Big Sandy Area Lakes - Excess Nutrients: TMDL Project

In 2006, Big Sandy and Minnewawa Lakes in Aitkin County were placed on Minnesota’s 303(d) List of Impaired Waters, for aquatic recreation due to excessive nutrients. The data indicated that these lakes had total phosphorus concentrations in excess of the MPCA’s state water quality narrative standard of 30 micrograms per liter for the growing season mean.

This project includes water quality and sediment monitoring, watershed and in-lake water quality response modeling, calibrating the modeling to the most recent monitoring data, reviewing the water quality goals for the lake, evaluating watershed control measures and in-lake management techniques for phosphorus load reductions, determining the margin of safety and specific waste load and load allocations for each source of phosphorus, and recommendations for implementation and compliance monitoring plans.

The TMDL was approved by USEPA in June 2011, and the Implementation Plan was approved by the MPCA in May 2013. Several projects are currently underway.

Map and location

Big Sandy and Minnewawa Lakes are located in Aitkin County, in the Upper Mississippi River Basin. Waters from the “2008 Minnesota Inventory of Impaired Waters” are shown on the map below, with red lines for impaired streams and red dots for impaired lakes and wetlands.

TMDL report and implementation plan

Meetings and events

  • Big Sandy TMDL informational meeting: Friday, September 25, 2009, from 2-4 pm, Fireside Restaurant in McGregor, MN.
  • Public Stakeholder Kickoff Meeting: Thursday, August 7, 2008, 7:00 p.m. Fireside Restaurant McGregor, Contact: Steve Hughes, 218-927-6565.


Big Sandy Area Lakes Watershed Management Project

Information contact

Anna Bosch, Project Manager
7678 College Road, Suite 105
Baxter, MN 56425