Stormwater Discharge Permitting for Industrial Facilities: TPDES Industrial Stormwater Permits Explained

What changed with the 2026 MSGP?

Mostly housekeeping, plus tighter benchmarks. The 2021 permit expired August 14, 2026, and the new one took effect that day. According to TCEQ's 2026 MSGP fact sheet (opens in a new tab), the changes include:

• A renewal period built into the application deadlines
• Six lower benchmark values, including zinc, iron, ammonia, phosphorus, cyanide and nitrate plus nitrite for certain sectors
• An option to keep the SWP3 electronically, as the construction permit allows
• A clarification that NOIs and other forms go to any MS4 receiving the discharge, whether TCEQ regulates that MS4 or not
• The SIC and NAICS tables moved to Appendix A and updated

If you renewed under the 2021 permit's habits, reread your sector's benchmarks. A result that passed in 2025 may not pass now.

Does my facility need coverage?

It depends first on your SIC code, then on exposure. "Stormwater associated with industrial activity" is defined at 40 CFR §122.26(b)(14), which TCEQ adopted at 30 TAC §281.25(a). The MSGP groups regulated activities into 30 sectors, A through AD, by SIC code.

Your SIC code is the one that best describes the main activity at the site, not the company as a whole. A distribution center, a fabrication shop and a concrete batch plant each fall in different sectors with different requirements.

Being in a sector is not the end. A facility can claim a conditional exclusion by filing a No Exposure Certification, if industrial materials and activities are sheltered from rain and runoff by storm-resistant shelter.

What does "no exposure" actually take?

Industrial materials and activities kept out of rain, run-on and wind. The fact sheet describes storm-resistant shelter as buildings or structures with complete roofs and walls, or a roof-only cover where nothing under it is exposed to run-on, runoff or wind. Tightly sealed drums and tanks can qualify under listed conditions. An outdoor dumpster pad holding process waste, a trailer staging yard with leaking equipment, or a partly covered raw material pile can defeat the certification.

Walk the site in the rain. If water touches an industrial material or activity before it leaves the property, plan on full permit coverage.

How is industrial stormwater different from construction stormwater?

Construction coverage ends with the project; industrial coverage runs with the operation. The construction general permit, TXR150000, covers land disturbance and ends when the site is stabilized. TXR050000 applies for as long as the regulated activity runs.

A new plant often needs both, one after the other. The construction SWPPP and its controls are separate from the industrial SWP3 you will operate under for years.

What goes in the SWP3?

A site-specific description of how stormwater could pick up pollutants, and what stops it. The plan identifies the pollution sources, drainage areas and outfalls, the controls you chose, the people responsible, and the inspection, training and records program.

Controls follow the sources. A concrete products plant needs pH and solids control for washout. A food plant with outdoor wash areas needs to keep organics out of the drains. Covered storage, berms, secondary containment, inlet protection and good housekeeping all count.

Before discharging, a new facility must prepare and implement the SWP3 and file its notice of intent through TCEQ's online system. Keep the plan current whenever the site, materials or drainage change.

What monitoring and inspections does the permit require?

A fixed rhythm through the year. The fact sheet describes these continuing requirements:

• Quarterly visual monitoring of the discharge, during normal operating hours
• Quarterly inspections of structural controls
• An annual site compliance evaluation, with a written report
• Benchmark sampling for many sectors, once per six months for the first two years of the permit term
• Annual hazardous metals monitoring against limits set under 30 TAC Chapter 319, Subchapter B
• Numeric limits and annual discharge monitoring reports for discharges subject to federal effluent guidelines

If your first two years of benchmark results are below the benchmark values, sampling in years three and four is not required. Results above benchmark keep you sampling, and they are a clear signal to revisit your controls.

How does SPCC fit with stormwater?

It is a separate federal program for oil, but it often covers the same yard. Under 40 CFR §112.1 (opens in a new tab), a facility generally needs a Spill Prevention, Control, and Countermeasure plan if it stores more than 1,320 gallons of oil aboveground, counting containers of 55 gallons or more, or more than 42,000 gallons completely buried, and could reasonably discharge oil to navigable waters.

Containment around tanks and fueling areas serves both plans. Design it once and describe it consistently in each.

What happens if a facility discharges without coverage?

It is an unauthorized discharge. The Texas Water Code prohibits discharging into water in the state without authorization. With coverage, the risk shifts to records. Missing inspection logs, an SWP3 that no longer matches the site, and runoff from areas the plan never identified are all things an inspector can find in an hour.

If you find a gap, get coverage and fix it promptly. Our post on self-reporting and TCEQ enforcement discretion explains how disclosure can change the outcome.

This post explains TXR050000 as general education. Your sector's part of the permit sets your exact requirements, so read it before you rely on any summary.

Frequently asked questions

Our operation is mostly indoors. Do we still need coverage?

If your SIC code is in a regulated sector, yes, unless you certify no exposure. That requires all industrial materials and activities to be sheltered. One exposed loading or storage area is usually enough to need full coverage.

We were covered under the 2021 MSGP. What do we do now?

Submit a renewal NOI, or a renewal No Exposure Certification, through TCEQ's online system by December 28, 2026. TCEQ's MSGP page posted a temporary email option while that system was down. Then update your SWP3 for the 2026 permit, including any lower benchmarks for your sector.

Does oil and gas stormwater fall under TCEQ now?

Yes, for non-exempt discharges. EPA approved the transfer of NPDES authority for stormwater from oil and gas exploration, production, processing, treatment and transmission sites to TCEQ on January 15, 2021, and the MSGP authorizes those discharges. Some uncontaminated runoff from these sites is exempt under the Clean Water Act, so check which side your site falls on.

I'm buying an existing industrial site in Texas. How do I tell whether its stormwater permit and SWP3 are in order before closing?

Ask for the NOI acknowledgment, the current SWP3, the last annual site compliance evaluation, quarterly visual records and benchmark results. Then walk the site and compare what you see with the plan. Coverage cannot be transferred. The new operator files its own NOI at least 10 days before taking control, and the seller terminates its coverage.

Do I have to send anything to the city?

If you discharge to a municipal separate storm sewer system, send a copy of your NOI, NOC or NOT to the MS4 operator when you submit it to TCEQ.

Related resources

• Industrial vs. Municipal Discharge Permits in Texas: Different Standards, Monitoring, and Compliance
• Discharging to a Storm Drain vs. Sanitary Sewer: Why Texas Contractors Get It Wrong on Pipeline and Tank Projects
• Ongoing Compliance After Permit Approval: What a Developer-Operator Needs to Track
• Permit Modification vs. Renewal vs. Amendment: When You Need to Change Your Discharge Permit

Is your Texas facility's stormwater coverage ready for the 2026 MSGP?

We check sector and exposure, write SWP3s that match the site, and design the drainage and containment the plan depends on.

We specialize in:

• TXR050000 applicability and no exposure reviews
• Site-specific SWP3 preparation and updates
• Outfall mapping and drainage area delineation
• Stormwater controls and containment design
• Construction SWPPP and erosion control plans
• Industrial site civil design

Modern Engineering Solutions, McKinney, Texas. Contact: (214) 833-6748 or mod-eng.com