SD-5 South Posterboard Session and
Public Meeting
1. Welcome and Introductions: Mr. Whitaker from the community involvement team at the Massachusetts Military Reservation (MMR) introduced himself and thanked everyone for attending. He stated that this was the first of several public meetings to be held concerning the Storm Drain 5 South (SD-5 S) groundwater plume. Mr. Whitaker introduced the technical staff in attendance; Mr. Jim Snyder, the Remedial Project Manager (RPM) with the Air Force Center for Environmental Excellence (AFCEE); Mr. Andy Miller, the Project Officer with Jacobs Engineering Group (JEG); Mr. Lee Perry, the Project Officer for the Air Force for the SD-5 South plume; Mr. Paul Marchessault, with the United States Environmental Protection Agency (US EPA); Mr. Len Pinaud with Massachusetts Department of Environmental Protection (MA DEP), and Ms. Nancy Caffyn the Mashpee Selectman. Mr. Whitaker expressed the importance of receiving public comment. Mr. Whitaker introduced Mr. Snyder to present information on groundwater plumes, and the available remedial technologies. 2. Groundwater Recharge Process: Mr. Snyder stated that the Sagamore Lens was Cape Cod’s drinking water aquifer. Mr. Snyder displayed a graphic of Cape Cod showing the contour lines, or different land elevations, around the plume. He stated that the MMR is on the highest level of the Sagamore Lens. Mr. Snyder stated that the groundwater recharge process was how the aquifer receives and produces water for the public’s everyday use. He displayed a cartoon diagram of the groundwater cycle and explained that precipitation (snow or rain) percolate into the soil and saturate the water table. Mr. Snyder stated that the ultimate surface discharge for all the water is at the salt water interface. He said that contamination occurs when it gets into the pathway of percolation, flowing with the water, entering at the water table and recharging into the surface water bodies. Consequently, if fuel or solvents had been spilled, the water leaking through would help the contaminants migrate into the water table, and eventually interact with some surface water bodies. Mr. Snyder stated that the silts, or finer grained, less water yielding soils, were located below the sand and above the bedrock. He said that the contaminants that migrate into the silts move very slowly and are difficult to remove. Mr. Snyder added that the models of the SD-5 plume predict that a small percent of contaminants will be "lost" to the silts, and stated that some of the data from the SD-5 plume account for that factor. 3. Groundwater Treatment Technologies: Mr. Snyder stated that there were two technologies for dealing with groundwater contamination. Extraction, Treatment, Reinjection: Mr. Snyder stated that the most common method of treating groundwater is to extract the water, treat it at the surface, and return the treated water to the aquifer. This process is referred to as "pump and treat" technology or extraction, treatment, reinjection (ETR). Mr. Snyder stated that a typical ETR system has three basic components:
Recirculating Wells: Mr. Snyder stated that recirculating wells are a recently developed technology. He explained that this technology is conducive to hydraulically sensitive environments in that it avoids any water table change and there is no localized hydrological effect. Mr. Snyder stated that with this system groundwater is drawn into the well from the bottom. He stated that the water mixes with air inside the well causing the volatile organic compounds (VOCs) to transfer from the water to the air. The treated water is then pumped back out of the well into another zone of groundwater at a different depth but at the same location. He then stated that the air containing the VOCs is carried up the well to the surface, where it may be piped to an activated carbon treatment system. Mr. Snyder pointed out that with this system the treated air is directed back into the well for additional removal of contaminants. He added that the air stream is monitored before and after treatment to ensure effective removal of VOCs. 4. SD-5 S Decision Criteria Process: Mr. Snyder displayed a map of the MMR and used Route 151 as a point of reference to identify the location of the SD-5 South plume. He stated that this plume actually refers to the southern section of a large plume. Mr. Snyder stated that at the MMR boundary they had just turned on the SD-5 North treatment facility. Mr. Snyder stated that the decision criteria process was developed to create balanced alternatives without unsatisfactory ecological or hydrologic impacts. He stressed the importance of community constructability. Mr. Snyder briefly explained the process. (*See