By Mario Carr EBS CONTRIBUTOR
A 40-mile stretch of Gallatin River has been formally declared impaired this month after the U.S. Environmental Protection Agency approved the listing by the Montana Department of Environmental Quality. The stretch runs from the border of Yellowstone National Park to Spanish Creek.
The impairment designation comes after five consecutive years of toxic algal blooms and several environmental groups petitioning the DEQ.
The next step in this process is to monitor water quality and determine a total maximum daily load, or TMDL, which could take upwards of six years to complete.
“A TMDL is the calculation of the maximum amount of a pollutant allowed to enter a waterbody so that the waterbody will meet and continue to meet water quality standards for that particular pollutant,” according to the EPA. The EPA acknowledges that identifying these pollutants and their effects can be an “iterative process.”
Back in April, the Montana DEQ stated that, “excess algae growth is usually the result of nitrogen and phosphorous, however the assessment revealed that the river is not impaired for nitrogen and phosphorus when compared to existing numeric criteria. Instead, the assessment of the response variables, such as macroinvertebrate communities and ash-free dry weight, indicate that the river is impaired by algal growth. Photos, videos and testimonials submitted with the petition further supported this outcome.” The direct cause of these algae blooms has yet to be determined.
“There has always been more algae downstream of Big Sky, but we have started to see more algae upstream as well,” said Kristen Gardner, executive director of the Gallatin River Task Force.
Some pollutants are easy to trace and figure out where they are coming from, these are point source pollutants. Nonpoint source pollutants originate from a variety of locations and are carried into storm drainage systems and creeks by storm water and other runoff.
Gardner wants the community to know that the Gallatin River Task Force has not been “sitting around waiting” for the river to be declared as impaired. They’ve contributed to the community efforts in upgrading the wastewater treatment plant in Big Sky, a number of large-scale restoration projects going on around the Gallatin, as well as a native landscaping program that encourages everyone to do their part in protecting the river by choosing native plants that don’t require large amounts of water or fertilizer.
Gardner also stated that the DEQ will be spending an additional $500,000 to $1 million on the river monitoring efforts, and that the GRTF will be working alongside the DEQ to help connect their team with the community.
