A banned gasoline additive has been detected above allowable levels in the water at a building that houses Shelter Island’s senior center and its only two medical practices.
Methyl tertiary butyl ether, or MTBE, was found at the South Ferry Road site last week following a routine test by the Suffolk County Department of Health Services, according to town officials.
The gas-blending compound is not regulated by the federal Environmental Protection Agency, but New York banned its use in 2004 and set the safe drinking water concentration at 10 parts per billion. Samples from the senior center showed MTBE at 10 parts per billion on May 16 and 12 parts per billion on May 21, according to a spokeswoman for the county health department.
“There’s been other tests that show MTBE [on Shelter Island], but not at the drinking water standard,” said town engineer John Cronin.
MTBE was first detected at the site at 5 parts per billion in 2010, according to the county health department.
A representative from the state Department of Environmental Conservation tested additional samples at the site this week to determine whether further testing is needed, Cronin said. If the DEC data shows elevated levels, the agency will likely pay for the installation of carbon filters at the site, Cronin said.
Residents are asked to avoid drinking the water at the center. Bottled water will be provided.
The contamination’s origin is unclear. One thousand gallons of gasoline was spilled nearby in 1990, according to the DEC, but Cronin said the compound may have come from a homeowner who failed to report a spill.
“You don’t really know what the source is,” Cronin said.
Studies indicate short-term exposure to MTBE is not highly toxic to humans, but many find the odor and taste disagreeable, according to a county notice posted by the town. Longer exposure can cause headaches, nausea, dizziness, irritation of the eyes, ears and throat and confusion.
It is not clear whether other properties could be affected, and town officials said it is up to property owners to have their individual wells tested. About 90 percent of Shelter Island properties rely on private wells, Cronin said.
Lucio Martinez, a chef who lives near the senior center, was alarmed to learn that the contaminant was found in a nearby well. His water was tested about a year ago and was found to be free of contaminants.
“I’ll get it [the water] tested as soon as possible and tell my wife not to cook with it,” Martinez said.