Storm Water - Municipal Separate Storm Sewer System (MS4) operators

MS4s are the operators of storm drainage systems and are usually municipalities.  Under Phase I of the NPDES Storm Water program, MS4s with a service population of 100,000+ are required to have an NPDES MS4 permit for their storm water discharges.  Phase II of the NPDES Storm Water program was promulgated Feb. 7, 2000, and addresses MS4s with populations under 100,000. 

The Water Enforcement Branch will be working with the Phase II regulations as they are implemented. Small MS4's are required to obtain their permits by March 10, 2003. Please direct any questions regarding Storm Water Phase II regulations to sw2@epamail.epa.gov or to George Utting of EPA's Office of Water or to Brent Larsen of EPA Region 6, or visit the EPA HQ's Office of Water Storm Water Phase II Web page for Small MS4s. Some additional information regarding Phase II is available at www.epa.gov/earth1r6/6en/w/sw/hottopp2.htm.

The 10th Annual EPA Region 6 MS4 Operator's Conference will be held the week of July 14, 2008, in Waco, Texas.

Small MS4 Permit in Texas: In Texas, the Texas Commission on Environmental Quality (TCEQ) is the NPDES Permitting authority for most of the State. The TCEQ issued TPDES General Permit TXR040000 (PDF) (Word) on August 13, 2007. This permit authorizes the discharge of storm water to surface water in the State from small MS4s. Information on this permit can be found on the TCEQ web page at: www.tceq.state.tx.us/permitting/water_quality/stormwater/WQ_ms4_small_TXRO4.html

The NPDES Genera Permit for Discharges from Small Municipal Separate Storm Sewer Systems was signed and issued for Region 6 on September 29, 2006. It will become effective January 1, 2007 and expire at midnight, December 31, 2012. Permit Numbers for this permit are OKR040001 (Indian Country Lands within the State of Oklahoma), NMR040001 (Indian Country Lands within the State of New Mexico, except Navajo Reservation Lands and Ute Mountain Reservation Lands and also the Pueblo of Sandia), and NMR040000 (the State of New Mexico, except Indian Country Lands). The Navajo Reservation lands are administered by EPA Region 9 and Ute Mountain Reservation lands by EPA Region 8. The Pueblo of Sandia denied CWA §401 certification of the general permit. Operators of MS4s discharging within the Pueblo of Sandia must file an individual permit application. MS4s automatically designated under 40 CFR 122.32(a)(1) are required to submit an NOI by April 1, 2007. MS4s designated under 40 CFR 122.26(a)(9)(i)(C) or (D), are required to submit an NOI within 180 days of notice of designation, unless the notice of designation grants a later date. An electronic version of the permit can be found at: www.epa.gov/region6/6wq/npdes/sw/sms4/index.htm

URBANIZED AREA defintion by the US Census determines what cities will need permits for Phase II. Check it out at: www.census.gov/geo/www/ua/ua_2k.htmlEPA Region 6 has compiled a list of Urbanized Areas in Arkansas, Louisiana, Oklahoma, New Mexico, and Texas.

Cenus Information:  The US Census is compiling new information as well as providing official 1990 data on their web site.  This site includes which areas are designated as "Urbanized".  You can go to http://factfinder.census.gov/java_prod/dads.ui.homePage.HomePage to create a map of your city looking a the census data to assist in determining if your municipality is in an Urbanized area.  Basically, most municipalties over 1000 in population that are in Urbanized areas according to the US Census will need to obtain an NPDES MS4 permit and comply with it by March 10, 2003.  Read the Phase II regulations for more details (see paragraph above).

Model Ordinances: EPA's Office of Water has put together a number of "Model Ordinances" for municipalites.

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MS4 Referral Form

MS4 operators that have "industrial activities" that are not complying with the NPDES storm water program may refer the cases to EPA Region 6's Water Enforcement Branch.  This Referral Form may be used to refer these cases.