Impact Area Review Team
Future Agenda Items:
Handouts Distributed at Meeting:
Agenda Item #1. Welcome, Agenda Review, Approval of July 26, 2005 IART Minutes
Mr. Murphy convened the meeting at 6:05 p.m., introduced prospective Impact Area Review Team (IART) member Earl Lantery of Sandwich, and invited Mr. Lantery to be seated at the table. Mr. Murphy then reviewed the agenda and the team members introduced themselves. He also asked if there any changes or additions to the August 23, 2005 IART meeting minutes. No comments were offered and the minutes were approved as written.
Agenda Item #2. Late-Breaking News and Responses to Action Items
Late Breaking News
LTC Tyminski of the Environmental & Readiness Center (ER&C) reported that on the weekend of October 15, 2005 an Army Reserve unit training at Camp Edwards fired approximately 2,000 rounds of 9-mm lead ball ammunition at a small arms firing range. The incident, which was reported to the regulatory agencies, was a violation of the military's Environmental Protection Standards (EPS), but did not pose a threat to public health. LTC Tyminski explained that some units training at Camp Edwards use lead ammunition at an indoor range that's operated by the U.S. Coast Guard (USCG). He also reported that in response to the incident, corrective procedures have been implemented to ensure that lead ammunition held at the ammunition supply point (ASP) is not inadvertently used at an outdoor range. The procedures include ASP personnel securing a letter from the USCG stating that the indoor range is reserved for a specific unit before releasing any lead ammunition, as well as signs posted on the outdoor ranges to remind everyone of the prohibition on the use of lead ammunition there.
Mr. Cambareri asked how the mistake came to be known. LTC Tyminski replied that an ammunition supply technician noticed a discrepancy when reporting how many rounds of ammunition had been withdrawn from the ASP, which led to an investigation that revealed what had happened.
Mr. Dow inquired about the study of tungsten bullets (green ammunition) and whether they corrode in soil. Mr. Gonser replied that a team from the Army Environmental Center (AEC) conducted some sampling between the firing points and the berm, and at the berm. The samples are in the process of being analyzed, but results are not yet available.
Mr. Mullennix asked if the 2,000 rounds that were shot were thought to have been released in the environment. LTC Tyminski replied that while the rounds would end up in the berm, the occurrence was a violation of the EPS and will be addressed by the E&RC and the Impact Area Groundwater Study Program (IAGWSP) in the future as range modifications and improvements are considered. Mr. Schlesinger questioned whether that means the E&RC needs to pick up the 2,000 rounds. LTC Tyminski replied, "Not immediately," but that may be part of future work.
Mr. Schlesinger also questioned whether tungsten analysis is being done elsewhere in the country as well. Mr. Gonser said that he thinks that three sites are going to be studied, with MMR being the first. He also noted that he couldn't recall the other two sites, but could track down that information.
Mr. Schlesinger then asked if tungsten bullets continue to be used out in the field. Mr. Gonser confirmed that the Army does continue to use tungsten. He also noted that in addition to the study that was just mentioned (to determine where the tungsten is going in the environment), the U. S. Army Center for Health Promotion and Preventive Medicine is conducting a toxicological study to determine potential health risks, if any. The two studies are occurring simultaneously and, once completed, may lead to a point where a decision is made either to continue using tungsten bullets, seek other alternatives, or return to using lead.
Responses to Action Item from the August 23, 2005 IART Meeting
Mr. Schlesinger inquired about an update to the reply to Action Item #3, his request that the IAGWSP consider developing a plume shell to depict RDX contamination coming from the J-1 Range. Mr. Gonser noted that this item would be addressed in detail as part of Mr. Gregson's "Remediation & Investigation Update" presentation.
Mr. Schlesinger also noted that the response to Action Item #4 (his request for both the IAGWSP and the Air Force Center for Environmental Excellence [AFCEE] to consider renewable energy as a supplemental source to run groundwater cleanup systems) pertains to AFCEE, but he'd like to know what the IAGWSP is doing with respect to renewable energy. Mr. Gonser replied that the IAGWSP is basically watching AFCEE, which is under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and therefore has some authorities that the IAGWSP doesn't have. He also said that he believes that AFCEE definitely intends to pursue putting up a windmill, and the IAGWSP is waiting to see what that process entails and whether it's successful.
Mr. Schlesinger said that he recalls some concern about the airfield and wonders about future plans for the base and how they might affect the potential use of renewable technologies such as wind. Mr. Gonser agreed that anything as tall as a windmill in the various flight paths would be a concern for aviators. He also noted, however, that little is known about the future aviation situation at the base, other than that the Air Guard has had some discussions with the Otis Air National Guard base regarding future missions and that the USCG is looking at its use of the airfield, depending on what happens with Otis.
LTC Tyminski added that in the current situation nothing can be done in terms of wind development in the northern 15,000 acres of the base because it's a water reserve. The capital construction that the windmills would require would be incompatible with that use, as well as with military use, which is mandated by law. Also, the southern 5,000 acres is home to an active airfield and the height of the windmills would conflict significantly with that use.
Mr. Schlesinger remarked that it doesn't make sense to him that renewable technologies such as windmills can't be built on the northern 15,000 acres, especially when it's okay to have petroleum-based engines there to run facilities. LTC Tyminski explained that it primarily has to do with the capital construction and the amount of land that would have to be cleared to install the windmills. Also, the law mandates military uses "and having windmills in the way of that" would be seen as a conflict. Mr. Schlesinger indicated that he looks forward to hearing more on this subject.
Agenda Item #3. Area Groundwater Study Program Overview
Mr. Gregson explained that he is providing an IAGWSP Overview presentation primarily for the benefit of prospective IART members expected to attend tonight's meeting. He then stated that the Massachusetts Military Reservation (MMR) was established for military training in the early 1900s, was very active during World War II, and continues as a training location today. He referred to a map of the area and pointed out the central portion of the base called the Impact Area, where throughout the years, as part of military training, mortars and artillery rounds were shot at targets using high explosives, pyrotechnics, and other items. Mr. Gregson also referred to an aerial photograph and pointed out the Cape Cod Canal, Peters Pond, Snake Pond, the airfield, the northern part of the base occupied by the Army National Guard, the southern part of the base occupied by the Air National Guard (Otis), USCG housing, Connery Avenue, the Impact Area boundary, firing ranges, the PAVE PAWS radar facility, the Southeast Ranges (which he explained were contractor-operated test ranges from the 1950s to the 1990s), the K-D firing range, and the areas of the Bourne wellfield and some Sandwich wells.
