Mr. Gregson pointed out the area in the J-2 Range to which those detections track back and said that an effort is being made to pinpoint the source area. He also noted that a number of additional wells are planned to help further define the extent of perchlorate and RDX contamination seen at those two locations.

Mr. Borci said that based on the modeling presented several months ago, detections at those two locations would not be related, but headed off in different directions. He asked if revisions to the model indicate that they might be connected. Mr. Gregson said that the attempt to answer that question is ongoing, but it is still unknown, and continues to be worked.

Mr. Gregson stated that the drilling program to investigate RDX and perchlorate contamination coming from Disposal Area 2 on the J-2 Range is ongoing. Perchlorate was detected in the series of wells along Wood Road, and the MW-296 on Jefferson Road tested nondetect for both perchlorate and RDX. Profile sampling results from well J2P-34 are expected within the next two days, and the drill rig was set up today to begin drilling well J2P-35. The next well to be drilled will be J2P-36. Based on results from those three wells, additional well locations will be identified to further define the extent of perchlorate and RDX contamination in that location.

Northwest Corner Recent Unvalidated Detections

Mr. Gregson showed a draft revised map of the Northwest Corner investigation area. He reported that profile sampling at MW-299, which was drilled to help define the upgradient extent of perchlorate contamination, showed no perchlorate detections. However, RDX was detected in that well at a depth of about 59 feet below water table, at a concentration of 0.32 ppb. He also noted that some 2,4-DNT was reported in the profile samples, but those detections typically turn out to be false positives. Mr. Gregson further reported that profile sampling at MW-309, which is located across the road from the tech school, showed perchlorate in five intervals at concentrations from 0.62 ppb to 1.15 ppb, at depths between seven and 47 feet below water table.

Mr. Gregson noted that drilling of NWP-14 was just completed, and NWP-15 will be drilled next to help define the northern extent of contamination. He also said that real estate issues are still being worked in order to obtain an easement from the property owner to drill well NWP-13.

Ms. Conron said that the plume depictions seem to show the plume getting wider and "going down farther." Mr. Gregson agreed and explained that there are additional data from the investigation, the purpose of which is to define the extent of perchlorate contamination. Ms. Conron inquired about the dark contour intervals on the map, and whether they represent source areas. Mr. Gregson explained that the darkest contours represent areas of higher perchlorate concentrations in the plume. He noted that the dark contour upgradient represents perchlorate contamination near the water table, which indicates a nearby source area, while the dark contour downgradient represents perchlorate contamination that exists deeper in the aquifer and indicates a more distant source area.

Mr. Cambareri asked Mr. Gregson to discuss Figure 4 in the presentation handout. Mr. Gregson explained that the figure has to do with some modeling being conducted by Jacobs Engineering to help select additional monitoring well locations for the J-2 Range plume investigation. He noted that the plume shells were extended out to Wood Road based on the detections there. He also pointed out the blue outline, which represents the ZOC for water supply well #2 based on a one million gallon per day (1-MGD) pumping rate, and the yellow outline, which represents that same ZOC based on actual pumping rates, which are considerably lower than the permitted 1-MGD rate. Mr. Gregson further noted that the monitoring well on Jefferson Road that tested nondetect for perchlorate is located within both of those ZOCs, and data from wells J2P-34 and J2P-35 should provide good coverage along Jefferson Road, across the ZOC for water supply well #2.

Mr. Cambareri observed that although the ZOC that's based on the actual pumping rate is narrower, it still includes the contaminant source area. Mr. Gregson noted that in cross-section it appears that the contaminants are underneath the ZOC. He also said that he would remember to bring that cross-section figure to the next meeting. Mr. Cambareri asked if RDX was detected in the well on Jefferson Road (MW-296), which tested nondetect for perchlorate. Mr. Gregson replied that he believes that profile sampling there showed a low level of RDX at about 0.3 or 0.4 ppb.

Mr. Cambareri asked Mr. Gregson to identify the monitoring well that generated last August's news release. Mr. Gregson pointed out MW-289, where perchlorate was detected at 300 ppb in profile sampling, and at 140 ppb in groundwater sampling. Mr. Cambareri inquired about the distance from MW-289 to Wood Road. Mr. Gregson replied that that distance is probably about 1,000 feet. He also said that the new monitoring wells on Jefferson Road are expected to provide key information - either the good news that they tested nondetect, or significant detections of perchlorate that would move the investigation farther downgradient. Mr. Cambareri then asked if the Upper Cape Water Cooperative has done any recent sampling of either the chemical wells or the far-field wells in that area. Mr. Gregson replied that he does not know when the most recent sampling was conducted, but the Co-op continues its routine sampling required under its permit and to date has not detected perchlorate in any of the sentry wells.

