June 30, 2017 — The Illinois EPA Bureau of Water, Lakes Unit, reported that they have received preliminary results for one of the microcystin samples that were collected near the boat dock behind 357 E. Lake Drive (see map below). The result was 36.2 ug/L, which exceeds the World Health Organization threshold for a high probability of adverse health effects during recreational contact (see chart below). It also exceeds USEPA’s draft recreational guidelines for no swimming.

If surface scum is present avoid all contact with the scum areas and any area that looks greatly discolored (very green). Keep pets away from the water. A test strip at the second location was negative but the EPA says conditions may have changed since samples were collected last Friday. Please observe water conditions and use good judgment before swimming. If it looks bad, it probably is not safe to swim in.

A sign that says CAUTION in red has been posted on the bank of the coves where residents reported possible blue-green algae blooms.  More about blue-green algae, more correctly known as cyanobacteria, is available at https://www.epa.gov/nutrient-policy-data/cyanohabs

Dock Sample – 36.2 ug/L lab confirmed
Cove Sample – Screening test was
     negative for microsystin.
     Lab confirmation not yet available