Whole-Water Antidegradation Review Under Texas Law: Commentary on Save Our Springs Alliance v. TCEQ & City of Dripping Springs

Whole-Water Antidegradation Review Under Texas Law: Commentary on Save Our Springs Alliance, Inc. v. TCEQ & City of Dripping Springs

I. Introduction

In Save Our Springs Alliance, Inc. v. Texas Commission on Environmental Quality and City of Dripping Springs (Tex. Apr. 11, 2025), the Supreme Court of Texas resolved a closely watched dispute at the intersection of environmental protection, municipal growth, and administrative law.

At stake was a permit authorizing the rapidly growing City of Dripping Springs to discharge up to 822,500 gallons per day of highly treated wastewater into Onion Creek, a high-quality Hill Country stream that contributes to the Barton Springs segment of the Edwards Aquifer. The environmental group Save Our Springs Alliance (SOS) argued that Texas’s “antidegradation” rules required the Texas Commission on Environmental Quality (TCEQ) to deny the permit because predictive modeling showed a substantial decrease in dissolved oxygen (DO) at the discharge point.

The case presented two central legal questions:

  1. How must TCEQ apply its Tier 2 antidegradation rule? Specifically, does “degradation” turn on:
    • a parameter-by-parameter approach (any non–de minimis worsening of a single water-quality parameter, such as DO, is forbidden), or
    • a whole-water, integrative assessment of “water quality” as a composite, in which parameter changes are evidence but not conclusive?
  2. Did TCEQ’s final permit order violate the Texas Administrative Procedure Act (APA) by failing to include a “statement of the underlying facts” supporting its ultimate antidegradation findings?

The Court affirmed TCEQ and the court of appeals, upholding the permit. In doing so, it announced two key propositions of statewide importance:

  • Under Texas law, Tier 2 antidegradation review is a whole-water-quality, narrative inquiry, not a rigid parameter-by-parameter veto triggered by any non–de minimis change in a single metric like DO, nitrogen, or phosphorus.
  • The APA’s requirement for a “statement of the underlying facts” in final orders applies only to ultimate findings cast in statutory language or mandated statutory criteria, not to findings that merely echo rules or non-mandated regulatory standards; moreover, objections to missing findings must be preserved with specificity at the agency rehearing stage.

This commentary analyzes the decision’s background, summarizes the Court’s holdings, examines its reasoning and precedent use, clarifies the complex regulatory concepts involved, and explores the likely impact on Texas water-quality regulation and administrative law.

II. Background: Facts and Regulatory Framework

A. The City’s Permit and Onion Creek

Dripping Springs has historically operated under a “land application” permit, using treated wastewater to irrigate designated fields. Population growth outstripped that framework, prompting the City in 2015 to apply to TCEQ for a permit to:

  • discharge up to 995,000 gallons per day of treated effluent,
  • initially into Walnut Springs, flowing roughly 0.43 miles to Onion Creek.

Onion Creek is a classified segment (No. 1427) with:

  • High aquatic-life use, and
  • a site-specific dissolved oxygen criterion of 5.0 mg/L (24-hour mean).

DO is a key indicator of the ability of a water body to sustain fish and other aquatic life; too little oxygen can be lethal or sublethal for sensitive organisms.

B. Texas Water Quality Standards and Antidegradation Tiers

Texas implements the federal Clean Water Act (CWA) through the Texas Surface Water Quality Standards (TAC, Title 30, ch. 307) and TCEQ’s permitting authority under the Texas Water Code § 26.027. The standards use:

  • “Narrative” (qualitative) criteria – e.g., nutrients “must not cause excessive growth of aquatic vegetation that impairs” uses.
  • “Numeric” (quantitative) criteria – precise limits (e.g., specific DO concentrations, temperature, bacteria levels).

Texas’s antidegradation policy is tiered (30 Tex. Admin. Code § 307.5):

  • Tier 1: Existing uses and water quality sufficient to sustain them must be maintained. If a discharge would impair existing uses (e.g., existing fish populations), it fails Tier 1.
  • Tier 2: For waters better than basic fishable/swimmable quality:
    • “No activities” that would cause “degradation” are allowed,
    • unless justified as necessary for important social/economic development (exception not invoked here),
    • and “degradation” is defined as “a lowering of water quality by more than a de minimis extent, but not to the extent that an existing use is impaired.”
  • Tier 3: Special protection for “outstanding national resource waters” (not at issue).

