Le Sueur declares state of emergency, installs bypass after wastewater released into river

On the morning of Tuesday, June 25 the city of Le Sueur’s Mayo Park wastewater lift station experienced a failure, due to being overcome by floodwaters, resulting in a release of wastewater into the Minnesota River. This release was concentrated near the Mayo Park area.

To protect public safety and the safety of remaining public infrastructure, a temporary bypass was put into place to ensure proper transmission of wastewater to the Le Sueur Wastewater Treatment Facility.

The bypass was successfully established on the evening of June 25. The bypass will be in place for an undetermined period of time, with removal to be considered based upon receding floodwaters and evaluation of the lift station.

The City of Le Sueur is operating in close consultation with Minnesota Pollution Control Agency (MPCA) and following recommended protocols provided by the MPCA as the wastewater permitting authority.

June 25 UPDATE

In an effort to bypass a rising tide of flood waters submerging the city’s wastewater lift station at Mayo Park, the Le Sueur City Council declared a state of emergency Monday.

The declaration marks the first time the River Valley community has entered a state of emergency since the onset of the COVID-19 pandemic in March, 2020. City Administrator Joe Roby said the motion will allow the city to act quickly as they move to construct a bypass to divert water from compromising the wastewater lift station.

The Mayo Park lift station collects wastewater from the city of Henderson, large companies based in Le Sueur like Cambria and Bimeda and from a number of other service lines before it’s transported to the wastewater treatment facility.

The station is fortified by a circular concrete wall to protect it from flooding. However, that line of defense and a sand and plastic levee constructed by city staff on Friday was not enough to completely stem the tide of rising water.

Roby reported to the City Council that the sump pumps designed to keep water out of the lift station were unable to keep up with the surge. One of the sump pumps went out completely, and staff went out to service the pump that morning.

In response, Roby said city engineers began designing a bypass plan to bring the wastewater around the lift station from a higher elevation to still get it to a wastewater treatment facility so they can effectively deal with the shutdown.

The city of Le Sueur shared its engineering plans with the county, state and the Army Corps of Engineers, the latter of whom gave the bypass proposal their approval. In order to construct the bypass from Mayo Park to the wastewater treatment plant, the city temporarily shut down one lane at the north end of Highway 22 for several hours on Tuesday morning. As of Tuesday afternoon, the road has been fully reopened.

But the pumps can not keep up with the rate of the rising water, so starting this morning. City engineers started designing a bypass plan to bring wastewater around the lift station from higher elevation to still get to the wastewater treatment facility so they can effectively deal with the shutdown of this lift station.