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Biologists Use New “Bug Index” to Evaluate Ohio River Water Quality

October 26, 2012

For years, biologists have analyzed fish tissue to gauge the water quality in rivers. But in the Ohio River, researchers are now looking at bugs, too.

Ryan Argo and Jamie Wisenall are standing in the shallows of the Ohio River, just outside Owensboro. With long nets, they reach towards the river bottom, scooping up the sediment.

They wade back to the boat, and examine their haul…lots of larvae, and one identifiable leech.

Argo and Wisenall are biologists with the Ohio River Valley Water Sanitation Commission, or ORSANCO. For the past seven months, they’ve spent hours of their time on the river, looking for bugs.

ORSANCO is an interstate commission responsible for regulating pollution on the Ohio River. Its biologists are charged with collecting data about the health of the river. And this year, for the first time, they’ve developed an index that looks at macroinvertebrates—or bugs—to determine whether the river is healthy.

The index is a way to determine water quality by looking at the quantity and quality of bugs in the river. It involves complicated calculations, but the premise is simple. Biologist Rob Tewes says some bugs are harbingers of health.

“Those are your mayflies, stoneflies and caddisflies,” he said. “By and large those species of those genera are fairly intolerant. And when you have high numbers and high diversity of those three species, by and large it’s agreed upon by the scientific community that you have a pretty good environment there from a water quality standpoint to support those organisms.”

Indexes aren’t anything new. ORSANCO has been sampling fish tissue for years, and using indexes to analyze the data. But macroinvertebrate indexes have historically been used on smaller tributaries. The recently-developed method for the Ohio River is one of the first times a bug index has been used on a body of water this large and complex.

Ryan Argo developed the index. He says using both fish tissue and macroinvertebrate indexes will give regulators a more complete picture over how factors like pollution and invasive species affect the Ohio River as a whole.

“And that’s kind of why you have more than one index because you can kind of assume that if there’s something going wrong with the fish, there’s something that’s going wrong with what the fish are eating,” Argo said. “That’s why we wanted to have another indicator, to basically give our assessments more strength and more power.”

The Ohio River serves a lot of different functions: it’s a major transportation thoroughfare, and provides water for electricity to coal-fired power plants and hydroelectric dams. And, oh yeah, it’s the drinking water for more than 3 million people. Tewes says it’s that last fact that makes the biologist’s work so important.

“So there’s a lot of impacts happening here, so trying to figure out how the bugs relate to that and how to relate those back to ultimately, the river being a source of water for municipalities is kind of a big deal,” he said.

The biologists take 10 samples from the river sediment, then motor downriver a bit to where a flag sticks out of the bank. Argo wades over, and pulls on a rope lying on the river bottom. Slowly, a concrete block emerges, with columns of masonite rising out of it.

“It’s basically like a macroinvertebrate condo,” he says.

This “condo” is covered with mud from the river. When  Argo carefully rinses the mud off into a bucket, then runs it through a sieve, the residents of the “bug condo” appear. Those samples, along with the ones collected from the river bottom, go into jars and are preserved with alcohol. Later, they’ll go to a lab, where scientists will identify the species. All of this data plays a part in the macroinvertebrate index, and when several years worth are collected the biologists will have more information to use when determining water quality.

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Regulators Grant Mercury Variance for Ohio River Plant

October 11, 2012

Ohio River regulators have voted unanimously to allow a West Virginia company five more years to comply with new, more stringent pollution requirements.

Right now, companies that discharge into the Ohio River are allowed a mixing zone, where the pollution mixes with the river and gets diluted; monitoring is done downstream to make sure the company is in compliance. But next October, no mixing zones are allowed. The pollution coming straight out of a company’s pipe has to meet new, stricter standards for mercury, set by the Ohio River Valley Water Sanitation Commission, or ORSANCO.

But PPG Industries, a chlor-alkali plant in Natrium, West Virginia, will have five more years of using a mixing zone. The variance allows the company to discharge a monthly average of 55 nanograms of mercury per liter of water. The number is far above the new standard (12 nanograms of mercury per liter), but reduced from the company’s historic numbers (which used to top 200 nanograms of mercury per liter, but more recently have been around 70).

Thomas Easterly is an ORSANCO Commissioner and the head of Indiana’s Department of Environmental Management. He says not granting the variance for PPG would have shut the plant down, and still not improved water quality. That’s because the grounds of the plant are contaminated, and a lot of the mercury pollution is coming in groundwater runoff.

Well that’s something that we would normally worry about but in this case, it wouldn’t matter if the plant operated because the pollution’s from the ground, so we need to deal with that,” he said.

Easterly also noted that even if the plant shut down, it wouldn’t be able to meet the new, strict 12 nanograms of mercury per liter standard.

Environmental groups fought the variance, arguing that there’s already a problem with high levels of mercury in the Ohio River. Mercury bioaccumulates in fish and eating fish with high levels of mercury can be harmful to children and women in childbearing years.

As one of the conditions of the variance, ORSANCO is requiring annual fish tissue samples. The mercury standard for fish is .3 milligrams per kilogram of tissue, and if the fish downstream don’t meet that benchmark, ORSANCO commissioners can reconsider the variance.

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Frequent Combined Sewer Overflows Continue in Jeffersonville

July 3, 2012

In the past three months, Jeffersonville has had eight combined sewer overflows, or CSOs. This is when water levels rise and the city’s sewer system releases untreated sewage and wastewater into the Ohio River so it doesn’t back up into people’s homes. The releases pollute the river and spread E. coli bacteria.

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Volunteers From Six States Expected to Participate in River Cleanup Tomorrow

June 15, 2012

Volunteers from Pittsburgh to Cairo, Illinois will gather along the banks of the Ohio River tomorrow for a concentrated effort to clean the river.

This is the 23rd annual Ohio River Sweep, and more than 15,000 volunteers from six states are expected to participate. The event is organized by the Ohio River Valley Water Sanitation Commission, and locally by the Metropolitan Sewer District.

There are six Louisville-area locations where volunteers will be gathering debris from the banks of the river from 9:00 a.m. to noon tomorrow. The sites are:

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