Solutions in sight for Sanger odor, wastewater woes

Sanger begins to address years of sewer smells, deferred maintenance under new city manager

(Kenny Goodman)
Serena Bettis
Published June 17, 2024  • 
11:30 am

SANGER – For years, Sanger residents have lodged complaints with their elected representatives and city officials about a foul odor coming from the sewer system that seems to permeate throughout the city for much of the year, particularly at dawn and dusk in the colder winter months. 

Nathan Olson, Sanger’s new city manager, said there is “no good excuse” for why residents have had to put up with the sewage smell, and one of his top priorities coming into the city is to address the issue as soon as possible. Much of the problem stems from deteriorating equipment at the city’s industrial wastewater treatment facility brought on by years of deferred maintenance, Olson said. 

“I think there was a sense of fear when the markets changed and when we had our water issue in Sanger, and the focus shifted to water and away from the wastewater plant,” Olson said. “Those are things that you can’t let go, you gotta run them simultaneously because water and wastewater, they go hand in hand. I blame it on management, I do. I think management didn’t take it seriously enough, and now we’re behind the eight ball.”

Sanger’s sewer system includes the processing of both domestic and industrial wastewater at the city’s treatment facilities. Wastewater is piped through the facility through five different steps — including primary sedimentation, activated sludge, secondary sedimentation, chlorination and disposal — that are meant to filter out large and small debris and other contaminants like bacteria and viruses. 

In order for this process to be done effectively, the wastewater treatment facility utilizes a variety of equipment that is in need of significant repair or replacement. Olson said the facility’s needs are well-known thanks to comprehensive studies conducted by outside engineers and the expertise of the facility’s operators, but those needs have not been acted on in a timely manner.

“Essentially, we’re running the plant in a very inefficient state and it’s gonna take us some time to incorporate the changes we need to make to get back into compliance with the state,” Olson said.

Addressing the odor

Olson said the primary source of the odor was from the storage ponds that the treated wastewater is held in. After wastewater runs through the treatment facility, it is piped into storage ponds before being discharged to farmland that is adjacent to the industrial wastewater treatment facility. 

While in those ponds, the wastewater is aerated in order to add dissolved oxygen to it, which helps to stabilize the wastewater and treat it for bacteria. Olson said many of the aerators in the ponds were not working, which limited the amount of dissolved oxygen in the ponds and worsened the odor coming off the water. 

Now that the city has replaced the aerators, Olson said he thinks they have gotten the odor complaints under control and have enough dissolved oxygen in the ponds to a point where the treatment facility is not a nuisance to residents, but there is still a lot more work to be done.

“We’ve already invested about a million dollars into the plant for maintenance since I’ve got here, so now I’m just at the state’s mercy and at the resident’s mercy … to give us the time to get the plant repaired, up and running,” Olson said.

To further help mitigate odors, Olson said the city is working with its industrial customers — primarily Pitman Farms and Gibson Winery — to implement pretreatment processes that will get them into compliance with state requirements and help with the odors down the line. 

Even with the city’s industrial customers on board, Olson said it will take time for them to get their new systems set up. It could take 12 to 18 months to implement the needed equalization tanks, which help control sewage flow rates, and ways to pretreat the wastewater before it gets to the city’s facility.

“It’s not something you just go buy off the shelf and plug and play, they’re designed for your plant and your specific output, but I’ve got full compliance with all my industrial users,” Olson said. “We have a great relationship with our industrial users and I honestly can’t say that was the case when I got there.”

Looking forward

While odors should be more controlled now, Olson said residents will experience bad odors again as the city works to clean and perform maintenance on the digester that treats both domestic and industrial wastewater. A digester is what dissolves the fats, oils and greases in the wastewater, Olson said. It uses microorganisms to break down biodegradable material, which is often then released as a gas. 

Olson said Sanger’s digester is not currently working, and in order to clean it, the city will need to haul off the waste that is currently inside of it and divert the wastewater sludge to the draining beds that are by the wastewater treatment plant. 

Considering that the city cannot stop taking in wastewater, it will bypass the digester equipment and send the wastewater out to a 2-3 foot deep pond with sand, where the wastewater will percolate and the solids in the water will dry up and be scooped off and hauled away.

“We’ll do everything we can to minimize odors on that, but I can in no way guarantee that we’re not gonna have some odor when that takes place,” Olson said.

The city will release a public service announcement when it is planning to do this so that residents will know when it is coming and what is going on.

Thanks in part to the wastewater rate increase passed last summer, the city does have the money needed to address these issues; however, the wastewater rate study conducted last year identified more than $11 million in wastewater treatment facility improvement costs, which cannot be done all at once. 

Before the city could consider getting a bond for the repairs, it has to finish its annual audits, which it is about two years behind on at the moment, Olson said. When that is complete, Olson said he can pursue a bond to get the rest of the money needed to address the wastewater system. In the meantime, Olson said he wants residents to know that the city is now actively working to fix this issue. 

“I know they’re frustrated, and I would be too, but I’m just asking for some grace for my public works department and my city at this point,” Olson said. “Give us time; I can assure you that it’s a top priority, and we are working through the issues to get it gone.”

Serena Bettis
General Assignment Reporter