Mr. Gregson then noted that in the 1980s and 1990s the Air National Guard and AFCEE, under Superfund (CERCLA) regulations, launched investigations of fuel spills and chemical spills in the southern part of the base. In 1997, the U.S. Environmental Protection Agency (EPA) issued Administrative Order #1 (AO#1) to the National Guard to look for any impacts to the groundwater from base activities that occurred in the northern 15,000 acres of MMR. The second Administrative Order (AO#2) was a sort of cease-fire order that prohibited the use of high explosives and pyrotechnics munitions on the base. AO#2 also mandated maintenance, cleanup, and stabilization of small arms berms. AO#3, which is essentially the cleanup order, determined which sites in the northern part of the base (identified through the investigation that started in 1997) would be cleaned up under Rapid Response Actions (RRAs) and which would be cleaned up under a more typical CERCLA-like process involving a feasibility study and remedial design.
Mr. Gregson referred to a map and pointed out several AFCEE sites in the southern part of the base being cleaned up under the Installation Restoration Program (IRP), including Landfill 1 (LF-1), Fuel Spill 12 (FS-12), and FS-1. He also pointed out Chemical Spill 19 (CS-19), a disposal area in the Impact Area, and CS-18, an old gun position, for which AFCEE is the lead agency. Mr. Gregson also noted the locations of the Upper Cape Water Cooperative's water supply wells 1, 2, and 3.
Mr. Gregson then reviewed sites being addressed by the IAGWSP, including Demolition Area 1 (Demo 1), a training and munitions disposal area that resulted in the release of explosives and perchlorate to the groundwater. The primary explosive of concern in the Demo 1 groundwater plume is RDX, but it also contains TNT and TNT breakdown products. An RRA groundwater treatment system is currently in place at the Demo 1 plume and last year about 40,000 tons of soil was excavated from the source area and thermally treated.
Mr. Gregson pointed out the Southeast Ranges and said that they have been the focus of the IAGWSP investigation over the past several years. He noted the radial pattern of groundwater flow from the top of the groundwater mound, which is located beneath the Southeast Ranges and is a complicating factor with respect to investigation and cleanup. He also pointed out the J-3 Range, previously operated by Textron, which conducted testing of munitions under government contracts. He noted that a number of potential disposal sites at the J-3 Range were cleaned up under a soil RRA and the IAGWSP is currently working on a groundwater RRA system for the J-3 Range plume. He also pointed out the J-1 Range, another contractor test range, and noted the disposal area in the middle, an RDX and perchlorate plume heading toward the northwest, and a small area of RDX contamination in groundwater at the southern part of the range. Mr. Gregson further noted that several plumes are emanating from the J-2 Range: the J-2 North plume and a couple of J-2 East plumes that are currently being investigated.
Mr. Gregson then pointed out Demolition Area 2, which wasn't used as heavily as Demo 1, and whose associated groundwater contamination does not contain perchlorate. He also pointed out the Northwest Corner site where RDX detections that might track back to the Central Impact Area are currently being investigated and there's a relatively large area of perchlorate contamination whose source is fireworks displays conducted by the Town of Bourne and also potentially the use of flares and pyrotechnics in military training at the Former A Range.
Mr. Gregson then pointed out the Central Impact Area, from which plumes of RDX and perchlorate are emanating, and the Western Boundary area, where an investigation was conducted upgradient of the Monument Beach wellfield after perchlorate was detected there several years ago. He noted that some additional soil sampling is being conducted as part of that investigation, which should be completed soon. He also said that sampling is being conducted at the small arms ranges and pointed out the former K Range.
Mr. Gregson stated that the IAGWSP is coming to completion on a number of site investigations and will be generating Remedial Investigation (RI) reports. Other sites, such as the Central Impact Area, are being worked through the Feasibility Study (FS) process, which involves looking at different cleanup alternatives and coming to agreement on the best one. Mr. Gregson said that overall the IAGWSP is in transition, from investigation to cleanup.
Mr. Mullennix inquired about any investigation and cleanup of lead contamination. Mr. Gregson replied that as part of AO#2, the IAGWSP cleaned up the berms, removed the lead, and stabilized them with a compound called mectite. He also noted that the lead bullets that can be found in the woods near some of the older ranges near Range Control will be addressed under the Small Arms Ranges workplan to assess the impacts of the lead. Mr. Gregson further noted that the IAGWSP's investigation found migration of the lead contamination beneath the berms to be limited to a few feet. Given the length of time that lead has been used at MMR, it doesn't appear that it reaches the groundwater very quickly.
Mr. Schlesinger expressed some discomfort with what he characterized as Mr. Gregson's implication that the perchlorate contamination at the Northwest Corner is the result of fireworks displays more than military training, as he doesn't believe that conclusion has been made yet. Mr. Gregson noted that the draft RI report on the Northwest Corner will be out next spring, at which time the investigation will be discussed again.
Ms. Jennings of EPA said that she was asked to speak about the role of the various entities that participate in IART meetings. She noted that while the Army is taking the lead in conducting the investigations, there are many other players involved in the process, including EPA, which looks at the IART as a public forum for receiving feedback on the investigations and cleanup work and for educating the community about base cleanup activities.
Ms. Jennings also noted that in addition to participating in IART meetings on a monthly basis, EPA and the Massachusetts Department of Environmental Protection (MassDEP) meet with the IAGWSP regularly to review documents, provide technical input, make suggestions on presentation of information, and so forth. The IAGWSP and the regulators try to come to IART meetings with consensus, or at least an explanation of where their opinions differ.
Ms. Jennings then said that she thinks the IART is at an interesting point in the process as the focus of the program transitions from investigation to cleanup and the group begins to debate the merits of responding to areas of contamination that have been identified or conducting further investigation of areas not yet adequately defined. She also said that given the work to be done off base (in areas where contamination has migrated beyond the border), the role of the citizen IART members is extremely important because the impact of construction activities in the neighborhoods "is pretty dramatic." In summary Ms. Jennings stated that the Army is doing the work, the regulators are directing the Army in ways they believe to be appropriate, they're looking for feedback from the IART (positive and negative), and they want the IART members to have an opportunity to hear the various opinions being offered in terms of the investigation and cleanup.
Mr. Dow asked if there's a Natural Resource Damages Assessment (NRDA) process associated with the Safe Drinking Water Act (under which the IAGWSP cleanup is being conducted) that's comparable to the NRDA process associated with AFCEE's cleanup under CERCLA. Mr. Walsh-Rogalski replied that there is not; however, to the extent that there are CERCLA hazardous substances involved, a claim could be made for natural resource damages regardless of where those substances are. He noted that this is right is held by the trustees who, in the case of the Natural Resource Trustee Council (NRTC) for groundwater at MMR, are the state as well as the Army and the Air Force. Mr. Dow said that it's concerned him that the Army and Air Force are not only members of the NRTC, but also responsible parties, which seems to be a conflict of interest. Mr. Walsh-Rogalski agreed there appears to be a conflict.
