Before 2003, the New York State Department of Environmental Conservation (DEC) cleaned up contaminated sites under certain set guidelines and to meet certain standards that they had at the time.

In late 2002, early 2003, research regarding vapor intrusion, which is the process by which volatile chemicals move from a subsurface source into the indoor air of overlying or adjacent buildings, began to yield more information.

After learning about the new threats of vapor intrusion, DEC staff went through records of sites that the DEC was involved with, either in an oversight or a managing capacity. The sites that were cleaned-up prior to 2003 and where remedial decisions had already been made, which include over 400 in New York State and approximately 80 on Long Island, are now going to be prioritized and then addressed and evaluated for the potential of vapor intrusion. The process of prioritizing the sites is expected to be completed by December, according to the DEC.

"All of the sites are going to be prioritized and we will be doing investigations based on sites that have the highest risk potential and those will be addressed and investigated first," said Maureen Wren, public information officer for the DEC. "Every site will be evaluated on a case by case basis and if there is a need for DEC or Department of Health staff to conduct indoor air quality tests, the homeowner, businessowner or other property owner would be involved."

Of the 400+ sites, approximately 14 are located within the Plainview Industrial Park. Paul Granger, superintendent of the Plainview Water District strongly emphasizes that the water is safe to drink. "Our water is absolutely safe to drink," said Granger. "Customers can call us and get an annual water quality report or also can call the health department - they are our regulatory agency and they will re-affirm the safety of our water."

Carol Meschkow, president of the Concerned Citizens of the Plainview and Old Bethpage Community, said she wanted residents to know that this is a pro-active procedure by the DEC and this does not mean that any areas are contaminated. "Although there is no evidence yet of vapor intrusion, the DEC, with new information recently learned and associated new investigative strategies, will perform pro-active testing procedures. At this point it should be noted that the DEC's program is only at the testing stage," she said.

According to the DEC, they will ask the party responsible for contaminating the site to pay for and perform the vapor intrusion evaluation, as well as any site investigations and the installation and long-term operation and monitoring of any mitigation system which would be required. If the responsible party refuses to perform these activities, or if no viable entity remains, the state will take responsibility for them, and will pursue cost recovery as in any Superfund site. This is the same with groundwater contamination.

Granger said that the water district has maintained a pro-active stance in the community with regard to ensuring that the water supply is safe. "We have been on top of this from a water quality perspective. There were meetings back in 2002 with the DEC requesting additional testing and monitoring because of our knowledge of what was going on in the industrial parks and we were able to stay on top of this issue and monitor our water quality closely," said Granger. "We have installed well-head treatment systems at two of our facilities because of this unfortunate issue."

This information on vapor intrusion is not new, according to Granger, as the DEC changed testing standards in 2003, but he said what is new is the additional study and testing. "We at the water district welcome the testing," said Granger. "We have expressed our concern in the past and wanted more information, which we are still trying to get. We want residents to know that our water is absolutely safe to drink."

"This issue only confirms Long Islander's justification in being ever so vigilant regarding our groundwater, toxic dumping and environmental pollutants as we can never be sure of the long-term longitudinal effects on our environment," said Meschkow. "It also highlights our concerns and the constant need to protect our vital sole source aquifer through curbing over-development of precious open space necessary for the recharge and maintenance of our public water supply."

Both Granger and Meschkow said they hope to schedule an informational meeting with the DEC and Department of Health for local residents to attend and get more information. Any information regarding an upcoming meeting will be posted in the Herald.

Residents are encouraged to call the following numbers for more information or with any questions: Plainview Water District - 931-6469; the DEC (a number set up specifically for the Plainview area) (518) 402-9621; DEC general information (631) 444-0204 and the Nassau County Department of Health's Drinking Water Department 571-3323.

According to the DEC's website, vapors can enter buildings in two different ways. In rare cases, vapor intrusion is the result of groundwater contamination, which enters basements and releases volatile chemicals into the indoor air. In most cases, vapor intrusion is caused by contaminated vapors migrating through the soil directly into basements or foundation slabs. Although the DEC historically has evaluated soil gas pathways, improvements in analytical techniques and the knowledge gained from remedial sites in New York and other states has increased their understanding of how vapor intrusion occurs.

"Historically, we thought that vapor intrusion was only an issue where the source of the contaminants was very shallow and the magnitude of the contamination was very great. We now know that our previous assumptions about the mechanisms that could lead to exposure to vapor intrusion were not complete. The result is that additional work may be required to investigate or remediate sites that are in the operational or monitoring phase, or that have already been closed. Separate ranking systems have been developed to account for the two different sources of contaminated vapors. Because we now recognize the need to take a different sampling approach, when the Department evaluates a site for vapor intrusion, both sources can now be effectively considered," according to the NYSDECs website.

According to the DEC, the evaluation at a specific site will initially involve a review of existing environmental data to see if sufficient information is already available to assess possible vapor impacts. If a vapor intrusion problem is suspected, the DEC may recommend additional sampling, monitoring or mitigation actions. Additional sampling would be used to determine the extent of soil vapor contamination and to verify their initial findings. Monitoring, or sampling on a recurring basis, is typically conducted if there is a significant potential for vapor intrusion to occur if building conditions change. Mitigation steps are intended to prevent exposures associated with soil vapor intrusion. Mitigation may include sealing cracks in the building's foundation, adjusting the building's heating, ventilation or air-conditioning system to maintain a positive pressure to prevent infiltration of subsurface vapors, or installing a sub-slab depressurization system beneath the building. In most instances, mitigation of residential structures will require a sub-slab depressurization system, according to the DECs website.

The DECs website further explains the testing process. "Subsurface vapor samples consist of both soil vapor samples collected from the ground away from buildings (soil gas samples) and sub-slab soil vapor samples collected from immediately beneath the foundation or slab of a building (sub-slab samples). Indoor air samples are collected from the basement or crawlspace and from the lowest level of living space. We collect these samples primarily during the heating season, because we believe that soil vapor intrusion is most likely to occur when a building's heating system is in operation and air is being drawn into the building. Outdoor air samples are collected outside of the buildings, and are used to characterize site-specific outdoor air background conditions. The length of a soil vapor investigation will depend on the data that is collected during the investigation, and is only considered to be complete when all of the exposures and potential exposures have been addressed."