MOUNT VERNON — Environmental advocates are concerned about the effects of allowing a Chesterville gravel company to discharge more sediment into the Kokosing River.
Around 84 people attended an Ohio Environmental Protection Agency (OEPA) hearing on Wednesday at Mount Vernon Nazarene University.
The National Lime & Stone Company in Chesterville asked to modify its NPDES (National Pollutant Discharge Elimination System) permit. The change would allow the company to discharge more total suspended solids (TSS) into the river.
“The permit is set up to require monitoring limits on those expected pollutants in the discharge. It’s ensuring that the receiving stream is protected and is not going to have a loss of use,” Allison Cyzck of the OEPA said.
The Kokosing is a warmwater habitat with mussels and hellbenders among its endangered species. OEPA last studied the river in 2007.
Gambier village councilman Phil Brooks said increasing the discharge is a bad idea.
“The river belongs to all of us; the river belongs to this region. So wherever the sediment lands is bad for us,” he said.
Gambier resident Stephen Van Holde said his children grew up playing in the river.
“I don’t think you can quantify the value of nature, of an intact ecosystem,” Van Holde said. “These are things that really are without price and that we need to value more and more as our world becomes more and more threatened.”
Curtis Castro represented Friends of the Kokosing Scenic River Group and the Onion Bag project.
“High TSS levels will increase turbidity, reduce light penetration and hinder photosynthesis for aquatic plants,” Castro said. “It could reduce sensitive mussel populations and harm the hellbender, including those recently reestablished in the Kokosing Scenic River.”
OEPA modifies gravel company’s request
National Lime & Stone plans to mine deeper into its quarry and applied to modify its permit in June 2025.
The current permit allows the company to discharge up to 28 million gallons per day (MGD). It also requires weekly TSS sampling and daily flow monitoring.
The company requested an increase in TSS to 30 mg/L monthly and 45 mg/L daily. It also asked to reduce sampling to once a month.
After considering earlier public comments, the OEPA modified the company’s request.
“We developed more stringent limits to ensure that the use of the river is maintained, and we did not agree to reduce the monitoring frequency,” Cyzck said.
The OEPA proposed that flows between 4 MGD and 28 MGD have monthly and daily concentration limits of 15 mg/L and 30 mg/L, respectively.
Flows under 4 MGD would have TSS rates of 30 mg/liter monthly to 45 mg/L daily.
The OEPA based its recommendation on a literature review.
“The information we have shows that it is a small impact, so the river can handle this discharge,” Cyzck said.
“There would not be an impairment of the use or the water quality, the wildlife, the fish. The habitat would be protected of this discharge and this volume and this concentration going out.”
The group was not convinced.
“If you haven’t studied this river since 2007, you don’t have a very accurate picture of the current wildlife in the river. Therefore, how would you be able to have an accurate indication of the impact of this increased discharge?” Mount Vernon resident Sam McDonald asked.
Monitoring and potential loss of groundwater
Residents who spoke were uncomfortable with National Lime & Stone self-monitoring and reporting data.
Cyzck said the national NPDES program is a self-monitoring system, but companies have to use approved labs.
“There are federal regulation methods that they have to follow. So they can’t use an in-house method for sampling suspended solids,” she said. “There’s an EPA-approved method that they have to follow.”
Additionally, Chloe Welch said OEPA staff review the data and physically inspect the facility to ensure the company correctly reports the number.
Two Chesterville residents were concerned about the effect on their groundwater if the company pulls out more water for use.
“The mine will have to get their permit through ODNR, and they have hydrologists that look at all of the groundwater concerns. I believe they’ve done that,” Cyzck said.
Knox County landowner Jay Dorsey noted that although there is a monitoring station just north of Mount Vernon, most of the sediment impact will occur within 0.25 to 0.50 miles of the quarry site.
He suggested that National Lime & Stone remove the sediment before discharge using a settling pond and pass on the cost to customers.
“We’re all using sand and gravel,” he said. “We’re all buying it. I think all of us would pay a few extra dollars to make that happen on the property.”
Madeline Moss said economic activity and environmental protection do not have to be opposing forces.
She encouraged EPA officials to require alternatives reflecting today’s best practices, such as closed-loop water systems, an enhanced settling basin, and vegetative repair.
“Leadership means setting a higher bar, not lowering it or becoming the minimum required,” she said.
OEPA’s draft permit: more stringent than around the state
Brian Riedmaier, environmental manager for the National Limestone Company, compared the draft permit to other statewide mining locations.
He cited several differences:
• The average monthly limit is half of what is required elsewhere.
• TSS sampling weekly vs. monthly.
• Monitor for dissolved oxygen weekly vs monthly.
• Flow rate monitoring during the summer months is daily vs. monthly.
• Requirement for downstream monitoring, something typically not required in other mining permits.
In addition to location and downstream monitoring, the company monitors upstream. Between August 2024 and September 2025, the three locations averaged about 5.8 mg/L for monthly TSS.
“The permit limit and the proposed permit is going to be 15 as a monthly average,” Riedmaier said.
The company has about 30 feet of rip wrap at the end of its discharge pipe, which dissipates the energy from the discharge and prevents scouring.
“It also provides an opportunity for oxygen to get back into that water. So we’re introducing highly oxygenated water back into the river,” he said.
According to Riedmaier, the company pumped for 107 days between August and September 2025. About 40 percent of the time, the flow rate was between 4 MGD and 7 MGD.
He said the company cannot sustain long-term pumping at the maximum capacity of 28 MGD.
“But we need to have the capability of pumping that much in the event of a flood [since we’re] in the floodplain,” he said.
Reidmaier said the company has met with Del-Co and ODNR scenic rivers.
“After our meeting last week, they were reassured. They were under the impression that all of our wash water was being pumped off the property,” he said.
“It does go through settling ponds. The majority of what we’re pumping off the property is probably 90 or 95 percent groundwater.”