Mr. Schlesinger said that he thinks it's important for Mr. Lantery to know that the IART has a technical advisor in Mr. Hood, who works at the University of Connecticut, and participates in EPA's Technical Outreach Services for Communities (TOSC) program. Mr. Hood indicated that he would speak with Mr. Lantery after the meeting.
Agenda Item #4. Remediation & Investigation Update
Mr. Gregson stated that the IAGWSP has been working on finalizing plans for two groundwater RRAs at the Southeast Ranges. The J-3 Range plume system will involve the installation of two new extraction wells and piping to the existing AFCEE FS-12 treatment plant where the extracted water will be run through separate (IAGWSP) carbon and ion exchange treatment vessels and then pumped to existing AFCEE injection wells. The system will treat 175 gallons per minute (gpm). The J-2 North treatment system will be slightly different than originally proposed - rather than having a centralized treatment plant, it will comprise two containerized units and a small treatment plant at the northern end of the plume in order to provide flexibility to adjust the flow at that end. This system will treat 375 gpm and both systems are expected to be operational by the end of 2006. Mr. Gregson also reported that piping and extraction wells are going to be added to the existing RRA treatment system at Demo 1, which will increase the treatment rate from about 0.5 million gallons per day (mgd) to 1.3 mgd.
Mr. Gregson then discussed investigations at the J-1 Range. He reported that monitoring well 401 (MW-401), drilled north of the J-1 North plume, tested nondetect for explosives and perchlorate. He also referred to the investigation into RDX detections in drive-points in the southern portion of the J-1 Range, pointed out where RDX was detected at about 300 parts per billion (ppb), and noted that MW-398 was installed at that location and showed RDX levels of about 120 ppb at a depth between 37 and 47 feet below the water table (bwt). A drive-point location just to the south tested nondetect. Also, an existing water table well at the fire station on Route 130 was extended (using a drive-point rig) to about 110 feet bwt, but also tested nondetect for explosives and perchlorate. Mr. Gregson then noted that MW-360, which is located near the likely source area for the southern RDX contamination, and which previously tested nondetect, showed RDX at 3.4 and 0.92 ppb in a recent sampling round. He also pointed out several more wells near the base boundary (one that had a 6 ppb detection, one that had a 120 ppb detection, and two that were nondetect) and said that a picture of the plume appears to be starting to emerge.
Mr. Gregson also spoke about the off-base work related to the investigation. He showed a photograph of a drill rig on Grand Oak Road and noted that drilling in neighborhoods is quite an intrusive operation, although there's little evidence left behind once the drilling's been completed. He reported that three wells have been drilled in the neighborhood (MW-400, MW-402, and MW-403), all of which tested nondetect for explosives and perchlorate. Although perchlorate was detected at about 1.7 ppb in a profile sample from MW-403, that detection was not repeated in the actual groundwater result from the well screen.
Mr. Gregson then pointed out the direction in which the modeled particle tracks run, which would lead one to look "down in this direction" where, however, no detections were found. He said that either the plume is short and hasn't reached that distance yet, something is wrong with the groundwater model, or the flow is causing the plume to go either to the south or the north. He noted that the IAGWSP is about to take a round of water table measurements in order to examine groundwater flow and refine the model. In the meantime, efforts are being made to obtain access to other drilling locations in the neighborhood to further delineate the plume and its downgradient extent.
Mr. Mullennix asked if the residences in that neighborhood are connected to town water. Mr. Gregson replied that the entire neighborhood is connected to town water, with no private wells being used for drinking water.
Ms. Conron asked Mr. Gregson to point out Peters Pond Drive on the figure being shown, which he did. Mr. Schlesinger asked Mr. Gregson to point out the location of the Sandwich supply wells, which he did, noting that they are not directly downgradient of the RDX detections. Mr. Schlesinger then asked if it's correct that there are some private wells downgradient of the contamination. Mr. Gregson replied that some private wells were identified about one mile downgradient of the base boundary, on Pimlico Pond Road. The wells were sampled and tested nondetect, and additional data collected since that time indicate that the plume is not heading toward those wells. Mr. Gregson also reported that the IAGWSP has hosted some neighborhood meetings and sent out notices to keep the public informed of investigation activities in the neighborhood.
Mr. Gregson then referred to MW-393, located on the access road to the USGC transmitter station and drilled to help define the extent of the J-2 East plume. He noted that RDX was detected there at about 0.78 ppb (less than half the RDX health advisory, 2 ppb) and perchlorate was detected at about 1.6 ppb. He also referred to MW-399, located to the north to help define the eastern boundary of the J-2 North plume, where RDX was detected at about 0.54 ppb. Based on that information, another monitoring well will be drilled downgradient of that location. If it tests nondetect or at a very low level, the assumption will be that the plume in that area is adequately defined for the purposes of moving forward with an FS.
Mr. Gregson reported that the J-3 Range investigation is continuing south of Snake Pond where a drive-point location tested nondetect for explosives and perchlorate, and several other drive-point locations are proposed. The purpose of this part of the investigation is to determine whether any contamination is flowing under the pond and help define the extent of the J-3 Range plume. Mr. Gregson also mentioned that the IAGWSP is awaiting final approval from the town and the conservation commission before moving forward with the additional drive-points.
Mr. Schlesinger inquired about the status of a state or federal perchlorate standard. Ms. Jennings replied that from the federal perspective, EPA continues to wait for guidance from EPA Headquarters regarding converting the reference dose put out by the National Academy of Sciences into a cleanup level for the purpose of cleanup actions. She also said that she has no estimate on when that guidance is expected. Mr. Pinaud reported that portions of MassDEP's rewritten regulations broke free from the regulatory process and will be promulgated this spring; however, perchlorate was not included in that package. He also said that he checked on the status of a state perchlorate standard today but was unable to obtain information about a timeline.
Mr. Schlesinger questioned how this would affect cleanup decisions. Ms. Jennings said that she thinks the perchlorate issue becomes most critical when it comes to formal decision documents, like the one pertaining to Demo 1. She also noted that in the Demo 1 Remedy Selection Plan (RSP), the Army committed to meeting whatever standard ends up being promulgated by the state. Similarly the RRAs that were proposed for the J-2 and J-3 Range plumes were evaluated on the basis of achieving the state's proposed 1 ppb perchlorate standard. Whether or not treatment is done to that level in the end depends on what standard ends up being promulgated.