Crucially, Tier 2 defines degradation in terms of a “lowering of water quality”, not in terms of changes in individual parameters.

C. Implementation Procedures and Modeling

TCEQ has issued detailed “Procedures to Implement the Texas Surface Water Quality Standards” (2010 Implementation Procedures, or 2010 IPs), which EPA has largely approved as consistent with CWA requirements. The 2010 IPs:

  • Explain how to conduct Tier 1 and Tier 2 reviews,
  • Identify “parameters of concern” (e.g., DO, nutrients, bacteria, toxic pollutants),
  • Describe screening tools such as “assimilative capacity” – essentially the buffer between current conditions and the relevant criterion,
  • Provide qualitative examples of when “degradation is likely to occur.”

The City’s initial QUAL-TX modeling projected that the proposed discharge would cause DO at the critical location to drop from at least 6.44 mg/L to about 5.04 mg/L or 4.87 mg/L at the mixing zone, with DO returning quickly toward baseline downstream.

TCEQ’s technical review tightened the draft permit, imposing:

  • Stringent TN and TP limits,
  • A higher DO requirement for effluent, and
  • Disinfection and provisions to protect the endangered Barton Springs Salamander.

TCEQ’s own modeling—based on the higher initial application flow (995,000 gpd)—predicted DO would not fall below the 5.0 mg/L site-specific criterion at the discharge point. The City later agreed to reduce the maximum permitted discharge to 822,500 gpd and to implement extensive reuse and storage measures, aiming in practice to minimize actual discharges.

D. Federal Oversight: EPA and USFWS

Because Texas runs a delegated NPDES-equivalent program (Texas Pollutant Discharge Elimination System), EPA reviewed the draft permit and TCEQ’s antidegradation analysis, consulting the U.S. Fish and Wildlife Service (USFWS) due to endangered species in the watershed.

EPA initially objected, seeking more detail on antidegradation compliance. After further explanation and documentation from TCEQ, EPA withdrew its objections, noting:

  • “very low” nutrient limits,
  • modeling showing any changes would be “de minimis (i.e., less than noticeable),”
  • no significant degradation and maintenance of existing uses in Onion Creek.

E. Contested-Case Hearing and Administrative Decision

More than a thousand comments were submitted and numerous parties requested a contested-case hearing; virtually all later settled except SOS. Settlement agreements required the City to:

  • Upgrade infrastructure to expand reuse and storage,
  • Reduce maximum daily discharge to 822,500 gpd,
  • Delay any discharge until actual wastewater volume exceeded 399,000 gpd, and
  • Use ultraviolet (UV) disinfection instead of chlorine.

These commitments, and very stringent effluent limits, made this “one of the most stringent” discharge permits in Texas.

At the SOAH hearing, once the administrative record was admitted, Gov’t Code § 2003.047 created a prima facie case that the draft permit:

  • meets all state and federal legal and technical requirements, and
  • protects human health, safety, the environment, and property.

SOS sought to rebut this presumption. The core substantive clash centered on:

  • the projected DO decrease at the discharge point,
  • expected increases in nitrogen and phosphorus, and
  • the proper interpretation of Tier 2: parameter-by-parameter vs. whole-water evaluation.

After a three-day hearing featuring competing experts, the administrative law judge (ALJ) issued a detailed 45-page Proposal for Decision (PFD), concluding:

  • The permit, as modified, complied with Tier 1 and Tier 2 requirements.
  • TCEQ had followed the appropriate antidegradation procedures.
  • Changes in DO, TN, and TP had not been shown to cause a “lowering of water quality by more than a de minimis amount.”
  • SOS’s experts were less reliable on Texas-specific standards and models than TCEQ’s and the City’s experts.

The ALJ expressly rejected SOS’s strict parameter-by-parameter interpretation, emphasizing that the proper focus is on overall water quality, not mere numeric changes in isolated parameters.

TCEQ issued its final order, with minor modifications to the PFD, adopting 142 findings of fact and 22 conclusions of law, and incorporating the Executive Director’s detailed response to public comments.

