For two days early this month, 2,000 customers of a northwest Ohio water supplier were told not to drink what came out of their taps.
That water, even after treatment, contained too much microcystin, a potentially deadly toxin produced by blue-green algae.
Carroll Township Water and Sewer District, in Ottawa County between Toledo and Port Clinton, became the first drinking water supplier in Ohio to have its product banned because of algal toxins, which can be as harmful as cobra venom or cyanide.
It is unlikely to be the last.
A Beacon Journal review of Ohio Environmental Protection data shows that such algal toxins are prevalent and widespread across Ohio, found in Lake Erie and numerous inland lakes, albeit mostly at low levels that do not trigger bans.
A total of 440 cases of algal toxins have been reported in 2013 on Lake Erie, at state park beaches and from Ohio public water supplies. That total — through Monday — is expected to grow in the coming weeks.
In 2012, Ohio listed 428 algal toxin reports, including 13 public water supplies. That number was 508 in 2011, according to the 49-page EPA report. That’s more than 1,376 reports over the past three years.
The toxins were found in raw (untreated) water from Lake Erie and inland lakes and also in water that had gone through treatment plants.
Such toxins are something “to be very careful of ... and are a big concern,” said Dr. Jeff Reutter, a Lake Erie expert at Ohio State University and director of the Ohio Sea Grant Program.
Those 1,376 cases “should be a fire bell in the night to regulators that Ohio has a problem with toxic algae,” said Jack Shaner of the Ohio Environmental Council.
“There’s no escaping from this toxic algae. There are a lot of toxins out there. It’s proof positive that Ohio regulators need to be serious about this problem,” he said.
Low levels of toxins were detected in Akron’s drinking water reservoirs and in the city’s treated water in 2011, but not in 2012 or 2013, said Jeff Bronowski, Akron’s water supply bureau manager.
No state park beaches in Northeast Ohio made the 2013 EPA list, either.
Ohio tests state parks only with swimming beaches. Additionally, it tests only after state personnel have spotted algal blooms and they have been tested to see what type of algae is involved in turning the water the sickly green color.
Operators of public water supplies may test, but they are not required to do so. Most submit their results to the EPA. The state agency requires extra precautions when microcystin levels exceed 0.25 parts per billion.
The state limit for drinking water is 1 part per billion.
Many inland lakes in Ohio are not tested at all for toxins.
Also alarming is the growing evidence that toxins might remain in Lake Erie and Ohio’s inland lakes for weeks or months — even after the algae blooms themselves disappear.
That means that absent the visual evidence of algae, the water still might not be safe for swimmers, anglers, boaters and others, said Linda Merchant-Masonbrink of the Ohio Environmental Protection Agency.
That makes it tougher for Ohioans to determine if they want to go back into the water, she said.
Previously, the general rule was that the water was believed to be safe after the bloom disappeared. It appears to be more complicated, Merchant-Masonbrink said.
Ohioans, she said, will need to make their own decisions about going into the water after checking state algae advisories. These are “serious toxins, not something to be sneezed at,” she said. They pose “a pretty significant threat.”
If in doubt, the best advice is to stay out of the water, said Merchant-Masonbrink.
The state advises that water enthusiasts rinse off after swimming. They should not swallow lake or river water and should avoid contact with water showing algal blooms or pea green in color.
Also, eat only fillets of fish caught in algal-filled waters because the toxins tend to concentrate in the fish guts.
Symptoms of algal poisoning include numbness of lips, tingling in fingers and toes, dizziness, headache, rash or skin irritation, abdominal pain, diarrhea and vomiting. For pets, signs include lethargy, staggering, convulsions, difficulty breathing and vomiting.
The toxins themselves are colorless, odorless and water soluble. They will naturally disappear over time. They move with winds, currents and water levels.
Not all algal blooms produce poisons.
Ohio has at least nine organisms that can trigger harmful algal blooms. They are native and common to Ohio’s lakes.
The most common toxic algae, microcystis, returned to Lake Erie in 1995.
High levels of microcystin are known to affect the liver. At low, prolonged doses, they promote liver tumors. Exposure to the toxins also can cause gastrointestinal and nervous system problems.
Phosphorus from farm runoff into the Maumee River produces the excessive algae in Lake Erie. Sewage treatment plants and sewer overflows also contribute to the algae problem.
Simply killing off algae releases the toxins, however, and may make matters worse, Merchant-Masonbrink said.
Ohio was unaware of the algal toxin problem until 2009, when federal water sampling results were released.
The state’s algal blooms got numerous headlines in 2010, when algal toxins were found in Lake Erie and 20 inland lakes. A total of 48 people were sickened and four dogs died after exposure to water from Lake Erie or at four inland beaches.
Locally, the algal problem was found in 2010 at Wingfoot Lake and West Branch state parks.
Toxins also were found that year in Akron’s three drinking-water reservoirs: Lake Rockwell in Portage County and East Branch and LaDue reservoirs, both in Geauga County. They were found once — at low levels — in Akron’s finished (treated) drinking water.
That year produced one of the largest algal blooms ever seen on Lake Rockwell, Bronowski said.
In 2011, Akron reported low levels of three toxins in treated water and in water from Lake Rockwell. What was found was microcystin, saxitoxin and cylindrospermopsin, all from algae, and all below EPA limits.
Bronowski called what happened in Ottawa County “very concerning” and “surprising.”
Most water managers had been confident that treatment methods were sufficient to make raw water with toxins safe to drink, but that didn’t happen in this case, he said.
Akron’s main weapon against the toxins is powdered activated carbon that is added to the lake water early in the treatment process. The toxins, if present, attach to the carbon, drop out of the water and settle into the sludge that is hauled away and turned into topsoil.
This summer has been rainy and not overly hot, and that gives Akron more flexibility in adjusting water flows to minimize algal blooms, Bronowski said.
You can access the Ohio EPA toxic algae list at: www.epa.ohio.gov/ddagw/HAB.aspx.
By Bob Downing - Akron Beacon Journal (MCT)
©2013 the Akron Beacon Journal (Akron, Ohio)
Visit the Akron Beacon Journal (Akron, Ohio) at www.ohio.com
Distributed by MCT Information Services