attached) 5. How to Submit Written Comment: Mr. Snyder expressed the importance of public comment and input. He stated that there were various means to submit comments and encouraged the attendees to do so. Web Site: http://www.mmr.org Mail: AFCEE/MMR Ms. Caffyn asked when the public comment period ends. Mr. Snyder responded that the public comment period closes on November 21, 1997. A member of the audience asked how long this project will take once it is started. Mr. Snyder stated that the various alternatives have projected ranges. He stated that the systems will be monitored, and will operate until they reach the desired results. A member of the audience asked where the system would be installed. Mr. Snyder responded that the most of the construction will conceivably be in the Briarwood neighborhood. He added that they would limit the construction to the easement right of ways as much as possible. The audience member asked about Willey Park. Mr. Miller stated that a couple alternatives had wells in Willey Park. 6. SD-5 South Plume: Mr. Miller from Jacobs Engineering introduced himself and stated that he would be explaining the plume response alternatives. He displayed an aerial photograph with the SD-5 plume superimposed on it, to orient everyone with its location and size. Mr. Miller stated that the SD-5 N treatment system had been running for about a month. A member of the audience asked if the eastern Briarwood plume was the Fuel Spill 1 (FS-1) plume. Mr. Snyder stated that it was not. Mr. Miller pointed out that the FS-1 plume was to the east, and actually off the map. Mr. Miller pointed out the location of the SD-5 South plume. Mr. Miller displayed a cross section of the SD-5 S plume. He stated that the portion of the SD-5 South plume that they are concerned with is approximately 40 - 100 feet below land surface, approximately 20 - 50 feet below the water table and about 40 feet thick. Mr. Miller stated that they are predicting a portion of the plume will discharge into Johns Pond and a portion of the plume will go underneath it. A member of the audience asked where the Chemical Spill 10 (CS-10) was located. Mr. Miller stated that CS-10 was further south and it did go underneath Ashumet Pond. The audience member asked if CS-10 and SD-5 South cross together. Mr. Miller stated that preliminary work suggests that they do not, however they are continuing studies between Ashumet Pond and Johns Pond. Mr. Miller stated that they had sampled eighteen wells in mid-July and preliminary results have just been submitted. He stated that the data should be validated within the next few weeks, and at that point the results could be released. A member of the audience asked if they had done testing near Willey Park and Hooppole Road. Mr. Miller pointed out the wells that were sampled in mid July. A member of the audience asked if they had gone down to the bedrock. Mr. Miller stated that they had tested at different levels within the aquifer. The audience member asked if any of the three new wells installed in May reached bedrock. Mr. Miller responded that yes they had been sampled. He stated that a number of wells between Johns Pond and Ashumet Pond had been studied. Mr. Miller stated that they will combine the results from all the different studies, including the ecological studies. A member of the audience asked if the new wells on the north side of Briarwood Beach had been tested. Mr. Miller replied that yes they had been sampled. The audience member then asked if the wells on the south side of Briarwood Beach had been sampled. Mr. Miller again replied that yes they had been tested. Maximum Concentration of Contaminants: Mr. Miller displayed a slide of the maximum concentrations of contaminants found in the SD-5 South plume in 1993 versus 1996:
Mr. Miller stated that concentrations have gone down, and stated that monitoring well (MW) 524 B had the highest hit. He stated that the highest concentrations of this plume have not changed dramatically. A member of the audience asked if someone could address the issue of natural compounds, the Royal Demolition Explosive (RDX) for example. Mr. Snyder stated that those compounds were in the impact area and not in the area of the SD-5 South plume. Ecological Design Targets: Mr. Miller stated that ecological design targets are considered when looking at the modeling for all of the alternatives. He stated that the targets include: acceptable water level influences, acceptable amounts of flux, and an acceptable percent of treated water contributing to a pond. Mr. Miller added that the five alternatives he would be discussing all meet the ecological design targets. Fate of Contaminant Mass with No Action: Mr. Miller stated that they