Infiltration, inflow remain concerns
By John Faucher
Hortonville Public Works Director Carl McCrary presented results of the Wisconsin Department of Natural Resources Compliance Annual Maintenance Report for the village’s wastewater treatment plant at a June 20 village board meeting.
McCrary said the purpose of the report is to evaluate wastewater treatment systems for problems and maintenance activities.
“It helps promote owner awareness and responsibility for wastewater collection and other treatment needs,” McCrary said. “Most of all, it evaluates our compliance with our wastewater treatment plant permit.”
McCrary said the now 10-year old plant is running “really well.”
“There were no significant issues, although we do have some infiltration and inflow issues on the collection system that we’re working on,” McCrary said.
Infiltration and inflow occurs when significant sources of clean water infiltrate the sanitary sewer collection system. It can come from excess rainwater, illegally hooked up sum pumps, loose manhole covers, cracked pipes and deteriorated laterals.
“You don’t want to treat clean water,” McCrary said.
McCrary noted the region has experienced above-normal rainfall for the past three to four years and the water table is high.
“Anytime you’re taking storm water and putting it into the sanitary sewer we have to treat that water and it overloads the systems, so you try to minimize (infiltration and inflow),” Village Administrator David DeTroye said.
“That’s why municipalities usually look for illegally hooked up sum pumps,” he said.
McCrary said much of the village infiltration and inflow comes from old laterals. Many are made of clay pipe, which become fractured, cracked or separated.
“It’s all over our communities,” said McCrary.
In the future after the State Highway 15 bypass is completed, McCrary said the village would need to look at the sanitary laterals underneath Main Street where much of the village’s infiltration and inflow comes from.
McCrary also said they see an above average amount of infiltration coming from around Hortonville High School.
“It’s something we’re looking at and it’s not going to be an overnight fix. In most communities, it takes time,” McCrary said.
Treatment plant in good shape
“Operationally the village should not have to do anything with the plant for another five to 10 years. It’s running fine and handling everything we can throw at it,” McCrary said.
He said the plant would take another 10 years to pay off.
“So we’re going to have higher rates for another 10 years,” McCrary said.
“Structurally that wastewater plant should be good for another 50 years. Long term, we’re going to be fine.”
New DNR permit required in 2020
McCrary said the village’s permit with the DNR is due next year, and he has already begun the process for a new application.
“We will be completing that in the next month or two and then we’ll see what the new DNR and (Environmental Protection Agency) requirements are for phosphorus discharges and how that will affect us,” McCrary said.
Changes in the current law could force municipalities to install new equipment to remove trace amounts of phosphorus from already treated water.
“Ideally it would be nice to have enough in the bank that if we had to spend half million dollars on a piece of equipment to further clean the water that we could just pay cash for it,” McCrary said.
“That’s the only long-term big expense I see, aside from a few valves and pumps here and there,” McCrary said, referencing projects inside the plant.
“Outside the fence we’ll be looking at replacing some old tired mains, upgrading lift stations and doing something about infiltration and inflow,” McCrary said.