Pass Lake exceeds the state standard for toxic algae, according to the state Parks and Recreation Commission.
People are advised against swimming in the Fidalgo Island lake, which is part of Deception Pass State Park. In addition, children and pets should be kept away from the water.
According to the commission, pets that lick the toxic water off of their fur may die. Boating and fishing are allowed as long as boaters and fishermen follow the guidelines.
Results of the test indicate an excess of microcystin in the lake, which, according to the Environmental Protection Agency, can cause abdominal pain, headaches, sore throat, vomiting, nausea, dry cough, diarrhea, blistering around the mouth and pneumonia in humans.
The CDC recommends anyone who comes into contact with the toxic water to rinse off with fresh water as soon as possible and seek help if they are poisoned or begin displaying symptoms.
Pass Lake has frequently tested above the state’s recommended recreational guideline for microcystins since 2016, according to data from the Washington State Freshwater Algae Control Program.