What is the Purpose of the NPDES Permit Program?

The National Pollutant Discharge Elimination System (NPDES) is a federally mandated program to regulate point source discharges into the waters of the United States. Under the storm water component of the permit program, the federal government requires municipal separate storm sewer systems (MS4s) serving a population of 100,000 or more to have a storm water NPDES permit.

About Urban Storm Water Runoff

Urban storm water runoff is a serious concern because storm water runoff may be contaminated with pesticides, fertilizers, animal droppings, trash, food wastes, automotive by-products and other toxic substances that are part of the urban environment. Storm water runoff that flows over streets, parking lots, construction sites and industrial facilities can carry these pollutants through the storm water drainage system directly into local bayous, channels and ditches. This contamination diminishes the value of our natural resources.

Storm Water Program History

On November 16, 1990, the United States Environmental Protection Agency (EPA) published the NPDES storm water discharge regulations. These regulations require that municipal separate storm sewer systems serving a population of 100,000 obtain NPDES permit coverage for storm water discharged to waters of the United States. The permit effectively prohibits discharges of anything other than storm water to the storm water drainage system and requires development of storm water management programs (SWMP) for municipal systems (or Storm Water Pollution Prevention Plans (SWPPP) for industrial facilities). A significant element in both SWMP and SWPPP is the use of best management practices (BMPs): activities, procedures and other practices to prevent or reduce pollution to the waters of the U.S.

What is the joint task force (JTF)?

In a cooperative effort to address the storm water permit requirements, four local entities chose to work together through a Joint Task Force (the "JTF") to prepare and submit a two-part joint permit application. Effective October 1, 1998, EPA Region 6 issued a NPDES storm water permit to the City of Houston, Harris County, Harris County Flood Control District (HCFCD) and Texas Department of Transportation (TxDOT) as co-permittees. This permit expired on September 30, 2003, but remains in effect under administrative continuance, pending issuance of a renewal permit by TCEQ.

This joint approach has worked well, providing consistency and efficiency among agency programs and economizing permit implementation costs. At the same time, each entity of the JTF is responsible for implementing its own program. EPA has commended the JTF for the quality of its application as well as the consensus, cooperation and partnership efforts of the four entities.

NPDES Storm Water Program Components

The permit requires each co-permittee to develop appropriate management programs to control storm water pollutants from the parts of the MS4 where it has jurisdiction over the discharges.

Management programs required by the NPDES permit include, among other things, the implementation and maintenance of best management practices (both structural and non-structural) to reduce pollutants in storm water runoff from residential, commercial and industrial areas and construction sites to the MS4.

The NPDES permit also requires each co-permittee to: (1) Effectively prohibit illegal dumping and disposal of hazardous chemicals, (2) Monitor and analyze storm water, and (3) Promote the proper management of pesticides, herbicides, and fertilizers.


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