Why does sewer lift station stink? Expert issues report // DOCUMENT

CALLAWAY — An engineering firm has figured out what caused the odor and corrosions at a sewer lift station in Callaway.

The analysis conducted by Louisville, Ky.-based engineering firm Webster Environmental Associates  (WEA) concludes the problem is that the existing odor control system is not designed to handle the amount of wastewater a city the size of Callaway releases.

“That report clearly says Callaway is not the responsible party of causing the damage that has occurred over time at that lift station,” said Callaway Mayor Thomas Abbott. The damage “has been caused by the fact that the system put in place there was the wrong system; it functioned the way it was supposed to, but it didn’t function the way that setup needed it to function. It’s that simple.”

The Advanced Wastewater Treatment (AWT) System is made up of Callaway, Parker, Springfield and Bay County, the operator.

Lift station “AWT-2” at Veterans Park in Callaway has been a point of contention over the past year. The lift station, at one time thought by the county to be highly combustive, emits high levels of hydrogen sulfide, which has caused extreme corrosion at the station and a lingering, rotten-egg odor at the park.

While significant hydrogen sulfide-related odor emissions and corrosion does exist at the station, it’s common in wastewater collection systems, WEA reports. And though injecting chemicals upstream in Callaway’s collection system could improve the odor, an additional air treatment still would be required at AWT-2.

“The existing AWT-2 air treatment system is misapplied and should be replaced with an odor control system more suitable for this application,” the report states.

The problems at the lift station incited a dispute over who should bear costs of repairs and odor control management there. The county already has footed about $300,000 in advance for repairs, but it expects reimbursement from the AWT.

Parker and Springfield have practically nothing to do with the lift station other than being members of the wastewater treatment group.

County Chairman Guy Tunnell didn’t give many comments on what he thought about the report or how the report could impact who’s held responsible for the deteriorated lift station.

“It’s really hard so say right now,” he said. “We have our consultants for the AWT. … They’re the people we rely on.”

County officials received the report from the city late Wednesday morning. Before noon the same day, the county sent out an email stating the anticipated tentatively set April 17 AWT meeting would have to be postponed to an undecided date.

Tunnell later said the county had expected to receive the report from Callaway earlier; therefore, plans to hold the meeting would have to wait until all parties, including respective consultant groups, could be available.

Abbott said the meeting will be key.

“I think what it’s going to come down to is this discussion among AWT members — about how do we pay for this project as an AWT group,” Abbott said.

The good part of it all, he added, is “we’re going to solve this problem.”

Report highlights

The report shows:

- Hydrogen sulfide is the primary cause of odor and corrosion problems in the wet well.

- The existing odor control system is not effective and needs to be replaced.

- Upstream chemical treatment is not a good alternative to replacing the current odor control system in this situation.