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Farm 'Treatment Train' May Be Key To Preventing Algal Blooms At East Fork

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Ann Thompson
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WVXU
Nearly half of the nitrogen run-off at Cornwell Farms, a test site in Jackson Township, is captured before it leaves the site.

Even the U.S. EPA is noticing Clermont County's innovative approach in efforts to prevent toxic algal blooms. Its Undersecretary has visited the site. The project involves a Jackson Township farm, a cover crop and an excavated waterway that captures pollutants miles before they reach East Fork Lake.

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Credit WCPO
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East Fork has warned swimmers of the danger with these signs since 2016.

For the last six years swimmers at East Fork Lake (Harsha Lake) have become all too familiar with the danger. Farm run-off is blamed for high levels of nitrogen and phosphorus which are harmful for people and aquatic life.

One solution may be fifteen miles away on a farm.

That's where the Clermont County Soil and Water Conservation District is testing a system it designed to "cover and capture" the fertilizer.

The District began planning the preventative system in 2014 even before algal blooms were a problem at East Fork. It turns out the idea, modeled after an urban one in the North Eastern U.S., is very effective. In the last three years it has captured 46 percent of the nitrogen, preventing it from going into a tributary to East Fork Lake.

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Credit Ann Thompson / WVXU
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WVXU
(from left) Jake Hahn, Hannah Lubbers, Laura Lair and John McManus study the detention pond, one part of the system to capture fertilizer run-off.

Here's how the system-collectively called a "treatment train," works:

Step 1

Nitrogen and Phosphorus run through a detention pond filled with gravel. It holds the water for a short period of time and lets the sediment settle out.

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Credit Ann Thompson / WVXU
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WVXU
Workers excavated a grassy waterway and made it a little bit wider and deeper so the farmer isn't losing much land.

Step 2

The remaining water and sediment is slowly filtered out through a pipe to a submerged vegetation that is downstream and that's where the nitrogen treatment takes place. The submerged plants consist of rushes, sedges and iris.

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Credit Ann Thompson / WVXU
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WVXU
This is the submerged vegetation that further treats the nitrogen. It consists of rushes, sedges and iris for color. The Farmer said he just didn't want cattails.

The District's Laura Lair regularly checks water samples to make sure the system is still working. It is refrigerated to preserve the samples.

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Credit Ann Thompson / WVXU
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WVXU
Laura Lair checks the samples. She can also do it remotely. The refrigerated system is powered by solar.

The USDA must still approve the idea. When it does, it's expected farmers can get money to install it. And the more farmers using it, the better says the Soil and Water Conservation District.

Ann Thompson has years of journalism experience in the Greater Cincinnati market and brings a wealth of knowledge and expertise to her reporting. She has reported for WKRC, WCKY, WHIO-TV, Metro Networks and CBS/ABC Radio. Her work has been recognized by the Associated Press and the Society of Professional Journalists. In 2019 and 2011 A-P named her “Best Reporter” for large market radio in Ohio. She has won awards from the Association of Women in Communications and the Alliance for Women in Media. Ann reports regularly on science and technology in Focus on Technology