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National Pollutant Discharge Elimination System (NPDES):
Under the Federal Clean Water Act, counties and municipalities are required to perform certain activities to reduce the amount of stormwater pollution entering our waters. Each government agency is issued a stormwater permit, also known as a National Pollutant Discharge Elimination System (NPDES) permit.
Pinellas County and 23 of its municipalities were issued their first permit in 1997 and have been operating under NPDES permit requirements ever since. These requirements include:
- Identify major outfalls and pollutant loadings (mapping for source tracking)
- Detect and eliminate non-stormwater discharges to the system (enforcement)
- Reduce pollutants in runoff from industrial, commercial, and residential areas (enforcement and drainage system maintenance and cleanup)
- Control stormwater discharges from new development and redevelopment areas (inspections and site plan process)
- Implement a monitoring program (monitor water quality)
As part of the evolving NPDES permit requirements, Pinellas County waters are included in a state and federal process known as the Total Maximum Daily Loads Program.
Total Maximum Daily Loads Program (TMDL):
Background:
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Under the Federal Clean Water Act
, surface waters of the United States must be evaluated to ensure they’re in good health. Any waterbody that is deemed impaired (or unhealthy) based on specific criteria must be improved, using a Total Maximum Daily Load (TMDL) issued by the state or federal government.
What is a TMDL?
A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet State Water Quality Standards
(remain “healthy”). A TMDL then could be considered a “pollutant diet” for a waterbody. The Florida Department of Environmental Protection
and the EPA use TMDLs as regulatory tools to ensure waters are returned to a healthy state. Local governments must then implement projects on a strict schedule to reduce pollutants and restore the health of the waters based on the TMDL.
What is a BMAP?
A Basin Management Action Plan or BMAP is like a road map that guides a community towards restoring water quality in impaired waters. A BMAP represents a comprehensive set of strategies designed to implement the pollutant reductions required by the TMDL including permit limits on point sources, urban and agricultural best management practices (BMPs), conservation programs, and financial plans.
Why TMDLs are important to Pinellas County:
Pinellas County has a large number and variety of surface waters, from lakes and rivers to estuaries, and is also very densely populated. This results in significant stormwater pollution to our waters. At this time, nearly all waterbodies in Pinellas County are considered impaired, largely due to the effects of urbanization.
TMDL and BMAP Status in Pinellas County:
There are currently 50 TMDLs in Pinellas County. Twenty-four are for dissolved oxygen and nutrients and twenty-six are for fecal coliform bacteria. Although there are currently no BMAPs for these TMDLs, the County is working diligently towards TMDL implementation through the NPDES permit. Pinellas County prioritized TMDLs and developed a 5-year plan for TMDL Implementation
in 2013. To date, two monitoring plans have been developed (Joe’s Creek and Long Branch Creek) and a Bacterial Pollution Control Plan for Joe’s Creek
has been finalized and approved as meeting NPDES requirements.
Top 3 Causes of Impairment in Florida Waters
- #1—Nutrients
- #2—Dissolved Oxygen
- #3—Bacteria