F. Judicial Review in the Lower Courts

  • Trial court: Reversed TCEQ, holding the permit violated Tier 1 and Tier 2. It accepted SOS’s parameter-by-parameter approach and concluded that undisputed increases in TN/TP and decreases in DO (from at least 6.44 mg/L to near 5.0 mg/L) were more than de minimis and therefore unlawful degradation under Tier 2.
  • Court of appeals (El Paso, 2–1): Reversed the trial court, reinstating TCEQ’s order. The majority held:
    • TCEQ’s narrative, whole-water antidegradation approach was consistent with the rules and 2010 IPs.
    • Substantial evidence supported TCEQ’s findings that existing uses would be maintained and that no significant degradation would occur.
    • SOS could not win “as a matter of law” just by pointing to numeric increases in certain parameters.
    The dissent accepted SOS’s view, focusing on nutrient increases and concluding degradation had been shown.

The Texas Supreme Court granted review, focusing on (1) Tier 2 methodology and (2) the APA “underlying facts” argument.

III. Summary of the Supreme Court’s Opinion

The Court, in an opinion by Justice Devine, affirmed the court of appeals and upheld the permit, holding:

  1. Tier 2 antidegradation review is whole-water, narrative, and qualitative, not parameter-by-parameter.
    • “Degradation” under 30 TAC § 307.5(b)(2) means a “lowering of water quality,” not a per se violation based on any non–de minimis change to a single parameter.
    • Texas’s 2010 IPs confirm that parameter changes (DO, TN, TP, etc.) are inputs to, but not dispositive of, the antidegradation determination.
    • Examples like a 0.5 mg/L DO decrease in exceptional-quality waters are guidelines triggering further evaluation, not automatic findings of degradation.
  2. Substantial evidence supported TCEQ’s Tier 1 and Tier 2 findings.
    • On Tier 1, modeling reasonably supported the conclusion that the DO criterion (5.0 mg/L) and existing uses would be maintained.
    • On Tier 2, TCEQ reasonably found that any lowering of water quality would be no more than de minimis, considering Onion Creek’s overall conditions and protective effluent limits.
    • The Court declined to reweigh conflicting modeling estimates (e.g., 4.87 vs. 5.0 mg/L DO) under the substantial evidence standard.
  3. TCEQ did not improperly “collapse” Tier 1 and Tier 2.
    • Although the standards overlap (both protect existing uses), Tier 2 adds a separate “no more than de minimis lowering of water quality” requirement.
    • The final order’s findings, read together, show that TCEQ addressed both elements.
  4. The APA’s “underlying facts” requirement did not invalidate the order.
    • SOS failed to preserve any specific complaint about missing underlying findings in its motion for rehearing at the agency.
    • In any event, APA § 2001.141(d) applies only to findings stated in statutory language or mandated statutory criteria, not to findings derived solely from agency rules like § 307.5.
    • Water Code § 26.027 does not mandate specific criteria or findings for permit issuance; thus, no additional underlying facts were required by statute for the antidegradation findings.

The Court emphasized its limited role under the substantial evidence and arbitrary-and-capricious standards, deferring to TCEQ’s scientific judgments so long as they have a rational basis in the record and comply with governing rules.

IV. Detailed Analysis

A. Precedents and Authorities Shaping the Decision

1. Substantial Evidence and Deference to Agencies

The Court relied on a line of Texas cases establishing that:

  • Substantial evidence review is “at its core” a rational-basis test, not a correctness inquiry.
  • Agencies receive “significant deference” on fact-intensive and technical questions within their expertise.
  • Courts may not reweigh conflicting evidence or substitute their judgment for the agency’s on disputed issues of fact.

Key authorities include:

  • Ammonite Oil & Gas Corp. v. R.R. Comm’n, 698 S.W.3d 198 (Tex. 2024): Reaffirmed that substantial evidence is a “reasonableness” or “rational basis” test.
  • Dyer v. TCEQ, 646 S.W.3d 498 (Tex. 2022): Confirmed that TCEQ may revisit the record, reweigh the evidence, and revise ALJ findings under Gov’t Code § 2003.047, subject to substantial evidence review.
  • Mireles v. DPS, 9 S.W.3d 128 (Tex. 1999): Stressed that the issue is not whether the agency’s decision was correct, but whether a reasonable basis appears in the record.
  • N.E. ISD v. Riou, 598 S.W.3d 243 (Tex. 2020): Warned against courts “usurping the agency’s adjudicative authority” by reweighing evidence.
  • PUC v. Texas Industrial Energy Consumers, 620 S.W.3d 418 (Tex. 2021): Emphasized the presumption of validity of agency findings.