predicted what would happen to the plume if none of the alternatives were implemented and displayed a slide depicting where the mass would be: Johns Pond…………………………..76 percent Model Boundary……………………..16 percent * this portion would remain in the aquifer SD5-N System………………………..3 percent Quashnet River……………………….3 percent Ashumet Pond………………………..2 percent Mr. Miller added that there would be approximately three percent of mass between Hooppole Road and Johns Pond shoreline. A member of the audience asked how many feet per day the plume is moving. Mr. Miller responded that the plume is moving one to three feet per day. He added that the closer the plume gets to the ponds the faster it moves due to steeper gradients. A member of the audience asked, with the plume moving one to three feet per day, wouldn’t the water be clean by 1999. Mr. Miller stated that it would not be clean water by 1999. Mr. Miller stated that it would take about ten years for a particle of groundwater to move from the SD-5 North system to the Johns Pond shoreline. Mr. Snyder added that contaminants retard in the soil, and it may take several flushes to remove contaminants out of the sand. A member of the audience asked if the SD5-North treatment facility removes all the contaminants out of the SD-5 plume. Mr. Miller replied that it is designed to intercept all the contaminants. Mr. Snyder added that they were doing performance monitoring downgradient of the treatment facility to monitor whether it is capturing all of it or not. Preliminary Layouts: Mr. Miller stated that there were five alternatives being considered and in general each alternative includes the following:
7. SD-5 South Plume Response Alternatives: Mr. Miller stated that there were fact sheets available that describe each of the alternatives in more detail. Alternative A:
Mr. Lewis asked if Mr. Miller could point out on the map where the top recirculating well was located. Mr. Lewis stated that the middle well is on an "alleged" piece of property. He added that he used the term "alleged" because he did not believe there was property available in that area. Mr. Lewis then stated that the most southerly well was at the boat landing. Mr. Miller concurred. He stated that the three recirculating wells were added to alternative A as a result of feedback received at the last Joint Process Action Team (JPAT) meeting. In addition, Mr. Miller stated that these were proposed well layouts, they were not definitive. He stated that they were depending on feedback from the public on the constructability and access issues. Mr. Snyder added that the recirculating wells were included in this alternative as a result of the last JPAT meeting. He stated that the recirculating wells stand alone, and they can be installed before the extraction fence therefore having an early benefit of capture. Alternative B
Mr. Miller stated that they were predicting that any wells along Hooppole Road or Highland Avenue would be placed in the right of way or in the street itself. He added that the reinjection wells would be installed very close to the extraction wells, however they would be reinjecting water at a deeper zone. Mr. Bowman suggested that Mr. Miller mention the treatment facility that would be associated with each of the alternatives. Mr. Snyder stated that the SD-5 South treatment facility would be similar to the SD-5 North treatment facility. He stated that it was likely that the central treatment plant would be on the MMR and they would pipe to the well locations. Mr. Lewis stated that he had been on a tour of the SD-5 North treatment facility . He stated that the public should know that the solution will involve a "temporary inconvenience" in that there will be digging and construction involved. Mr. Snyder stated that the piping project would be similar to what is involved in a water main project. Mr. Miller added that the contaminated water would be piped from the extraction well to the treatment plant, and clean water would be piped back. A member of the audience asked where the SD-5 N treatment facility was located. Mr. Miller pointed out its’ location on the map. He stated that if you go past the Falmouth entrance to the MMR, and continue straight on the "dirt" road until it makes a sharp right, and the treatment center is on the left at the end of the road. Alternative C:
