Iowa DNR deciding what to do with manure tank built in karst terrain without permit

The Iowa Department of Natural Resources is trying to decide what to do with a cattle producer that built an underground manure tank in karst terrain — a risky area because of the potential for groundwater pollution — without getting a permit.

Environmental groups are concerned about manure leaks in karst topography because of how quickly contaminants can spread through the Swiss cheese-like bedrock to pollute drinking water wells and streams.

Tim and Joe Johnson, owners of Johnson Brothers, a feeder calf operation in Mitchell County, say they didn’t know they needed a permit for the tank. The water monitoring system proposed by the Iowa DNR to make sure groundwater in the Cedar River watershed isn’t being polluted would cost $100,000, Tim Johnson said.

“Every solution they came up with will entail spending a lot of money,” he told The Gazette in an interview. “I said, ‘You can’t come up with any other solution?’”

Johnson thought installing the tank would fix a problem, which was not having a place to put manure during the winter months when Iowa law bans application on frozen ground.

On Feb. 2, 2016, the Iowa DNR cited Johnson Brothers for violations including putting manure on frozen ground and not having a manure management plan, according to a consent order filed in 2020.

Johnson Bros Consent Order (002) by Gazetteonline on Scribd

On April 1, 2016, the Johnsons filed a manure management plan and submitted a letter that said they were “consulting with engineers and builders to design and construct an additional manure storage structure,” the Iowa DNR reported in the 2020 order. The Johnsons also said they would submit a construction design letter before beginning any work, the department reported.

A few days later, on April 4, 2016, the Iowa DNR sent Johnson Brothers a letter reminding them they would need a permit for tank construction. But the department never got a design statement or a permit request, the 2020 order states.

And yet, when inspector Sheila Bly visited the facility for a routine inspection April 17, 2019, there was a new manure storage tank. An investigation near the tank showed karst not much deeper than the 10-foot concrete reservoir, Bly told The Gazette last week.

The Sierra Club and other environmental groups have spoken out about their concerns about animal confinements in karst terrain.

“Leakage from the structure into the soil and then into karst terrain may cause pollution of the shallow aquifer and wells that draw from the aquifer,” Steve Veysey, an Ames water quality advocate collaborating with the Sierra Club, said in an email Friday to The Gazette. “More and more shallow wells in northeast Iowa routinely measure high in nitrate (above the 10 parts per million limit) and often show levels of E. coli, which is very disturbing.”

Nov. 24, 2020, the Johnson Brothers signed the consent order requiring them to pay $10,000 for building the tank without a permit and without following minimum setbacks from karst soils.

“When an operation fails to comply with the application and permitting process, the department is denied the opportunity to ensure the construction adequately protects the environment and human health,” the order states. “This failure is particularly concerning when manure storage structures are constructed in karst terrain, as improper construction can have long-term impact on groundwater in these regions.”

That order required Johnson Brothers to hire an licensed engineer to investigate the groundwater level around the tank and “implement a groundwater lowering system if necessary.“

The Johnsons got an estimate on the work but have not done it because it would be too expensive to excavate around the tank, which is only 12 feet away from other tanks, Tim Johnson said.

“If the pit was out in an open area, it wouldn’t be an issue,” he said. “But it’s got the existing pits on two sides and a building on a third side.”

The company has paid the penalty.

Bly said she is working with other Iowa DNR officials to decide whether the Johnsons should be allowed to continue using the tank, which had manure in it until recently.

“We’re trying to work out what available options there are so we can be assured we don’t have a leaking tank in karst terrain,” Bly said.

Because the initial plan to monitor groundwater for six years is too costly for the producer, the department is trying to come up with options. These could include monitoring nearby wells rather than a groundwater lowering system below the tank, Bly said. But there’s also the option of telling the Johnsons they can’t use the tank.

“It’s not usually the first option for us,” Bly said. “But it is a possibility we are considering.“

The Iowa DNR also doesn’t want to force a situation in which a producer can’t use its storage tank and then applies the manure on frozen ground, which also has risks to groundwater, Bly said. The Johnsons now are keeping fewer than 500 calves, which means they are classified as a small animal feeding operation.

“We’re working through that process now,” Bly said. The Iowa DNR hopes to have a decision in coming weeks.

Comments: (319) 339-3157; erin.jordan@thegazette.com