Regulatory Background

The Texas Commission on Environmental Quality (TCEQ) designated the regulated small (Phase II) Municipal Separate Storm Sewer Systems (MS4s) and issued its first stormwater discharge general permit for these entities in August 2007. The TCEQ general permit to discharge to waters of Texas (TXR040000) is under provisions of Section 402 of the Clean Water Act and Chapter 26 of the Texas Water Code. The general permit provides authorization for point source discharges of stormwater and certain non-stormwater discharges from MS4s to surface waters in Texas.
The District obtained coverage under the small MS4 TPDES general permit (TXR040000) from the TCEQ to discharge municipal stormwater. Since obtaining permit coverage in August 2007, the permittee has conscientiously conducted activities to assure compliance with the permit.
The SWMP is organized around the following five major stormwater pollution prevention and control sections:
▪ Public Education, Outreach, and Involvement (MCM1)
▪ Illicit Discharge Detection and Elimination (IDDE) (MCM2)
▪ Construction Site Stormwater Runoff Control (MCM3)
▪ Post construction Stormwater Management in New Development and Redevelopment (MCM4)
▪ Good Housekeeping and Pollution Prevention (MCM5)
Each of the following sections describes MCM requirements, existing conditions, and the proposed implementation plan that will be accomplished over the five-year permit term. The implementation plan will be developed to identify activities required to meet each measurable goal. Progress toward measurable goals will be evaluated annually in the MS4 Annual Report.


Illicit Discharges

The Texas Commission on Environmental Quality (“TCEQ”) regulates known discharges of contaminants to surface waters in the state of Texas. In an effort to address this type of pollution, stormwater management regulations were established to reduce the impact of contaminated stormwater runoff from certain MS4s. Under the regulations outlined in 40 CFR 122.26(b)(8), the District is required to comply with these requirements.

As a condition of the stormwater regulations, regulated MS4s are required to prohibit illicit discharges. An illicit discharge is any discharge to the District’s storm sewer system that is not composed entirely of stormwater with the exceptions of State recognized exclusions or activities covered by a specific discharge permit. Examples of illicit discharges include overland drainage from car washing or cleaning paint brushes in or around a catch basin.

As part of the District’s commitment to environmental stewardship, all illicit discharges to the District’s stormwater system are prohibited, as set forth in the District’s Rate Order, and the District has the legal authority to carry out inspection surveillance and monitoring procedures to comply with this policy

No District public service employee, visitor, resident, business, commercial or industrial facility, contractor, or construction site personnel shall cause or allow discharges into the District’s storm sewer drainage system which are not composed entirely of stormwater, except for the allowed discharges listed in Section B. Prohibited discharges include but are not limited to: oil, anti-freeze, grease, chemicals, wash water, paint, animal waste, garbage, and litter.

Types and Sources of Illicit Discharges

Stormwater runoff contains pollutants that can harm human health, degrade water quality and aquatic habitat, and impair ecosystem functions. On its way to streams and other bodies of water, stormwater runoff accumulates pollutants such as oil, gas, and other hydrocarbons, heavy metals, deicers, pesticides, fine sediment, fertilizers, and bacteria, all of which can impair water quality. Runoff from fertilized lawns contributes excess nutrients to waterbodies, which can lead to algal blooms and in extreme cases, fish kill events due to low dissolved oxygen levels. Elevated fecal coliform levels impair water quality and can lead to restrictions on the use and enjoyment of natural resources, such as, shellfish beds and swimming areas. Other stormwater pollution of concern includes toxic contaminants, such as heavy metals and pesticides, which can originate from vehicles and businesses or from homeowner activities.

All of these pollutants have the potential to wash into receiving waterbodies during storm events. Understanding the sources of these pollutants and the impacts each pollutant has can help inform municipal planning and assist in identifying priority goals and objectives when managing stormwater. The following table summarizes common stormwater pollutants, their sources and potential impact.

Common Stormwater Pollutants, Sources and Impacts
Pollutants Sources Impacts
Sediments Construction sites; eroding stream banks; and vehicle/boat washing. Destruction of plant and fish habitat; transportation of attached oils, nutrients and other pollutants; increased maintenance costs, flooding.
Nutrients (phosphorus, nitrogen) Fertilizers; bird and pet waste; vehicle/boat washing; grey water; decaying grass and leaves; sewer overflows; leaking trash containers; leaking sewer lines. Increased potential for nuisance or toxic algal blooms, increased potential for hypoxia/anoxia (low levels of dissolved oxygen which can kill aquatic organisms).
Hydrocarbons (petroleum compounds) Vehicle and equipment leaks; vehicle and equipment emissions; pesticides, fuel spills; equipment cleaning; improper fuel storage and disposal. Toxic to humans and aquatic life at low levels.
Heavy metals Vehicle brake and tire wear; vehicle/equipment exhaust; batteries; galvanized metal; paint and wood preservatives; fuels; pesticides; and cleaners. Toxic at low levels; drinking water contamination.
Pathogens (Bacteria) Bird and pet wastes; sewer overflows; and damaged sanitary lines. Risk to human health leading to closure of shellfish areas and swimming areas; drinking water contamination.
Toxic Chemicals Pesticides, dioxins, Polychlorinated Biphenyls; spills; illegal discharges; and leaks. Toxic to human and aquatic life at low levels.
Debris/litter Improper waste disposal and storage; fishing gear; leaking rubbish containers; cigarette butts, littering. Potential risk to human and aquatic life and aesthetically displeasing.

SOURCE Modified from Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assessments Center for Watershed Production, 2004, p. 12, Table 2.

