Stay out of Brownlee Reservoir this weekend. Officials say the water is a health hazard.

Public health officials on Friday warned against entering the water at Brownlee Reservoir, issuing a health alert due to bacteria.

Recent samples taken in the reservoir found high concentrations of bacteria-producing blue-green algae that may cause illness to humans and animals.

Blue-green algae bacteria occur naturally in waters with high levels of nutrients, such as phosphorus and nitrogen.

Under certain conditions, some types of algae can release toxins into the water that are harmful to people, pets and livestock.

The blooms are generally green, or blue-green, and may form thick mats along shorelines. These may look like a surface scum, resembling pea soup and can have an unpleasant odor.

Southwest District Health warned that people and animals should not drink or enter the water. Fish from the reservoir should be cleaned and rinsed with clean water before consumption. Only the fillet portion of the fish should be consumed, and all other parts should be discarded.

According to the Centers for Disease Control and Prevention, people who are exposed to water with high concentrations of blue-green algae may experience nausea, vomiting, diarrhea, difficulty breathing, skin irritation, allergic responses, liver damage or neurotoxic reactions such as tingling in fingers and toes.

Symptoms in humans are rare, but anyone with symptoms should seek medical attention. Boiling or filtering the water will not remove blue-green algae toxins.

For more information about harmful algal blooms, visit the Department of Environmental Quality’s website.