High river levels increase water flows, costs
By John Faucher
The new emergency generator for New London’s wastewater treatment plant arrived on Dec. 11 and was successfully installed.
Ben Greuel, wastewater treatment plant chief operator, told the New London Board of Public Works committee that the generator was wired up, inspected and, “Works like a charm,” at its Jan. 4 meeting.
“The question is now what you want me to do with the old generator,” said Greuel.
Jeff Bodoh, director of public works said, “Typically we do put these items out for bid, but first we’ll have to take a look at how they will take out the old one. We’ll have to discuss that and make a decision at the next meeting,” said Bodoh.
Clear water infiltration
Greuel said the heavy rains received in late December caused some issues at the plant.
Committee chair Mike Barrington asked, “Are we running more clear water?”
“Oh yes,” said Greuel. “Three times the normal amount.”
Four inches of rain in the city and to the north brought up river levels where the river water begins flowing into the treatment plant via the sanitary sewers around town.
“Our normal daily flow is around 1 million gallons per day. However, we have had flows totaling 3 to 3.6 million gallons per day for almost a week (as of Dec. 21),” said Greuel.
“It actually makes treating the water worse.”
The cooler temperatures and clear water disrupt the bacteria and other natural processes normally involved in treating the wastewater.
“It actually costs about $1 per thousand gallons of water and nobody is paying for it,” said Greuel.
He has been working with Bodoh and Don Goodreau to find where the leaks into the sanitary sewer are coming from so they can get them fixed.
New rotating assemblies approved
The committee approved replacing three rotating assemblies for the plant’s three high rate filter pumps. Greuel said the existing pumps were installed in 1987 and have been rebuilt many times since then. The casting of the rotating elements that the mechanical seal sits inside have become pitted and out of spec due to the ferric chloride in the seal water and the numerous machining to “true up” the cavity.
“In other words the rotating elements are worn out,” said Greuel. “To rebuild the rotating assembly it has been costing us roughly $8,000 per pump, and we are lucky to get a year out of them. Right now there are two that will need rebuilding soon.”
Greuel said that because of the unknown limits that the Wisconsin Department of Natural Resources will impose on the plant’s phosphorus and nitrogen limits in the next 10 to 20 years, it doesn’t pay to buy new pumps for the building, as the flow schematic may change dramatically depending on how strict the limits are.
He said replacing the pumps would cost the city $75,000 to $90,000 per pump.
“I can’t see investing so much money in something that that may be obsolete within 10 years,” said Greuel.
They found a company that can cast new rotating assemblies to drop right in place for the existing pumps. “This way we can keep the existing pumps in place and reuse the motors which were reworked in the mid-2000s. The piping will also stay the same saving the city thousands of dollars,” said Greuel.
The use of seal water, which Greuel reported was the main culprit, will be eliminated by using flush less mechanical seals.
“With this setup we may be able to go ten-plus years without an expensive rebuild,” said Greuel.
He told the committee that the price quote of $52,857 includes time and materials to remove, retrofit and place back the rotating assemblies into service.
The committee unanimously approved the purchase.
East end of Beacon Avenue vacation
Several property owners at the east end of Beacon Avenue on the Wolf River asked the city to vacate the eastern portion of the Beacon Avenue right of way from Wood Lane to the Wolf River.
Bodoh explained that the property owners want to limit access on this end of Beacon because of the unclaimed boats and debris that are currently in the right of way. The property owners have maintained the property for the past 25 years.
Bodoh said the right of way would be divided evenly between the two property owners, and a noted utility easement would be noted on the property. He also said he would check into the legal aspect of an egress easement for the fire department to use the property as an emergency access point to the Wolf River.
“What you are approving tonight is just moving forward to begin the process of the street vacation,” said Bodoh. There would still have to be a class three notices published and a public hearing before going to council for a vote.
Committee member Denis Herter moved to proceed and Bob Besaw seconded the motion. The motion carried unanimously.