MoDNR: city must upgrade sewer treatment facility with disinfectant system

Linda Trest
Staff Writer

City Engineer Terris Cates broke some bad news to the Board of Aldermen at their June 13 meeting. The Missouri Department of Natural Resources would require the city to install a disinfecting system to their waste water treatment facility by September 2020. The facility was designed by Cochran Engineering of Union.

The most cost effective way to achieve this, Cates told the board, would be an ultra-violet system which would run about $135,000. Excavation and other miscellaneous costs would push to price closer to $158,000. Ultra-violet lights would be placed in the water. The light will disinfect the water. 

But that wasn’t all. 

Cates also told the board that frequent problems with the current pumps were costing the city too much money. He suggested the city correct a design flaw and install screens to filter the water before it enters the pumps in the lift station. Currently, the water is screened only after it leaves the lift station.

Cates also suggested adding valves to allow the operator to control the water flow. 

These improvements would cost an estimated $58,000. 

Public Works Director Nick Grube explained to The Republican exactly how the system works.

All sewer lines in Gerald lead to the waste water treatment facility north of town on Wheeler Road. 

The waste water immediately enters a lift station where the water is pumped into the facility. 

Grube says it is not uncommon for the pumps in the lift station to need to be pulled three times a week to remove debris. He says he and his crew have pulled shirts, underwear, rags and personal care items from the pumps. Keeping the pumps free, is much less expensive than replacing them. A new pump can cost up to $6,000 to replace. Even repairing them is costly at around $1,700. Currently, the facility has one pump pulled for repair with a second pump needing repair when the first is back in service. 

The proposed new screening process would eliminate much of that trash from entering the lift station. It would consist of a bar screen to block larger items, plus a dirt and grit chamber to keep gravel and sand from entering the pumps. The screen and chamber would be cleaned daily. 

Such a screening was part of the original design, according to Grube who was a laborer in the department during its construction. He said he was told then that the screens were removed from the design before the project was completed. 

Cates was asked about this by Aldermen Ed Adams. 

“It should have been part of the original design,” Cates replied. 

As the water is pumped out of the lift station, it is filtered through a micro screen to eliminate smaller debris before heading to the aeration basin. There, six pipes shoot the water into the air, which helps to purify it. 

Then, it goes to the clarifier basin, where solids settle, while clear water rises to the top. 

The clean water is then sent to the creek to head back to nature. 

Cates told the board he projects the total cost to the city for both projects would be somewhere around $230,852. The city has about $100,000 in reserve for repairs to the facility. Cates said he didn’t feel a bond issue would be the best way to go to fund the additional $130,852 needed. He suggested the city use another certificate of purchase to finance the project. This a lease/purchase program which the city has used in the past for projects. 

As of the end of 2018, the city still owed $1,991,806.42 on the loan the construct the waste water treatment facility, according the City Clerk Jane Hungler. 

Of course, the city has no choice in installing a disinfecting system. A raise in sewer rates will most likely be necessary to pay for the project. All four aldermen seemed determine to keep that hike as low as possible.