A TOTAL MAXIMUM DAILY LOAD (TMDL) IS A CALCULATION OF THE MAXIMUM AMOUNT OF A POLLUTANT THAT A WATERBODY CAN RECEIVE AND STILL MEET WATER QUALITY STANDARDS AND AN ALLOCATION OF THAT AMOUNT TO THE POLLUTANT SOURCE. THE TMDLs ARE REQUIRED BY THE US ENVIRONMENTAL PROTECTION AGENCY. DRAFT LOAD REDUCTION (AMOUNT OF POLLUTANT THAT NEEDS TO BE REMOVED TO MEET STANDARDS) WILL BE AVAILABLE FOR EACH IMPAIRED LAKE BY THE TMDL MEETINGS.
There are several completed TMDLs for water bodies in Chisago County, including Lake St. Croix, Six Lakes, North Branch of the Sunrise River, and Chisago Lakes Chain of Lakes Watershed. TMDLs that are in progress include Sunrise River Watershed and Rock, Rush, Goose Creek Watershed.
These studies include background research into the watershed of the waterbody(s) under evaluation. Land cover, amount of impervious surfaces, animal operations, septic system status, and storm drain systems are all important information. Some baseline monitoring is also done at important locations.
Once the background information is gathered and analyzed, modeling can be done to determine where the greatest pollutant loading is coming from. Identifying the sources are very important for the next step, which is determining what level of pollutants the waterbody can handle and how much reduction is needed. The final step is to create and implement a plan to reach the goal reduction.
Stay tuned to this website for updates on the TMDLs that are in progress. Dates, times, and locations of public meetings will be posted.