These precedents are crucial to the Court’s refusal to:

  • elevate SOS’s preferred modeling result (4.87 mg/L DO) over TCEQ’s modeling (≥ 5.0 mg/L), or
  • accept as “undisputed” parameter changes that the ALJ had discounted under a competing evidentiary view.

2. Arbitrary-and-Capricious Review

The Court invoked City of El Paso v. PUC, 883 S.W.2d 179 (Tex. 1994), and PUC v. Gulf States Utils., 809 S.W.2d 201 (Tex. 1991), for the established principle that an agency acts arbitrarily or abuses its discretion if it:

  • fails to consider a mandatory factor,
  • considers an irrelevant factor,
  • applies the right factors but reaches an utterly irrational result, or
  • fails to follow its own regulations.

SOS’s argument that TCEQ “used the wrong standard” under Tier 2 was framed in these terms, but the Court rejected it, concluding that TCEQ’s whole-water approach tracks the text of its rules and IPs.

3. Construction of Agency Rules

The Court relied on TCEQ v. Maverick County, 642 S.W.3d 537 (Tex. 2022), which held that:

  • Agency rules are construed under ordinary statutory-construction principles.
  • Courts must adhere to defined or plain meanings and may not “restate” definitions in ways that add or subtract substantive requirements.

This principle underpins the Court’s refusal to rewrite “lowering of water quality” as “lowering of water-quality parameters” or similar language more favorable to SOS.

The Court also cited TCEQ v. City of Waco, 413 S.W.3d 409 (Tex. 2013), for the notion that qualitative water-quality standards involve a “somewhat subjective assessment,” reaffirming that exact quantification is not always required.

4. APA “Underlying Facts” Requirement

The Court’s analysis of APA § 2001.141(d) draws on:

  • Texas Health Facilities Comm’n v. Charter Medical-Dallas, Inc., 665 S.W.2d 446 (Tex. 1984):
    • Distinguishes between:
      • Underlying/basic facts: the specific factual determinations, and
      • Ultimate facts: conclusions that satisfy statutory standards (e.g., “public convenience and necessity”).
    • Holds that underlying facts are required only for ultimate findings “set forth in statutory language” or mandated criteria, not for all ultimate findings.
    • Invalidated an order where alleged “underlying findings” were merely recitals of testimony, conclusory statements, or did not logically support the statutory criteria.
  • Presbyterian Hosp. N., 690 S.W.2d 564 (Tex. 1985): Reinforced that adequate, non-conclusory underlying facts must support mandated statutory criteria in agency orders.
  • Hooks v. TDWR, 645 S.W.2d 874 (Tex. App.—Austin 1983, writ ref’d n.r.e.):
    • Requires parties to designate missing findings with specificity in their motion for rehearing to preserve the issue.
    • General complaints about “lack of underlying facts” are insufficient.
  • BFI Waste Sys. of N. Am., Inc. v. Martinez Env’t Grp., 93 S.W.3d 570 (Tex. App.—Austin 2002, pet. denied):
    • Restates that only ultimate findings mirroring mandatory statutory criteria require underlying facts.
    • Confirms preservation requirements.
  • W. Tex. Utils. Co. v. OPUC, 896 S.W.2d 261 (Tex. App.—Austin 1995, no writ): Explains the distinction between basic and ultimate facts and the limited reach of the underlying-facts requirement.

These cases collectively support the Court’s two-pronged disposition:

  1. SOS failed to preserve any specific complaint about missing underlying facts in its rehearing motion.
  2. Even on the merits, TCEQ’s antidegradation findings are not expressed in statutory language or in statutorily mandated criteria, so APA § 2001.141(d) doesn’t require further supporting detail.

5. Federal Clean Water Act and EPA Guidance

Although the Court acknowledges the Clean Water Act’s goals (33 U.S.C. § 1251(a)) and EPA antidegradation regulation (40 C.F.R. § 131.12), it emphasizes:

  • The federal question whether EPA lawfully approved Texas’s standards is not before the Court; this is purely a state-law judicial-review proceeding.
  • EPA has approved Texas’s antidegradation standards and 2010 IPs; the Court assumes they comply with federal law and focuses on whether TCEQ followed them “as written.”

