WINDSOR, ONT. -- Around 50 Leamington homes will be affected by a boil water advisory issued Tuesday evening.

Windsor-Essex medical officer of health Dr. Wajid Ahmed issued the advisory for homes on the north and south side of Mersea Road 10 between Highway 77 and Kent Rd 1. This includes Mersea Road 12 (addresses 958 to 1018) and Kent Road 1 (addresses 949 to 1019).

“This is a notification of an adverse water sample and possible contamination of the water supply,” a news release from Windsor-Essex County Health Unit states. “The boil water advisory will remain in effect until further notice.”

The boil water advisory impacts around 50 houses. The Union Water System has hand delivered notices house to house.

“What we are looking for is basically a coliform count, which is an indication that basically informs that some sort of contamination happened," Dr Ahmed said of how water testing is conducted. 

Ahmed says sample testing is often performed in situations where there is a water main break due to construction

“Once it’s fixed, they can do more flushing, test the water and ensure the water is safe for consumption," he said. "A follow up test is almost always needed before the advisory is lifted.”

No illnesses have been reported.

WECHU is asking residents to only use bottled water or water brought to a hard boil for one minute to be used for consumption or food and ice preparation.

- With files from CTV Windsor's Sijia Liu