Mr. Mullennix asked if the regulators plan to comment on the Northwest Corner Draft Data Summary Report. Mr. Pinaud and Mr. Borci both said that the agencies will be releasing their comments soon, but not this evening.

Demolition Area 2 Recent Unvalidated Detections

Mr. Gregson reported that profile sampling in MW-311 showed RDX detections, but in shallower intervals than expected. He said that the IAGWSP is looking into the possibility that there might be a source located in a cleared area just to the south. He also noted that both a shallow screen and a deeper screen (to correspond to the main body of the plume emanating from Demo 2) were set in MW-311. Mr. Gregson also reported that the next Demo 2 well location is D2P-6, where drilling activities began several days ago.

Dr. Dahmani commented that 3-D depictions (like those shown earlier in the meeting) of the Northwest Corner and other MMR sites would be very helpful, especially in terms of understanding plumes that are different depths. He suggested that it would not be difficult for the contractor to extend the 3-D depictions to other locations. Ms. Conron added that she thinks that 3-D depictions would help her ensure that she's sharing accurate information with the public. Mr. Gregson said that he could at least provide some detailed cross-sections the next time.

Ms. Conron inquired about the color coding on Figure 4. Mr. Gregson noted that the various colored areas represent zones of perchlorate contamination greater than 100 micrograms per liter (g/L), greater than 18 g/L, 4 to 18 g/L, 1 to 4 g/L, and nondetect to 1 g/L. Ms. Conron noted that the Bourne Water District is hooked up to the Co-op system, and asked why, as a citizen of Bourne, she shouldn't be concerned about this contamination in the ZOC. Mr. Gregson replied that the supply wells themselves are tested for perchlorate, which hasn't been detected in any of them. Also, sentry wells that are five years travel time upgradient of the supply wells have had no perchlorate detections. And the travel time between the supply well and where perchlorate has been detected is 10 to 20 years. While the data indicate that there's no perchlorate near the supply wells, the question that the IAGWSP is trying to answer as quickly as possible is how far the perchlorate extends toward the supply wells.

Ms. Conron asked if the perchlorate is moving in one specific direction, and if so, if it's moving toward the supply wells. Mr. Gregson pointed out the source area in the southern part of the map and explained that the perchlorate is migrating from there toward the supply well #2. He said that the investigation is trying to determine the distance between the maximum extent of perchlorate downgradient and the water supply well itself. Ms. Conron noted that the IAGWSP certainly would want to clean up that area of contamination very quickly. Mr. Gregson agreed.

Mr. Mullennix mentioned that he believes that the Bourne Water District hasn't had to draw water from the Co-op wells for at least the past 18 months.

Mr. Cambareri asked to be provided with profile results from J2P-34 and J2P-35 as soon as they become available. Mr. Gregson agreed to e-mail those results to the IART members.

Agenda Item #6. Open Discussion

Mr. Sullivan of the E&RC stated that the lease extension information Mr. Judge had mentioned earlier is available on the E&RC website. He said that tomorrow he would contact Mr. Judge (who had left the meeting early) to let him know that and to put him in touch with Lynda Wadsworth, the E&RC's community involvement person, regarding acquiring information from the Governor's office. Mr. Murphy asked Mr. Sullivan to contact Ms. Hayes as well, and Mr. Sullivan agreed to do so.

Mr. Pinaud reported that on February 2, 2004, DEP's drinking water program sent a letter to public water suppliers in Massachusetts requiring them to test for perchlorate in their water supply twice this year, once in April and once in September. Mr. Pinaud explained that DEP is moving toward establishing a state maximum contaminant level (MCL) for perchlorate in drinking water supplies, and information gathered from the suppliers will be used to establish a current database for proceeding through the process of establishing an MCL.

Mr. Murphy reported that tomorrow EPA will be sending out a news release to announce that the agency is seeking citizens from Sandwich to serve on the IART. He noted that interested individuals will be asked to fill out a membership application, attend the March IART meeting, and come before the team at the April meeting to introduce themselves and answer questions. However, the process will differ somewhat from the past outreach to Bourne citizens in that the agencies plan to compile a list of questions and try to ask the same questions of all the applicants. Mr. Murphy noted that membership applications are available at this meeting, and will soon be available on the EPA and IAGWSP websites.

Dr. Dahmani said that he thinks that Mr. Racheotes, the gentleman from Bourne whose private well has had perchlorate detections, wanted to ask a question of the team. Mr. Racheotes said that he would defer his comments until after he hears EPA's comments on the Northwest Corner report.

Agenda Item #7. Adjourn

Mr. Murphy stated that the IART would meet next on Tuesday, March 23, 2004 at the Falmouth Holiday Inn. He then adjourned the meeting at 9:05 p.m.

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