Due to the low public turnout, an informal meeting was convened at 7:05 PM. Ms. Rustad began her presentation by explaining the difference between remedial actions and removal actions. She noted that removal actions are addressed by the Engineering Evaluation/Cost Analysis (EE/CA) process. She mentioned that an example of a removal action is the thermal treatment units installed in 1996 and 1997.

Mr. Dow asked if the thermal treatment systems were emergency actions. Ms. Rustad said that she was not sure, but added that the units were probably not time-critical removal actions. Mr. Dow remarked that they were time-critical; he said that he remembered that the approval process was expedited. Ms. Rustad stated that the actions to be discussed at this meeting are not time-critical.

Ms. Rustad explained that removal actions deal with the removal or treatment of contaminants, and not necessarily the removal of soil or groundwater. She said that in-situ remedies treat contaminants in place, an example of which is Fuel Spill 4 (FS-4). She explained that it qualifies as a removal action because it is treating contaminants. Ms. Rustad also stated that EE/CAs are developed to document decisions made regarding short-term removal actions, and in that manner they take the place of feasibility studies and proposed plans.

Ms. Rustad reported that the purpose of the EE/CA, as required by the National Contingency Plan under Superfund, is to identify the objectives of the removal action and to develop various alternatives that might satisfy those removal actions. The EE/CA also recommends the appropriate removal action and appropriate response, and provides a vehicle for public involvement.

Ms. Rustad said the first step of the EE/CA is to summarize the site history and previous site investigations. The next step is to identify the scope and objectives of the removal action. Then potential removal action alternatives are developed and evaluated using the general criteria of effectiveness, implementability, and cost. A preferred alternative is then recommended.

Mr. Dow asked if there is any difference between the kind of approval that comes from the United States Environmental Protection Agency (US EPA), the Massachusetts Department of Environmental Protection (MA DEP), and the Air Force Center for Environmental Excellence (AFCEE) on an EE/CA vs. remedial action. Mr. Hoda explained that the main difference is that a remedial action is the final remedy and ends with a record of decision (ROD). An EE/CA is an interim action, and it can be followed by another action. Mr. Dow asked if there are fewer layers of review and interaction. Mr. Hoda replied that there are not fewer layers of review, but more expedited action and less paperwork. He said that an EE/CA provides a more focused evaluation of the technology needed for an expedited action, not less oversight. Mr. Minior added that the cleanup standards are basically the same.

Mr. Dow asked if the interim remedy provided by the EE/CA process is different from the long-term remedy provided through the ROD process, and if there eventually has to be a ROD. Mr. Hoda replied that the interim decision is folded into the overall ROD if the remedy removes all contaminants.

Mr. Dow asked if there is some kind of monitoring for an EE/CA. Mr. Hoda replied that most of the sites are soils and there is no need for ongoing monitoring because the soil can be scooped up. He added that for FS-4, a bioventing system is being installed, which will continually monitor the effectiveness of the remedy.

Ms. Rustad continued with a discussion of the seven sites addressed by this EE/CA: Chemical Spill 5 (CS-5); CS-11; FS-18; United States Coast Guard Chemical Spill 4/Fuel Spill 1 (CS-4 [USCG]/FS-1 [USCG]); FS-4; FS-7; and the Drum Disposal Operable Unit (DDOU). She noted that the USCG sites are not related to the CS-4/FS-1 groundwater plumes that originate at separate source areas.

Mr. Dow asked why the DDOU sites near the sewage treatment plant were cleaned up separately from the infiltration beds. Mr. Minior replied that the DDOU site was added to the program at a later date, and that there was a different document path tracking it, separate from CS-16 and CS-17.

Ms. Rustad then proceeded to give a history of each of the seven sites. She reported that CS-11 is a former pesticide storage and mixing shop used by the Air National Guard (ANG) and Army National Guard (ARNG) from 1970 to 1983. She stated that the contaminants that were found in soils off the washpad area were apparently chemicals spilled during washing and mixing. She also reported that the dieldrin and metals that were found in the soil off the mixing area pose a potential risk to human health and ecological receptors.

Mr. Uchmanowicz asked what pesticides were used. Ms. Rustad directed his attention to a summary table of the contaminants in the handouts. Mr. Dow asked why heavy metals were found, since this is an area where pesticides were utilized. It was noted that the source was unknown. Mr. Peterson mentioned that some of the previously used pesticides contained inorganic compounds, which may be the source of the metals. Mr. Dow stated that some of these contaminants were biocides.

