Inspection crews began performing smoke tests in New City Wednesday in an effort to locate breaks and defects in the sewer system.
For the past six weeks, similar tests have been conducted in Clarkstown and Ramapo, where white smoke could be seen billowing out of manholes and vent stacks of houses.
City officials emphasized, however, that the smoke is not toxic and does not create a fire hazard.
Prior to the beginning of testing, homeowners received notices from the county sewer district asking them not to be alarmed by the sight of smoke.
However, in Nanuet and Monsey, the testing reportedly became a nuisance for fire officials who have received false alarm calls from homeowners and passersby, apparently unaware of the tests.
Smoke testing in Ramapo will continue until Thanksgiving, while Clarkstown residents can expect to see the testing in sewers through mid December.