WILLMAR -- The old wastewater treatment plant site may be used for future storm water management after the new treatment plant begins operation, under action taken by the Willmar City Council.
The council this week revised the contract with Donohue and Associates to redesign the plan for decommissioning the old plant.
The revised plan would allow for future storm water improvements at the old site.
Donohue, the consultant overseeing the new wastewater treatment project, will redesign and revise the plan at a cost not to exceed $87,275.
The new plant, located west of the city, will replace the old plant, located just east of the Kandi Mall. The old plant uses failed treatment technology and has odor problems.
The original decommissioning plan called for removal of the top three to four feet of the majority of the old plant's buildings and equipment, covering the area with soil and planting turf grass.
Under the revised decommissioning proposal, the structures would be removed in their entirety and the site would be left as a depression to allow for future storm water improvements.
The storm water improvement being discussed by the city envisions a pond where storm water from the nearby County Ditch 23A could theoretically be diverted, held temporarily and then be released back into the ditch as water levels downstream drop.
Also, officials believe the pond could be used to settle out sediments in the storm water to comply with storm water quality requirements.
Use of the old treatment plant site for storm water management topped the list of five areas recommended as storm water retention projects by the Storm Water Task Force. The task force was appointed by the council in 2008 to find solutions to flooding problems caused by heavy rain storms.
Barr Engineering is analyzing the five areas for storm water management purposes and the first study to be completed was the analysis of the old treatment plant site.
Recent discussions between city staff and Barr Engineering prompted discussions with Donohue and the Minnesota Pollution Control Agency to use the old plant site for storm water management. Those discussions prompted the idea to revise the decommissioning contract with Donohue.
The new waste treatment project is being financed in part with a wastewater loan from the Minnesota Public Facilities Authority. Public Facilities Authority rules do not allow use of wastewater loans for storm water projects, said City Administrator Michael Schmit.
If the city were to proceed with a storm water project, the cost would have to be financed with a storm water loan, he said.