Ms. Rustad described the CS-5 site as a weapons repair shop for the U.S. Army from 1941 until 1946, and a refueler maintenance shop and spray paint shop for U.S. Air Force from 1955 until 1967. She said it is believed that contaminants found in the soils at all three areas (Areas 1, 2 and 3) are due to spills associated with refueler truck emptying and maintenance weapons cleaning, and spray painting. She noted that tests indicate that fuel-related contaminants, polychlorinated biphenyls (PCBs), and lead, are present in the surface soils, and may pose potential risks to human receptors.

Mr. Dow questioned how, if the area was contaminated by fuel spills, the PCBs got there in concentrations of 17 parts per million (ppm). He said his recollection is that the US EPA standard is 1 ppm. Mr. Peterson said there is no evidence of specific PCB sources in these areas. Mr. Hoda suggested that transformer repairs might be a possible source. Mr. Minior remarked that there is no need to speculate about the source, but there is a need to address the contamination that has been found.

Mr. Dow asked if the PCBs are concentrated in one of the three areas or spread throughout all three. Ms. Rustad replied that she thinks it is concentrated in Area 2. She added that the plan is to keep that area separate during the characterization, to prevent cross-contamination of any of the other soil.

Mr. Dow expressed concern about moving soil off-site. Ms. Rustad explained that the cost analysis assumes that most of the soil from this area would be sent off site, because the levels of PCBs are probably unacceptable for asphalt batching.

Mr. Cui noted that he was unsure which area is highest in lead. Ms. Rustad stated that Area 1 is highest in lead. She also stated that the soil would be fully characterized.

Mr. Dow asked if the characterization would involve just contaminant level measurements or if leaching tests or other tests would also be conducted. Ms. Rustad replied that the soil is sampled to measure the contaminant levels, but leaching potential tests are also done. Mr. Minior explained that most places that take contaminated soils require that such tests be conducted.

Ms. Rustad reported that the FS-4 site is located at the site of a former fuel pumphouse located on the base airfield. She stated that there were six underground aviation gasoline storage tanks at this site, one of which failed a leak test in the late 1980s. She added that the site was recommended for an EE/CA when the underground storage tanks were removed during the Fuel Systems Upgrade Program in 1994, and field screening results at that time indicated volatile contamination in deeper subsurface soil, at depths of 10 to 22 feet. She said that it is possible that residual fuel-related contaminants are present, but quantities and types of contamination are unknown. She also stated that more sampling data is needed before deciding whether soil removal is warranted at this site.

Ms. Rustad then reported that USCG Sites CS-4 and FS-1 include the area around Hangar 128, which was primarily used for aircraft maintenance. During a records search the site was identified due to the potential for disposal of solvents and petroleum-based oils and lubricants onto the hangar floor. She noted that there were two aviation fuel spills at this hangar. Ms. Rustad pointed out on the map the area proposed for soil excavation and explained that this is the area where fuel-related contaminants and metals were identified in shallow soil up to three feet deep, posing a potential risk to human health and ecological receptors.

Ms. Rustad then discussed the DDOU, a site in a clearing in a wooded area near the former wastewater treatment facility. She reported that drums were discovered on the surface here in 1994; the contents were analyzed and the drums were disposed of off base. She noted that pesticides, metals, and semivolatile organic compounds (SVOCs) were found in soil at depths of up to five feet and added that more data is needed to determine the extent of contamination at this site.

Mr. Dow asked Ms. Rustad to identify the SVOCs at this site. He said that the detected level of approximately 250,000 ppm seemed to him an "astronomical level." No one present at the meeting was able to provide an answer at this time. Ms. Brand stated that the information being sought would be researched.

Ms. Rustad then described FS-18 as a former World War II motor pool and fuel transfer site. She said that four underground storage tanks at the site, which were believed to contain diesel fuel and motor gasoline, were removed in 1985. She also reported that five leaching wells and four vehicle maintenance pits were identified at the site and removed, along with some contaminated soil, during the Drainage Structure Removal Program (DSRP) in 1996. She explained that the drainage course receives stormwater discharge from the paved portion of the site. She also said that fuel-related contaminants in surface and shallow subsurface soil, up to six feet deep, were identified and may pose a potential risk to human health and ecological receptors.

At this point, Mr. Peterson read the names of some SVOC contaminants that were detected at these sites, including 2-chlorophenol, 1-2-4 trichlorobenzene, 2-4 dinitrotoluene, and phenanthrene. He noted that these are listed in Table 2.1 of the EE/CA document, along with the concentrations detected.

Ms. Rustad described the FS-7 site as a fuel spill near former Building 1820, where fuel oil leaked from an underground storage tank that was removed in 1985. She reported that the fuel-related compounds identified in the surface soil there are believed to pose a potential risk to future human receptors and ecological receptors.

