About $900,000 in upgrades will prevent the type of sewage mishap that occurred last winter at the former wastewater treatment plant.

Wednesday, August 25, 1999

About $900,000 in upgrades will prevent the type of sewage mishap that occurred last winter at the former wastewater treatment plant.

During that mishap about 1.4 million gallons of sewage were re-routed directly into Albert Lea Lake when a valve at the former plant failed. Also flooding a pump room at the lift station, the sewage was re-routed into the lake to prevent it from backing into basements. The former plant is used to pump sewage to the new wastewater treament facility.

But with the upgrades approved by the City Council Monday, two valves would have to fail before a lake discharge would become necessary.

&uot;We can build a pumping station so we don’t have the same problem we had last winter,&uot; said Albert Lea Mayor Marv Wangen. &uot;If we have a failure of one pump, we will be able to divert it (the sewage) to another pump so we can repair it.

&uot;We’re trying to find a way to make it more failsafe,&uot; Wangen added. &uot;I don’t know if it’s good news or not. It’s going on your water bill.&uot;

But additions to the former plant can’t prevent all potential problems. If the power system and a backup generator both fail, major discharges are possible. The same is true if more than one pump failed.

Discharge coming into the plant is also hard to control, said City Manager Paul Sparks.

During heavy rains this summer, the city’s utility staff was forced to bypass rain-diluted sewage onto city streets and into the storm sewer system.

&uot;It is not possible to make it 100 percent fool proof because the input side of the sewer equation is not easily controlled,&uot; Sparks said. &uot;The input side is the water coming into the system from residential property and single family homes as well as existing tile.&uot;

Sparks said city staff have also started a door-to-door search, checking for sump pumps that are illegally connected to the sanitary sewer system. This search will cost the city $250,000 to $500,000, the mayor said.

Eliminating illegal connections will help prevent sewage bypasses, but heavy rains are also a problem, and the city can’t control the weather, Sparks said.

Many older homes don’t include foundation drain tiles; during heavy rains, water enters into these basements and reaches the sewer system through drains.

After one heavy rain day this summer, 21 million gallons of rain-diluted sewage was processed at the wastewater treatment plant. It averages about five million gallons.

&uot;Acts of God are beyond the control of the city of Albert Lea,&uot; Sparks said.

But he said the council will consider other safeguards. Adding a half-day storage tank to the former plant is currently in the discussion phase. This would allow staff to make repairs while sewage is bypassed into the tank, rather than the lake.

A last-option chorine system is also being discussed.

&uot;It wouldn’t be as enviromentally damaging as if it went (into the lake) raw,&uot; Wangen said.

Prior to 1983, the city maintained settling tanks that treated sewage with chlorine prior to releasing it into the lake. This system was used to treat sewage for seven days that year when a pipe burst at the new treatment plant.

But Sparks said the Minnesota Pollution Control Agency forced the city to destroy the old system when federal dollars were approved for the $34 million new treatment plant.