Sewer Authority reviews Foley pipeline proposal
Fri, 10/25/2013 - 10:56am admin
A discussion of a proposal to link the City of Foley with Clear Lake and Clearwater through a 20-mile pipeline that would carry municipal wastewater to a shared treatment facility was among the items discussed at the regular meeting of the Clear Lake/Clearwater Sewer Authority (CCSA) at Clear Lake City Hall Oct. 17. The committee also heard proposals for five alternate versions of a wastewater treatment expansion for Clear Lake and Clearwater.
Attendees included Clear Lake Mayor Tim Goenner (Chairman), Clearwater Mayor Pete Edmonson (Vice-Chair), members from both cities and a delegation from Foley that included Mayor Gary Gruba and Public Works Dir. Roger Schotl. Also attending were Edward Nevers and Timothy Korby of Donohue & Associates, the engineering firm that had been hired to conduct a wastewater treatment alternatives study.
Foley currently has a pond system for wastewater treatment, which is licensed by the Minnesota Pollution Control Agency (MPCA). According to the current city newsletter, the city has a problem with “inflow and infiltration”, with storm water and other sources adding to the flow to the treatment pond through cracks in existing sewer pipes and other sources. The added inflow threatens to overwhelm the existing system, reportedly to the extent that the city could lose its MPCA license if the matter is not addressed.
The city is currently conducting an I/I (Inflow and Infiltration) inspection in the city, and has conducted open houses and other workshops to educate citizens on the means by which they can help control waste water, including the installation of sump pumps, roof gutters and other water control measures. The city is also pursuing grants from a number of sources to fund necessary corrections to the system.
The pipeline proposal discussed at the CCSA meeting would involve the creation of an estimated 20 miles of underground pipeline from Foley to Clear Lake, following an as-yet undetermined route that could include portions of Hwy 25, Co. Rd. 16, Co. Rd. 6 and Hwy 24. The engineer’s report indicated right-of-way issues for the plan “probably would not be an issue” if it were to go forward. The firm has done similar projects in Moose Lake and the Horseshoe Chain of Lakes areas, Korby said.
He put a “ballpark figure” of $8 to $10 million dollars on the project, though additional costs could arise depending on the size of the pipe determined to be needed, while the municipalities would have to factor in bond ratings and debt loads. Foley is not in “crisis mode” yet, the report said.
While Foley would have to bear the lion’s share of the pipeline costs, the report stated a number of grants from government agencies that could be applied for to fund the Sewer
project. The report also urged the involvement of lake associations around the three cities to assist with the funding process, and suggested a meeting with local legislators, which will be set up in December.
The negatives involved in a pipeline project were also addressed which include potential cost increases depending on the size of pipe needed, as well as corrosion, leakage and odor issues that would ensue in the event of a breakage in the underground line.
The CCSA will continue to review the matter, Goenner said, considering the feasibility of the proposal and seeking to uncover any “hidden costs” and liabilities the participating cities might face if the project goes forward. A special meeting will be held on Thursday, Nov. 18, to continue the discussion and receive more detailed engineering reports.
Once the matter of the Foley pipeline had been discussed, the CCSA reviewed an “Effluent Reuse and Biosolids Handling Evaluation” survey that had been approved earlier in the year. Donohue & Associates provided four alternatives to the current surface water discharge system now in use.
These included a spray irrigation with surface discharge system ($343,000 initial cost, $83,800 annual operation/maintenance cost); a rapid infiltration basin system - future ($1,087,000 cost, $53,000 annual operation/maintenance cost); rapid infiltration system basins – current ($729,000 cost, $48,000 annual operation/maintenance cost); and spray irrigation with rapid infiltration basins, ($1, 306,000 cost, $60,000 annual operation/maintenance cost).
Several of the proposals may require changes in the current MPCA discharge permit, the study noted, and the authority will also need to comply with expected new restrictions on phosphorous content limits in waste water, the report noted.
The report also included a discussion of “geotube” and container filter dewatering systems, which have estimated initial costs of $346,000 and $731,000, respectively, with operations and maintenance costs of $7,400 and $5,100.
The geotube system involves storage of biosolid waste in large porous tubes above ground, from which water is drained and treated until the solids are compacted into “mulch” which can then be sold or provided to residents for gardening purposes, which is being done in cities which use the system, Nevers said.
The downside of the geotube system is that the exterior, above-ground tubes could raise aesthetic and odor control issues, while the container filter dewatering approach could require restarting an aerobic digester system.
The final draft of the engineering report is scheduled to be presented to the CCSA Nov. 8, with a meeting with local legislators to be scheduled in December.