The Rockford City Council Aug. 27 received an engineering report for the Waste Water Treatment Modifications project.
The city’s engineer, Jared Ward of Wenck, along with Peter Daniels and Jim Miller, walked the council through the project, which focuses on two major objectives: how to handle phosphorus removal, and biosolids management. This project was in the planning stage with the city’s previous engineer, and part of it is in response to recent state mandates and carries a pressing time line.
Two recommendations were made to the council regarding phosphorus removal.
The first was chemical removal. What’s needed for this method is a 6,000 gallon storage tank and metering pump building, chemical pumps and feed-lines, electrical and controls and metal salts to precipitate phosphorus. The capital costs for going with chemical removal are estimated at $500,000 with annual operating and maintenance costs of $114,000.
Biological removal of phosphorus is a little more complex and would require a larger footprint with the addition of a lift station, mixers for anaerobic and anoxic zones, and an aeration basin and sludge pump. The capital costs for this process are estimated at $1,530,000, with $94,600 in operating and maintenance costs annually.
The biological option clearly has more start up expense, but fewer operating costs. It requires fewer chemicals and provides complete nitrogen removal.
The chemical method’s capital start up price tag comes in over a million dollars less, but does have about $20,000 a year more in chemicals and other operating expenses. This procedure does not fully remove nitrogen.
After some discussion, the council reached a consensus, choosing the chemical process for the improvement project, citing the capital cost as a deciding factor. Additional improvements were recommended including the replacement of facility water line, pumps, electrical conduit and the purchase of clarifier weirs and laboratory testing equipment. The overall cost of the project is estimated at $1,340,000. There is grant money, up to 50% of project costs, for those improvements directly related to phosphorus removal.
The council approved the wastewater treatment facility plan and directed the engineer to prepare plans and specs, and advertise for bids.
The engineer will submit plans and specs to the Minnesota Pollution Control Agency (MPCA) by Dec. 1 for review, and is planning for construction to begin in June 2014, and completion June 2015. This time line complies with the MPCA mandate.
Biosolids management will continue to be investigated and will come before the council at a later date. Currently, the city disposes of about 800,000 gallons of biosolids on Rockford Township property by land-application at a cost of $50,000. The alternative staff is considering are alternate sites for disposal including Buffalo and Big Lake.
READING’S ON THE ‘UP’
In other news, Theresa Jacobs from the Rockford Public Library spoke to the council about what Great Rivers Regional Library (GRRL) services consist of, and what’s available in Rockford.
She said that volunteers have helped host events and reading programs that are up significantly in the number of participants, and readers, from previous years. Legacy funding has allowed the library to bring in several programs and traveling authors, but it will see a reduction in 2014. Jacobs said staff and volunteers may have to get more creative moving forward, and that she is always looking for local talent.
The City of Rockford provides the building for the library and some minor funding related to it. Library staff and materials are paid for by the GRRL and Wright County.
In other news, the city’s engineer expects to have plans for a drainage channel at the Hurst Woods development ready for council review at its Sept. 24 meeting. A water and erosion issue has plagued some properties in the development, and the city assisted in obtaining some help from the developer, a company that no longer builds in the city, last year. The payment was made with the contingency that it was a one-time, final contribution. Owners of the property also contributed to preventative work in 2012 for severe erosion affecting their property.
The engineer said that the work needs to be done before next spring to prevent additional erosion, and could be done well into fall.
The council also approved a bid for $19,851 to repair the city hall roof from B&B Sheet Metal and Roofing.
The next regular meeting of the Rockford City Council is Tuesday, Sept. 10, at 7 p.m. at the Rockford City Hall (6031 Main St.).