Mr. Mullennix inquired about influent perchlorate concentrations at the Demo 1 RRA systems. Mr. Gregson replied that while he doesn't know for certain offhand, he believes that the influent concentrations at the Frank Perkins Road system are in the 50 ppb range and at the Pew Road system are in the 10 ppb range.
Mr. Dow referred to the J-1 Range plume that moves south toward the base boundary but hasn't been detected off base and asked whether the IAGWSP, from its sampling in the J-1 Range source area, had been able to calculate the mass of contaminants and compare that with the mass found in the plume. Mr. Gregson replied that it hasn't been possible to do that yet. He also explained that the IAGWSP is conducting an investigation of that portion of the J-1 Range to look at magnetic anomalies and try to find the source. He agreed that it would be helpful if information obtained through that investigation can be used to calculate mass and see how it fits into the model.
Hydrologic Investigation at Peters Pond
Ms. Jennings reviewed the history leading up the Peters Pond hydrologic investigation by noting that off-base sampling of residential wells was conducted in response to contaminant detections at the Southeast Ranges, which led to the discovery of perchlorate in a residential well on Peters Pond Drive. Many individuals concluded that the perchlorate must be coming from the base, but the monitoring wells that the IAGWSP installed between the residential well and the base boundary all tested nondetect for perchlorate, so the situation became "a very interesting puzzle." Following a substantial amount of investigation on the part of the IAGWSP, the regulators agreed that the likelihood of the perchlorate being tracked back to the base was very slim, primarily because of the depth of the contaminant in the residential well. Nevertheless, perchlorate levels detected in the residential well were as high as 2.2 ppb, and so an investigation to try to determine the source of the contamination and whether a higher slug of contamination was heading toward the residential wells on Peters Pond Drive was undertaken. Ms. Jennings also mentioned that other residential wells on the Peters Pond Drive tested at essentially nondetect levels (or at the threshold of the detection limit for perchlorate), which added to the peculiarity of the situation.
Ms. Jennings stated that once it was established that the perchlorate contamination couldn't be tracked back to the base boundary, EPA, working together with the state, continued with an investigation, enlisting the help of the U.S. Geological Survey (USGS). She then turned the presentation over to Mr. LeBlanc of USGS.
Mr. LeBlanc stated that the USGS conducted the Peters Pond investigation work as part of its standing agreement to provide technical assistance to EPA Region 1 on various issues. He then showed an aerial photograph that included the Forestdale area of Sandwich and pointed out Peters Pond, the gravel operation off of Route 130, the Sandwich public school at the intersection of Quaker Meeting House Road and Route 130, the base boundary, the Southeast Ranges, the top of the groundwater mound, and the groundwater table contour lines, which, he noted, indicate that the water table in that area slopes to the southeast. He also pointed out the location of the Peters Pond Drive residential well where perchlorate was initially detected in May 2004, and consistently thereafter at levels ranging from 0.3 to 2.2 ppb.
Mr. LeBlanc noted that because there was very little site-specific data in the area, the IAGWSP utilized its groundwater flow model and the well driller's information to simulate the contributing area to the residential well. The well driller had reported that the well screen was set just below the water table, and to be conservative, the IAGWSP assumed in its model that the well was pumped at a continuous rate of about 2 gpm, or almost 3,000 gallons per day. The simulations indicated that the source of perchlorate had to be close to the residential well. Water that recharged farther away, on the base, would have tended to go much deeper, missing the well and traveling beneath it. Mr. LeBlanc stated that the USGS and other groups, including EPA, reviewed the IAGWSP's work and concluded that it seemed technically sound, and that given the shallow nature of the residential well and the low pumping rates, the source of perchlorate was likely to be nearby rather than far away. Due to the lack of data in the area, however, the USGS came in to do some further investigation.
Mr. LeBlanc explained that rather than launch a large plume investigation in the area, which is all private property, the plan was to look at the groundwater flow system and determine whether the field data agree with the simulated flow system used by the IAGWSP, and to collect additional chemical data that might provide some information about a potential source. He then pointed out on the aerial photo two shallow wells that the USGS installed right on the edge of Peters Pond Drive, another installed on Quaker Meeting House Road, and a number of existing wells. He noted that water level measurements were taken at all of the wells on September 7, 2005 and the direction of the slope of the water table, or hydraulic gradient, was calculated. The water level data that were measured and the groundwater flow direction that was calculated (south/southeast) were consistent with the contributing area in the IAGWSP's simulation. This confirmed that the model appeared to be physically plausible and technically correct.
Mr. LeBlanc further noted, however, that that was just one snapshot in time, and the thought was that perhaps the gradient direction varies with time. The next step, therefore, was to look at the newly updated regional groundwater flow model for western Cape Cod, which was developed by his colleague (Don Walter), who had looked at groundwater flow and groundwater levels through a period of time, including the drought of the 1960s, with variations in recharge based on climatic data. He noted that Mr. Walter then used the same approach used for the actual field measurements and calculated the hydraulic gradient with time. Mr. LeBlanc referred to some line graphs that illustrated the change in direction and magnitude of the hydraulic gradient as the water levels went up and down and pointed out the shifting in directing that seems to be quite closely correlated with high and low water levels. He also noted, however, that at most the total range is 10 degrees, and in fact the average variation is only 4 or 5 degrees, which indicates that although something unknown could have happened in the past, that snapshot from September 2005 "is pretty representative of the typical direction."
Mr. LeBlanc noted that if the perchlorate contamination had originated from the base, by the time it reached the Peters Pond Drive area it would be too deep to be picked up by the shallow residential well. Therefore, the USGS checked for evidence of vertical flow near the residential well by installing a three-well cluster (at depths of 105, 140 and 180 feet) in very close proximity to the residential supply well, carefully surveying them relative to each other, and measuring the water levels in each. The indication was no evidence of a strong upward or a strong downward gradient at that location that would be driving the water up or down.
Mr. LeBlanc also said that as part of its investigation, the USGS looked at chemical data from the residential well and the well cluster to see if they would provide information about the source of perchlorate. He displayed a schematic drawing showing the depth of those wells and a shaded area representing the interval where the IAGWSP detected perchlorate in a drive-point it had installed very close to the residential well. He then displayed a data table and noted that the residential well and the shallow, middle, and deep well in the cluster all were sampled on September 7, 2005. The samples were analyzed for perchlorate, and the one from the residential well tested at around 0.2 ppb. A dissolved oxygen (DO) analysis was also conducted and showed around 11 milligrams per liter (mg/L) in all but the deep cluster well, which was around 4 mg/L. Mr. LeBlanc noted that the higher value represents near saturation levels, while a well that's heavily contaminated with organics contamination would have zero DO, like a landfill leachate. He also said that the lower DO in the deepest well is not uncommon and means that the water is quite old, having traveled a long flow path during which various natural processes had consumed some of the oxygen.
