BE’s big $7.5 million project
The $7.5 million construction project at the Blue Earth Wastewater Treatment Plant is moving along, despite a battle against the elements.
The project started last fall and continued through the winter. The plan is that all the work will be completed later this fall.
The project includes both rehab and replacement of some of the older equipment, plus new construction of buildings that will house some of the new equipment at the plant.
“When it is all done we will basically have a new plant, that should last for many years,” Public Works Department director Jamison Holland says. “We are replacing equipment that goes back as far as the 1960s.”
Last Monday afternoon the Blue Earth City Council took a tour of the under-construction plant to check out the progress.
Holland first showed the council members the current control/head works building. The building is actually five stories tall, but four of the floors are underground.
“We are replacing this vertical building with two new, above grade horizontal buildings, with all new equipment inside,” Holland explained. “One building will house a new laboratory testing station.”
Having the operation above ground will give the plant operators a safer environment to work in, Holland said. It will also be much easier to repair or move equipment around in the new buildings.
Another upgrade is happening with the two large primary clarifiers. The equipment inside the clarifiers is all being replaced.
“The equipment in the clarifiers was completely rusted and falling apart,” Holland said. “The old steel items are being replaced with stainless steel. One clarifier is done and back on line while the other one is now closed and being worked on.”
Still to come is a brand new lift station and entry pipeline into the plant. Holland says a huge hole is being dug that will be 45 feet deep and will contain four pumps inside it. Two are standard operation pumps that will lift the raw sewage up into the new buildings, and two are large, storm, high-flow pumps.
“We are rerouting and replacing the old line into the plant,” Holland explained. “It will be the last thing done. Then we will switch everything over at once and see how it all works, but we will keep the old system operational until the new one is fully proven.”
Holland says when the new system comes on line, it will help with handling high flows due to heavy rains, but it will not handle a catastrophic event.
However, Holland pointed out that the city is taking other efforts in that area, by locating the manholes in low areas near the river and raising them up.
“We are trying to do repair and mitigation so what happened during the June rain won’t happen again,” Holland said. “We usually have a high flow into the plant of about 1,500 gallons per minute. That day we had closer to 7,000 gallons per minute, maybe more.”
That was caused by those low manholes blowing open and letting the river flow directly into the plant, causing the plant to lose power and be shut down.
When the flow into the plant hits 2,000 gallons per minute, a bypass pump comes on, the plant manager explained. If it goes higher, then a bypass gate closes off the plant and another gate opens to the river.
“We probably had 1,500 gallons of raw sewage go into the river, but it was with thousands and thousands of gallons of river water coming in and going out to the river,” Holland said. “And in one day we got all the pumps operational and were back up.”
Holland said one thing he would like to note is that residents of Blue Earth should not let their sump pumps go into the floor drain in homes, but instead be pumped out to the curb and into the storm sewer system.
All of the construction at the city waste water treatment plant will help with many of the past issues at the plant and Blue Earth will have a first rate facility.