Cleaning up thousands of tons of illegally dumped contaminated material, such as that found at four sites in Islip and Babylon, can take months to complete -- and fill deposited in fragile wetlands presents an even more complicated challenge, experts said.
Remediating contamination -- as the process is called -- involves identifying a site, testing and ultimately removing the soil or capping it in place.
In some cases, that process can take "a year or two," said Robert Schick, director of the state Department of Environmental Conservation's Division of Environmental Remediation.
But addressing dumping in protected wetlands -- as authorities say occurred at Sampawams Creek off Brook Avenue on the Islip-Babylon border -- can take much longer because of the fragile nature of the aquatic habitat, Schick said. He spoke generally and not in reference to that or the other three dumping sites being investigated by the Suffolk County district attorney's office.
"To clean one of these wetlands up means essentially destroying it and putting it back in place," Schick said.
Wetlands, with their rich soil made of generations of decaying plant life, are "the base of the food chain" and essential for the health of Long Island's ecosystem, said Steve Englebright, a Democratic assemblyman and sedimentologist who teaches Long Island natural history at Stony Brook University.
They are also sensitive and easily damaged both by the initial dumping and by the remediation efforts that would be necessary to remove the fill, Englebright said.
"You alter it rather dramatically when you run heavy equipment across it or scoop it up or remove it," he said. "Disturbance in the wetland itself is very difficult to reverse."
Threat from plants
Heavy equipment can compact the soil and scrape it away along with the contaminated fill, leaving the area ripe for harmful invasive plants to gain a foothold and push out native species, he said.
But leaving the fill in place also comes with costs -- the material smothers the wet soil and blocks out light for native plants, and contaminants, such as heavy metals, can migrate further into the wetland and poison plant life, Englebright said.
"You're working for all practical purposes to try and get back to an equilibrium that cannot be easily restored," he said. "It's not that it's impossible, but it's very difficult."
Schick said it's sometimes better environmentally to leave fill in place in a sensitive wetland. Authorities can weigh other alternatives, such as building a wall upslope from the wetland to keep contaminated soil from sliding farther into the sensitive habitat.
But even dumping sites that aren't in wetlands present challenges that can extend the remediation process for months and even years.
"Bigger sites with less pre-existing knowledge of what the source can be are the ones that take longer," Schick said.
The process of remedying a site generally begins with sampling to determine the nature and extent of any contamination, he said.
"The whole goal of it is to find out what's there, how high the concentrations -- the levels -- are and how widespread it is," he said.
What is found and where it is found can help determine the solution, Schick said. The agency considers public health, protection of groundwater and protection of ecological resources in determining whether to remove contaminated soil or cap it in place, which involves covering the fill with a liner, then covering the liner with clean soil.
Monitors are used
Removing the soil is done along with the use of air and dust monitors, Schick said, while water is sprayed to keep dust from becoming airborne during the removal.
Suffolk District Attorney Thomas Spota opened a criminal investigation April 8 into the dumping at Roberto Clemente Park in Brentwood, where dumping had been occurring as early as June 2013.
So far, none of the sites being investigated by Spota -- Roberto Clemente Park, a parcel on Islip Avenue at Sage Street in Central Islip, a six-home development on Veterans Way in Islandia and the Deer Park wetlands area on Brook Avenue that forms part of the Great South Bay watershed -- has been remediated, although sampling that showed various levels of contamination, including heavy metals, took place at all four.
The Suffolk County health department has said that neither the park nor the Islip Avenue parcel poses a current threat to public health, but also that it's impossible to know what the threat might have been while the dumping occurred.
The DEC, which requires landowners to submit remediation plans for the contaminated sites, has received a plan from the Long Island Builders Institute for the Islandia parcel, DEC spokeswoman Emily DeSantis said.
Plan being reviewed
A revised plan for the site is under review, and the agency is awaiting plans from owners of the other three dumping sites, DeSantis said.
Inez Birbiglia, deputy commissioner of the Islip parks department, said the town is in talks with the DEC over how to dispose of the estimated 50,000 tons of contaminated fill dumped at the park.
The town's remediation plan "is in its initial stages" and is expected to be submitted to the DEC for approval by late August, she said.
Gerard Glass, a Babylon attorney who represents the Brook Avenue property owner, said his client is cooperating with town, county and state officials but does not have enough assets to remediate the property.
"We are looking towards the district attorney's office to require restitution as part of any criminal disposition," Glass said.
An attorney representing Tommy Lau, who is registered with L-C Real Estate Group, which owns the Islip Avenue property, did not respond to a request for comment.
Mitch Pally, chief executive of the Long Island Builders Institute, said his preliminary remediation plan involves removing the fill -- about 1,000 cubic yards containing traces of banned pesticides, heavy metals and petroleum-based products that Spota said were hazardous or acutely hazardous under state environmental law.
"Obviously we would like to get it done as quickly as possible," he said. But, he added, "we're kind of in a holding pattern at the moment."
One of the issues under discussion, Pally said, is whether the contaminated fill could be segmented, with parts that were found to have low levels of contaminants sent to a Long Island landfill, where hazardous waste cannot be dumped, and portions of fill that tested at higher levels sent elsewhere.
"It's not a question of taking it all out," he said. "It's a question of what happens to it afterwards."