[USA] It looks awfully gross, like a mossy-colored layer of thin paint. It’s nasty, too, full of toxins that can cause rashes, nausea, severe headaches, even liver damage.
Turns out, it’s the worst toxic bloom in the history in the Ohio River, according to authorities that monitor the health of the river.
The last time an algal bloom was reported on the Ohio River was seven years ago. It bloomed for two weeks, spread across 30 miles.
As of Thursday, this month-long bloom ran 500 miles in length – from near Wheeling, West Virginia, to past Louisville.
And it’s not expected to go anywhere, anytime soon. So long-planned river cleanups have been canceled, as has the Great Ohio River Swim that was scheduled for Sept. 27 and is now tentatively rescheduled for Oct. 10. Health officials advise staying out of the water for now.
No cases of sickness have been reported, so why should we care about toxic algae? What threats does it pose? Could we, like it so happened in Toledo, wake up one morning to advisories not to drink or bathe in the water coming from our taps?
Q: Is this normal?
A: The Ohio River Valley Sanitation Commission, which monitors and helps regulate pollution on the Ohio River, calls this unprecedented. So, in short, no.
All kinds of algae occur naturally in the environment and most are harmless. In fact, the blue-green toxic kind is always in the Ohio River, according to Greg Youngstrom, an environmental specialist with the Ohio River Valley Sanitation Commission , but there is usually far, far less of it.
Q: Why is this bloom so big?
A: Two factors are key to the size of these blooms: the amount of nutrients in the water and water conditions. Toxic algae thrive on nitrogen and phosphorus – nutrients contained in fertilizers spread on farms and lawns that wash into creeks and streams when it rains. They’re also byproducts of wastewater treatment plants and industrial processes along the river, Youngstrom said.
The second factor – water conditions – seem to be a bigger factor when it comes to this particular bloom, said sanitation commission Executive Director Richard Harrison. The commission monitors the amounts of nitrogen and phosphorus in the water; recent trends show a slight increase in phosphorus but not a significant change in nitrogen since the 2008 bloom. So it is not that we’re putting higher amounts of these nutrients in the water.
For the last several weeks, the river has been slower than normal. Generally, it flows between 1/2 mph to 1 mph. Lately it’s been less than a 1/4 mph, creating “lake-like conditions.” Slow water also means clearer water (because there’s less movement to stir things up), allowing the sun to penetrate the water with ease and promote algae growth.
The air temperature, and therefore the water temperature, has been relatively warm. Blue-green algae likes warm conditions.
Q: What does it matter that this algae exists in our waters?
The fossil record shows that cyanobacteria, the official name for this algae, has been around for 3.5 billion years, so what’s the big deal? Well, it creates a toxin called microcystin, which can cause nausea, diarrhea, vomiting, severe headaches, fever and even liver damage. It can be particularly dangerous to children, the elderly and those with low autoimmune systems.
High levels have claimed animal’s lives, including dogs, in the United States. In Brazil, 52 people died in 1996 due to a liver toxin, cyanobacteria, according to a report published in Environmental Health Perspectives, a journal supported in part by the National Institute of Environmental Health Sciences.
Q: Could our water supply be compromised?
That’s “very unlikely,” says Jeff Swertfeger, superintendent of water quality at Greater Cincinnati Water Works. The water works and the Northern Kentucky Water District, which extract a large portion of the region’s drinking water from the Ohio River, have advanced systems to get the algae and toxins out of the water.
River water is sucked into water works intakes and pumped through a series of basins where the algae is removed by allowing it to settle and running it through sand filters, Swertfeger said. Two steps include adding carbon, powdered at the front end and granular-activated at the back end. Carbon absorbs the toxins and then the carbon is removed.
Toledo did not have as sophisticated a system and was dealing with a higher concentration of toxins, Swertfeger said. In Cincinnati, the water is tested throughout the process and has never risen above limits outlined by the U.S. Environmental Protection Agency, Swertfeger said.
Q: What is being done?
About this bloom? Monitoring and essentially nothing else, Harrison of the sanitation commission said. The toxins exist inside the cells of the algae; breaking them open would disperse the toxins more. So we have to let nature take its course.
In the bigger picture, the agricultural and water treatment industries are dealing with pressures, even from the legislative level, to reduce their discharge of nutrients. There are fertilizers on the market that don’t contain nitrogen and phosphorus, too.
Q: How long will the bloom stick around?
Hard to say. Underlying conditions have to change. So a hard rain that will get the river moving more could help as could prolonged cooler temperatures, according to the folks at the sanitation commission.
Q: What can the public do?
Keeping rain water where it falls, either with rain barrels, rain gardens or green roofs can help. Otherwise, just stay out of the river for now. Anyone who thinks they may have gotten sick or developed a rash because of toxic algae is encouraged to report it to their local health department.
Photo: (Photo: The Enquirer/Patrick Reddy)
View original article at: What you should know about a 500-mile algal bloom on Ohio River