Mr. LeBlanc stated that specific conductance, which is very easy to measure in the field, is the water's ability to conduct an electrical current, a reflection of the amount of ionic salts that are dissolved in it. He noted that uncontaminated groundwater on Cape Cod typically has a specific conductance level of 40 to 80 micro-siemens per centimeter (ÁS/cm), while sea water has a specific conductance of 64,000 ÁS/cm. Mr. LeBlanc said that although levels measured in the Peters Pond investigation wells weren't nearly as high as that, it was surprising to find that specific conductance in the residential well was quite high, about 258 ÁS/cm, the shallow cluster well was about 176 ÁS/cm, and the other two cluster wells were more typical of uncontaminated water. He noted that this prompted him to inquire immediately whether the homeowners had a water softener on their well, but he learned that they did not. Mr. LeBlanc also reported that sodium and chloride levels in the residential and shallow cluster well were clearly elevated, around 30 mg/L, while the deeper cluster wells showed lower values. He noted that an obvious source of sodium and chloride would be road salt, but added that any kind of a waste disposal septic or tank effluent could also be sources.
Mr. LeBlanc then said that most surprising was that the residential well had a nitrate concentration of 14.3 mg/L, which is above the drinking water standard of 10 mg/L, and an indication of some type of contamination, whether from wastewater from an on-site septic tank disposal, fertilizers, or something else. He also reported that no ammonium was found in any of the four wells, which was not surprising, given the high DO levels. He further noted that although boron is generally found at very low concentrations (6 or 7 ppb) in Cape Cod sand, it was found at substantially elevated levels in the shallow cluster well (13.9 ppb) and particularly in the residential well (56.3 ppb). He explained that boron, a whitening agent commonly found in detergents and cleaners, is often used as a good indicator of wastewater.
Mr. LeBlanc stated that the chemical data in the table show that the residential well is affected by a contaminant source, as is the shallow cluster well to some degree, while the deeper cluster wells are not. He said that although he can't say exactly what the source is, it would appear to be a typical wastewater septic tank effluent. On the other hand, the sodium and chloride point to road salts, although sodium and chloride are fairly elevated in sewage effluent as well, given that people consume a lot of salt.
Mr. LeBlanc then noted that where the residential well is reported to be screened is so close to the water table today that it would have to go dry during dry periods. That plus the fact that the residential well is reportedly screened above the drive-point interval where perchlorate was detected leads one to suspect that the well might actually be screened deeper than the driller reported, perhaps by about 10 feet. Mr. LeBlanc recommended double checking the depth of the residential well after the home is hooked up to town water. He also said that the USGS did particle backtracking from a deeper point at the residential well to see where the water would be coming from if in fact the well screen was deeper than reported, and noted that while the contributing area clearly shifts upgradient, it's only by about 500 to 600 feet, which means that the contaminant source would still have to be quite close to the well.
Mr. LeBlanc also noted that the USGS asked the IAGWSP to provide specific conductance profiles from a number of drive-points and monitoring wells in order to determine whether the higher levels seen at the residential well on Peters Pond Drive didn't exist at locations across Route 130, thereby perhaps indicating road salt or a septic system as potential contaminant sources. He then showed specific conductance profiles for the Peters Pond Drive residential well and three other locations (one along the school access road, one between the base boundary and Route 130, and another at the base boundary) and pointed out the slightly elevated values in the upper part of the aquifer in all but the base boundary well, which has background values. Mr. LeBlanc stated that it's a complicated situation, with many sources of contamination (not perchlorate or explosives necessarily) being added to the natural water, and he would guess that some of it is related to the roads and suburban development. However, with the sparseness of data, it's impossible to sort out.
Mr. LeBlanc then reviewed the following summary statements: the observed flow direction is consistent with the predicted direction used in the models; the flow direction measured in September 2005 is typical of average conditions; there's no evidence of significant vertical flow; water in the residential well contains perchlorate, a high level of nitrate, and other contaminants; and the evidence is consistent with a source of water closer to the residential well than the base. He also said that it would probably take a bigger drilling and sampling program than anyone would be willing to undertake in order to determine exactly what the perchlorate source is, especially since levels are declining so rapidly.
Mr. Schlesinger remarked on the distance between the upgradient monitoring wells that tested nondetect and the residential well where perchlorate was detected and suggested that perhaps a well wasn't installed in the right spot. Mr. LeBlanc asked if Mr. Schlesinger was referring to the profile wells and Mr. Schlesinger confirmed that he was. Mr. LeBlanc then said that "it's very difficult to take a water level gradient direction and project it any distance without increasing uncertainty as you go upgradient." He explained that it all comes down to the size of the plume that's being investigated - the smaller the plume, "the less likely you are to ever hit it." And in this case the focus was not so much to be able to project upgradient and find a particular source, but more to confirm the modeled flow direction.
Mr. Schlesinger mentioned that the water at the top of the mound would traverse the range area. Mr. LeBlanc agreed and added that there's really no doubt that the residential well is downgradient from on-base perchlorate sources. However, the water could not have traveled that far and be shallow enough to be drawn into the well. Mr. LeBlanc added that although he wouldn't say that it's entirely impossible that the water came from the base, the preponderance of evidence would suggest a source much closer to the residential well.
Mr. Schlesinger inquired about the age of the nearby developments and whether any off-base activity was known to have occurred in that area prior to their construction. Mr. Gregson noted that the IAGWSP has looked at aerial photographs going back to the 1940s, and then pointed out a neighborhood that was built in the 1970s and another that was built much more recently. He also said that the area was mostly woods prior to the 1970s and it doesn't appear that any significant activities occurred there.
Mr. Schlesinger also asked about the length of time "within that 690 feet" that was shown as a potential source. Mr. LeBlanc replied that the travel time was calculated to be 0.6 to 1.5 feet per day, so using 1 foot per day as the average, the distance between Route 130 and the residential well was estimated to be roughly 1.5 years travel time.
Mr. Mullennix thanked Mr. LeBlanc for leading "a really superb piece of detective work." He then said that based on the data that was laid out tonight, he concludes that there's a localized source of contamination. He noted that Mr. LeBlanc spoke of septic tank disposal, and the contaminants that were detected are very much in alignment with what is found in septic tank wastewater. He also mentioned the high sodium and chloride levels and the well's location downgradient from Quaker Meeting House Road and said that the source could also be road salt. Mr. Mullennix further noted that the most recent perchlorate measurement was about 240 parts per trillion, a low quantity that he believes could be the result of a single road flare left on Quaker Meeting House Road.
