Ossining Changes Water Source To Relieve Taste, Odor Problems

OSSINING, NY — Ossining Water Department officials are now only using water from the Indian Brook Reservoir to supply residents. They expect that the switch will gradually reduce the taste and odor problems caused by an organic compound in the Croton Reservoir and give them time to take the next necessary steps.

New York City engineers determined that the taste and odor issues stemmed from a specific organic compound 2-Methylisoborneol (MIB).

The Ossining Water Department has been conducting additional tests under the guidance of Kirk Nowak, Ph.D., an expert on taste and odor issues associated with potable water, to gain additional information and develop more effective strategies to address the issue.

"Today, we received results from Engineering Performance Solutions, an outside laboratory that specializes in testing algae that can cause taste and odor issues," they wrote residents on Wednesday. "It was found that the Croton water source had a result of 105.0 (ng/L) MIB, and Indian Brook had a result of <1.0 (ng/L) MIB. We immediately called the Westchester County Department of Health to get authorization to move to 100% Indian Brook as our source."

Officials said they will use this time period to design and implement a Powder Activated Carbon System to address this and similar issues in the future.

"In the interim, we will continue to use 100% Indian Brook as our water source while we continuously monitor reservoir levels. System demand is low this time of year, so it will take several days for the Croton Reservoir water already in the system to flush itself out. During this time, you may continue to detect taste and odor issues. However, within the next week or two, we anticipate significant improvements," they said.

This condition has never been experienced during the 33 years of the water treatment plant operation. Further, this is not an Ossining-only issue. The taste and odor has affected all municipalities that draw from the Croton Reservoir. Despite the taste and odor, the water has been and remains safe to drink.

"As we embark on the construction of a new water treatment facility, we will be working closely with experts to incorporate technologies needed to prevent this and similar issues in the future," they said.

Rockland County has also recently had problems with an organic compounds in the water supply. This fall residents complained of stinky water. Engineers found that algae naturally in Lake DeForest released geosmin, which according to scientists at Brown University, literally translates to "earth smell." The 4-mile long, 6-billion gallon reservoir is in Clarkstown.