Impaired Water - Lake Saint Croix (St. Croix Lake)
Pierce, St. Croix County, Wisconsin
SC01, SC02
2601500
7,695.89
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
On the state's 303(d) impaired waters list since 2008 for Total Phosphorus. This water was assessed during the 2012 listing cycle, and total phosphorus sample data were insufficient to assess against 2012 WisCALM listing criteria for the recreation use; however, chlorophyll a levels exceed recreation use listing thresholds. Additional monitoring is recommended to identify the pollutant causing excess algal growth. Fish and aquatic life thresholds for total phosphorus and chlorophyll were not exceeded, per 2012 WisCALM.

This water was assessed during the 2014 listing cycle: total phosphorus sample data overwhelmingly exceed 2014 WisCALM listing thresholds for the Recreation use, but not Fish and Aquatic Life use, and chlorophyll data exceeds both REC and FAL thresholds.
Listing Details
Pollutant
Total Phosphorus
Listed For
Recreation
Impairments
Eutrophication, Excess Algal Growth
Current Use
Restricted Recreation
Listing Status
TMDL Approved
Attainable Use
Full Body Contact - Swimming, Boating
Priority
Not Applicable
Designated Use
Full Body Contact - Swimming, Boating
303(d) ID
2008-20
Listing Date
4/1/2008
Impaired Water Notes
Lake St. Croix is impacted by phosphorus from point and nonpoint sources in the basin.

Rapid population growth and accompanying land-use changes have affected the water resources of the St. Croix River Basin. Based on a 39-percent projected population growth in the Basin by the year 2020, water resources will continue to degrade under the current circumstances. In response to this threat, the St. Croix Basin Planning Team conducted a detailed review of nutrient and sediment research and developed recommended water quality goals that would return Lake St. Croix to conditions that existed prior to 1950, before major ecological changes were experienced. These goals will require a 20-percent reduction in total phosphorus loading within the St. Croix Basin.
Date
11/7/2007

Impaired Water Notes
On the state's 303(d) impaired waters list since 2008 for Total Phosphorus.
This water was assessed during the 2012 listing cycle, and total phosphorus sample data were insufficient to assess against 2012 WisCALM listing criteria for the recreation use; however, chlorophyll a levels exceed recreation use listing thresholds. Additional monitoring is recommended to identify the pollutant causing excess algal growth. Fish and aquatic life thresholds for total phosphorus and chlorophyll were not exceeded, per 2012 WisCALM.
Date
7/11/2013

Impaired Water Notes
This water was assessed during the 2014 listing cycle: total phosphorus sample data exceed 2014 WisCALM listing thresholds for the Recreation use, but not Fish and Aquatic Life use, and chlorophyll data exceeds both REC and FAL thresholds.
Date
3/24/2014