The Court also references:

  • 63 Fed. Reg. 51164, 51193 (Sept. 24, 1998): EPA’s approval of Texas’s delegation, explicitly acknowledging:
    • EPA has not mandated that states apply Tier 2 “on a parameter-by-parameter basis,” and
    • States may adopt a “waterbody-by-waterbody” approach, as Texas has.
  • EPA guidance (e.g., the Water Quality Standards Handbook and a 2005 Office of Science and Technology memorandum on assimilative capacity), which EPA itself describes as nonbinding policy rather than law.

The Court rejects SOS’s attempt to elevate these federal policies into controlling requirements that would override the text of Texas’s rules.

B. Legal Reasoning on Antidegradation

1. Tier 1: Maintain Existing Uses and DO Criteria

Tier 1 requires TCEQ to ensure:

  • Existing uses of the water body are maintained (e.g., support of aquatic life and recreation), and
  • Water quality sufficient to support those uses (including site-specific DO criteria) is preserved.

SOS argued that a City model projecting DO as low as 4.87 mg/L demonstrated that Onion Creek’s 5.0 mg/L DO criterion would be violated, failing Tier 1 as a matter of law.

The Court rejected this, emphasizing:

  • Other modeling, including TCEQ’s, predicted DO would remain at or above 5.0 mg/L under worst-case conditions.
  • All modeling used the City’s original requested flow (995,000 gpd), not the lower 822,500 gpd ultimately permitted; this made the modeling conservative.
  • Under substantial evidence review, TCEQ was not required to accept the single lowest modeling output rather than its own analysis and expert testimony.

Accordingly, substantial evidence supported TCEQ’s Tier 1 finding that:

  • the DO criterion would be met,
  • aquatic-life use would be protected, and
  • existing uses would be maintained.

2. Tier 2: “Degradation” as a Lowering of Overall Water Quality

The core dispute was how to interpret “degradation” under § 307.5(b)(2). The Court’s key moves are:

  1. Textual focus on “water quality,” not parameters.
    The rule defines:
    • “Degradation” = “a lowering of water quality by more than a de minimis extent, but not to the extent that an existing use is impaired.”
    The Court:
    • Refuses to rephrase this as “lowering of water-quality parameters” or “components,”
    • Stresses that the relevant inquiry is the condition of the water body as a whole, not individual metrics in isolation.
  2. Use of the 2010 IPs to clarify, not rewrite, the rule.
    The IPs:
    • Identify multiple “parameters of concern” (DO, nutrients, bacteria, toxic substances, temperature, etc.).
    • Describe how to model and assess each parameter.
    • Explain that antidegradation review is ultimately a qualitative, narrative assessment of whether water quality is being lowered more than de minimis.
    The Court reads the IPs as:
    • confirming that parameter-specific analysis is a starting point,
    • but the final determination is a holistic, case-specific judgment about water quality.
  3. Assimilative capacity and DO special treatment.
    The IPs discuss “assimilative capacity”—the room between existing conditions and criteria—and provide a screening rule:
    • If a new discharge uses less than 10% of the assimilative capacity at the mixing zone, it is “usually not considered to constitute potential degradation,”
    • If it uses 10% or more, it is not automatically presumed to be degradation but triggers “further evaluation.”
    Critically:
    • The IPs specify that this screening “is not applicable to dissolved oxygen.”
    • Even for parameters where it is applicable, using ≥10% of assimilative capacity does not automatically equal degradation; it just necessitates a closer, whole-body analysis.
  4. “Examples where degradation is likely to occur” are guidelines, not rules.
    SOS heavily relied on an IP example:
    Increased loading of oxygen-demanding substances that is projected to decrease dissolved oxygen by more than 0.5 mg/L for a substantial distance in a water body that has exceptional quality aquatic life and a relatively unique and potentially sensitive community of aquatic organisms.
    The Court notes:
    • Onion Creek is classified for high aquatic life, not “exceptional,”
    • The example assumes a >0.5 mg/L DO drop over a “substantial distance” (not just at the discharge point),
    • The IPs explicitly state that these are “general guidelines”:
      • They “do not define degradation,”
      • Final determinations are “case-specific,”
      • Lower increases may be degradation in some circumstances, and higher increases may not in others.
    Thus, even under this example, a significant DO reduction is an indicator requiring further evaluation, not a per se violation.
  5. Rejection of a 10% change or 0.5 mg/L DO rule of thumb as binding.
    SOS urged the Court to adopt quantitative thresholds (e.g., >10% DO reduction, > 0.5 mg/L DO drop) as legal triggers of “degradation.” The Court refused, observing that:
    • Texas’s rules and IPs do not codify any such formal threshold.
    • EPA guidance documents recommending such thresholds are explicitly non-binding.
    • EPA has approved Texas’s waterbody-based approach.

