Lake Shaokatan Phosphorus Total Maximum Daily Load Report

Document
Description
The Minnesota Pollution Control Agency (MPCA) has listed Lake Shaokatan as impaired for the designated uses of aquatic recreation and aquatic life under Section 303(d) of the Clean Water Act. Excessive phosphorus loading is the main cause of the impairment. This Total Maximum Daily Load (TMDL) document assesses the current phosphorus concentrations and the load reductions needed for Lake Shaokatan to comply with Minnesota's water quality standards. The specific problems and recommended approach and actions to control phosphorus loads are highlighted below. The area of concern is Lake Shaokatan and its surrounding watershed, which includes an area of 13.9 square miles. Agricultural land (cropland, pasture and hayland) and grasslands dominate the land use in this watershed. There are no urban areas in this watershed. The 13.9 square mile watershed is headwaters of the Yellow Medicine River. This lake has been the subject of several investigations including an intensive MPCA Clean Water Partnership Diagnostic and Feasibility study and a successful implementation project that spanned the period of 1991-1996. Summer mean total phosphorus concentrations declined from a range of 275-350 micrograms/liter (μg/L) in 1989-1992 to 90-110 μg/L in 1994-1995 in response to several implementation activities within the watershed. The focus and primary intent of this project is to better characterize phosphorus levels, probable sources, and estimate reductions required to meet the TMDL water quality goal. Watershed wide phosphorus loading was estimated to assess the magnitude of nonpoint and point sources and establish a cause-effect linkage of loading sources and subsequent in-lake phosphorus concentrations.
Date Issued
2012-08-01
Number of Pages
54
Decade
Associated Organization
Publisher
Minnesota Pollution Control Agency (St. Paul, Minnesota)
Publication Series
Body of Water
County
Rights Holder
Minnesota Pollution Control Agency
Rights Management
Public Domain