Bay Shore toxic plume monitoring scaled back, report says

More than half of the groundwater test wells monitoring a series of toxic plumes near a former gas-manufacturing plant in Bay Shore have been reduced from quarterly to yearly sampling.

A report by GEI Consultants, the firm hired by site owner National Grid to monitor and oversee remediation at the site, says 55 percent of the hundreds of monitoring wells drilled into and around the plumes are now sampled yearly, while 5 percent are no longer monitored at all.

In addition, soil vapor monitoring, which examines the presence of vaporized toxins apparent in soil, has been eliminated, except where a treatment method known as ozone injection is taking place.

The report, released in October, says the reduction in sampling was justified because the remediation has largely addressed the plumes. "The groundwater quality data indicate that remedial activities have generally been successful at reducing the overall concentrations of COCs [constituents of concern] in groundwater," it said.

The monitoring reduction comes as new pockets of contamination have been discovered beneath at least two homes on the plume that have led National Grid to conduct new tests and new remediation work. Last week, toxins at hundreds of times background levels were found beneath the basement of a home on North Clinton Avenue, near the site of the large treatment facility.

One state senator said he was surprised to hear about the reduction in testing, and has called for greater action by National Grid to assist a woman living in the affected home.

"I do not expect them to reduce monitoring until we are one thousand percent sure that the plume is completely eliminated," said Sen. Phil Boyle (R-Bay Shore), adding that he nevertheless "greatly appreciated" National Grid's efforts to date.

SEE PHOTOSSuffolk County Water Authority

The house on North Clinton Avenue, which is occupied by an 84-year-old woman, "greatly concerns me," Boyle said. "This house was particularly close to the source. I believe that for those houses closest to ground zero of the former plant, they should most seriously be considered for potential purchase."

Irving Like, a lawyer representing 97 residents suing National Grid over the contamination and cleanup effort, said: "I think the residents would be furious. How can you say that you don't need more monitoring if you have these two incidents occurring at two separate homes?"

The GEI report says the state Department of Environmental Conservation, which is overseeing the site from its Albany headquarters, approved the reductions in monitoring in a letter Aug. 22, 2012. A DEC spokeswoman didn't respond to requests seeking a copy of the letter and an explanation.

National Grid spokeswoman Wendy Ladd said the company "has completed a majority of the remedial activities at the Bay Shore site" and "continues to monitor groundwater conditions and the performance of the remedial systems."

But Boyle said the results at the North Clinton Avenue home and others show that more information needs to be released and studied to convince neighbors the cleanup effort is largely completed.

"I intend to push National Grid and GEI to release all relevant information," he said.