Mr. Dow asked if the polynuclear aromatic hydrocarbons (PAHs) found in the soil at FS-7 are thought to be from oil spills rather than combustion products. Ms. Rustad confirmed that was the case, since it appears that the soil surrounding the tanks was returned to the hole following the removal of the tanks.

Ms. Rustad referred to the summary table and noted that it lists the contaminants that are driving the removal actions, the maximum concentrations identified, and the estimated number of cubic yards of soil impacted. She then reported that three alternatives were developed to address the seven sites. She said that at six of the sites (all but FS-4), there is surface or shallow subsurface contamination, (two to six feet deep) which can be addressed through excavation activities. She stated that FS-4 will be addressed by an in-situ remedy.

Ms. Rustad then listed the alternatives as follows: Alternative 1 - Excavation and on-base desorption and/or off-base treatment and disposal for six sites; Alternative 2 - Excavation and on-base batching and/or off-base treatment and disposal for six sites; and Alternative 3 - Excavation and off-base treatment and disposal for six sites.

Ms. Rustad reported that for each of the alternatives the first step is a pre-design study that is meant to determine wetland areas at FS-18, delineate the extent of contamination at the DDOU, and determine the need for a future removal action at FS-4.

Mr. Dow asked for a breakdown of cost estimates for Alternatives 1 and 2 that would show the difference in cost for treatment on the site and off the site. Mr. Minior referred Mr. Dow to page 8 of the fact sheet, where the cost of each alternative is estimated. Mr. Dow stated that the numbers in the fact sheet combine the costs of on-site treatment and off-site treatment. He said he is asking for the difference between on-site costs and off-site costs.

Mr. Rustad explained that all of the alternatives include an on-site component that will be conducted if the soil is found to be acceptable; the soil that is unacceptable will be taken off site because it cannot be run through the on-site treatment unit. She stated that the big difference between Alternative 1 and Alternative 2 is that, after the thermal desorption process, because of the level of inorganics in the soil at the six sites, more soil will be sent off site for Alternative 1, as inorganics will not be treated with low-temperature thermal desorption. She also stated that all those costs are rolled into the final cost, however, because the EE/CA report made assumptions regarding how much soil will be sent off site.

Mr. Dow remarked that perhaps he had not made himself clear. He said it seemed to him that Alternative 3, in which all contaminated soil from six of the sites would be taken off base, would be more expensive than on-site treatment. Also, it seems that asphalt batching is less expensive than thermal desorption, where residue containing heavy metals still would need to be addressed. He said that he is trying to determine if Alternative 3 would be cheaper when the hidden costs, such as this one, are considered.

Mr. Minior stated that the $100,000 difference between AFCEE's preferred alternative (Alternative 2) and Alternative 3, shipping all the soil off site, is worth paying because of liability issues. He explained that with the asphalt batching of Alternative 2, the liability for most of the contaminants would stay on the base and there would be less chance of being held liable in the future for problems at an off-site disposal facility. He said that every thousand dollars that is paid for off-base solutions could save money in the long run.

Mr. Hoda added that just moving the contaminants would do nothing to lessen the volume of the contaminants. Mr. Dow said that it was his understanding then that the contaminated soil could be treated off site, and at a lower cost. Ms. Rustad stated that keeping the soil on base presents less exposure potential than transporting it elsewhere.

Mr. Minior explained that the criteria for recommended alternatives involves a lot more than just cost. Mr. Dow said he was aware of that, but added that the neighbors might feel more secure if the soil were removed from the Massachusetts Military Reservation (MMR). Mr. Minior pointed out that transporting the soil off base would still require handling the soil and potentially trucking it through residential neighborhoods with greater populations, so there is more potential that way for exposure.

Mr. Dow noted that the amount of soil that would have to be shipped off site is the same in Alternatives 1 and 2. Ms. Rustad stated that this is not the case. She explained that the levels of inorganics that were identified in the soil will not be addressed by thermal treatment, and therefore these soils would still need to be treated for inorganics, which needs to be done off base. She noted that with asphalt batching, less material will need to be moved off base.

Ms. Rustad then began to explain the general components of the potential removal action alternatives. She stated that pre-design studies are important in order to determine wetland areas, verify the extent of contamination at the DDOU, and determine the need for a removal action at FS-4. She said that all the alternatives call for excavation of an estimated 2900 cubic yards of subsurface and shallow subsurface soil. She also reported that there will be air monitoring during excavation. Depending upon the alternative, there will be on-base treatment and/or off-base treatment and disposal. Ms. Rustad noted that there will be in-situ treatment of the deeper soil at FS-4, if warranted by pre-design investigation. She also reported that there would be site restoration activities, including wetlands restoration at FS-18, and backfilling and reseeding of all excavated and impacted areas.