Summing up, the Court holds that Texas law:

  • permits TCEQ to evaluate potential degradation using an integrated, professional judgment about overall water quality;
  • does not mandate denial of a permit solely because individual parameters (e.g., DO, TN, TP) will change by more than de minimis levels, unless those changes demonstrably lower overall water quality more than de minimis.

3. Section 307.5(c)(2)(B) and DO-specific Analysis

Amici supporting SOS pointed to § 307.5(c)(2)(B), which provides:

For dissolved oxygen, analyses of degradation under Tier 2 must utilize the same critical conditions as are used to protect instream criteria. For other parameters, appropriate conditions may vary.

The Court interprets this as:

  • Requiring analytical consistency (use the same hydrologic and seasonal assumptions in Tier 2 that are used for DO criteria protection),
  • Not as imposing a special, parameter-level threshold that equates any modeled DO drop with legal degradation.

In other words, DO is still analyzed as part of the broader water-quality picture; § 307.5(c)(2)(B) does not convert the whole-water standard into a DO-specific veto.

4. Alleged “Collapsing” of Tier 1 and Tier 2

SOS argued that TCEQ and the court of appeals improperly “collapsed” Tier 1 and Tier 2 by focusing on existing uses and failing to independently analyze “lowering of water quality.”

The Court disagreed, pointing to findings such as:

  • FOF 78: “An antidegradation review ensures that a proposed discharge does not impair the uses or degrade the water quality of the receiving waters.”
  • FOF 88: Tier 2 is satisfied because DO will be maintained at levels “that support a healthy aquatic life community” and nutrient limits will protect water bodies that exceed fishable/swimmable quality.
  • FOF 90: Tier 2 review confirmed that “no significant degradation of water quality is expected” and that existing uses will be maintained.

The Court acknowledges that analyzing the two tiers separately is difficult because:

  • both require protection of existing uses, and
  • Tier 2 adds only the qualitative, de minimis-based “no lowering of water quality” overlay.

However, the presence of express “no degradation” findings, coupled with record evidence and the ED’s detailed technical and public-comment responses, persuades the Court that TCEQ did conduct a distinct Tier 2 analysis.

C. APA Section 2001.141 and “Underlying Facts”

1. Structure of the Requirement

APA § 2001.141(b), (d) provides:

  • A final agency order must include separately stated findings of fact and conclusions of law.
  • If a finding of fact is “set forth in statutory language,” it must be accompanied by “a concise and explicit statement of the underlying facts supporting the finding.”

Based on Charter Medical and its progeny, this means:

  • Ultimate findings that directly track mandatory statutory criteria (e.g., “the project is needed,” “public convenience and necessity require…”) must be supported by specific, non-conclusory underlying facts.
  • But ultimate findings that merely express the agency’s general conclusions, or that reflect criteria created only by rule (not mandated by statute), do not trigger the underlying-facts requirement.

2. Preservation: SOS’s Motion for Rehearing

The Court first disposes of SOS’s APA argument on procedural grounds:

  • SOS’s motion for rehearing before TCEQ contained only general references to missing “underlying facts.”
  • It did not specifically identify the allegedly omitted findings (e.g., baseline DO, post-discharge DO, quantified assimilative-capacity loss) now claimed as “minimally required.”

Under Hooks and BFI Waste, such generalized complaints:

  • fail to give the agency a fair chance to correct or explain alleged omissions, and
  • do not preserve the issue for judicial review.

