Hartland — The Hartland Conservation Commission advises members of the public to avoid the water in Lulls Brook below the Martinsville covered bridge due to high levels of E. coli.

The Conservation Commission tested the water below the bridge and found 325 E. coli per 100 milliliters, Conservation Commissioner Dean Greenberg said in a Listserv post on Thursday. That’s significantly higher than the Vermont Department of Health deems safe for swimming.

A similar test last week also revealed a high level of E. coli, Greenberg wrote.

“Clearly there is a problem and the public are well advised to avoid contact with the water below the bridge,” he wrote.

Exposure to some types of E. coli can cause people to develop stomach cramps, vomiting and diarrhea lasting up to 10 days, according to the Vermont Department of Health. Most people fully recover, but some develop a serious complication called hemolytic uremic syndrome that can sometimes be fatal.

People who may be sick should call their health care provider.