Rules and Regulations : CWA / NPDES / TPDES
In 1972 , amendments to the Clean Water Act prohibited discharge of any pollutant from a point source into U . S . waters . The USEPA regulates stormwater through the National Pollutant Discharge Elimination System ( NPDES ), pursuant to subsequent amendments to the Clean Water Act . The Texas Commission on Environmental Quality ( TCEQ ) operates the NPDES program under the Texas Pollutant Discharge Elimination System ( TPDES ).
Three stormwater activities are regulated : municipal separate storm sewer systems ( MS4s ), industrial activities and construction activities .
Issued in 1990 under the Clean Water Act , Phase I of the USEPA ’ s stormwater program relies on NPDES permit coverage to address stormwater runoff from :
• Medium and large municipal separate storm sewer systems ( MS4s ) generally serving populations of 100,000 or greater
• Eleven categories of industrial activity
• Construction activity disturbing 5 or more acres of land
Phase II regulates construction activities covering between 1 and 5 acres and regulated small MS4s . Phase II expands the Phase I program to include additional operators of MS4s in urbanized areas and operators of small construction sites . Phase II requires such operators , through the use of TPDES permits , to implement programs and practices to control polluted stormwater runoff . Phase II is intended to reduce even further adverse impacts to water quality and aquatic habitat ; it institutes the use of controls on the unregulated stormwater discharge that have the greatest likelihood of causing continued environmental degradation .
Key Terms : NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM ( NPDES ): a provision of the Clean Water Act ( CWA ) prohibiting discharge of pollutants into waters of the United States unless a special permit has been issued by the USEPA , a state , or where delegated a tribal government on a Native American reservation .
TEXAS POLLUTANT DISCHARGE ELIMINATION SYSTEM ( TPDES ): The State of Texas has assumed the authority to administer the NPDES program in Texas . The Texas Commission on Environmental Quality ’ s TPDES program now has federal regulatory authority over discharges of pollutants into Texas surface water , except for discharges associated with oil , gas , and geothermal exploration and development activities , which are regulated by the Railroad Commission of Texas .
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