Suffolk County will begin investigating whether contaminated fill dumped at four sites in the county has impacted the groundwater, after initial test results showed elevated levels of some contaminants in water near two of the locations, according to a report to county legislators.
The county's Health Services Department plans to sink 13 temporary wells at Islip Town's Roberto Clemente Park and proposes to install five to seven wells at each of the other three sites where the Suffolk district attorney has said the illegal dumping occurred, according to the report, which was distributed Friday.
Besides installing the wells at and around a six-home development for veterans in Islandia, a vacant lot in Central Islip and a Deer Park industrial property abutting a protected wetlands area, the report recommended testing Sampawams Creek, which runs along the industrial site.
The goal is to determine whether contaminants from the fill have entered the groundwater, which is Long Island's sole source of drinking water. All groundwater is treated to remove contaminants before it is delivered to the public, and no contaminants from the fill have been found so far in public-supply wells.
Sampling done in June on the creek found several metals immediately downstream from the dumping site at levels that were not found upstream from it.
Those metals included lead and cobalt, both of which were found at less than 1 part per billion upstream, but at 1 part per billion downstream, and zinc, found at less than 5 parts per billion upstream, but at 256 parts per billion downstream.
The report cautioned that "no definitive conclusions" could be drawn from such a limited amount of data and additional sampling was needed.
The fill at all four sites contains hydrocarbons, pesticides and metals, the report said.
Three monitoring wells that the town had drilled at the Brentwood park last year showed 16 parts per billion of lead in the well south of the park's recharge basin, and 5 parts per billion in the well southeast of the soccer fields, but no lead in the well drilled north of where the dumping occurred, an October study found.
Groundwater in the area flows southeast, according to Enviroscience Consultants Inc. of Ronkonkoma, which performed the study for the town.
While Enviroscience concluded that the results showed "no significant impacts" to the groundwater from the contaminated fill, the county's report, examining the same data, said the results warranted a "groundwater investigation at this site."
One groundwater expert who was shown a copy of the county report and the town's study said the presence of lead in the water in that area was "unusual."
"The lead was 16 parts per billion downgradient and nothing upgradient, and lead was a contaminant of concern in the fill," the source said. "That would raise questions."
While the amount of lead found at the monitoring wells was below state standards for groundwater, the lead at the well by the recharge basin was above the level at which a public-water supplier must take action to reduce the amount of the metal in the water.
The nearest public-supply well is over a mile away from the park, according to the county, which plans to increase the amount of testing it does at that well site to twice a year. The county said the last round of testing it conducted there, in June, showed the drinking water met all state and federal standards.
Greg Menegio, a senior scientist with Enviroscience, said he still felt the sampling showed the groundwater near the park had not been significantly impacted by the fill.
"Based on the distance of the wells from the impacted area, it didn't seem likely that it's from the contaminated fill," Menegio said.
But, he added, "based on just one round of sampling, it's sometimes difficult to draw broad conclusions."
The Islip Town Board voted last week to allow the county to drill wells at the park. Islip officials did not respond to requests for comment.
The county's report comes nine months after the district attorney began an investigation into the dumping, in which prosecutors said thousands of tons of contaminated fill was illegally deposited at the four sites.
Last month, six men and four companies were indicted in Suffolk because of their alleged roles in the dumping scheme. All pleaded not guilty and are due back in court March 10.
The report was created at the behest of the Suffolk County Legislature, which last month passed a resolution directing the health department to begin testing the groundwater at the park for toxins and to decide whether the other three sites also should be examined.
The Suffolk County Water Authority has expressed concern about whether its well fields could be impacted by the contaminated fill -- especially the dumping at Veterans Way, which is near one of the authority's well fields. The authority has said it has since increased its testing for contaminants at that well field.
Legis. Monica R. Martinez (D-Brentwood), who sponsored the bill along with Legis. Kara Hahn (D-Setauket) and Legis. Thomas Barraga (R-West Islip), said she was "very pleased" that the health department planned to test all four sites.
"I think it's necessary we have a separate entity also helping out," she said.
Legis. Tom Cilmi (R-Bay Shore), who has been named as a contender for the vacant Islip Town supervisor seat, said he felt the county "should have began monitoring and drilling immediately in all four sites" once the dumping became known.
"I hope now that the report is issued, that the health department takes immediate action to protect in whatever way we can the wetlands at Sampawams Creek, and the groundwater and residents in the other areas," he said.
Richard Groh, chief environmental analyst with the Town of Babylon's Department of Environmental Control, said the town was "very supportive" of the county's plans.
"We're confident that they're going to thoroughly determine exactly what's happening there," Groh said of the Deer Park property. "Is that material moving from the piles or is it blocked in there? That's the important thing to determine -- is it migrating off the site?"