Mr. Mullennix went on to comment that the USGS's analysis provided a great service to the Peters Pond Drive community because it led to the discovery of nitrate levels above the state and federal drinking water standard of 10 mg/L, which were set because of "blue baby" syndrome. He noted that this is a real concern for the young mother from Peters Pond Drive who attended a past IART meeting to voice her concern about the perchlorate issue, and in his opinion the residents there should "source their water elsewhere." Mr. Mullennix again remarked on the good that came from the USGS's investigation in that a problem, unrelated to the base, was identified and can now be rectified.
Mr. LeBlanc then began discussing possible perchlorate sources by saying that it can never be known for certain what happened in the past - if, for example, some munitions disposal occurred in that area. He also noted that because the Peters Pond Drive area is near a major intersection where plenty of accidents probably have occurred, the possibility of road flares as a source was considered, but he knows of no documented case to make that link. Another possibility is road salt, especially given that some salts come from Chile and some of the highest levels of naturally-occurring perchlorate are found in the Atacama Desert in Chile. Another thought is that the mining process adds trace levels of perchlorate to the salt. Mr. LeBlanc further noted that the MassDEP perchlorate occurrence report speculates that perchlorate levels as high as 1 or 2 ppb may be coming from septic systems because of the use of household bleaches that contain contaminants. He concluded that there's no way to sort out what the source is; it could be anything from some unknown activity to household bleach.
Mr. LeBlanc also said that he looked into the possibility of doing isotopic analysis to identify the different types of perchlorate, but found that although the analysis can separate out manufactured perchlorate from natural perchlorate, virtually all the perchlorate that's manufactured (whether it's in flares, fireworks, match heads, munitions, etc.) is made by the same process and has the same isotopic signature.
Mr. Dow asked if the USGS had the capability to separate out nitrates sources "by the nitrogen stable isotope nitrogen discrimination values." Mr. LeBlanc replied that while it's possible to differentiate the nitrates source - to see if it's clearly a septic tank effluent versus a fertilizer, for example - that is not something that the USGS had thought to do. Mr. Dow indicated that he thinks it should be considered.
Mr. Cambareri stated that some interesting information has come to light through the study and mentioned the nitrates above the drinking water standard. Mr. LeBlanc made a point of noting that that detection was based on one sample only, and suggested resampling before reacting too strongly. Mr. Cambareri then mentioned specific conductance and the nitrates problems in private wells on Outer Cape Cod, in towns such as Truro and Wellfleet. Mr. LeBlanc said that it would be interesting to test those wells, which are clearly affected by wastewater disposal, for perchlorate. Mr. Cambareri agreed and noted that it's also interesting that only one of the residential wells on Peters Pond Drive has seen consistently higher levels of perchlorate than its neighbors, which seems to indicate that a septic system had "short-circuited."
Mr. Cambareri asked if the cluster wells were installed on the private property where the residential well is located. Mr. LeBlanc replied that because the drill rig would have damaged the property, the cluster wells were installed just on the shoulder of the road, about 60 feet from the residential well. Mr. Cambareri asked if the cluster wells are conventional 2-inch wells and Mr. LeBlanc confirmed that they are. Mr. Cambareri asked if the residents might have access to those wells for water supply. Mr. LeBlanc said that he thinks that point is moot, since town water is now there.
Ms. Jennings stated that the investigation performed by the USGS for EPA was limited in scope in that it focused on just two things: filling some data gaps to confirm (by an independent expert) the IAGWSP's modeling of the direction of flow, and continuing to evaluate the level of contamination to determine if there was potential for a slug. Ms. Jennings noted that from the beginning, Mr. LeBlanc and EPA's own technical experts said that the likelihood of finding the actual source was quite slim.
Ms. Jennings also reported that since the investigation began, the Town of Sandwich installed a water main down Peters Pond Drive and although she's not certain whether the property owners with the residential well that's had perchlorate detections have had their home connected to it, some of the residences there have already been connected to the water main. In addition Ms. Jennings reported that the IAGWSP continues to sample the residential well on a monthly basis, with the perchlorate analysis being conducted by EPA's laboratory in Chelmsford, MA. She noted that concentrations continue to decrease, having peaked earlier this year at about 2.2 ppb, and then decreasing in June to 1.1 ppb, in July to 0.5 ppb, and in August to around 0.19 ppb. Therefore, the theory that a higher-concentration slug might be heading that way is not a concern at this time.
Ms. Jennings then noted that the 2.2 ppb concentration occurred right around the end of the high road salt season, and EPA was curious about whether a similar peak might be seen again. As a result, the decision was made to continue to sample the residential well for at least another few months in the hope that those data will indicate whether the contamination is tied to some road runoff or perhaps to a septic system. She said that rather than install additional wells and try to "find the needle in the haystack," the plan is to continue monitoring and look for any changes in trends, although she doesn't expect to see another spike.
Mr. Walsh-Rogalski asked if the perchlorate levels would be more consistent if the source were a septic system. Mr. LeBlanc replied that he doesn't really have an answer to that, and explained that the MassDEP report noted that specific brands of bleach contain perchlorate while others do not.
Mr. Schlesinger expressed concern that the extent of the continued sampling of the residential well would be inadequate in terms of the timing of the road salt season, and recommended continuing sampling for at least six months. Ms. Jennings replied that she thought that could be done. Mr. Pinaud mentioned that MassDEP could inquire of the Massachusetts Highway Department where the road salt used in that area was purchased.
Mr. Dow recommended looking at whether the nitrates detection at Peters Pond Drive occurred around the time of a rainstorm that followed a period of dry weather, which may have caused temporary high levels of nitrates.
Mr. LeBlanc said that the location in question is "very deep to water" and so there's a transport time in the unsaturated zone that's probably measured in months, if not a year or more. He also said that although it wasn't included in the presentation, the concentrations over time were plotted out, but the question is "will it keep going down or it will have another up-tick on a year time scale." Mr. LeBlanc also said that regardless of what happens this year, "we're looking at road salt from two or three years back, and it's important to keep in mind that road salt might not even be a source."
Mr. McDonagh said that if MassDEP is going to sample the road salt, it might want to consider taking a look at the source of road salt used over the past year or two. He mentioned the Chilean sources of road salt and suggested that if a sample is taken now, the source of it needs to be known in order to "correlate it to the detection." Mr. McDonagh also asked if MassDEP has done any sampling for perchlorate near road salt storage facilities. Mr. Pinaud replied that he doesn't know, but if such sampling did occur it would have been noted in the perchlorate occurrence report.
Ms. Conron inquired as to who was paying for the town water connections on Peters Pond Drive. Ms. Jennings replied that the installation of the water main was funded through a betterment tax and the homeowners are responsible for paying for the individual hookups themselves.
