Army Corps of Engineers plans Cd'A River work

KELLOGG — Those who may recreate or spend time in the South Fork of the Coeur d’Alene River near Kellogg will need to find an alternative area for a month or so starting next week.

The U.S. Army Corps of Engineers and the city of Kellogg announced on Aug. 23 that contractors with Wood Environmental and Infrastructure Solutions Inc. will be conducting work in the South Fork just west of Bunker Avenue near Exit 49 from Sept. 3 to 30.

USACE representative Rod Zion explains that the construction is directly related to the ongoing Bunker Hill Central Treatment Plant and Groundwater Collection System project.

“Currently, the existing treatment plant discharges the treated effluent right into Bunker Creek. Under the upgraded plan, which will treat both mine and ground water from under the Central Impoundment Area, effluent will be piped over the top of the CIA to the north and then come down and discharge into the Coeur d’Alene River.”

In order to route this water to where they want it to go, work crews will be installing an in-water treated effluent outfall structure.

This elaborate structure is made up of a system of connected perforated pipes that will lie underneath the riverbed. It is designed to have the treated effluent almost naturally flow into the river from the ground up, similar to a bubbler in a fish tank — minus the bubbles.

USACE stresses that there will not be pipes on the shoreline or elsewhere dumping into the river.

“It will be pretty much invisible,” Zion said.

The goal is to keep the area looking the way it currently is with no visible pipes or structures.

Construction of the structure will require crews to get into the river itself and construct barriers to control the flow of water.

“This is going to be pretty invasive in the river bottom, so we’ll have heavy equipment in the river and it will be stirring up a lot of turbidity,” Zion said. “To control that, the contractor will basically make a perimeter of a silt curtain and cofferdam structure to isolate the work area and draw the water down.”

Water levels downstream of the construction site are not expected to be affected, but there is a small possibility that stirred soils could temporarily change the color of the water.

To ensure safety for the public, the city of Kellogg requests that all persons including floaters, kayakers, etc., avoid this area until construction has been completed and until the in-water control features have been removed. Signage will be placed upstream as an added precaution to remind those who may be recreating in the area.

The construction effort will be entirely in the water and is not expected to cause any road closures in the area.