Erik Burgess, Published July 15 2013
Smelly situation! Moorhead looks into residents' complaints about stinky sewage lift stations
Standing on her front porch in north Moorhead on Monday afternoon, resident Kari Plienis said even briefly walking outside is sometimes overwhelming, especially on sweltering summer days.
“It makes me almost puke,” Plienis said of the “sour smell” that emanates from the sewage lift station near the corner of 15th Avenue and 11th Street North, less than a block from her home.
In a non-voting meeting Monday, City Council members discussed spending up to $1.5 million on as many as three new buildings designed to curb the rotten-egg stink caused by hydrogen sulfide gas, and prevent corrosion of the city’s wastewater pipes.
The buildings would be injection sites to drop into the city’s sewers ferrous chloride, which prevents hydrogen sulfide gas from entering the atmosphere. The chemicals alone would cost about $228,000 per year, said City Engineer Bob Zimmerman.
It could be paid for with bonds backed by increasing wastewater rates over the next few years.
Plienis thinks it would be money well spent. Her neighbor Faith Olsen agrees, arguing that the odor hurts property values in her neighborhood.
“If (the smell) doesn’t appeal to people, they’re not going to want to live here,” Olsen said.
A possible rate bump
The foul odor comes from the city’s wastewater lift stations, which collect the city’s sewage in pits and push it along until it reaches the wastewater treatment facility on Moorhead’s north side. There are 49 such lift stations in Moorhead, some of them stinkier than others, said Andy Bradshaw, utilities engineer for the city.
Lift station No. 39 on 34th Street North is smelly to the point of being dangerous to city workers, according to a study completed for the city last year by Apex Engineering Group. The station had hydrogen sulfide readings of more than 250 parts per million before Apex did a chemical injection there late last fall.
Most people can detect the rotten egg smell at .01 part per million, and amounts higher than 10 parts per million are considered hazardous to workers, the study stated.
In a pilot study, Apex did three injections of ferrous chloride between Oct. 15 and Nov. 13 at a handful of lift stations, including No. 39. After the study, the amount of hydrogen sulfide at No. 39 dropped to about 25 parts per million. Apex recommended the city look at building injection stations.
Zimmerman recommended using general obligation revenue bonds, backed by wastewater rates, to pay for the proposed stations. It could be done in one or two bond issuances. Those details should be decided later this summer, he said.
If the project is done in one bond issuance, it would result in wastewater rate increases of 8 percent in 2014, 7 percent in 2015, 3 percent in 2016 and 3 percent in 2017, and the city would use reserves to absorb some of the blow, Zimmerman said.
The average resident now pays about $22 a month in wastewater rates, Zimmerman said. The proposed increases would mean monthly rates of about $24 next year, $26 in 2015, $27 in 2016 and $28 in 2017, he said.
Zimmerman asked the council to consider adopting a plan by August. City staff would then develop a financing plan, with the council issuing bonds by fall. Bids would be advertised for work in the winter, with the contract being awarded by next spring.
Councilwoman Nancy Otto said Monday night the rate increases would be “very noticeable” to residents, but also said the lift stations are causing some major odor problems.
“It gets so bad,” she said, speaking of the main lift station at 911 5th Ave. N. “I don’t know how some of those neighbors can tolerate it, truthfully.”
Fargo uses injection
Fargo has pumped ferrous chloride into its wastewater since 1993. There are two Fargo sites where the chemical is dumped at about 20 to 25 gallons an hour, said Jim Hausauer, Fargo’s wastewater utility director.
Fargo leaders started the program to prevent corrosion, not to clear odors, Hausauer said.
Hydrogen sulfide can break down into sulfuric acid, which destroys piping, Zimmerman said. Some piping at Moorhead’s main lift station is only six years old, but is already experiencing extreme corrosion from the hydrogen sulfide, he said.
Over the years, ferrous chloride has also proven to be an efficient way to curb odor in Fargo, Hausauer said. There haven’t been many complaints about smelly lift stations in recent years, he said. Fargo pays about $300,000 annually on ferrous chloride.
“We’re finding that that’s probably dollar-for-dollar one of the most efficient chemicals out there that we do use for (odor control),” he said.
There were more complaints than usual last summer, Hausauer said.
“It was hot and dry and there wasn’t a whole lot of fresh water getting into the system,” Hausauer said. “We had to dose more to keep the complaints down or kinda get ahead of the complaints.”
West Fargo does not do any odor control work at its lift stations, said Terry Rust, pre-treatment coordinator and wastewater operator for the city.
Rust said using ferrous chloride isn’t needed in West Fargo because lift stations there cycle the sewage quickly, which doesn’t allow for the buildup of hydrogen sulfide. Sewer lines there are also newer, and many of the longer lines are plastic and don’t succumb to corrosion, Rust said.
The West Fargo City Commission in May asked the city’s public works department to fix the foul odor from the 400 acres of sewage lagoons.
Public Works Director Barry Johnson said the study is moving slowly because vendors are telling the city that completely eliminating the smell would be impossible.
“That’s not acceptable,” Johnson said, adding that he’d like a “guaranteed” solution in place by next spring, when the lagoon stink tends to worsen.
Readers can reach Forum reporter
Erik Burgess at (701) 241-5518