KEY WEST, Fla. (AP) — Florida Keys residents have yet another concern as they rebuild after Hurricane Irma: dirty water.

The Florida Department of Health in Monroe County on Monday issued an advisory for all public beaches throughout the island chain due to potential effects from Hurricane Irma.

Spokeswoman Cammy Clark said in a news release that the advisory is precautionary, adding that swimming is not advised.

Clark says four environmental teams will conduct tests to determine the water quality. Results from the tests will take about seven days. Until then, she says people should assume that water may pose an increased risk of disease.

She also says residents should avoid contact with flood water, which may contain fecal matter from sewage systems, agricultural and industrial waste and septic tanks.