Written by Denise Nash Thursday, 04 June 2009 16:12
New York State in 2005 decided to do something few other jurisdictions had yet considered - re-open hundreds of pollution cases to determine whether new science could shed light on old cleanups.
The state took on the task of tracking down whether chemical vapors were lingering at these sites and posing threats to public health. Three years later, the Department of Environmental Conservation (DEC) has made significant progress in tracking down and evaluating more than 400 sites around the state, DEC Commissioner Pete Grannis said. And a leading vapor-intrusion watchdog has called New York’s program the “most systematic and proactive” in the nation.
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 approximately 80 on Long Island, are now going to be prioritized and then addressed and evaluated for the potential of vapor intrusion.
There are two categories of sites - legacy sites and active sites. With legacy sites, the cleanup decision was made prior to Jan. 1, 2003 and DEC officials will be taking a second look at them. There are 421 legacy sites in New York State and three that are found within the Plainview Water District’s boundaries - the Old Bethpage landfill, the Claremont Poly Chemical Corporation and the Cherry Lane Lithography site.
Active sites are currently in the cleanup program and that will now include an evaluation of the vapor intrusion pathway.
So far, 147 investigations have been completed. Of those, the state found that 19 required mitigation (ventilation systems) to alleviate vapors discovered on-site or in neighboring buildings, 46 required monitoring only and 82 needed no further action (levels did not trigger mitigation or monitoring).
In addition, mitigation has been determined necessary at 11 sites where investigations are still ongoing.
“Of all the states and (U.S.) Environmental Protection Agency regions, New York has the most systematic and proactive program for identifying and addressing vapor-intrusion sites,” said Lenny Siegel, executive director, Center for Public Environmental Oversight, a group that has monitored vapor intrusion sites around the country.
“Vapor intrusion is an issue that wasn’t even on the environmental map a generation ago,” Commissioner Grannis said. “But as the science has developed, New York has put together an aggressive and methodical plan for addressing potential vapor-intrusion sites. There is more work to be done and the state remains committed to attacking this issue.”
New York State Health Commissioner Dr. Richard F. Daines noted that the state developed a comprehensive guidance document for investigating vapor intrusion and providing a sound basis for determining when homes and buildings need mitigation. “This program has resulted in removing the potential exposure to soil vapor from the lives of thousands of New York’s citizens,” Dr. Daines said. “Vapor intrusion” refers to the process by which volatile chemicals move from a source below the ground surface (such as contaminated groundwater or contaminated soil) into the indoor air of overlying or adjacent buildings. Over the last decade, science about vapor intrusion has developed dramatically.
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 vapors from contaminated materials migrating through the soil directly into basements or foundation slabs.
DEC and the Department of Health (DOH) developed a joint strategy to evaluate the vapor intrusion pathway at all of the remedial sites that had been previously addressed through the Superfund, brownfields or other cleanup programs in the state. That generated the list of 421 sites to be investigated; please note – the 421 sites do not necessarily represent a confirmed vapor concern. Rather, New York State proactively decided to go back and review these sites to determine if there was a vapor concern.
As a public water supplier, the Hicksville Water District welcomes DEC’s aggressive program to monitor vapor intrusion resulting from sub-surface plumes as well as fully supports a strong DEC enforcement program targeted at groundwater cleanup, whether from legacy or active sites, according to Karl Schweitzer, chairman of Hicksville Board of Water Commissioner. “We actively monitor DEC’s enforcement programs in the community for their possible impacts and to ensure that studies and cleanups are progressing as they should,” Schweitzer said.
According to Schweitzer, Hicksville Water District has the responsibility to provide water at all times that is fully compliant with New York’s rigorous drinking water quality standards. “The district monitors its drinking water quality with a comprehensive testing program and is proud of its record of supplying excellent quality water to its consumers,” he said, adding, “The Hicksville Water District remains vigilant on groundwater quality issues and has invested in water treatment facilities for over 25 years to protect the drinking water quality. The district is fully committed to maintain this same strong stance moving forward.”
For information, visit DEC’s web page for vapor intrusion at www.dec.ny.gov/regulations/2588.html. For State Health Department information on vapor intrusion, go to www.health.state.ny.us/environmental/indoors/vapor_intrusion/. Additionally, a list of the sites is available at www.dec.ny.gov/regulations/51715.html.