TCEQ is screening data center authorizations claimed without a permit. Its letter never names backup generators.

A Texas data center campus that runs its backup generators only for emergency or standby service can rely on a Texas Commission on Environmental Quality (TCEQ) permit by rule. If the units meet its conditions, it asks for no registration and no fee. TCEQ's Oct. 19, 2026 letter to Governor Greg Abbott says the agency "is screening claimed authorizations that do not require the agency to affirmatively issue a permit and, where possible, is suspending such authorizations for data center activities."

That rule, 30 TAC §106.511, is a claimed authorization of exactly that kind. A generator duty it does not cover needs another authorization, and the standard permits and case-by-case permits TCEQ points to start with an application. The same letter says TCEQ has paused each pending permit application that falls under the Governor's directive.

Two facts shape how the pause can reach a campus's generators: the duty the owner or operator claims for them, and the size of the fleet. Units used only for portable, emergency or standby service can be claimed under §106.511 with no filing. That holds while they stay within the rule's cap on annual run hours and meet the general conditions in 30 TAC §106.4, including its emission caps. Fleet size matters because a bigger fleet can pass those caps. A fleet that would pass them needs a filing: a certified registration that holds its emissions under the caps, or a permit application. On the letter's own words, the pause covers pending permit applications, and a unit claimed with no filing has none. The letter does not say whether TCEQ is screening those unfiled claims, so an owner or operator cannot tell from it whether TCEQ might suspend them.

A §106.511 fleet can still involve a filing. In a certified registration, filed on TCEQ Form PI-7-CERT, the permit holder certifies emission limits for the registered equipment. TCEQ's potential-to-emit guidance, RG-625, treats those limits as federally enforceable and counts them toward the site's potential to emit, so the holder has to stay within them. Amazon Data Services filed a certified registration revision for the 15 generators at its ALE60 data center in Bexar County. TCEQ's March 11, 2025 review of that filing records the site-wide limit on generator operating hours that Amazon Data Services proposed. The letter does not say whether TCEQ treats a certified registration as an application it pauses, so a new or revised registration may wait too. So before a campus adds generators, it should find out whether they need any filing, because that filing could decide when the generators can be commissioned.

Inside Climate News, which linked the letter in an Oct. 19 article, says TCEQ's director of external relations, Ryan Vise, provided it. TCEQ also posts the letter on its own site as TCEQ's response to Gov. Abbott's Sept. 21 directive (PDF), checked Oct. 22, 2026, and the letter text quoted here matches that copy. The Governor's Sept. 21 letter had directed TCEQ "to pause the issuance of all permits related to data center projects until ERCOT completes its review" (TCEQ's data center permit pause and ERCOT's pause on approvals to energize).

What TCEQ told the Governor

Besides the screening sentence quoted above, the letter, signed by Interim Executive Director Steven Schar, makes two statements about permits:

• "TCEQ has paused the issuance of all permits related to the construction or development of infrastructure directly supporting data centers."
• "If a permit application is subject to the directive, TCEQ has paused that permit application in accordance with your directive."

The letter names no rule, no permit by rule and no project. It describes what TCEQ has paused as permits for the construction or development of "infrastructure directly supporting data centers." The Governor's letter opens by directing TCEQ to halt "all permits sought by data centers" and later directs a pause on permits "related to data center projects." A utility applies for the permits for a water line or wastewater plant it builds to serve a campus. Those permits could fall outside the Governor's opening words and still count as infrastructure directly supporting a data center, so TCEQ's wording may reach further than the Governor's. The letter does not define the phrase, so which permits it covers is unknown.

Inside Climate News reported the same day on a review of TCEQ records by the watchdog groups FracTracker Alliance and Public Citizen. Public Citizen's own summary says TCEQ "issued eight certifications for Permit by Rule registrations, although one was later cancelled, between September 23 and October 16." The same article quotes the Governor's press secretary, Andrew Mahaleris: "No permits have been approved." Sitebraid has not checked the groups' records against TCEQ's databases and found no TCEQ statement confirming their counts.

What §106.511 covers

The rule is one sentence and a definition. It covers "Internal combustion engine and gas turbine driven compressors, electric generator sets, and water pumps" and sets three limits on the duty a campus can claim:

• Use: generator sets "used only for portable, emergency, and/or standby services."
• Hours: annual hours that "shall not exceed 10% of the normal annual operating schedule of the primary equipment."
• Standby: "For purposes of this section, 'standby' means to be used as a 'substitute for' and not 'in addition to' other equipment."

TCEQ's page for the rule says "This PBR does not require you to register or pay a fee." The general conditions of 30 TAC §106.4 still apply. Records must "demonstrate compliance for a rolling 12-month period" and be kept on site.

The rule defines "standby." It leaves "emergency" and "primary equipment" undefined. For a campus whose primary power comes from a utility rather than its own equipment, the rule text does not say how the 10% limit applies.

