Impaired Water - Mallalieu Lake (Mallalieu Lake)
St. Croix County, Wisconsin
SC02
2607100
289.08
Water is impaired due to one or more pollutants and associated quality impacts.
Notes
Mallalieu Lake was placed on the 303d list in 2004 for eutrophication and pH impairments due to high phosphorus levels.

Mallalieu Lake was evaluated for phosphorus and algae every two years between 2012 and 2020. Chlorophyll-a values were too high as seen in algal blooms on the lake during the summer months. This lake is covered by a restoration plan: Implementation Plan for the Lake St. Croix Nutrient Total Maximum Daily Load (expires 2025).
Listing Details
Pollutant
Total Phosphorus
Listed For
Recreation
Impairments
Eutrophication, Excess Algal Growth, Elevated pH
Current Use
Restricted Recreation
Listing Status
TMDL Development
Attainable Use
Full Body Contact - Swimming, Boating
Priority
High
Designated Use
Full Body Contact - Swimming, Boating
303(d) ID
702
Listing Date
4/1/2004
Impaired Water Notes
This water was assessed during the 2018 listing cycle; new chlorophyll sample data exceeded 2018 WisCALM listing thresholds for the Recreation use.
Date
7/12/2017

Impaired Water Notes
Bi-weekly lake sampling from May-Sept. 2003 (pH exceedances on 2 of 6 dates).
Date
5/11/2005

Impaired Water Notes
TP and/or chlorophyll data from the period 2006-2010 were insufficient to assess per 2012 WisCALM. However, the previous assessment(s) were carried forward, and the lake remains listed as impaired.
Date
6/13/2011

Impaired Water Notes
This water was assessed during the 2016 listing cycle; total phosphorus sample data exceeded 2016 WisCALM listing thresholds for the Recreation use and Fish and Aquatic Life use.
Date
12/31/2015

Impaired Water Notes
This water was assessed during the 2020 listing cycle; new chlorophyll sample data exceeded 2020 WisCALM listing thresholds for the Recreation use. This lake is covered by a restoration plan: Implementation Plan for the Lake St. Croix Nutrient Total Maximum Daily Load (2025).
Date
7/24/2019