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Stormwater Permitting Requirements for Phase II (Small) MS4s

Authorization options, control measures required, annual reporting requirements, and links to best management practices for operators of Phase II MS4s.

Stormwater Management Program

If you operate a regulated small municipal separate storm sewer system (MS4), then you must develop and submit to the TCEQ, a stormwater management program (SWMP) that includes at least these six minimum control measures (MCMs):

  • MCM 1: Public Education, Outreach, and Involvement

  • MCM 2: Illicit Discharge Detection and Elimination

  • MCM 3: Construction Site Stormwater Runoff Control

  • MCM 4: Post-construction Stormwater Management in New Development and Redevelopment

  • MCM 5: Pollution Prevention and Good Housekeeping for Municipal Operations

  • MCM 6: Industrial Stormwater Sources (- only if your MS4 serves a population more than 100,000)

These minimum control measures must be developed by identifying and applying best management practices (BMPs). See the EPA’s “Menu of BMPsExit the TCEQ for examples and guidance. (Depending on the rainfall conditions and topography in your area, some of these BMPs might have to be adapted to your local situation.)

EPA's MS4 Permit ResourcesExit the TCEQ

On April 14, 2010, the U.S. EPA adopted the MS4 Permit Improvement Guide and during 2016 through 2017 EPA published five Compendiums with examples of MS4 permit requirements. . The primary purpose of these guidance documents is to assist permit writers at EPA and the states in strengthening Phase I and Phase II MS4 permits.

During the renewal of each individual Phase I permit, as well as during the Phase II general permit (TXR040000) renewal, the TCEQ reviewed these documents and determined the extent to which the recommendations in these documents would be incorporated into the TPDES MS4 permits.

Effluent Limits for Construction

On December 1, 2009, the U.S. Environmental Protection Agency (EPA) published effluent limitations guidelinesExit the TCEQ (ELGs) and new source performance standards (NSPS) to control the discharge of pollutants from construction sites, 40 CFR Part 450Exit the TCEQ . The regulation was effective on February 1, 2010 and amended in 2014. After this date, all permits issued by EPA or states must incorporate the final rule requirements.

The TPDES Small MS4 General Permit TXR040000, includes an optional 7th minimum control measure for the permitted MS4 operator to include all of the municipal construction activities for which is a regulated operator into its MS4 authorization.

According to the ELGs, all construction sites that are currently required to obtain permit coverage must implement a range of erosion and sediment controls and pollution prevention measures.

TCEQ is also adopting 40 CFR Part 450 by reference into state rules at 30 TAC §305.541Exit the TCEQ , Effluent Guidelines and Standards for TPDES Permits. For additional information, see our rules.

2019 Small MS4 General Permit Issued

General Permit TXR040000 Adobe Acrobat PDF Document was signed and made effective on January 24, 2019, and authorizes the discharge of stormwater from certain small MS4s.


Notice of Intent Microsoft Word Document (NOI) – Form number (TCEQ- 20368) for Stormwater Discharges from Small Municipal Separate Storm Sewer Systems (MS4) under the TPDES Phase II MS4 General Permit (TXR040000)

Annual Report

If permittees are participating in a shared SWMP, then they must contribute to a system-wide annual report. Each permittee must sign the report, but only one report must be submitted.

If any changes to the SWMP are proposed, then a notice of change (NOC) form must also be submitted. The NOC form must be submitted to the address shown on the NOC form, and must be submitted separately from the annual report.

The annual report must be submitted to the TCEQ’s Stormwater Team at the address below.

Stormwater Team Leader
TCEQ Water Quality Division
P.O. Box 13087
Austin, Texas 78711-3087

In addition, a copy of the annual report must be submitted to the appropriate TCEQ regional office.

Contact us if you need more information about this general permit.