Tuesday, August 24th, 2010
Toxins drop considerably
Lake Loramie advisory lifted
By Nancy Allen
GRAND LAKE - Algae toxin levels in Grand Lake have dropped substantially, and a water quality advisory for Lake Loramie has been lifted after two consecutive weeks of good results, the Ohio EPA says.
Though toxin levels have dropped, a no contact advisory for Grand Lake remains, warning people to avoid any and all contact with the water. Ohio EPA spokeswoman Dina Pierce said that advisory will be lifted after two consecutive weeks of non-detection for anatoxin-a, saxitoxin and cylindrospermopsin and microcystin levels below 20 ppb.
Pierce said there is no way to know if Grand Lake's blue-green algae problem is coming to an end for the year.
"That's the hope, that it is winding down, but it can definitely fluctuate depending on the weather" Pierce said. "August and September are peak seasons for blue-green algae blooms, but Grand Lake is a bit different because it's so shallow and it warms up pretty quickly."
Pierce said toxin level results from samples taken last week are promising, but there are no guarantees.
"It's just a matter of continuing to monitor and keeping an eye on things and hoping we've seen the worst of it."
Microcystin levels from water samples taken last week at the three state park beaches and near Pizza Hut ranged from 4.1 to 14 parts per billion (ppb). The 14 ppb was recorded at the east beach in Auglaize County. Microcystin levels the week prior ranged from 2.5 to 20.2 ppb.
The World Health Organization's recreational safety exposure limit for microcystin, a liver toxin, is 20 ppb. The WHO deems the toxin a severe health risk when they reach 2,000 ppb, which it did in Grand Lake last month.
Anatoxin-a levels also were down, with levels at all three beaches below 1.0 ppb this week. Those levels ranged between 6 to 10 ppb the prior week.
No saxitoxin was detected at any of the beaches or near Pizza Hut, and only the east beach had a measurable level of cylindrospermopsin, at 0.062 ppb, just above the detection limit of 0.05 ppb.
Anatoxin-a and saxitoxin are both neurotoxins, while cylindrospermopsin is a liver toxin.
The advisory at Lake Loramie was lifted after samples collected from the park's beach last week did not contain microcystin, cylindrospermopsin, saxitoxin or anatoxin-a.
In fact, Lake Loramie never had toxin levels of any real safety concern, Pierce said. The first water samples taken two weeks ago after a blue-green algae bloom was spotted produced a reading of 0.2 for microcystin and nondetect for anatoxin-a, saxitoxin and cylindrospermopsin.
Advisories for the lake at Dillon State Park, Muskingum County, and at the lake at Lake Hope State Park, also have been lifted, the EPA said.