The Silver Bay City Council approved a wastewater preliminary treatment project to move forward into the bidding stage at their meeting Monday, May 20. This project was postponed for nearly a year because funding for the project was tied up.
"The project was designed a little over a year ago, but funds were held up in Legislature," said Brian Guldan, an environmental engineer with Bolton and Menk, the city's contracted engineering firm. "They were cleared a few months ago now so they can move ahead with the proper funding in place."
The project mainly consists of two components, adding a better pretreatment process and changes to aid mercury removal.
Improved pretreatment removes rags and larger debris from wastewater before it enters the system. Removing grit such as sand or other inert material before it goes into the system is essential since it aids with the long-term maintenance and life of the equipment.
The second part of the project deals with mercury limits. The Minnesota Pollution Control Agency enforces mercury limits on wastewater systems that are near the Lake Superior Basin. To ensure the wastewater plant continues to meet these mercury limits, the project will place covers on five clarifiers at the facility. The covers limit rainwater contamination.
"Rainwater actually has a higher level of mercury in it than the wastewater in the clarifiers, so if we keep that rain from coming in, that's less mercury that we're adding to our system," Guldan said.
The mercury removal enhancements also ensure the project qualifies for point source implementation grants (PSIG) funding from the Minnesota Public Facilities Authority (PFA). The project also qualifies for a Water Infrastructure Fund grant from the PFA, and with the PSIG, these grants will pay for an estimated $1.4 million of the proposed $3.2 million project.
The rest of the project will be funded with a low-interest 20-year loan from the PFA and/or a grant from the Iron Range Resources and Rehabilitation Board.
The council unanimously approved the project to move into the bidding stage; councilor Carlene Perfetto was absent.
If the bids come back within range, construction is slated to begin later this summer and continue for about a year.