Suffolk County health officials will test about 34 private wells in Brookhaven for possible contamination after tests revealed the presence of ammonia and volatile organic chemicals, like chlorobenzene, an ingredient in some pesticides, Newsday reported. A nearby farm, Hamlet Organic Garden, also found low levels of pollution in one of its wells, and is drilling another, deeper well to bypass the pollution.

Ammonia and volatile organic compounds have been detected in some Brookhaven wells.The likely cause is a municipal landfill, closed in 1980 and capped in the 1990s to prevent leachate, or leakage. In the late 1980s, municipal water lines were extended to residents near the old landfill, but not all chose to hook up to them.  Since the closure, there has been ongoing groundwater monitoring but no mapping of the migration of the so-called leachate plume.

The amounts of VOCs discovered in the tests are below safe drinking water standards. There are no drinking water standards for ammonia, which is "very toxic to fish," Robert Waters, supervisor of the Suffolk County Health Department's Marine Bureau, told Newsday. Consequently, the New York State Department of Environmental Conservation will conduct tests next year to determine if brook trout or other marine organisms have been adversely affected.