Ms. Rustad continued by discussing the on-base thermal desorption process. She reported that the on-site thermal desorption process begins with excavation of soil, which will be transported to the site, where it will be characterized, and a determination will be made as to whether it is acceptable for on-site thermal desorption. The acceptable soil will be screened. Oversize material will be steam-cleaned and used as backfill material. Material that is acceptable will be sent to the thermal desorption chamber. Basically, the soil is fed into an oven at 200-300 degrees, to remove volatile contaminants. Afterward, the soil is re-characterized. If found to be clean, it is sent to be used as backfill. If not, it can be reprocessed. Or, if the characterization shows that the contaminant levels are too high, the soil will be sent off base for treatment and disposal.

Ms. Rustad further reported that the on-base asphalt batching process also begins with excavation of soil, which is transported to the treatment site. There it is characterized for acceptability for batching. Soil that is unacceptable will be sent off base for treatment and disposal. In the case of the CS-5 site, the Area 2 soil would be characterized on site so that it would not be cross-contaminating any other soil with PCBs. Acceptable soil would be screened and crushed, and put through the asphalt batching process, where the asphalt emulsion would be added. The treated soil would be allowed to cure for approximately 72 hours, and then used as a subgrade paving material at the MMR.

Mr. Dow asked if putting treated sand back into the excavated areas would change the porosity of those areas. Ms. Rustad replied that the oversized material would be steam-cleaned to remove the contamination and then also used as backfill, therefore the rocks will be recombined with the treated sand.

Ms. Rustad then reported that Alternative 3 is basically excavation, minimal characterization, and transport off base for treatment and disposal. She then showed an illustration of a conceptual section view of a low-flow soil vapor extraction system, also called a bioventing system, which is proposed for in-situ treatment at FS-4.

Mr. Dow asked if the geology of the area is all uniform sand. Ms. Rustad replied that it is believed to be, but this would be studied during the pre-design investigation. She reminded the audience that no decision has yet been made as to whether soil at the FS-4 site will need to be removed. She said there are two ways that the system can address the contamination there. The first is to physically strip contaminants from the soil, by using high flow-rates of air. The second way is to use smaller flow-rates of air to promote biological degradation, or in-situ destruction of the contaminants right in the ground. Oxygen would promote the degradation of the contaminants. Ms. Rustad explained that pre-design investigation would first determine a need for treatment, then would be used to optimize the flow rate and optimize the type of mechanism used to address the contamination. She also said that it may be advantageous to use a system that just injects air into the subsurface and allows biodegradation to take place without actually pulling contaminants out of the subsurface for treatment above ground.

Mr. Dow asked when it would be determined which method would be used. Ms. Rustad replied that a lot of information will be obtained from the pre-design investigation sampling. She said that much of that decision will depend upon the type of contamination present. She noted that the heavier fuels and some of the residual fuel contamination would not require the physical stripping. Mr. Dow stated that his question was how long that would take. Mr. Minior replied that it would take less than six months.

Ms. Rustad said that it is important to keep in mind that the sampling may show that no further action is needed. Mr. Dow asked if that means there will be another public comment period following the pre-design characterization. Mr. Peterson said public involvement and regulatory review would continue. Mr. Hoda said that he does not know if there would be official public comment, but information will be shared with the public. Mr. Minior explained that if a decision were made that there is not sufficient contamination present to warrant any action, the Installation Restoration Program (IRP) would go back into the decision document process, which does include a comment period prior to a final decision.

Ms. Rustad reported that the alternatives were evaluated under criteria mandated by the US EPA. She said that in summary these criteria are effectiveness, implementability, and cost. Under effectiveness, considerations are overall protection of human health and the environment, compliance with laws and regulations, and long- and short-term effectiveness in reducing contaminant toxicity, mobility, or volume of contaminants through treatment. Under implementability, the evaluators look at the administrative feasibility of the alternative, whether services and materials are available, state and community acceptance, and construction, operation, and maintenance costs.

Ms. Rustad stated that, following the evaluation and based on the evaluation, the EE/CA presents a preferred alternative, which in this case is Alternative 2 — on-base asphalt batching and/or off-base treatment and disposal for six sites and in-situ treatment for FS-4. She said that specific components of this alternative include the pre-design activities previously mentioned; site preparation, which includes equipment mobilization and construction of the asphalt batching site; trench drain removal at USCG Sites CS-4 and FS-1; soil excavation and transportation to the batching site; and on-base asphalt batching following characterizations to determine acceptability.

