The distance between a proposed coal ash landfill’s liner to the natural water table was the primary subject of a nearly six-hour hearing Tuesday night.
The Franklin County Board of Zoning Adjustment took under advisement the appeal filed by citizens and the Labadie Environmental Organization.
It was argued that Ameren Missouri’s proposed landfill design does not comply with Franklin County’s land-use regulations. The citizens argue that the landfill design would not satisfy the county's requirement that there be a 2-foot buffer between the landfill liner and the natural water table.
But Franklin County and Ameren disagreed.
Ameren stated in its landfill construction permit application that the natural water table elevation at the site is 464 feet, according to the citizens' attorney, Maxine Lipeles.
Ameren admits that the landfill liner will be in “intermittent” contact with the groundwater and that portions of the landfill will actually be 1 to 2 feet below the natural water table, Lipeles said.
Despite these issues, Franklin County’s land-use administrator, Scottie Eagan, determined that the design is in compliance with the county’s requirements, Lipeles said.
“That is wrong,” Lipeles said, adding that the citizens want BOZA to reverse that decision and issue an order denying the zoning permit.
The 2-foot buffer requirement is designed to protect groundwater, which, she said, is used for drinking and agriculture.
In its construction permit application filed with the Missouri Department of Natural Resources, the Public Service Commission and the county, Ameren states that the natural water table elevation at the site is 464 feet, Lipeles said.
That elevation “clearly” puts portions of the landfill in contact with the groundwater, she added.
So as a result Ameren then “manufactured” another water table elevation to make it look as if the landfill would meet the county’s requirement, Lipeles said.
But an independent engineering firm hired by Franklin County said the natural water table elevation is lower than 464 feet.
Kenneth Liss with Andrews Engineering Inc. said his firm reviewed data and estimated the average natural water table elevation at the site to be 457.17 feet. Liss said that is 8.8 feet below the landfill liner subgrade of 466 feet.
Thus the landfill design would be in compliance with Franklin County’s regulations, Liss said.
Teresa Entwistle, a professional engineer and floodplain manager, testified for Ameren that the average natural water elevation at the site is 459.4 feet, which she called “conservatively high.” She said that is based on over 1,600 groundwater measurements at the proposed landfill site.
The landfill design is robust and has multiple layers of defense to protect groundwater, said Craig Giesmann, an Ameren engineer and the project manager.
He said Missouri regulations “expressly contemplate” groundwater touching the liner. That is the point of having a liner, he said.
The proposed Ameren liner would be 100 times less permeable than Missouri DNR requires, Giesmann added.
Even if the liner failed, there would be monitoring wells in place to warn of a leak, he said.