MOORESTOWN, NEW JERSEY - FREQUENTLY ASKED QUESTIONS
Questions on Site History and Mitigation
Q. If the same chemicals were discovered at a site today, would the same techniques still be used to mitigate the issue?
Yes, we’ve reviewed alternative processes with our environmental contractor, and determined that our current system is the best method for mitigation. In response to recent research about vapor intrusion (VI), which is defined as the process by which volatile chemicals move from a subsurface source into the indoor air of overlying buildings, we are, under the guidance of the NJDEP, including vapor intrusion testing in our mitigation plan.
Q. Has Lockheed Martin conducted any previous VI studies relating to the facility?
In 2007, at the request of the NJDEP, we conducted a VI study at the Chesterbrook Academy day care facility to ensure there was no VI at that facility. At the same time we also obtained an air sample in one of our buildings.
The results of the sample analysis at Chesterbrook and our facility did not detect the chemicals (specifically TCE and related degradation compounds) associated with our groundwater remediation project.
Q. What groundwater sampling has been performed offsite?
In 1991, we installed four offsite groundwater monitoring wells and have been conducting monitoring annually as directed by the NJDEP. Two of these wells showed no evidence of contamination during a three-year period of sampling and were closed in coordination with the NJDEP. The third well, which we continue to monitor, has never shown the presence of TCE or related compounds. The fourth well has shown steady decreasing levels of TCE (160 parts per billion in 1991 to 8.7 parts per billion in August 2008. We continue to monitor these two wells.
Questions on Risks Related to Chemicals
Q. What are the specific chemicals that Lockheed Martin has found in the groundwater?
Trichloroethene (TCE), cis-1, 2-dichloroethene (cis-1, 2-DCE) and vinyl chloride. TCE is the main contaminant in groundwater at the site. It is a nonflammable, colorless liquid at room temperature with a somewhat sweet odor and a sweet, burning taste. It was mainly used as a solvent to remove grease from metals parts. It can also be found in low concentrations in some household products, including typewriter correction fluid, paint removers, adhesives, and spot removers. TCE was once used as an anesthetic in surgery.
Q. How are you keeping these chemicals from entering the municipal water we drink now?
In 1992, all of the original residences in this area were transferred from well water to municipal water, and all homes in the area are now connected to the municipal water system. The municipal water comes from groundwater wells in an area that is not affected by the site. In addition, there is a natural clay barrier, called the Woodbury Formation, located beneath the affected groundwater at the site and the deeper aquifer that supplies the public water.
Q. How can trichloroethylene vapors affect my health?
Exposure to trichloroethylene can cause a variety of effects, depending on the type of exposure, the duration of the exposure, and the concentration of the chemical. There are a variety of publicly available studies that discuss these effects. At lower levels, exposure to airborne trichloroethylene may cause headaches, lung irritation, dizziness, poor concentration and difficulty concentrating. Exposure to high levels of airborne trichloroethylene may result in more serious health effects. For example, some studies of people exposed over long periods to high levels of trichloroethylene in drinking water or in workplace air have found evidence of increased incidence of cancer
Questions on Vapor Intrusion Testing
Q: What happens if vapor intrusion is suspected?
Anytime volatile organic chemicals are in soil or groundwater, there could be vapor intrusion into nearby buildings. If there is contamination from a spill or leak at a gas station, dry cleaner or other industrial plant, the possibility that vapor intrusion is occurring should be investigated. NJDEP has published guidance on how to conduct vapor intrusion studies. Studies begin by collecting soil, groundwater and soil gas samples to look for the presence and levels of chemicals. If chemicals are present in soils or groundwater above certain levels near buildings, samples of soil gas beneath the slab or samples of indoor air will be collected. Indoor air samples are typically collected over 24 hours using specialized canisters. After the air sample is collected, it is brought to the laboratory for analysis.
Many factors affect vapor intrusion, such as weather, time of year, type of building construction, and ventilation. Indoor air sample data can be difficult to interpret. Indoor air quality varies greatly from day to day, and from building to building. Many of the chemicals that may be present in soil vapor can also be found in common household products, certain building materials, cigarette smoke, and vehicle emissions.
Q. How is soil vapor intrusion investigated at sites contaminated with volatile chemicals?
Four types of environmental samples may be collected: soil vapor samples, sub-slab vapor samples, indoor air samples and outdoor air (sometimes referred to as "ambient air") samples.
We plan to collect one ambient air sample upwind outside of the plume area per six residences. We will obtain one near slab vapor sample from each residence. In addition, we will be conducting further investigation on township right of ways using soil vapor screening and hydropunch groundwater sampling to better define the groundwater plume.
To investigate the subsurface soil of the subject property, direct-push soil sampling
techniques are used. Direct-push technology or hydropunching allows for the collection of undisturbed, four-foot sections of soil, extracted from pre-determined levels above and below the groundwater. Hydropunch technology uses a hydraulically driven GeoProbe sampler mounted on a truck-operated unit to collect samples in right of ways. A hand anger will be used to obtain near slab samples from residential properties. If near slab testing results reflect the need to conduct indoor air testing, we will test the indoor air in the basement.
Q. If the results of the near slab testing effect a need for further sampling in the home, how will the testing process work?
The investigation process has four primary steps. Step one is the pre-sampling survey of the building. A floor diagram will be created noting the building layout for chemical storage and use areas (including the presence of household products that could affect the test results), if there are household hazardous waste items homeowners want to dispose of, we will collect and dispose as part of our standing community household hazardous waste program (i.e. basement sumps, plumbing, electrical conduits, elevator shafts, etc.) Step two is the placement of air sampling equipment based on the pre-sampling survey. Step three is the retrieval of the equipment, analysis of samples, evaluation of results, and discussion with building occupants and other interested parties. Step four is the preparation of a report summarizing the results and conclusions.
The indoor air sampling process will be conducted under conditions that represent normal building use. That means heating, ventilating, and air-conditioning systems will be operated normally for the season and time of day. The sampling time period will take place over a twenty-four hour period. All doors and windows must be closed during testing. All activities will be conducted in accordance with the NJDEP Vapor Intrusion Guidance.
Q. When will the home occupants be briefed on the results of the VI testing?
Each homeowner will be briefed on the results of the testing as soon as the results are analyzed and reviewed.
Q. How do you determine which houses to test?
Following NJDEP guidance, we’ll be performing precautionary near slab testing in the residential area including portions of the Wexford development across from Borton Landing Road. This guidance sets out criteria to determine which residences to test. We’ve expanded the state’s recommended buffer at 100 ft. to 200 ft. to encompass a greater number of residences. If we do not initially identify your house within our expanded testing area, we will keep you updated regarding the need to test. If in fact we do see a need to test your house in the future, we will be more than happy to do so. We are continuously conducting research on this matter, so please be patient with us as we complete this phased process.