By LeAnn R. Ralph
COLFAX — What if — instead of discharging to the Red Cedar River — the Colfax wastewater treatment lagoons could irrigate nearby farm fields?
The Colfax Village Board’s public property committee met August 24, and the idea of using water from the lagoons to irrigate farm fields was among the topics discussed.
The public property committee had toured village facilities at a meeting August 22 to begin assessing facility needs.
The state Department of Natural Resources will be setting a lower phosphorus discharge limit for Colfax, said Rand Bates, director of public works.
Colfax is pilot testing now to see how much the phosphorus discharge can be reduced by adding alum to the lagoons.
The alum costs about $15,000 per year, and when the DNR sets a lower limit, the alum could cost $30,000 per year, Bates said.
Colfax also would be required to do pollutant trading to make up the difference for the level of phosphorus discharged and the limit set by the DNR, he said.
Under a pollutant trading agreement, Colfax would pay another municipality upstream — or would pay farmers upstream — for the amount of phosphorus the other sources had been able to remove but which could not be removed from the Colfax discharge.
The lower phosphorus limits are part of the Total Maximum Daily Load implementation plan to reduce phosphorus loading into the 1,900 square-mile Red Cedar River Watershed.
Phosphorus is the nutrient implicated in fueling the toxic algae blooms in Tainter Lake and Lake Menomin.
Alum binds with the phosphorus and causes it to settle out to the bottom of the lagoon.
The Colfax wastewater treatment lagoons have been in operation since the early 1980s, and to date, about nine inches of sludge has accumulated at the bottom of the lagoons.
Adding alum to the water will increase the rate of sludge accumulation so that the village would end up dredging the lagoons sooner or more often.
The cost of alum along with the cost of pollutant trading could add up to maybe $170,000 for Colfax over a ten-year period, Bates said.
The village also would need to install an eyewash station and a shower at the lagoons because of the chemicals added to the wastewater, and a building would be needed to house the alum distribution system, he said.
Right now the alum tank is sitting out in the open because Colfax is conducting a pilot project, but if the alum became a permanent part of the village’s operation at the lagoons, the DNR would require a building to house the alum tank, Bates said.
Bates said he had talked to an engineer about the possibility of using the wastewater from the third lagoon to irrigate nearby farm fields.
Under normal operations, the wastewater eventually makes its way to the third lagoon where it is discharged into the Red Cedar River during the fall to give the village enough room in the third lagoon for winter storage.
The water from the lagoon could be piped under the railroad to nearby farm fields where a center pivot irrigation system would apply the water to farmland, Bates said.
The village would need to pump 60,000 gallons per day, and the engineer said 25 to 30 acres would be needed for 70,000 gallons per day, he said, noting that the discharge for an irrigation system might occur once a week.
All together, a couple of hundred acres of farm fields are available nearby for using the wastewater to irrigate, Bates said.
Scott Gunnufson, village president, suggested the possibility of the village purchasing 25 or 30 acres of farm field for the discharge.
The village could then also receive some income from renting out the land for farming, he said.
If the village could use the wastewater to irrigate a field, then there would be no DNR requirements for phosphorus limits because the water is not being discharged to the Red Cedar River, Bates said.
The village would incur the cost of piping the water to the field and for the irrigation system, said Dave Wolff, village trustee and chair of the property committee.
“But look at what it would save down the road,” he said.
The DNR also is monitoring ammonia at the lagoons, and nitrogen will be the next nutrient that the DNR most likely will be monitoring and regulating more closely, Bates said.
Building a mechanical wastewater treatment facility for Colfax to control the amount of phosphorus and other nutrients discharged to the Red Cedar River would cost about $5 million.
“If we don’t do the discharge (and operate a lagoon system), we would be required to have a processing facility, and that would be millions of dollars,” Niggemann said.
Other facility needs the committee discussed included a vehicle exhaust system for the Colfax Rescue Squad at an estimated cost of $26,000, handicapped accessibility for the Colfax Municipal Building, a new salt-sand storage shed and demolition of the building on Evergreen Street currently used to store salt-sand, the Colfax police department and the need for an evidence room and an interview room, and the Department of Public Works building and the lack of floor drainage to deal with snow melting from snow removal equipment and vehicles during the winter.
The Colfax Rescue Squad also does not have a floor drain for snow melting off the ambulances during the winter.
The public property committee planned to meet again August 31 to continue discussing facility needs and setting priorities for the 2017 budget.