3. Substantive Scope: Statutory vs. Regulatory Language

The Court then addresses the merits, holding that § 2001.141(d) does not apply to TCEQ’s antidegradation findings, because:

  • The contested findings mostly track regulatory language (from 30 TAC § 307.5), not statutory language.
  • Water Code § 26.027:
    • authorizes TCEQ to issue or refuse permits, and
    • allows it to refuse a permit that would violate any state or federal law or rule,
    • but does not prescribe specific, mandatory criteria or findings the agency must make when granting a permit.

In contrast to the statute at issue in Charter Medical, § 26.027 does not contain enumerated factors that TCEQ “must” use in deciding whether to grant or deny a discharge permit. Thus:

  • There is no statutorily mandated set of factual criteria that TCEQ’s antidegradation findings must embody,
  • and therefore § 2001.141(d) is not triggered.

The Court also notes the practical and doctrinal problems with SOS’s interpretation:

  • If § 26.027’s broad reference to “any state or federal law or rule” required supporting findings for each applicable legal requirement, then every TCEQ permit order would have to:
    • enumerate every applicable statute/regulation, and
    • set out granular supporting facts for compliance with each.
  • This would be “impossibly onerous,” inconsistent with the presumption of validity in § 2003.047 (prima facie case of compliance), and contrary to the APA’s narrowed “statutory language” trigger.

Accordingly, the Court holds that the final order:

  • meets APA requirements by separately stating findings and conclusions;
  • adequately explains the basis for TCEQ’s antidegradation decision, especially when read with the ED’s technical summary and public-comment responses;
  • is not invalid for lacking more detailed, parameter-specific “underlying facts” about DO and nutrient baselines and projected changes.

V. Complex Concepts Simplified

1. Antidegradation and Tiers

  • Antidegradation policy: A requirement, under the CWA and state law, that water quality already better than the minimum necessary to meet designated uses should not be unnecessarily degraded.
  • Tier 1: Protects existing uses and the water quality needed to support them. Think “do not make current uses worse.”
  • Tier 2: Additional protection for high-quality waters; even if uses continue to be supported, regulators must prevent more than de minimis lowering of overall water quality, unless justified by important social/economic need.
  • Tier 3: Special protection for the best, most unique waters; essentially no lowering allowed.

2. Dissolved Oxygen (DO)

  • DO is the amount of oxygen dissolved in water, usually expressed in milligrams per liter (mg/L).
  • Aquatic organisms need sufficient DO to survive; chronic low DO can stress or kill fish, invertebrates, and sensitive species.
  • Texas sets DO criteria (e.g., 5.0 mg/L mean) tailored to the aquatic-life use class (high, exceptional, limited, etc.).

3. Narrative vs. Numeric Criteria

  • Numeric criteria specify precise allowable levels (e.g., bacteria counts, specific DO concentrations).
  • Narrative criteria use qualitative language (e.g., “no nuisance conditions,” “no excessive algal growth”) and rely on professional judgment, field observations, and modeling to interpret.

4. Assimilative Capacity

  • The “room” a water body has to receive additional pollutants before exceeding its water-quality criteria.
  • Often approximated as the difference between current conditions (ambient concentrations) and the standard.
  • Used as a screening tool in antidegradation review; using more assimilative capacity means moving closer to the threshold beyond which uses might be harmed.

5. De Minimis

  • A Latin phrase meaning “about minimal things.”
  • In this context, a change in water quality so small that it is negligible and not of regulatory concern under Tier 2.

6. Contested-Case Hearing and SOAH

  • A contested case is like a trial before an administrative law judge (ALJ), where parties present evidence and witnesses.
  • SOAH provides neutral ALJs to conduct the hearing and issue a Proposal for Decision, which the agency may adopt, modify, or reject within certain limits.

7. Substantial Evidence Review

  • The reviewing court asks only whether the agency’s decision has a reasonable basis in the record, not whether it was the “best” or “most correct” decision.
  • Agencies can choose between competing expert opinions; courts do not reweigh the evidence.

VI. Impact and Future Implications

A. Solidifying a Whole-Water Antidegradation Standard

This decision squarely confirms that, in Texas:

  • Tier 2 antidegradation review is not governed by strict numerical “triggers” on a parameter-by-parameter basis.
  • Parameter changes (e.g., DO dropping from 6.44 to 5.0 mg/L) are evidence, but must be tied to a demonstrated lowering of overall water quality more than de minimis.
  • TCEQ retains substantial discretion to weigh scientific evidence and make qualitative judgments about water-body health.

