Stanley Wastewater Operator Nick Martin addressed the council for approval to purchase a replacement aeration basin gearbox at the cost of $14,253.36 from Crane Engineering at the regular council meeting on Monday, Nov. 20. Martin, who has a degree in Wildlife Science and Natural Resource Management, explained why the gearbox needed to be replaced. He stated that the gear box runs the aeration discs on the Orbal or “Oxidation ditch” that gives the biological treatment at the plant and is in operation 24 hours a day, 7 days a week.
“If we lose the gear box, essentially we would lose treatment,” Martin explained that gear boxes were last updated in 2016 and the time it takes to get a gear box or refurbish a gear box is time that the city could be left out of compliance in various areas.
He explained that the gear box they currently have could be refurbished for $10,712.59 which will take 8 to 10 weeks and wouldn’t have a warranty or buy a new one for $14,253.36 which could be obtained in two weeks and would have a one-year warranty.
“It’s a nightmare to replace them,” Martin commented, noting the installation requires a crane and comes with a high cost.
Alderperson Jason Meyer commented that some companies take oil from the gear boxes and have them tested periodically. He asked Martin, “Do you have any type of preventative maintenance program like that?”
Martin mentioned that one of the wastewater operators had sent some oil in for testing and it looked fine. “So, you’re doing everything you can to get ahead of this,” Meyer said.
Martin discussed that it was noticed upon startup of the update, that the two center ones had a wobbly motion which is believed to flex on the seal and allow oil to leave the gear box prematurely.
Mayor Al Haas commented that the issue could have been caused by poor installation.
“Yes,” Martin nodded.
Haas asked if there were two of them that were wobbling and Martin said that both had been wobbling but when the spare was recently installed, the wobbling was fixed on the other one at the same time. He added that now they are “rock solid.”
Alderperson Mike Henke interjected that the warranty on a new gear box is 12 months and told Martin to install the new one right away when they get it.
“But what’s the cost to take it out and put it in?” Alderperson Jacob Huff asked.
“Somewhere in the ballpark of about $5,000,” Martin answered him.
“Is it worth doing that?” Huff continued and recommended using the new one as a spare due to the high installation price.
The Council unanimously approved the purchase of a new replacement aeration basin gearbox.
Eric Lynne from Donohue and Associates shared his findings with the Council on the recent wastewater plant study. The original City of Stanley Wastewater Treatment Facility was constructed in 1984 with major upgrades in 1991 and 2017. Lynne explained the wastewater flows and loadings. He stated that the three significant wastewater industrial dischargers are Archer-Daniels-Midland (ADM), Ace Ethanol (ACE), and the Stanley Correctional Institution (SCI).
He said that the facility’s digester can’t stabilize the sludge and mentioned that a lot of the sludge goes to landfill.
Meyer asked, “Is there quite a bit of cost savings if we could digest it?”
Martin answered that they have no other option but to haul it to a landfill year-round at the annual budget cost of $55,000.
Lynne mentioned that land spreading wouldn’t reduce the budget cost to zero.
Alderperson Mark Fitzsimmons added that the biggest problem is if no one wanted it then the city would be stuck with it.
Martin agreed that depending on the weather, area farmers don’t want their land being torn up. He continued that the 60,000-gallon capacity digestor has to be emptied every seven days or it will overflow. He added that they are wasting 19,000 gallons a day and they are never going to break the maximum of seven days digestion. “There’s no breathing room as an operator,” he said.
Lynne informed the council that the city of Stanley has a 0.075mg/L 6-month discharge phosphorus limit that is challenging to maintain due in large part to the excess phosphorus load provided by the industrial users, namely the Stanley Correctional Institution (SCI).
He reminded the council that when he addressed them in 2021, he and Martin mentioned phosphorus trading that in his opinion has potential to help the situation. He shared that Martin is doing everything he can but “a little bit of trading would be a long way.”
Meyer addressed the excess phosphorus load from the Stanley Correctional Institution. “Is there anything somewhat practical that they could do on their end to send less phosphate rich material to the water treatment plant?”
Lynne mentioned that SCI could implement food scraps program or composting. Haas asked if the issue of food scraps was ever discussed with the SCI. Martin stated that it was because of the past food and various other items found in the wet well, including whole oranges, dental floss picks, and name badges.
He commented it would help if they had a food muncher and a fine screen to catch those types of items.
Fitzsimmons asked if the SCI could be required to do a compliance study because “they’re amplifying our problems here.”
Henke asked, “Their phosphorus since April, has it changed at all?”
Martin answered, “It’s been over what is considered residential phosphorus since the day I’ve been here.” He stated that their phosphorus is high concentrations of orthophosphate which is usually from food. “It’s high concentrations of orthophosphate which is a soluble type of phosphorus so it’s not a common derivative of a chemical that doesn’t break down. That’s what leads us to believe that it’s a food waste,” he said, further adding that soap could be a contributing factor, but those high numbers of orthophosphate are typical of food waste.
The council went on to discuss the Wastewater Treatment Plant Phosphorus Trading Plan with Martin and Lynne to help the city to comply with the total phosphorus limit as the current wastewater treatment facility has had trouble maintaining the 0.075 mg/L effluent total phosphorus concentration. The plan mentioned the 300 tillable acres that the City currently leases.
“In the end I still feel like the trading is a really good choice for you guys,” Lynne mentioned, adding that it would leave more breathing room to the current situation.
Martin explained that the level of detection is .05 which is the lowest amount that can be read with scientific instruments today. “My limit is .075. Our limit is almost at an unreadable number. If it was below .05 it would not be detectable with today’s technology. It’s hard to wrap your head around how low the City of Stanley’s phosphorus limit is. That all goes to the contributing fact that our discharge point is rated at a world class warm water sport fishery,” he said.
Meyer asked, “If we took land being used that’s farmed on and put it in prairie, would we get any credit for that?”
Lynne answered, “You’d get more credits.”
Haas said, “I think what we need to know before we make any decisions on it is, how many acres does it take for that?”
Lynne replied, “My gut is if you said 80 acres it would take us to the level that we are looking at and put it into non farmed prairie grass kind of scenario.” The more acreage that is put into the program, the greater the phosphorus limit is increased.
“Non farmed prairie grass and it would still take eighty acres?” Haas questioned.
“I think so,” Lynne reiterated.
“Is the land on the east side better than the west side?” Henke asked and stated that the city has about one hundred acres on each side.
Lynne said that the storm property has the better ratio.
“The West Park is state certified now, state site certified. You really don’t want to be putting that in a five-year plan anymore,” Haas stated.
“Almost have to work with the East,” Henke said and said there are 180 acres there.
Martin said that now the DNR allows open market trading where the City can purchase credits from another water shed to obtain a variance on the .075 limit. “I can’t consistently hit it,” Martin said of the tight limit.
“I think that what we are going to end up having to do is going to purchase from an outside source,” Haas said.