First bioreactor comes to county

Thursday, June 18, 2020
Wood chips are placed into a lined 30 x 150 foot trench at the Jim Heidesch farm northeast of Remsen. The structure is a bioreactor which will filter nitrates from water fed from a tile line in the field before it runs to nearby Deer Creek. It is the first bioreactor in Plymouth County.
(Photo Contributed)

REMSEN — Plymouth County has its first bioreactor and it is located on the Jim Heidesch farm northeast of Remsen.

The structure was installed Tuesday, June 9, and is intended to keep nitrates from farmland going into waterways.

Gregory Marek, interim watershed coordinator with the Deep Creek Watershed Project, explains what a bioreactor is.

“A bioreactor is a buried trench filled with wood chips. Tile drains from the field carry excess water from the plant root zone, and divert a portion of the drainage water into the bioreactor. Microorganisms on the wood chips consume the nitrates in the water and expel it as nitrogen gas. The average bioreactor can be expected to remove up to half of the nitrates in water flowing through it,” he said.

Bioreactors are installed at the edge of a crop field, before a tile line empties into a creek or ditch.

At the Heidesch farm, the trench is 150 feet long and approximately 30 feet wide.

“The filtered water outlets into a road ditch which outlets into Deep Creek which is only a few hundred feet away,” he said.

The wood chips will need to be replaced every 10 to 15 years.

“Kristi Silverthorn, the previous watershed coordinator, convinced Mr. Heidesch to put in the bioreactor,” Marek said.

“This is the first bioreactor to be installed in Plymouth County, and one of the few installed in this part of the state. Mr. Heidesch was interested in doing his part to improve the nitrates that flow into Deep Creek, as the town of Remsen is located downstream from his farm and Remsen’s city wells sometimes are high in nitrates. The state of Iowa is paying 100 percent of the cost of the bioreactor,” Marek said.

There is a bioreactor in Sioux County at the Dordt University farm, as well as in Buena Vista and Lyon counties.

The Plymouth County Soil and Water Conservation District is in its sixth year of the Deep Creek Water Quality Watershed Project Area. Local farmers were given the opportunity to learn about conservation practices designed to keep phosphates and nitrates from contaminating waterways and drinking supplies. Land included in the Deep Creek Watershed is in certain sections in the townships of Elgin, America, Fredonia, Marion, Meadow and Remsen townships in Plymouth County.