Total Maximum Daily Load (TMDL) Basics
On a semi-annual basis, the Utah Division of Water Quality (DWQ) develops lists of impaired waters in the state. “Impaired waters” are those waterbodies that currently fail to meet water quality standards established by the state even after point sources have implemented the minimum required levels of pollution control technology. The semi-annual assessment conducted by DWQ is mandated under section 303(d) of the Clean Water Act and results in the listing of impaired waters on what is known as the 303(d) list. Subsequent to listing, the State is required to develop a Total Maximum Daily Load (TMDL) to reduce pollutant levels in impaired waters. A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive on a daily basis and still meet water quality standards. The TMDL process consists of the following steps:
- Review existing water quality data
- Identify sources and causes of pollutants
- Identify water quality goals
- Establish the amount of pollutant that can be allowed in total
- Allocate allowable pollutant loads
- Identify and implement measures to achieve and maintain water quality standards
- Monitor to assure that goals are met
The TMDL process results in load allocations to each pollutant contributor. These allocations often result in regulatory controls and mandates.
For more information please visit……
http://www.waterquality.utah.gov/public%20notices/2004303dlist-01-15-04.pdf
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