A new and improved headworks system at the city’s wastewater treatment plant will better serve St. Clair and its residents as expansion occurs, an engineer told the board of aldermen earlier this month.
Jeremy Lay of Bartlett & West Engineering updated board members and the administration on his findings last week as he continues to study the project and make recommendations to the city on how to improve efficiency at the plant located on Highway AB at Happy Sac Road.
Design engineering for the project is included in the 2013 budget, City Administrator Rick Childers said.
Headworks refers to the screening and removal of grit at the plant. St. Clair’s system currently has average daily flow and peak flow problems as well as a lack of preliminary treatment.
“Our existing headworks is almost non-existent,” Public Works Director Ed Bliss said during the June 17 board of aldermen meeting. “It’s very minimal when it comes to sewage treatment.”
Lay has studied St. Clair’s system for about two years and is to the point where he can recommend ways to improve treatment at the plant.
“This project is long overdue,” he said.
Lay went through a short presentation with the aldermen in which he outlined existing problems, solutions, costs and benefits.
“The plant is just not keeping up (with flows),” he said, adding that the system cannot handle liquid amounts from the city’s new pumps. “You can get more peak flow to the plant, but the plant can’t handle it without improvements.”
And that’s where the headworks project comes in, he said.
As far as the lack of preliminary treatment, Lay said not to have that as part of a 1-million-gallons-per-day system “is very uncommon.” Preliminary treatment includes screening and grit removal as well as taking care of abrasive materials and unwanted debris.
Lay said the lack of preliminary treatment has resulted in a failed belt filter press and appurtenances, an aged clarifier mechanism and worn pumps with reduced capabilities.
Lay’s solution is the headworks proposal, which would provide the preliminary treatment and improve primary treatment through a microscreen process.
“Upgrades to the wastewater treatment plant will reduce the volume of treated solids and combined with ongoing reductions in I and I (inflow and infiltration) has potential for increasing the rated capacity of the plant,” Childers said.
The proposed solution uses a microscreening process that includes a belt that lifts solids, a water wash and an auger press. Estimated costs are about $900,000 for a unit that could handle 3 million gallons per day and $1.2 million for 6 million gallons.
Going that route would allow an additional 2,000 to 3,500 individuals to use the system safely.
“This is the lowest cost way to increase rated capacity,” Lay said.
This system also would increase peak flow capacity by 25 to 35 percent, Lay said. He also said other equipment used would gain an extended life and operational cost savings could total about $14,000 annually.
“This is the year of working on our wastewater system,” Childers said. “We will continue to move forward with this.”
There was no decision needed from the board.