The following connections are prohibited, except as provided in Section (B) below:

Any drain or conveyance, whether on the surface or subsurface, which allows any non-stormwater discharge, including but not limited to sewage, process water, waste water, or wash water, to enter the stormwater drainage system, and any connections to the storm drain system from indoor drains or sinks.

Allowed Non-Storm Water Discharges

The District adopted the Allowable Non-Stormwater Discharges identified in the TPDES General Permit No. TXR040000 for coverage of small (Phase II) municipal separate storm sewer systems (MS4s). The listing of Allowable Non-Stormwater Discharges, as specified in Part II.C of the permit, includes the following discharge types:
1. Water line flushing (excluding discharges of hyperchlorinated water, unless the water is first dechlorinated and discharges are not expected to adversely affect aquatic life);
2. Runoff or return flow from landscape irrigation, lawn irrigation, and other irrigation utilizing potable water, groundwater, or surface water sources;
3. Discharges from potable water sources that do not violate Texas Surface Water Quality Standards;
4. Diverted stream flows;
5. Rising ground waters and springs;
6. Uncontaminated ground water infiltration;
7. Uncontaminated pumped ground water;
8. Foundation and footing drains;
9. Air conditioning condensation;
10. Water from crawl space pumps;
11. Individual residential vehicle washing;
12. Flows from wetlands and riparian habitats;
13. Dechlorinated swimming pool discharges that do not violate Texas Surface Water Quality Standards;
14. Street wash water excluding street sweeper waste water;
15. Discharges or flows from emergency fire fighting activities (fire fighting activities do not include washing of trucks, run-off water from training activities, test water from fire suppression systems, and similar activities);
16. Other allowable non-stormwater discharges listed in 40 CFR § 122.26(d)(2)(iv)(B)(1);
17. Non-stormwater discharges that are specifically listed in the TPDES Multi Sector General Permit (MSGP) TXR050000 or the TPDES Construction General Permit (CGP) TXR150000;
18. Discharges that are authorized by a TPDES or NPDES permit or that are not required to be permitted; and
19. Other similar occasional incidental non-stormwater discharges such as spray park water, unless the TCEQ develops permits or regulations addressing these discharges.

Report Illicit Discharge

To protect the quality of our streams and public health, please report sources of pollution you witness in the District, including:
▪ Changing oil or antifreeze over or near the storm drainage system
▪ Paint being poured into or near the storm drainage system
▪ Washing vehicles where the runoff could drain into the storm drainage system
▪ Blowing leaves and grass into or near the storm drainage system

You can do this anonymously by calling the Illegal Storm Sewer Dumping Hotline at:
(866) 414-9950
Report Illegal Discharges!

Please provide the following information:
▪ Location or Address of illicit discharge
▪ Type of discharge/description
▪ Date of occurrence
▪ Name of company and/or description of individuals


Please remember that reporting violations of environmental laws is a serious matter, and could result in criminal and/or civil sanctions being assessed against the person or company being reported. Knowingly or intentionally making a false complaint is a violation of Texas Law.

The District provides this service to allow concerned citizens to file voice mail reports regarding the discharge of pollutants to rivers, creeks, and the storm sewer system within the District’s boundaries. A tracking number will be assigned to each complaint received and an investigation initiated. The results of the investigation and any actions taken shall be documented and submitted to the Texas Commission on Environmental Quality in the District’s annual storm water program report.


Recycle or properly dispose of household products that contain chemicals, such as insecticides, pesticides, paint, solvents, and used motor oil and other auto fluids. Don’t pour them onto the ground or into storm drains.

Auto Care
Washing your car and degreasing auto parts at home can send detergents and other contaminants through the storm sewer system. Dumping automotive fluids into storm drains has the same result as dumping the materials directly into a waterbody.
▪ Use a commercial car wash that treats or recycles its wastewater, or wash your car on your yard so the water infiltrates into the ground.
▪ Repair leaks and dispose of used auto fluids and batteries at designated drop-off or recycling locations.

Lawn Care
Excess fertilizers and pesticides applied to lawns and gardens wash off and pollute streams. In addition, yard clippings and leaves can wash into storm drains and contribute nutrients and organic matter to streams.
▪ Don’t overwater your lawn. Consider using a soaker hose instead of a sprinkler.
▪ Use pesticides and fertilizers sparingly. When use is necessary, use these chemicals in the recommended amounts. Use organic mulch or safer pest control methods whenever possible.
▪ Compost or mulch yard waste. Don’t leave it in the street or sweep it into storm drains or streams.
▪ Cover piles of dirt or mulch being used in landscaping projects.

Pet Waste
Pet waste can be a major source of bacteria and excess nutrients in local waters.

When walking your pet, remember to pick up the waste and dispose of it properly. Flushing pet waste is the best disposal method. Leaving pet waste on the ground increases public health risks by allowing harmful bacteria and nutrients to wash into the storm drain and eventually into local waterbodies.

Residential Landscaping
▪ Permeable Pavement—Traditional concrete and asphalt don’t allow water to soak into the ground. Instead these surfaces rely on storm drains to divert unwanted water. Permeable pavement systems allow rain and snowmelt to soak through, decreasing stormwater runoff.
▪ Rain Barrels—You can collect rainwater from rooftops in mosquito-proof containers. The water can be used later on lawn or garden areas.
▪ Rain Gardens and Grassy Swales—Specially designed areas planted with native plants can provide natural places for rainwater to collect and soak into the ground. Rain from rooftop areas or paved areas can be diverted into these areas rather than into storm drains.
▪ Vegetated Filter Strips—Filter strips are areas of native grass or plants created along roadways or streams. They trap the pollutants stormwater picks up as it flows across driveways and streets.