Mr. Dow interrupted Ms. Rustad's listing of components to ask where the asphalt batching site would be. Mr. Minior informed him that no site has been selected yet.

Ms. Rustad continued by noting that air monitoring would be conducted during both excavation and asphalt batching activities. She said that off-base treatment and disposal were considered, as was in-situ treatment at FS-4, both of which were already discussed. She noted that site restoration was also already discussed.

Ms. Rustad then explained why Alternative 2 is the preferred alternative. She stated that it reduces human health and ecological risk at the seven sites; it greatly reduces the amount of contaminated soil that would be required to be transported off site, thereby reducing exposure potential; it reduces the volume and mobility of contaminants; it recycles material and allows for its reuse as an environmentally stable product; and it is cost-effective.

Ms. Rustad presented an overview of the removal-action schedule. She said that the end date for any in-situ treatment at FS-4 is not known; it would continue until objectives are met. She noted that the EE/CA is available at public libraries in Sandwich, Bourne, Mashpee, and Falmouth, at the USCG library on base, and at the IRP office. She stated that the fact sheet provides an overview, but the EE/CA itself is the document on which public comments will be received. She also mentioned that the fact sheet is available on the AFCEE/MMR website, but the EE/CA is not.

Mr. Cui asked if the intent was to use asphalt batching for all road repairs at the MMR. Mr. Minior replied that that is yet to be determined. Mr. Cui asked how many layers the road would have when asphalt batching is used. Mr. Minior replied that it would be a typical road. Mr. Cui asked which layer would contain the contaminants. Mr. Minior replied that it would be the middle layer and noted that the top coat will be a hot mix of regular asphalt. Ms. Musgrave added that the asphalt batching process produces a cold mix.

Mr. Dow asked if the placing of a hot layer on top of the cold mix could volatilize any of the contaminants. Mr. Minior replied that he was not aware that this could occur and he noted that many miles of MMR roads were paved using this process under the DSRP. Ms. Rustad explained that the curing process binds the contaminants and prevents volatilization.

Mr. Dow referred to Ms. Rustad’s statement that pre-design characterizations may find some soils unacceptable for asphalt batching. He then asked if the concern is that it may be difficult to immobilize the contaminants, or that the contaminant levels might be so high that the process of asphalt batching might increase the risk of exposure to workers or others. Ms. Rustad replied that it was probably a combination of both concerns.

Mr. Cui said that he believed that there may be some reaction in the mix that could cause further leaching of the contaminants. He also questioned how worker safety would be addressed. He said that tests have shown that asphalt does not always have sufficient binding power, particularly when it comes to metals.

Mr. Dow asked Mr. Cui if he meant that cold-mix asphalt batching cannot be used when there are a lot of heavy metals in the soil, because the metals would not be chemically bound up in the asphalt. Mr. Cui indicated that that was what he meant.

Mr. Dow asked if PCBs can be effectively bound with asphalt, no matter how high the levels are. Mr. Cui said that the process would do a lot better with PCBs. Mr. Dow stated that he is still concerned that PCBs might not bind with asphalt.

Mr. Minior asked Mr. Cui to explain how the state establishes maximum allowable concentrations, and whether those maximums are based on risk. Mr. Cui reported that allowable concentrations would be lower if one were putting contaminated soil in a backyard, but for a road, the allowable concentrations are higher. For example, total petroleum hydrocarbons (TPH) can go 100,000 higher, because it is the same material. PAHs can also go higher, because asphalt itself contains a lot of PAHs. Mr. Cui stated that asphalt has a lot of organic material, including gasoline, so many volatile organic materials can be added. He also noted that when a road is torn up, some of the old asphalt gets recycled into the aggregate for the new road.

Mr. Dow speculated that, since PCBs are not very soluble in water, they would not leach very much from asphalt. Mr. Cui stated that he thinks PCBs are allowed only in concentrations less than 2 ppm. Mr. Dow said that that must mean that if PCBs were found in contaminated soils at a level of 17 ppm, the MassDEP would not allow those soils to be used in asphalt batching. Mr. Cui replied that that is correct. Ms. Rustad noted that this is a question at Area 2 at CS-5.

Mr. Dow said the PCB issue gets back to his original question about whether the concerns were mechanical and chemical interactions with the asphalt, or whether some soils simply would be too toxic. Ms. Rustad and Mr. Cui both said that it is a combination of those factors.

Ms. Brand reminded the attendees that the public comment period would begin the next day. She then adjourned the meeting at 8:12 PM.