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Improvements to city lagoon estimated at near a million

GLENWOOD CITY — The city council and members of the Downing Village Board met in a public meeting Tuesday evening, October 27 to discuss future upgrades to the City’s Wastewater Treatment Facility to replace aging equipment and to meet requirements of the State Department of Natural Resources.

The City and Downing both use the facility located along County Highway G just south of the schools. Downing’s use is about 17 percent of the total volume pumped into the facility.

The council and village officials met to review a facility plan from Foth Infrastructure and Environment LLC out of De Pere, Wisconsin. Foth was retained by Cedar Corporation to prepare a facilities plan for the City’s Wastewater Treatment Plant (WWTP). The plan as presented at the meeting noted: “The need for the facilities planning process was based on the WWTP needs to address upcoming phosphorus and ammonia limits.”

The 170-page document contains a mountain of information about the Wastewater Treatment Plant and makes recommendations and conclusions about upgrading the plant. It notes that some of the equipment at the facility has reached its useful life and needs to be replaced.

The report noted five areas that needed to be addressed including: a facilities plan or phosphorus removal as required by the DNR; replacing the present aeration system, which is in poor condition; and completing the recommendation from a 2011 ammonia removal study. The city must have construction plans to the DNR by October 1st, 2016. Also the city must be in compliance with phosphorus limits by July 1st, 2018.

“The facility currently has two aerated ponds. Each has an approximate surface area of 2.3 acres with a capacity of 6.2 million gallons each,” the facility plan states. It further goes on about the size of the ponds. A third pond, “called a settling pond is 1.5 acres with a capacity of 3.8 million gallons and the big pond which is called an artificial wetland. It is about 23 acres and holds up to 44 million gallons.”

The large pond holds the treated wastewater during the winter and then as the water temperature raises during the summer the pond is allowed to drain from its maximum depth of six feet down to one foot. The discharge is by gravity to the wetland area around the facility and to Tiffany Creek.

Some of the conclusions in the plan include that the total project capital cost for the recommended upgrades to the facility will be $959,000. That figure will cause an increase in user fees of $11.00 to $15.00 per month the report stated. Also in the plan were cost figures to optimize the existing plant at a cost of $3,139,000.00 and to build a new Wastewater Treatment Plant would bring the cost to over five million dollars.

Recommendations made in the plant include: “the city experiences WWTP flows that exceeds the USEPA criterion of 120 gallons per capita per day during rainfall events. The increase in flows are generally the result of prolonged rain events and not considered excessive infiltration. However, it is recommended that the City continue to reduce inflow and infiltration by locating and repairing problem areas in the collection system.”

Another of the eight recommendations include “Replace the existing aeration system in ponds one and two to maximize ammonia reduction in the system. Excess solids should also be removed during replacement of pond equipment.”

“Replace existing outfall structure between the artificial wetland and the natural wetland tributary to Tiffany Creek and install monitoring equipment for continuous pH monitoring.”

“Periodically remove excess sludge from the settling pond to minimize carry-over of biological solids to minimize discharge of total phosphorus.”

Also included is a recommendation to install a new flow meter at the treatment plant site to accurately measure influent flow from the Village of Downing. Currently the flow from Downing is measured on the amount of time the pumps in the village operate.

And finally, it is recommended that the “existing piping between ponds one and two be replaced to eliminate capacity issues observed by treatment plant operators.”

The study stated that the facility has, “based on historical monitoring data, the existing system has the ability to consistently meet the 1.1-milligram per liter total phosphorus effluent limit without the need for additional phosphorus control strategies.”

The report states that, “limited increases in flows and loads are anticipated from residential growth and unplanned industrial contributors over the 20-year design period. The design flows and loads are expected to remain below the design capacity of the existing system.”

The study indicated that plant had a daily flow of about 175,000 gallons of wastewater and the existing design flow is 262,000 gallons daily.