The Silver Bay City Council unanimously approved plans for the 2019 sanitary sewer improvement project and to move into the bidding stage Monday, April 15.

City-contracted engineer Joe Rhein of Bolton and Menk gave the council an update on the project, which is actually a combination of three projects: the east and west sewer projects and the trunk line sewer project.

The sewer bridge project will repair two sewer bridges in the city: the west sewer bridge (south of Arthur Circle) and the east sewer bridge (south of the Black Beach Campground).

The west bridge requires less rehabilitation and no special permission from landowners, also known as an easement. It is estimated at about $55,000.

The east bridge, which requires an easement from Northshore Mining and far more rehabilitation and construction, is estimated at about $242,000.

The trunk line sewer project seeks to replace approximately a half-mile main flow sewer pipe to the wastewater treatment plant. This portion of pipe runs along the hillside from the city along the northwest side of Water Plant Road and crosses East Lakeview Drive along Industrial Park Road. It's the main pipe that carries wastewater from the city.

The pipe starts at a steep angle, then quickly levels out to a flatter run, which could cause a problem when the water treatment plant builds a new pretreatment system in 2020. The pipe needs to be raised 4.5 feet to generate enough of a push.

Bolton and Menk explored several options for the pipe route and settled on four possible routes, before narrowing the field down to two routes. The first route would follow the existing pipeline but would require more raising of the road and more fill work.

The other feasible route was a combination of two possible routes. This route would stick with the old pipe route along the bottom portion of the line, then deviate to a new route further along. This plan also required an easement from Northshore Mining and was found to be the most cost effective route. It is estimated to cost $931,000.

Access to Black Beach would be closed during the construction of the trunk line project. Campers could still access the park by foot, but the beach itself would likely have to be closed to all motor traffic.

Because the east sewer bridge project and the trunk line require easements from Northshore Mining to move forward, and they both deal with similar work, Rhein recommended combining all three projects into one project to acquire a better bid price.

"These had been proposed as separate projects because they had been on different schedules. We thought the bridges were going to be significantly ahead of the trunk sewer and get constructed quickly," Rhein said. "But sometimes things take longer to develop than you anticipate and in the course of project development, we realized we needed to get an easement for both projects, which puts them on the same schedule."

Rhein said talks with the mining company were going well and that he anticipated receiving the completed easement by the end of April at the latest. The combined costs of the three projects add up to $1.12 million - about $16,000 less than if the projects were bid separately.

The council should expect to receive the final bids for the project by the first week of June. Construction is anticipated to start shortly after the Fourth of July.