One of the natural gas industry's selling points on why New Yorkers should welcome drilling of the vast Marcellus Shale is that the method of choice, hydraulic fracturing, has never contaminated a drinking well or water supply, or caused any environmental mishap in this state.

Never. That's a pretty definitive word, allowing no exceptions. But in this case, it may require an asterisk. Or a bunch of them.

He claims agency files fail to include water contamination cases in western counties.

ALBANY -- State environmental and health officials are looking into at least 24 sites in the Capital Region, where toxic vapors may be rising from underground pollutants previously considered contained. "Vapor intrusion" may be exposing people -- outdoors and indoors -- to carcinogens.

A graphic providing a history and explanation of Methyl tertiary butyl ether (MTBE).