Darryl Bautista/Poughkeepsie Journal Old plants that used to manufacture gas are leaching tar into the Hudson River. This one, in Newburgh, is the largest and most contaminated of these sites.

Darryl Bautista/Poughkeepsie Journal A sign at the old Newburgh manufactured-gas plant site warns against flammability hazards.

NEWBURGH -- A former gas plant site in Newburgh is leaching tar into the Hudson River, accounting for the largest contamination among nearly two dozen similar sites along the river.

These long-defunct manufactured-gas plants once supplied light and heat to communities from the late 1800s into the first half of the 20th century, before electric power plants and natural gas lines took their places.

They transformed coal -- or in the case of the Newburgh plant, coal and oil -- into gas, which was piped to homes. A thick liquid waste tar was produced in the process. It seeped into the ground, or in cases such as Newburgh, was piped directly into the Hudson River.

Regional utilities are liable for tens of millions of dollars in cleanup costs at the old plants, many of which were operated by predecessor companies.

Moving toward cleanup

A decade after identifying them as a potential threat to the environment and human health, the Department of Environmental Conservation is moving forward, in cooperation with willing utilities, on the first plans to clean the sites up.

New York is ahead of most states in its efforts to investigate and have old manufactured-gas plant sites cleaned up. Dredging the tar from the river bottom muck could set precedents for other cleanups in the still-young field of river remediation.

Of about 300 statewide, the DEC lists 22 manufactured-gas plant sites in communities adjacent to the tidal portion of the Hudson River, south of the Troy dam. Several others are found in the freshwater reach of the river north of the dam, or along tributaries, including one in Wappingers Falls on the Wappinger Creek.

It's unclear how many of the sites have polluted the Hudson River; the Newburgh plant is one of at least five that did.

''We do know of several others on the river, but most are early investigations and none have the large amount of contamination we've seen at the Newburgh site,'' DEC spokeswoman Wendy Rosenbach said.

Cleanup will cost millions

The Newburgh cleanup could cost Central Hudson Gas & Electric Co. $22.9 million, if the DEC settles on its preferred plan. Environmental groups and some in Newburgh are agitating for a more extensive cleanup that would include more dredging of contamination in Hudson sediments, at an additional cost of $5.1 million.

After the City of Newburgh sued Central Hudson, the company agreed to pay for the cleanup, which it negotiated with the DEC. The cleanup is part of Newburgh's plan to redevelop old industrial sites on its waterfront -- a desire common to all riverfront communities.

It's the DEC's job to define a cleanup plan, and Central Hudson isn't commenting on specifics while the DEC is considering public comments about it, spokesman John Maserjian said.

In a statement released March 16, Vice President of Environmental Affairs and Engineering James P. Lovette indicated the cost of the cleanup would ultimately be covered by customers who purchase electricity from Central Hudson: ''From the first, Central Hudson's goal has been to conduct thorough, professional investigations of the environmental impacts and possible health risks of the former Newburgh [manufactured-gas plant] site and to ensure that any impacted area can remain in safe and valuable use. Central Hudson is committed to conducting an effective cleanup of the site, and will continue to work with the DEC and the City of Newburgh.''

Central Hudson purchases power from producers and distributes it to most Dutchess and Ulster county residents.

Central Hudson expects to spend $1.9 million this year on environmental compliance, which includes cleanups, according to a recent filing with the Securities and Exchange Commission.

The company has investigated, or is investigating, seven other former manufactured-gas plant sites, three of which are not considered hazardous, Maserjian said.

Other utilities that serve the Hudson Valley face greater liability.

Niagara Mohawk has identified 51 manufactured-gas plant sites in New York, according to a recent SEC filing. Together with other environmental compliance requirements, it has a liability of as much as $535 million.

Consolidated Edison expects to spend $90 million this year on environmental projects, including investigations and cleanups at 33 old manufactured-gas plants, according to a recent SEC filing.

Of the 22 former manufactured-gas plants on the Hudson River Estuary, cleanups are under way at three: Niagara Mohawk plants in Troy and Hudson, and an Orange and Rockland Utilities Inc. plant in Nyack.

Dredging may be part of plan

At least one site, in Beacon, was redeveloped, and a Tarrytown site cleanup that included dredging was completed in January.

Cleanup plans typically involve digging up contaminated soil and, if the river was contaminated, sometimes dredging river sediment.

Dredging of a polluted Hudson River bay was ordered at the Hudson plant as part of a $22.4 million cleanup plan issued in 2001. That dredging is complete, and a separate plan will be developed to address lower levels of contamination in the river itself, DEC spokesman Gabrielle Done said. The contamination on land will be addressed this year, she and Niagara Mohawk spokesman Alberto Bianchetti said.

The Troy and Nyack cleanups will cost more than $30 million, and $11.8 million, respectively.

Neither cleanup plan addresses polluted river sediment, however. In both cases, decisions about how to handle contamination in the Hudson itself were deferred in favor of discussing contamination on land.

The tar produced by manufacturing gas was a liquid that contains volatile organic compounds including benzene, a carcinogen. It also contains polycyclic aromatic hydrocarbons, or PAHs.

Like the most notorious Hudson River contaminant, polychlorinated biphenyls, or PCBs, some PAHs can ''bio-accumulate'' in the tissues of living things.

Bio-accumulation can threaten fish and animals, including humans, at the top of the food chain. Those creatures that live longer and eat more contaminated food accumulate more pollution.

However, PAHs have not been studied enough to know what risk they might pose to wildlife or fishermen, Katherine von Stackelberg said. Von Stackelberg is a scientist who has created a model to predict how PCBs accumulate in Hudson River, and produced a cleanup plan for a manufactured-gas plant site in Missouri. She works for a consulting firm, Menzie-Cura & Associates, Inc., which has offices in Massachusetts, Maryland and Maine.

The body breaks down PAHs into metabolites that have not been studied, she said.

''Here's where the story gets a bit more complicated,'' she said. ''We don't know the toxicological significance of the metabolites. But they could have the potential to cause direct DNA damage -- which is never a good thing.''

PAHs are also very common. They are created by burning anything -- from fuel in a car to chicken on a barbecue.

''I'm not that worried about these chemicals in the food web,'' von Stackelberg said. ''It's not ideal, of course, but as compared to PCBs I'm a lot less worried about these.''

Cumulative exposure to the chemicals, as wildlife moves through the river, could be a concern, she said. But specific studies would be needed to predict whether the multiple sites pose a risk of cumulative exposure.

The DEC believes each of the 22 sites on the river has a limited, local impact -- not a cumulative effect on a river whose tides move both ways, and which has an abundance of migratory fish.

''What department staff have discovered in working to clean up these sites,'' Done said, ''is that a majority of contamination in the river is localized to relatively small portions of heavily contaminated river sediments.''

Dan Shapley can be reached at dshapley@poughkeepsiejournal.com

On the Web

For more information, visit the Department of Environmental Conservation's Web site: www.dec.state.ny.us/website/der/mgp/