Residents in Rockland are being told to have their private wells tested for arsenic after a United Water supply well tested positive for the poison. Without testing, well owners can't tell if arsenic exists in their water because it is odorless and tasteless. However, long-term exposure has proven to cause cancer. Residents can have their water tested by the town for $40.

United Water points out that their well that tested positive for arsenic is not used for water supply in Rockland, but as back-up supply. Officials at the water company say there is no harm. However, County Executive Scott Vanderhoef still wants the water company to conduct more tests.

Earlier in the week, Vanderhoef demanded United Water cut back on releasing water from Lake Deforest Reservoir to New Jersey. The county wants United Water to slow down its releases the next two weeks to help the reservoir refill, since it is already at a dangerously low level.