Agenda Item #5. Open Discussion
Mr. Schlesinger stated that he'd like to see included on an IART meeting agenda the topic of "Wellhead Treatment versus Aquifer Cleanup." He said that he realizes this is a contentious issue, but it's important to discuss "whether it's necessary to completely clean up the aquifer as opposed to treating wells before people drink water" since water supply was the driving issue behind the study and cleanup. Mr. Schlesinger also said that he would prefer to have his tax money used for progressive measures rather than for paying contractors to clean up water that no one is ever going to drink in the first place. Mr. Murphy said that this topic could be added to a future IART agenda.
Agenda Item #6. Central Impact Area Treatability Study and Post-Screening Investigation
Mr. Gregson explained that post-screening investigation occurs during the feasibility study process when the goal is to collect more data before evaluating alternatives and making a selection. In August the IAGWSP issued a workplan to fill some data gaps at the Central Impact Area and is proceeding with aspects of that investigation at this time. As part of the data gap characterization, the IAGWSP will evaluate the size and distribution of explosives particulates in the environment, perform additional work to delineate the source area, make an estimate of unexploded ordnance (UXO) density, and conduct a treatability study.
Mr. Gregson referred to the particulate distribution evaluation and noted that high-order explosives produce smoke containing the very fine particles that, because of their size, dissolve rapidly to the water table. However, also found in the environment are a variety of different sized and shaped particles that occur from incomplete detonation of explosives; these dissolve more slowly because they are larger and have a lesser surface to mass ratio. Mr. Gregson stated that the IAGWSP has proposed a microscopic analysis of soil samples to obtain some idea of the presence and type of particles containing explosives, the size, surface area, and nature of the particulates, the mass of explosive particles and distribution, and the number of particles associated with each size fraction in order to see what kind of future source they might pose to the groundwater.
Mr. Gregson said that the next part of the post-screening investigation has to do with the extent of soil contamination. He showed a figure and pointed out the Central Impact Area study area boundary, Turpentine Road, Tank Alley, and the High-Use Target Area (HUTA). He noted that the IAGWSP has been identifying continuing soil source areas based on water table detections and pointed out that the figure shows red wells (where RDX was detected at the water table) and green wells (where it was not). Mr. Gregson said that the plan is to refine that concept by putting in additional drive-points, collecting samples right from the water table, and getting a good amount of data at relatively little cost.
Mr. Gregson then referred to the UXO density component of the post-screening investigation and noted that although the AEC has done some work to estimate the corrosion and dissolution rates of UXO, what's missing is information on the number and types of UXO that are out there. He also noted, however, that the IAGWSP has done some mapping/estimating of UXO density based on information from the HUTA investigation, UXO clearance for the RRAs at targets 23 and 42, and soil removals done in 2000 at an armored personnel carrier and mortar target 9 in the Impact Area. Now the plan is to do field checking to determine whether predictions about areas that have high, medium, or low density of UXO are accurate. Proposed field activities involve vegetation clearance, surface UXO clearance, a geophysical survey, and an intrusive anomaly investigation. Information from the field will be used in combination with corrosion, dissolution, and leaching modeling to estimate loading in the future from UXO in the Central Impact Area, and all of that information will be part of the feasibility study.
Mr. Gregson stated that in conjunction with the post-screening investigation, the IAGWSP is looking at innovative in-situ (in place) soil treatment technologies, none of which have really been applied anywhere on a large scale. Some benefits of these technologies are that they are non-intrusive, they can treat large areas, and there would be reduced environmental impacts and reduced safety hazards. In addition to the Central Impact Area, some of the gun and mortar positions might also be good locations to use this kind of technology. Mr. Gregson noted that the purpose of the treatability study is to conduct laboratory and field studies to examine the feasibility of in-situ treatment technologies to break down explosives in soil. The results, if promising, may be used to support cleanup alternatives to be evaluated in the feasibility studies for the Central Impact Area and the gun and mortar positions.
Mr. Gregson explained that all of the technologies being studied involve topical amendments. One type is alkaline hydrolysis, which has been tested at Redstone Arsenal, and the other two are organic amendments, tested at the Aerojet facility in Nevada. Alkaline hydrolysis is basically application of lime that's been mixed with water to produce a slurry for ease of application and to help the lime penetrate the surface soil more readily. If the application works, the result would be a chemical reaction that's rapid and complete - an effective technology for breaking down RDX.
Mr. Gregson noted that one of the organic amendments is a combination of soy bean oil and peat moss. He explained that explosive compounds adhere to the peat moss, which supplies a surface area for biological activity and retains moisture nutrients. The soy bean oil adds to the benefits of the peat moss by providing a carbon source for biological breakdown, thereby enhancing the biological activity and, it is hoped, the biodegradation of explosives. Mr. Gregson also mentioned that soy bean oil and peat moss are relatively inexpensive and readily available.
Mr. Gregson stated that the other organic amendment being considered is local organic waste, which involves using locally-available organic material as a carbon source to stimulate biological activity. He noted that this is similar to composting to clean up explosives, which is a proven technology that's been used at a number of different plants and Army depots in Louisiana, Texas, Wisconsin, California, and Illinois. Unlike composting, however, the soil would not be dug up and mixed into a compost pile. Rather, the organic material would simply be piled on top of the contaminated soil, and the process would rely on the nutrients to percolate into the surface soil and break down the explosives, with the organics providing a carbon source for microbes, enhancing biological activity, and increasing the soil's ability to sorb the explosives and thereby prevent further migration. Mr. Gregson noted that the locally-available organic waste that's being tested includes potato peelings from Cape Cod Potato Chips, cranberry hull waste from Ocean Spray, wastewater bio-solids from Ocean Spray, horse manure solids, and yard compost.
Mr. Schlesinger inquired about seaweed as an organic amendment. Mr. Gregson replied that seaweed collection hasn't been considered, and would probably require filing an environmental impact report. He also explained that the idea is to have a source that can provide a lot of material at little or no cost and also benefit the party that's looking to get rid of the waste.
Mr. Gregson then noted that the first portion of the treatability study is a laboratory assessment to: determine appropriate amounts for lime application; provide proof-of-concept that the topical treatment layer (peat moss and soy bean oil, local organic waste) will enhance the biodegradation and breakdown of RDX and DNTs at the Central Impact Area and gun and mortar positions; and determine proper application rates for the field demonstration. The field study would involve characterization of the study area, selection of the study grids to do the testing, baseline monitoring to determine existing levels, amendment application, performance monitoring, and reporting of the information, which would be worked into the feasibility study, if appropriate. Mr. Gregson said that the field assessment would be done at target 34 in the Impact Area and at gun positions 10 and 11 to the south, as these areas have relatively high concentrations of explosives and propellants. He also said that the work would involve both soil sampling and the installation of lysimeters to assess the performance of the amendments.
