Knife River Total Maximum Daily Load

Listed: 2002

Impairment(s):  Turbidity and pH (will be delisted).

Current Status:  Physical and chemical monitoring is complete.  Preliminary data quality checks have been completed, and the actual document is partially complete.  The draft TMDL document will be submitted to the Minnesota Pollution Control Agency (MPCA) by December 31st, 2007.  It will then be submitted to the Environmental Protection Agency (EPA) for approval. 

The Process: First all existing data was gathered and put in to a uniform format.

Then monitoring commenced (3 years of monitoring) and that data along with any other available data (no previous data in this case) is used to find current load.

Using water quality standard for a Type 2A Stream (Cold Water Fishery) a target load will be calculated.  In this case the turbidity standard for a Cold Water Fishery is 10 NTU (measurement of light dispersion), which is essentially water clarity.

 

Preliminary analysis has indicated that the target load is around 205,000 kg/water year.  The water year used in this instance is 195 days long.

 

2004 and 2005 loads were around 1,256,000, which means to reach our target we would need a 82% reduction in turbidity.  We may find that certain branches of the Knife may be naturally "murky" and this would cause us to increase the target load.

 

After the monitoring and analysis is done a TMDL is sent to the MPCA and the EPA for approval, and an implementation plan will be designed. 

 

Click Here for the EPA TMDL Fact Sheet for Minnesota

Click Here for available data.  This is the MPCA Electronic Data Access page.

Knife River Watershed Map