Boyer Slough Station

The Boyer Slough station has been monitored every year since 2012. It is the most highly polluted site that we monitor, as shown by consistently elevated levels of total phosphorus which can lead to toxic algae outbreaks and the growth of invasive weeds. The pollution is primarily attributed to the discharge of inadequately treated wastewater from the Kootenai Ponderay Sewer District (KPSD) into the slough for a significant portion of the year. 

We are very pleased that KPSD was recently awarded a grant and a low interest voter approved loan, totaling more than $32 million, which will be used to upgrade the facility. Their permit’s compliance schedule requires the upgrades to be complete by August of 2028, however we hope they are able to complete the upgrades sooner! 

In the meantime, it would be prudent for KPSD to suspend offering new connections to subdivisions, residences, and businesses. We urge the district to halt all new connections until they upgrade their treatment facility and water quality improves. We applaud them for raising funds to update the system, and now it’s time to get the job done!

ICL is invested in this clean-up effort for the long run. We participate in the Kootenai Bay Watershed Advisory Group that aims to permanently clean up this highly polluted area of Lake Pend Oreille. The group, convened by the Idaho Department of Environmental Quality, also includes a representative of the sewer district. We are hopeful that together, we can develop a new plan that restores this waterway to a swimmable, fishable, drinkable condition. In the meantime, swimming in the slough is strongly discouraged.