Mr. Gregson then reviewed next steps for the Central Impact Area, as follows: complete the risk assessment, complete the post-screening investigation, finalize the treatability study plans, complete the feasibility study screening report, and prepare the feasibility study for soil and groundwater.
Mr. Walsh-Rogalski questioned the validity of the corrosion study and suggested that it essentially involves sticking a UXO item in a box with sand and water, which doesn't simulate the actual environment in which UXO exist. He recommended that it would be more useful, for example, to look at the 22 rounds that were blown up in the Impact Area on August 5, 2005. Mr. Gregson replied that since the project began the IAGWSP has been gathering information on the condition of rounds found out in the field, which will be considered along with the findings of the corrosion study.
Ms. Conron inquired about a timeline for the Central Impact Area work. Mr. Gregson replied that the post-screening investigation is expected to be completed early next spring. He also said that some of the initial laboratory work for the treatability study has been done. The IAGWSP is awaiting EPA's final comments on that so it can assess EPA's concerns and look toward beginning the field work for the treatability study next spring also. Ms. Conron asked if it would be problematic to apply amendments in the winter. Mr. Gregson confirmed that it would.
Mr. Lantery said that although Mr. Gregson alluded to the cost savings associated with in-situ soil treatment, he thinks it should be added to the list of benefits shown on one of the presentation slides. Mr. Gregson agreed that the cost of excavating and treating soil or shipping it to an off-site disposal facility is significant (about $1,000 a ton), so it's worthwhile to reduce that cost.
Mr. Schlesinger raised the issue of ecological risk posed by topical amendments and recommended consulting an ecological officer about whether harm would be done to state-protected local species, in which case it might not make sense to carry out the treatability study in the first place. Ms. Jennings assured Mr. Schlesinger that his previous request to have the ecological community involved with the screening of alternatives for the Central Impact Area has not been forgotten. She also referred to the timing of doing so, however, and said that she'd like to have someone from Natural Resources speak to the IART "when we get to actually making conclusions about the alternatives that are going forward." She further noted that it's her understanding that ecological concerns expressed by Natural Resources will be an integral part of the feasibility study in terms of evaluating effectiveness and implementability issues.
Ms. Jennings also said that it might have been better to postpone the Central Impact Area presentation until the regulators had completed their review of the workplans. At this point the regulators are still in the process of providing written comments, and although it probably will be possible to achieve resolution on the characterization effort soon, questions and issues pertaining to the treatability study itself still need to be addressed. She noted that the regulators have some fairly significant concerns about the effectiveness of the treatability study, and once the IAGWSP, which she believes has some reservations as well, receives those comments (in the next week or so), it could be that the decision is made not to go forward with the study. If the issues are resolved and the decision is made to move forward with the treatability study, however, she thinks that the better way to proceed is a small-scale effort that provides information as to what the impacts would be. Then, Natural Resources could be brought in and a decision could be made in terms of whether or not to carry the study through the detailed analysis.
Mr. Gallagher noted that part of any in-situ soil treatment plan would be an eco-monitoring component such that the ecology would be monitored as the amendments are being applied. He also referred to the corrosion study and said that the AEC model that tracks it is not based on "putting a piece of UXO in a box," but "on actual measurements taken from UXO from different ranges." He also said that there are a number of other corrosion models that have been used to determine actual or approximate corrosion rates.
Mr. Walsh-Rogalski said that corrosion is one part of the munitions destruction process, but one of the more important ones is munitions landing on munitions, as well as "just a munition flying 15 miles or 10 miles before it hits a target." Mr. Gallagher stated that munitions that have been breached are considered low-order rounds. However, the corrosion study is looking at intact munitions and the amount of time it takes them "to actually corrode through."
Mr. Schlesinger asked how long impacts to natural resources would be monitored. Mr. Gallagher replied that the Natural Resources manager in the IAGWSP office wrote part of the plan for monitoring resources throughout the duration of the treatability study. If one of the topical amendments were selected as a remedy, however, it's likely that there'd be a requirement to monitor ecological impacts throughout the course of treatment.
Mr. Cambareri remarked that he doesn't necessarily think that the regulators have to "wait until they've got their act together" before receiving input from the IART. He also said that while he thinks the concepts for in-situ treatment are interesting, he's having difficulty imagining how it would be implemented in the field. Mr. Gregson said that how the amendments would be applied in the real world is one of the IAGWSP's major concerns. He also said that something like a lime slurry would be easier to apply than organic amendments. Mr. Cambareri said that he'll be interested in hearing more details on this subject.
Mr. Cambareri also said that he wonders about the reality of monitoring the effectiveness of a topical amendment over time, given that explosives in soil are dispersed throughout the Central Impact Area, and often they can't be found in soil but can be detected in groundwater. He also mentioned the lag time of vertical transport and said "whatever you do on the surface, if performance is at the water table, it may be years before we see the benefit." Mr. Gregson agreed.
Mr. Dow referred to alkaline hydrolysis and recommended that consideration be given to the low pH rain that falls on Cape Cod in terms of determining the alkalinity needed to carry out the hydrolysis. Regarding the organic amendments, Mr. Dow suggested adding dissolved organic carbon (DOC) as a food source for the bacteria, as Cape Cod groundwater has very low levels of DOC, which the bacteria require. He also noted that in addition to DOC, nutrient amendments are often needed; phosphorus is commonly added because microbial organisms in nature are often limited by phosphorus. Mr. Dow further noted that something else to consider is that anaerobic conditions will kill off the protozoa needed to interact with the bacteria and keep them in a high rate of growth. Mr. Gregson replied that Mr. Dow's remarks will be considered during the treatability study work.
Agenda Item #7. Adjourn
Mr. Murphy announced that the IART will meet next on January 24, 2005 at the Forestdale School in Sandwich.
Mr. Mullennix recommended waiving the protocol for accepting new IART members and welcoming Mr. Lantery to the team this evening. Mr. Murphy replied that although he can't waive the protocol tonight, he does intend to expedite Mr. Lantery's membership application through the channels and "much quicker than ever before."
Mr. Mullennix also referred to the Massachusetts Department of Public Health (MDPH) Update (regarding the Bourne study) on the IART future agenda items list and said that he contacted MDPH several times and was told that if there was something to report, it would have been presented to the IART. He then asked the IAGWSP to investigate whether MDPH ever intends to provide an update to the IART, and if not, he would suggest deleting the item from the list.
Mr. Murphy adjourned the meeting at 9:07 p.m.