Mr. Miller stated that the recirculating wells do not require a central treatment plant or extensive piping. A member of the audience asked if they require construction at the site of the wells. Mr. Snyder stated that the construction was more difficult due to the size of the sub surface vault. He stated that a 30 feet by 30 feet below ground concrete vault would be used. A member of the audience expressed concern about the size of the vaults considering the road is only 22 feet wide. Mr. Miller stated that preliminary modeling predicted that five wells along Hooppole Road would intercept all of the contaminated groundwater flow coming through it. He reiterated that the modeling was preliminary and stated that additional testing will be required. Mr. Miller stated that regardless of what type of well is installed, they will be installed in the road. Mr. Lewis stated that although the five wells do have 30 feet by 30 feet area of open construction, when the construction is completed, a manhole cover is all that would remain. He also stated that despite the fact that there would not be any piping, there would be people frequently going in and out of the manholes. Mr. Lewis also stated that the current technology includes a shed above ground. Mr. Lewis asked what the proposed capture rate of alternative C would be versus alternatives A or B. Mr. Miller responded that each well fence along Hooppole Road intercepts 99 percent of the plume flowing toward it. He stated that the ETR system is 100 percent effective. Mr. Miller stated that according to their current knowledge of the recirculating wells, they intercept close to 100 percent of the water flowing towards them. He added that their treatment efficiency is such that they will remove 90 percent of the contaminants in the water. Mr. Lewis stated that the ETRs have a higher drawdown. Mr. Miller stated that the maximum drawdown of any alternative is one to two inches. A member of the audience asked if in fact the recirculating wells were a new technology. Mr. Miller concurred. Mr. Snyder added that the recirculating wells have not had as much use as the pump and treat system. He stated that they are currently pilot testing the recirculating wells. Mr. Lobo stated that at the last Briarwood meeting he had asked if any radioactive material was ever stored or dumped at the MMR. He then stated that he had never received an answer. He also asked if these types of materials could be in the plumes and if so could the extraction system remove them. Mr. Lobo also stated that at the last Briarwood meeting he brought up the issue of miscarriages around Willey Park, and stated that as far as he knew there had been six. Mr. Snyder responded to the radioactive issue and stated that they did not have a site history dating back to the 1930’s. Mr. Snyder stated that he would follow up on Mr. Lobo’s concerns. Mr. Miller pointed out that a line of wells intercepting the plume along Hooppole Road would not capture 100 percent of the plume mass. He stated that time was also a factor. Mr. Miller stated that there would be a three year time lag from the present to the start up of whichever alternative is chosen. He added that due to the time lag, a portion of the plume will escape, and a portion of the plume will go to Johns Pond. A member of the audience asked what effect that would have on Johns Pond. Mr. Miller stated that preliminary calculations indicate that the level of contaminants would be extremely low, less than 1 part per billion (ppb). Mr. Perry of AFCEE stated that natural attenuation is an alternative that is compared with the other alternatives. Mr. Snyder added that there would be a matrix coming out in 30 days which would include a risk assessment. Mr. Bowman stated that there was a concern regarding Briarwood Beach. Mr. Snyder stated that the risk assessment would look at different scenarios of exposure. Alternative D:
Mr. Miller stated that this alternative, with five wells, does not intercept as much of the plume as a line of wells along Hooppole Road. Mr. Lewis asked if this alternative involved the digging up of more roads than the other alternatives. Mr. Miller responded that there was more piping involved with alternative D than alternative E. Mr. Perry stated that alternative D would capture mass sooner. Mr. Lewis asked if in fact there would be "less capture sooner". Mr. Miller concurred. A member of the audience stated that alternative A had fences along Highland Avenue as well as Hooppole Road and asked if that would capture the plume in both the early stage and late stage. Mr. Miller stated that their intention is to present a number of different alternatives. He stated that one alternative is not likely to please everyone, and noted that suggestions to modify existing alternatives have been made. Alternative E:
