Friday, July 10th, 2026
New clean water technology to be tested in Mercer Co.
By William Kincaid
CELINA - A global conservation organization is seeking permission to use a small stretch of land near Beaver Creek owned by Mercer County to conduct a two-year pilot test of a system designed to remove nutrients from surface waters.
The Nature Conservancy wants to set up its algal raceway technology on the corner of Cassella-Montezuma Road and Guadalupe Road near the Montezuma Club Island wastewater treatment plant.
"They will be building a small raceway, which is going to be about 500 feet long and maybe 3-foot wide," Mercer County ag and natural resources director Theresa Dirksen told The Daily Standard. "The goal is to pump water from the creek into this raceway, and the goal of the raceway is to grow algae on it to remove nutrients before the water goes back into the creek."
The Mercer County Commissioners tabled a land use agreement with The Nature Conservancy this week to allow for a legal review by the Mercer County Prosecutor's Office.
The H2Ohio program awarded funding to TNC for a project to better understand the performance of algal raceway technology for reducing nutrient loading in surface waters of Ohio, Ashlee Decker, a senior restoration ecologist with TNC, said in an email to the newspaper.
"The grant will cover the cost of constructing the pilot project, monitoring, reporting, and decommissioning the project. There will be no cost to Mercer County and the property will be returned to the same condition as it is today," Decker said.
TNC is a global conservation organization aimed at using science to "create innovative, on-the-ground solutions to our world's toughest challenges so that nature and people can thrive together," according to the group's news releases. It currently works in 83 countries to tackle climate change, conserve lands, waters and oceans, provide food and water sustainably, and help make cities more resilient, often collaborating with local communities, governments, the private sector and other partners.
Stephen Jacquemin, an environmental sciences professor at Wright State University-Lake Campus, will monitor the results of the Mercer County pilot test.
"It's going to be a very shallow, very long, almost like a trough or a gutter shape," Jacquemin said of the raceway. "It's going to be about a meter in width and maybe … up to 5 centimeters deep."
Water from Beaver Creek will be pumped into the raceway and flow over a shallow, sloped surface.
"Natural algae that's already in the water will begin to colonize the raceway, and they will … take out all sorts of dissolved nutrients out of the water," Jacquemin explained. "So the hope is that you have nutrient-rich water going in and then you have clean water going out."
The raceway will likely consist of a natural or synthetic product that is porous and rough with lots of surface area for the algae to attach itself to, according to Jacquemin.
"The algae that's going to really colonize this raceway is going to be benthic algae. So it's algae that likes to attach itself to surfaces and grow almost like a biofilm over surfaces," Jacquemin said. "When you take a few of them and you give them the exact habitat that they want - something rough that they can attach to that's shallow and sunny and nutrient-rich - they'll grow like crazy."
Once the algae thickens, it will be harvested and removed from the raceway, Jacquemin said.
"A part of the pilot is understanding growth rates of algae in this setting, which will determine how frequently the algae must be harvested," Decker said. "We estimate once every two weeks, but that could change. The algae from this pilot will be discarded because quantities will not be viable for commercial uses, however, large scale projects could have enough quantities for commercial uses including as a soil amendment, compost, or feedstock, or energy.
TNC would like to begin construction on the raceway at the end of July.
"This is an extremely uncommon practice. There are not that many replicants of this out there. And so part of the reason that the TNC and the State of Ohio are partnering with us at Wright State to monitor it is so that we can better establish … the degree of efficacy of nutrient removal," Jacquemin said.
He has high hopes for the pilot test.
"When I look at all these different styles and flavors of nutrient reduction technologies that are out there, the practices that incorporate the aspects of nature, that do what we already know they do, always seem the most promising to me," he said. "This is the natural system. You're going to leverage the power of the algae that's already in the system. You're just going to encapsulate it, amplify it and then use it to do some good."
