MRC Comments: Fox River Implementation Plan
12.01.2022 | Nitrogen & Phosphorus Pollution | No Comments
The Mississippi River Collaborative (MRC) consists of ten state organizations – as well as other regional and national partners – working to protect water quality in the Mississippi River Basin and the Gulf of Mexico.
The MRC strongly supports the Fox River Implementation Plan (FRIP) insofar as it supports dam removal and associated riparian restoration, wastewater treatment plant (WWTP) upgrades, and upstream load reductions. The dams clearly are destructive of water quality. Reduction of phosphorus effluent concentrations from major point sources to 0.5 mg/L will continue the progress that has been made although reductions to 0.1 mg/L or lower will almost certainly be needed in the future. The run-‐of-‐river impoundments, integral components of the Fox River system, should be the focus of more concerted effort until the dams can be removed because they exacerbate the undesirable dissolved oxygen and algal conditions. Work must also be done in Wisconsin and the Fox Chain O’Lakes region to reduce phosphorus and algal loadings to the study reach.
However, the MRC wishes to make clear several points regarding the draft report and the long-‐term goals for the Fox River, many of which are also relevant to other Mississippi River tributaries:
1. 149 µg/L cannot be a valid water quality standard or endpoint for final efforts
We appreciate that it is not the intention of the FRIP to establish 149 µg/L sestonic chlorophyll as a water quality standard and that it is not the expectation of the Fox River Study Group (FRSG) to conclude efforts to reduce unnatural algal levels after this extremely high and unhealthy level of chlorophyll is consistently achieved. As discussed in the attached letter from Dr. JoAnn Burkholder, 149 µg/L is much higher (by 10-‐ to 100-‐fold) than desirable levels to maintain the designated use of the Fox River for beneficial aquatic life. Accordingly, meeting 149 µg/L should be seen at most as reaching a milestone on a journey that will continue long after that milestone is reached.
2. More work is needed on the model if it is to continue to be used as a tool to direct actions to protect the Fox River from eutrophication
We recognize that action cannot wait while a “perfect” model is achieved and agree that it is often wisest to go forward to take steps recommended by a model than to wait until the model can be improved. Indeed, we are pleased that many Fox River dischargers have already taken many steps to reduce phosphorus loadings based on the modeling done for the original 2015 FRIP. It is our understanding that at that time the FRSG was not confident enough in the model calibration to recommend dam removal on the Fox River. Now with the improvements made to the model over the last seven years, the FRSG, is comfortable recommending the combination of further phosphorus loading reductions and dam removal in this 2022 FRIP update.
However, for the reasons detailed by Dr. Burkholder, it must be recognized that the model used in the FRIP is at most valid for making decisions as to steps to be taken in the next few years. We are pleased that the FRIP contains plans for future data collection and model recalibration in order to continue to improve the model’s representation of the actual Fox River.
3. Effluent limits well below 0.5 mg/L will almost certainly be required in the future
Rome was not built in a day and reducing WWTP discharges to 0.5 mg/L phosphorus certainly reflects major progress from 1990s levels. Further, we believe that, as dischargers work to achieve consistently the 0.5 mg/L effluent limits, operational and technological improvements will happen that over years will substantially reduce effluent phosphorus concentrations.
However, it is clear from even the current model that reduction of phosphorus effluent concentrations to 0.1 mg/L significantly reduces levels of unnatural algae. Further, improvements in the model and elimination of dams will almost certainly show that further reduction of phosphorus loadings are needed to meet dissolved oxygen standards and protect the Fox from unnatural algal blooms.
Moreover, climate change, which is expected in the Midwest to result in higher temperatures and more extreme changes in flows, will result in a much higher risk of
cyanobacteria blooms if nutrient levels are not reduced substantially below the levels currently contemplated in this stage of the plan.
4. It will be necessary to consider nitrogen pollution in future planning
The FRIP has focused on phosphorus and dissolved oxygen as anticipated. However, for the reasons discussed by Dr. Burkholder, the initial studies show that nitrogen pollution is a factor and limits on nitrogen loading will have to be considered in the future.
5. Downstream effects may also require enhanced controls in the future
The Illinois River, portions of the Mississippi and the Gulf of Mexico are also impaired by nutrient pollution. The Illinois River Watershed Study Group and the Gulf Hypoxia Task Force are working to study and reduce loadings of nitrogen and phosphorus that are causing these impairments. While the Fox River obviously is only a small portion of the loading to these downstream water bodies, further reductions in loadings to the Fox may well be called for as part of a plan to protect these downstream waters.
The MRC looks forward to continuing to work with the FRSG to improve water quality in the Fox River and the Mississippi Basin.
Sincerely,
Albert Ettinger, Counsel to Mississippi River Collaborative
Robert Hirschfeld, Senior Water Quality Specialist, Prairie Rivers Network
