The Minnesota Pollution Control Agency (MPCA) has proposed adding a segment of the St. Croix River from Taylors Falls to Lake St Croix to their impaired waterbody list due to excess phosphorus. MPCA is currently accepting public comment through January 14th, 2020 and plans to submit the final impairment list to the U.S. Environmental Protection Agency in April, 2020.
Minnesota’s Impaired Waters List - https://www.pca.state.mn.us/water/minnesotas-impaired-waters-list
The St. Croix River segment from Taylors Falls to Stillwater, MN is proposed to be listed as impaired for excess nutrients, specifically phosphorus and increased levels of algae (expressed as the amount of chlorophyll a) in response to this excess phosphorus.
Impaired Waters are those waters that do not meet water quality standards for one or more water quality parameters, thus, they are “impaired” or not supporting their designated uses. This impairment listing is for “aquatic life,” meaning that the level of nutrients detected in the water may be detrimental to aquatic life.
The river is vulnerable and will always be vulnerable. This impairment designation is a reminder that continual work and public action will be necessary to preserve and protect the St. Croix River.
Water quality is a watershed-wide issue and will require a watershed-wide approach. Local, state, and federal government agencies, not-for-profit groups, and residents in both states and along all the tributaries are responsible for addressing this issue.
People can continue to use the river for recreation (swim, paddle, fish, and enjoy). Excess phosphorus leading to an overabundance of algae can be detrimental to aquatic life; therefore, this is an “aquatic life” impairment and not a recreation, consumption, or fish consumption impairment.
Water quality within the river is actually improving and getting better. Current actions to improve water quality within the watershed are successful. Water quality data collected by the Metropolitan Council from the St. Croix River at Stillwater show a steady decline in phosphorus concentrations from 1976 to 2015.
The St. Croix River is a national treasure, with national park status and wild and scenic river designation. Urgent and thoughtful action will be necessary to seek additional resources, funding, and partnerships to make water quality within the St. Croix watershed a priority.