Environmental and health officials continue to investigate the MTBE contamination discovered in the Manorville Pine Barrens earlier this month.
So far, they have found dangerous levels of the toxic gasoline additive MTBE in two residential wells on Oakwood Drive and a lower level of the substance in a third.
As first reported by RiverheadLOCAL on Dec. 15, an initial test of Clare and Marc Bennett’s well water, sampled Dec. 6 and 13, showed MTBE levels of 110 parts per billion, more than 10 times higher than the drinking water standard set by the N.Y. State Department of Health. (See prior story.) A subsequent test done by the State Department of Environmental Conservation returned a result of 120 parts per billion.
A neighbor’s well on Oakwood Drive returned a reading of 220 parts per billion, according to the county health department. A third well on Oakwood Drive had a reading of 2 ppb, below the state drinking water standard of 10 ppb.
The county health department is working to collect and test samples from 26 properties they’ve identified for investigation, a department spokesperson said.
Investigators do not yet know whether the MTBE contamination is isolated or whether it is evidence of a contamination plume traveling in an underground aquifer that is currently or will eventually affect other wells.
The source of the contamination remains unknown.
“DEC is aggressively conducting an investigation to quickly identify the source and extent of the MTBE contamination and address it in order to protect the public and the environment,” the agency said in a statement.
The DEC has supplied residents whose wells are affected with cases of bottled water and advised them not to drink or cook with it and to limit physical contact with the water. The state will supply affected homes with whole-house filtration systems.
There is no public water supply in the area; all homes have private wells.
MTBE, which stands for Methyl-Tertiary-Butyl-Ether, is a blending additive was used as an oxygenate and to raise the octane number in gasoline to prevent engine knocking, beginning in 1979 — to replace lead. MTBE was banned as a fuel additive in New York State as of Jan. 1, 2004.
High levels of MTBE in air can cause a number of symptoms, including irritation of the eyes and respiratory tract, headaches, lightheadedness, stupor, dizziness, nausea and confusion, according to health officials. Though MTBE has caused cancer in laboratory animals, it is not known whether it can cause cancer in humans.
There are approximately 19 homes in the small Manorville neighborhood nestled within that portion of the Central Pine Barrens, a pine forest preserve of more than 100,000 strictly regulated acres overlying the largest source of pure groundwater in New York State. The woodlands immediately surrounding the homes are charred as a result of a large wildfire in April 2012 that burned about 1,000 acres and destroyed one of the homes on Oakwood Drive.
There are few commercial uses nearby; the state Pine Barrens Protection Act bars most commercial uses in the core preservation area and those that do exist were built before the law took effect in 1993.
Underground water flow in and around the affected area — lying south of the groundwater divide and east of William Floyd Parkway — is generally to the southeast. The source of the MTBE contamination would logically be to the northwest of the affected wells.
After the State DEC receives all the sample results from the county health department, it will develop an investigation plan for locating the source. Investigators will collect groundwater samples at several depths consistent with the location of the impacted wells and groundwater flow. In that way, the agency can determine the possible source and the extent of the contamination, as well as and other potentially impacted private wells.
“There’s so much northwest of there,” L.I. Pine Barrens Society executive director Richard Amper said yesterday. “We don’t know if it happened on one piece of property or represents a plume of larger contamination. The greater the number of contaminated sites, the larger the concern of the overall size of the plume,” he said.
Amper said officials should keep in mind the thousands of cars stored for months on the former Grumman site after they were ruined by Superstorm Sandy’s flooding. The Town of Riverhead and a private property owner leased land to insurance adjustment companies to store the storm-ravaged vehicles at the site.
“We went crazy over that,” Amper said. He said officials should not discount the possibility that the cars brought there and stored are the cause of the contamination, though officials say that is “unlikely.”
“I am not presuming or accusing anyone,” Amper said. “But the fact of the matter is there has been a pattern of irresponsible contamination in that area and this should scare the bejesus out of anybody,” he said.
“The water in the Pine Barrens was the purest in the State of New York. It’s hard to imagine how somebody screwed this up.”