This raises the bar for environmental challengers. They can no longer simply point to:

  • percentage changes in a single parameter, or
  • isolated modeling outputs predicting somewhat lower DO or higher nutrients

and claim a per se Tier 2 violation. Instead, they must develop a more comprehensive, ecology-based case showing how those changes—given flow regimes, habitat conditions, biological communities, and cumulative effects—will lower overall water quality beyond a de minimis extent.

B. Deference to TCEQ’s Technical Judgments

The opinion underscores a high level of judicial deference to TCEQ on:

  • choice and interpretation of models (e.g., QUAL-TX),
  • effluent-limit design and mixing assumptions,
  • interpretation of narrative criteria and IPs.

Combined with the burden-shifting framework in Gov’t Code § 2003.047, this means:

  • Once TCEQ has built a reasonably documented technical record and responded to comments,
  • challengers face a steep uphill battle to overturn permits on antidegradation grounds.

C. Limits on APA-Based Attacks on Agency Orders

On the administrative law side, the Court’s reading of § 2001.141(d) significantly constrains the use of “underlying facts” arguments to set aside agency orders:

  • Only findings embodying statutorily mandated criteria or language trigger the underlying-facts requirement.
  • Findings tracking rules (even important ones, like antidegradation standards) generally do not.
  • Parties must carefully and specifically identify missing findings in motions for rehearing or risk waiver.

Agencies—including TCEQ, PUC, and others—can rely on this decision to:

  • avoid over-elaborate findings for each regulatory requirement,
  • focus on clear, non-conclusory findings for statutorily mandated criteria, and
  • treat responses to public comments and technical summaries as part of the explanatory package, even if not styled as numbered “findings.”

D. Implications for Other High-Quality Waters and Discharges

The ruling is likely to influence:

  • Permits discharging into Hill Country streams, spring-fed systems, and other high-quality surface waters.
  • Challenges involving sensitive species (e.g., salamanders, mussels) where DO and nutrient changes are central concerns.
  • How Texas addresses cumulative impacts: While this case focuses on a single discharge, its logic allows TCEQ to consider cumulative effects qualitatively, but does not require any particular cumulative threshold metric.

Environmental advocates may respond by:

  • Filing more science-heavy, whole-ecosystem challenges.
  • Shifting some litigation to federal forums (e.g., citizen suits under the CWA) if they believe EPA’s approval or oversight is deficient.
  • Pursuing legislative or rulemaking changes to codify more quantitative triggers for degradation.

E. Municipal Planning and Beneficial Reuse

The Court highlights the City’s commitments to:

  • Expand reuse (watering parks, medians, golf courses, etc.),
  • Increase storage to avoid discharges during low-flow conditions,
  • Use advanced treatment and UV disinfection.

The decision implicitly signals that:

  • Municipalities that design highly protective permits, pair discharges with aggressive beneficial-reuse programs, and negotiate robust settlement agreements can expect judicial deference if TCEQ signs off.
  • Conversely, applicants proposing minimal controls will likely face more scrutiny, especially if they cannot convince TCEQ that overall water quality is protected.

VII. Conclusion

Save Our Springs Alliance v. TCEQ & City of Dripping Springs is a landmark Texas decision in both environmental and administrative law.

On the environmental side, the Court:

  • Decisively endorses a whole-water, narrative-based Tier 2 antidegradation standard.
  • Rejects attempts to convert isolated numeric changes in a single parameter into automatic legal violations.
  • Affirms TCEQ’s discretion to balance modeling, narrative evidence, and professional judgment in deciding whether overall water quality is lowered more than de minimis.

On the administrative-law side, it:

  • Clarifies that APA § 2001.141(d) applies only when ultimate findings track statutory language or mandatory statutory criteria.
  • Limits the reach of “missing underlying facts” challenges, particularly where those challenges were not preserved with specificity at the rehearing stage.
  • Reinforces the substantial evidence and arbitrary-and-capricious standards as highly deferential, especially in technical, science-driven agency contexts.

The practical effect is to make it significantly harder to overturn TCEQ-issued discharge permits on antidegradation grounds absent a clear legal misinterpretation or a stark evidentiary deficiency. Future challengers will need to grapple not only with the scientific complexity of whole-ecosystem impacts, but also with the doctrinal guardrails that this decision has now firmly put in place.

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