Water/sewer continues to be hot topic for city

By Marcie Klomp

The sewer project is always the elephant in the room for city council. The project is estimated to cost $2.2-2.6 million and needs to be up and running by February 2017. That’s not very far away when talking about such a large enterprise.

Mayor Pro Tem Kevin Bill explained the current sewer plant still works the way it was designed to, even being over 30 years old, which is close to the life expectancy of a sewer plant. It just doesn’t meet DNR regulations, which have changed over the years.

Iowa was one of the states that accepted the EPA’s Clean Water Act of 1999, and the DNR is charged with upholding that decision.

The biggest reason the plant has to be updated is because of ammonia issues. Public Works Director Casey Sebastian explained ammonia is found naturally in waste. It is released into the air when water conditions are 45 degrees and warmer.
Waste comes through the sewer into the lift station and travels into cell one, cell two and cell three.

There is plenty of time for the ammonia to be released from the water before it is discharged at the north side of the lagoon. That water goes into an “unnamed creek” that ends up in the Upper Iowa River.

“Because the Upper Iowa River is a pristine watershed area. We have higher standards than other towns. It is called that because people fish, canoe and boat on the Upper Iowa,” the Public Works Director stated. In fact, the Upper Iowa River Watershed has been recognized by the state of Iowa as having some of the highest quality and priority waters in the state.
Everything works well until it starts getting colder and the water goes below the 45-degree mark.

“The ammonia in summer is at zero, because it’s warm. Numbers are highest late February and early March, when ammonia stacks up in the water,” Sebastian noted.

The trick to releasing the ammonia is trying to keep the water warmer longer and then heat it up as fast as possible in the spring.

There are three different ways to get the ammonia to release itself from the water year-round.

1. A black mat-like material lays over the cells. The black mat attracts sunlight to warm up the water. Sebastian said the mat is so strong a person can walk across it.

2. Bio-domes are what the city engineer is looking at proposing. There would be several domes in each cell that would be insulated and build their own heat, allowing the ammonia to be released. It is a newer concept and hasn’t had as much testing.

3. The third is SAGR (Submerged Attached Growth Reactors), which consists of a clean stone bed that is fully aerated using an aeration system.

Choosing one of those three options is just part of the project. The DNR also wants the water disinfected, but chlorine cannot go into the creek. The City will have to chlorinate the water and then take the chlorine out again or use UV lights. Both courses of action are expensive, with neutralizing the chlorine with another chemical requiring less maintenance.

The timeline is getting tight. Design work needs to be finalized by February 2015, plans and specifications should go to DNR by April 2015,with bids going out in August and construction starting in 2016. Getting it up and running that fall and into December will allow time to tweak the system before it needs to be online February 2017.

Updating the wastewater system is not something the council wants to do, because of the cost, but it is a requirement of the DNR.

Besides making decisions on the best treatment for Lime Springs, Council has to find a way to finance the $2 million-plus project. Raising water and sewer rates the first of July was just the first step in figuring a way to pay for it.
They are working with a finance company and Upper Explorerland to find grants and other means of raising money.


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