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Working to clean up the BE River

By Staff | Apr 10, 2016

This group of county employees and commissioners and others were on hand for starting up the bioreactor.

The largest bioreactor in the entire country is now online. And, it is located just north of Blue Earth.

But, don’t get too concerned. This is not a nuclear reactor, but rather it is an elaborate nitrate filtration system designed to improve water quality.

“This is the first project of its kind to be built on a public drainage system,” says Merissa Lore, Faribault County drainage manager. “And it is by far the largest one ever built anywhere.”

The bioreactor is located right alongside the west side of Highway 169, just three miles north of Blue Earth.

It is actually three bioreactors placed in a row. Each one is 135-feet long by 25-feet wide by 5-feet deep, Lore explained. And, each one is filled with wood chips.

Merissa Lore, Faribault County drainage supervisor, pulls one of the boards out of a pipe which allowed water to enter the three bioreactors located at the site just north of Blue Earth on Highway 169. Faribault County commissioner Tom Loveall looks on.

But don’t expect to see a large structure along the highway when you drive by. The entire bioreactor is buried in the ground, covered with topsoil, and will soon have grasses planted on top of it.

What you will see are several pipes of various sizes sticking out just a little bit above ground level.

The idea is that drainage water goes through the wood chips and the nitrates are all removed, before the water re-enters the county drainage pipe and then dumps into the Blue Earth River. The county line carries water that drains off a 750-acre watershed.

On a chilly afternoon last Monday, a group of people gathered at the site to officially open up the flow from the county drainage pipe and divert it into the bioreactors.

The group at the official start up ceremony included employees of the Faribault County Soil and Water Conservation office and County Drainage Department, representatives of I&S Group the engineering firm in charge of designing the project, county commissioners and the landowner Neal Mensing.

Several people took turns removing four boards located underground which had been preventing the water from entering the bioreactor. The only way to tell what was happening was to look down a 24-inch pipe to see water rushing past about five feet down, headed to the first bioreactor.

The County Drainage Department has received over $190,000 in grants for the project, which were applied for and administrated by the SWCD.

Lore has said in the past that there are 114 drainage systems in Faribault County, with 209 miles of open ditches and 714 miles of public tile lines.

The concern by the SWCD is that much of this drainage water ends up in the Blue Earth River. The bioreactor project is one way to filter nitrates out of the water that is drained from watershed areas before it hits the river.

“We are concerned with water quality and conservation practices,” Brandee Douglas of the SWCD office says. “Not just getting rid of drainage water, but also doing it in a way that protects the environment. That is what this (bioreactor) project is all about.”

Later this summer the county drainage department and the SWCD office will hold a Drainage Field Day, both at the site of the bioreactor and at a meeting site.

“We will highlight the bioreactor but also discuss many other conservation practices used by farmers,” Douglas says. “There are many techniques being used by several area farmers which help with improving water quality.”