One TCEQ record shows how a data center fleet handled it. TCEQ's March 11, 2025 technical review covers a certified permit-by-rule registration for Amazon Data Services' ALE60 data center in Bexar County (Project No. 388567). It reviewed 15 existing generators (EG1 to EG15) under §106.511, plus two diesel tanks under §106.472. The review's notes say Amazon Data Services "proposes a modified limit of 2,025 hrs/yr across all generators at the site with no more than 876 hours total operation per generator." The 876-hour per-generator figure is 10% of 8,760, the review's stated maximum operating schedule. Its overview gives the site-wide figure as 2,055 hours per year, and Sitebraid has not seen the certified form that would show which figure was certified. The registration was certified, carries an application fee reference and lists federal engine standards NSPS IIII and MACT ZZZZ.

Where a bigger fleet or a wider duty goes

A no-registration claim still has to fit §106.4. Total actual emissions authorized under a permit by rule from a facility cannot exceed 250 tons per year of carbon monoxide or nitrogen oxides, or 25 tons per year of volatile organic compounds, sulfur dioxide or particulate matter. Lower caps apply to fine particulates. Unless at least one facility at the account has been through public notice and comment, the same caps apply to all permit-by-rule facilities at the account combined. The facility must also meet the applicable federal new source performance standards and hazardous air pollutant standards. And §106.4 says "No person shall circumvent by artificial limitations the requirements of" the state's permit applicability rule.

Size brings a second test. TCEQ's potential-to-emit guidance, RG-625, counts a permit-by-rule source at the lower of the §106.4 limits, any limit in the specific rule, or its capacity running "continuously 8760 hours per year." In general, a site's potential to emit is the sum of its sources. At or above the major-source thresholds, the site is subject to TCEQ's federal operating permit rules in 30 TAC Chapter 122. To set a lower, federally enforceable limit, the holder of "a non-registered PBR claimed" may submit Form APD-CERT. RG-625 says the owner or operator must then show on an ongoing basis that the certified limits are met, and keep documentation "for at least the past five years." That is the trade: a lower counted potential to emit, in exchange for a filing and five years of records.

For a facility that cannot meet the permit-by-rule conditions, TCEQ's page points to "Types of New Source Review Authorizations for other options." RG-625 lists the preconstruction authorizations: case-by-case New Source Review permits, standard permits, permits by rule and de minimis sources. A certification, a registration, a standard permit and a case-by-case permit each start with a filing at TCEQ. The Oct. 19 letter says TCEQ pauses a pending permit application when the directive covers it.

What TCEQ has not said

The one-page letter does not say:

• which claimed authorizations TCEQ is screening, or whether §106.511 claims are among them
• how TCEQ screens a claim that carries no registration, or how an owner or operator would learn of a suspension
• what "where possible" covers
• whether generators claimed under §106.511 before Sept. 21 are inside the screen
• whether an APD-CERT or a certified registration for an emergency fleet counts as an application it pauses
• what "infrastructure directly supporting data centers" includes
• when the pause ends; the Governor's letter ties it to ERCOT completing its review

Before the next generator commitment on a Texas campus

These are the sponsor's calls, made with counsel. The steps below gather the facts for them. None of this is legal advice.

1. For each campus site, list every generator set and turbine with its air authorization: a §106.511 claim, a certified registration with its registration and project numbers, a standard permit or a case-by-case permit. Name the owner or operator that claimed or holds each one.
2. Write down the duty each unit is authorized for. Next to it, list every duty a contract asks of the same unit: tenant service terms, a utility or ERCOT program, a lender case, demand response, bridge or peak service. Decide with counsel which authorization each duty outside "portable, emergency, and/or standby services" needs before anyone signs.
3. Pull the §106.8 records for each §106.511 unit: copies of §106.4 and §106.511 and the rolling 12-month compliance records, kept on site.
4. Record the hours basis the campus uses for the 10% limit and the run hours to date. Decide with counsel how "normal annual operating schedule of the primary equipment" applies to the campus.
5. Recompute site potential to emit under RG-625 for every planned addition, and check the §106.4 facility and account totals. If the plan needs a new or revised certification, registration, standard permit or case-by-case permit, mark generator delivery and commissioning as dependent on TCEQ processing under the pause.
6. Carry that dependency into any tenant, lender or utility condition that ties money or a date to generator availability.
7. Keep every unit inside the duty and limits of its current authorization while TCEQ's screen is open. Decide with counsel how to respond if TCEQ gives notice of a suspension.
8. Check TCEQ's air permit pages and the Governor's news page for further notice on claimed authorizations. TCEQ's §106.511 page lists airperm@tceq.texas.gov and 512/239-1250 for permit-by-rule questions.

If your backup generators were authorized without a permit review, our Entitlements & community work maps the air authorization your campus needs and fits it to your build schedule.