The floodwater has receded from the Truro area after Monday's heavy rains, but what is left behind could be a health hazard for homeowners with wells.
The province is concerned about bacteria that has made its way into the water supply after heavy flooding in the Truro-Bible Hill area.
Officials with the Department of Environment said there are plenty of dangers the eye and palate may not detect.
"Flood waters can deposit chemicals and bacteria into the well water. So it's very important that during, and especially after, a flood that people stop drinking the water, bathing in it, and cooking with it until they know it is safe," said Paula Putnam, district manager for the department.
Putnam said that means getting it tested from a certified lab, such as the Colchester Regional Hospital in Truro.
Environment officials say homeowners need to pick up bottles from a lab, sterilize the faucet, fill with tap water, then return the samples to the lab.
A testing facility in Bible Hill has already detected E. coli and fecal coliform in some samples.
But since testing is up to property owners, the province can't measure the full extent of the problem.
Putnam said the local office has received calls concerning water quality in the area but the Department of Environment is not able to pinpoint one specific source for the contamination.