Impaired Water Status
IMPAIRMENT STATUS FOR ALL OF LCO
COLA and the LCO Tribe completed an assessment of five years of sampling data and determined that levels of dissolved oxygen adequate for cold-water fish habitat are not being maintained in LCO primarily because the phosphorus concentration has been increasing and is near the level that will result in the extinction of the cold-water fish in LCO. In addition, the current level of phosphorus is resulting in spiraling degradation of LCO water quality (more algae and algal blooms. a decrease in water clarity and excessive aquatic plant growth) as evidenced in recent years.
This assessment was provided to the WDNR with a request that WDNR list all of LCO as impaired for depleted dissolved oxygen caused by the pollutant.... phosphorus. The WDNR included LCO, all of it, in its list of 2018 list of Impaired Waters. But it stated that “low dissolved oxygen” was an indicator, or symptom, of that impairment without citing phosphorus as the cause of the impairment. They claim that there is no evidence of a link between high phosphorus concentrations and low dissolved oxygen in LCO.
COLA and the LCO Tribe welcome the impairment status as a big step forward In their efforts to preserve and protect the LCO lakes because, with impairment status comes the regulatory/legal framework to implement the phosphorus reductions necessary to restore and preserve LCO water quality. In addition, with impairment status comes access to federal and state grant monies to pay for phosphorus reduction improvements and restoration dollars to cleanup Musky Bay, Stuckey Bay, and the West Basin.
MUSKY BAY
After five years of COLA and LCO Tribal effort, the United States Environmental Protection Agency (U.S. EPA), on June 25, 2014, declared Musky Bay to be “impaired water” under the federal Clean Water Act. The water quality in Musky Bay had been severely degraded over the years because too much phosphorus is being dumped into and is accumulating in the Bay that in turn is causing algae blooms and algal mat production, excessive aquatic plant growth and, when all this biomass dies and decomposes, it depletes the oxygen level in the water resulting in fish kills and disruption of muskellunge egg development. The overall result is that the recreational use (swimming, paddling, boating, and fishing) in Musky Bay was “impaired” and must be fixed according to federal law.
Nonetheless, in 2020, WDNR removed Musky Bay from its “impaired water’ list using the justification that since Musky Bay is a “shallow drainage lake”, separate from Lac Courte Oreilles, the appropriate phosphorus standard for Musky Bay should be 40 ppb.
Water quality monitoring data collected by the LCO Tribal Conservation Department over several decades show that the waters of Stuckey Bay are being degraded by excess phosphorus, and Stuckey Bay is close to exceeding the threshold (15 ppb) for determination as impaired water. Because the water in Musky Bay mixes with water in Stuckey Bay and the West Basin, the whole West Basin of LCO is headed for impairment status.