Health advisory remains in place on lake

CELINA - Beaches around Grand Lake remain under an elevated recreational public health advisory, despite the Ohio Department of Health on Thursday incorrectly sending out notifications that the advisories had been lifted.

Around 8:27 a.m. Thursday, the state's department of health sent out email notifications that the advisories at Windy Point, Main West and the state park campground had been removed by the Ohio Department of Natural Resources.

The advisories remain in place, according to ODNR spokeswoman Stephanie O'Grady. The Ohio BeachGuard website was displaying old advisories, and those recently were closed or re-instated to reflect current conditions, she said Thursday.

An elevated recreational public health advisory is put in place when algal toxins have been detected at unsafe levels. People are advised to avoid all contact with affected water sources when this advisory is in effect.

While state contact advisories remain in place, levels of microcystin - the toxin produced by the lake's blue-green algae - have been low recently.

Data collected at the Celina City Water Treatment Plant on May 11 showed microcystin levels falling below detectible levels. Previous samples collected by the plant on May 4 and April 24 showed microcystin levels of 0.46 micrograms per liter and 0.49 micrograms per liter respectively. Samples collected by ODNR at Windy Point and the East and West beaches on May 17 show levels hovering around .3 micrograms per liter.

For comparison, last year the lake's microcystin levels measured by the Celina Water Treatment Plant ranged between 39.7 and 47.2 micrograms per liter during the month of May. Microcystin levels had jumped near the end of April, when levels increased from 9.1 micrograms per liter at the start of the month to 32.4 micrograms per liter by April 28.

A level of 20 micrograms per liter triggers an elevated recreational public health advisory. Signs warning of a bloom would still be present with microcystin levels higher than 6 micrograms per liter, as well.

ODNR typically begins monitoring microcystin levels during the swimming season, from May to September. Blue-green algae typically grows after or during warmer weather.

Microcystins can harm the liver, cause gastrointestinal symptoms and rashes and can sicken people and kill small animals.

Phosphorus-fed toxic blue-green algal blooms have resulted in state-issued water advisories on Grand Lake every year since 2009. The local watershed is the only one in the state designated as distressed due to unsafe algal toxin levels, a designation the watershed received in January 2011 after animals and humans were sickened by the toxins in 2010.