Mr. Miller pointed out that with this alternative there would be no piping. Questions and Answers: A member of the audience asked if this would be a seven to fourteen year period. Mr. Miller stated that due to the short distance the plume has to travel, they project the operation time to be about twenty to thirty years. He added that they estimate two and three flushes through the aquifer before it would be clean. Mr. Marchessault stated that once the system was operating the Air Force would be required to monitor the system every five years to determine how well the system is operating, what percent of contaminants are being removed, and what if any modifications need to be done. Mr. Marchessault stated that the EPA would do an evaluation every five years to determine if the system removed as much mass as possible. Mr. Lobo asked who would monitor the charcoal filters. Mr. Miller stated that samples would be taken before it enters the carbon filter and as it goes through the carbon filter. He stated that there would be two different sets of carbon canisters. Mr. Snyder stated that when the carbon filters become saturated they would be replaced by contractors and base employees. Mr. Lobo asked if the public could monitor the carbon filters and inform the Air Force when they need to be replaced. Mr. Snyder clarified that they monitor the water flow through the carbon. Mr. Lobo asked if there would be a gauge to determine if the carbon needed to be replaced. Mr. Snyder stated that monitoring would determine if the carbon filters were saturated. Mr. Lewis asked what the present readings were. Mr. Miller stated that maximum concentrations of TCE are located in the hot spot at a maximum of 40 - 50 ppb. Mr. Lewis then asked Mr. Miller to relate those numbers to "doing nothing". Mr. Miller stated that preliminary results from monitoring indicate that if nothing is done, the aquifer will be clean in 20 to 30 years. Mr. Snyder stated that the level of contaminants does not rise Mr. Lewis then asked if there is any merit in doing nothing. Mr. Marchessault stated that natural attenuation is an alternative and it includes monitoring. Mr. Snyder added that the no action alternative does not include monitoring. A member of the audience asked if nothing was done, would the plume go into the Mashpee drinking water. Mr. Perry stated in the future they would see what they see happening now, some of the plume going under the pond and a portion of the plume entering Johns Pond. Mr. Marchessault stated that if everyone affected by the plume is on town water there would not be any potential to install a well. Mr. Marchessault stated that institutional controls may have to be enforced to prohibit the installation of new wells. Mr. Lewis stated that even if residents living near Ashumet or Johns Pond are put on town water, their property value still goes down because of the contaminated water bodies. A member of the audience stated that Mashpee holds approximately 30 percent of the water on Cape Cod. A member of the audience stated that the plume will not just "go away". He then stated that there was no sense in abandoning the project and added that if they can stop it now, they should before it spreads the contaminants further. Mr. Snyder stated the Matrix will explain where the uncaptured portion of the plume goes. A member of the audience stated that even if a portion of the plume goes by, it will still be a threat. A member of the audience asked what percentage of the plume goes under the pond. Mr. Miller responded that if no active system were installed, 76 percent would go to the pond and 16 percent would continue on into the aquifer. The audience member stated that 16 percent of 40 ppb would be on the other side of the pond. Mr. Marchessault clarified that not all the concentrations are at 40 ppb. Mr. Miller stated that 40 ppb was the highest level found. He added that the worst case scenario would assume that the entire plume was at the maximum level of concentration. The audience member asked if 8 ppb was the maximum. Mr. Miller concurred. Mr. Perry clarified that the audience member was confusing the contaminant level in the water and the amount of water that goes into the pond. Mr. Perry stated that the core of the plume is at 27, yet 76 percent of that plume will enter the pond, and 16 percent will go under the pond and proceed to other locations. Mr. Marchessault stated that AFCEE is investigating the area between the ponds, and on the east side of Johns Pond. He added that the portion of the CS-10 plume and SD-5 plume that may be underflowing each pond has not been forgotten. Mr. Miller displayed a slide depicting the outline of the plume. He pointed out the area of the plume where the groundwater exceeds five ppb of TCE which consequently exceeds the Maximum Contaminant Level (mcl) of TCE. Mr. Miller pointed out the inner line and stated that this area exceeds ten ppb. Mr. Miller stated that it is probably less than the maximum of 40 -50 ppb that they were finding in that area. Mr. Lewis asked if that was the reasoning behind putting the test well at Willey Park. Mr. Miller stated that yes that was the reason. Mr. Miller pointed out the "hot spot", or area of highest concentration. Mr. Bowman complemented everyone on the correct pronunciation of Willey Park. Mr. Lewis asked AFCEE to discuss the logistics of the solutions as they approach the decision date, specifically at the subsequent public meetings to be held October 8, 1997 and November 12, 1997. Mr. Snyder stated that the project will be run as any town public works projects are run, in that they will always keep one lane for traffic open, and hire security service for around the site. Mr. Lewis stated that there is only one way in and one way out of the location being discussed. He asked that AFCEE explain the time of year they plan on beginning the construction and the length of time involved, at subsequent meetings. Mr. Snyder stated that the total mass and volume of contaminants in the largest plume, CS-10, are all dissolved. He added that the average concentrations in the CS-10 are 2500 kilograms (kg) or the equivalent of eight 55 gallon drums. Mr. Snyder stated for comparison that SD-5 has about 25 kg of mass, or the equivalent of four gallons of contaminants. A member of the audience asked if VOC’s were being found in the public water supply. Mr. Snyder responded that in one location in Bourne near the LF-1 plume, some constituents have been detected in that public well. The audience member asked, if there were VOC’s in the public water supply, would there be any benefit to trying capture them with charcoal filters within individuals’ households. Mr. Snyder stated that they cannot have residential carbon filtration units. He stated that they work with the water districts for the various towns as well as the Air Force to put residents on public water. The audience member asked if there was any evidence of a rise in cancer levels. Mr. Snyder stated that there was a rise in cancer levels at various locations. He stated that the Public Health Office could better answer those questions. The audience member then asked if there was presently an active ecological survey. Mr. Lobo stated that a woman from Atlanta, Louise House, had told him that surveys and blood tests were given in the Deer Crossing neighborhood to show results of the cancer studies. He added that the data was not valid due to the fact that some of the residents had not lived in the area for extended periods of time. Mr. Lobo stated that he knew of six miscarriages in Willey Park. Mr. Snyder stated that the MA DPH has an office on the MMR, and will be able to answer those types of questions. Mr. Snyder stated that Louise House is available as well. Ms. Caffyn stated that there would be more of a focus on following up on concerns and encouraged Mr. Lobo to submit his comment. Mr. Lobe responded that he already had. Ms. Caffyn stated that more could be done now due to the fact that a full office is located on the MMR and they are expected to follow up on questions and concerns from the public. She added that she knew of three to four miscarriages on that street as well and there may be a correlation. Ms. Caffyn stated that there is an attempt now being made by the Air Force and the State of Massachusetts to set up a Health Department and follow up on these health issues and possible connections. Mr. Marchessault stated that due to the latency period, they would have to acquire names of residents that have been living in the area for at least ten to twenty years. A member of the audience added that the children who grew up in that neighborhood, and have since moved out of the area, would also have to be contacted. Mr. Snyder stated that AFCEE was looking into ways to contact people. He expressed the difficulty due to the logistics. A member of the audience asked if Mr. Miller had a performance slide. Mr. Miller responded that they were still in the preliminary stages of the modeling, and he would have one available at the next meeting. Mr. Miller stated that each alternative being considered capture about the same amount of the plume. He added that the alternatives with a line of wells along Hooppole Road do a better job than those without. Mr. Miller stated that they would have results from the modeling available at the next meeting. Ms. Brand of CH2M HILL stated that the Matrix Document would be available in early October. Mr. Marchessault expressed the importance of input from the community in helping the technical staff to better inform the public on specific areas of concern. Mr. Whitaker thanked everyone for coming and adjourned the meeting at 8: 15 P.M.
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