More Litigation Concerning Plastic Pollution: Can Claims Be Both Novel and Traditional at the Same Time?

Last month, I advised plastics manufacturers to prepare for more litigation.  Although I am generally loath to speculate, it already looks as though this prediction is coming true.  Earlier this month, PennEnvironment and Three Rivers Waterkeeper filed suit against BVPV Styrenics and its parent company.  BVPV manufactures expandable polystyrene at its facility in Monaca, Pennsylvania. 

The complaint alleges a number of violations of the Clean Water Act, but all of them relate to allegations that BVPV discharged nurdles – an excellent neologism that will soon be part of common vocabulary.  The legal claims assert both that BVPV failed to identify its discharge of nurdles in its permit application, resulting in unpermitted discharges, and that the discharge of nurdles violated specific permit conditions prohibiting discharges of floating solids and discharges of any substances in harmful amounts.

What’s noteworthy about this case is not just that, according to Lexis/Nexis (subscription required), the plaintiffs are explicitly conveying that the point of the suit is to send a message; it’s that the complaint seems actually to succeed in doing so.  This isn’t like the case brought by New York State, which tries to fit the round sale of plastic products into the square peg of public nuisance law.

Whatever the ultimate merits of the complaint, the plaintiffs here have done what appears to be a very solid job of preparing their case and fitting their claims into traditional Clean Water Act citizen suit jurisprudence.  The only thing different about this case is that the discharges that are the subject of the suit are not traditional toxic or carcinogenic compounds.  I’m not going to go into all the details alleged, but any lawyer who works in this area, whether for environmental groups or industrial dischargers, will understand how PennEnvironment and Three Rivers Waterkeeper put together their case.

And what this means is that plastics manufacturers really do have to prepare for more litigation.  It may not be novel claims such as those brought by New York.  It may be bread and butter CWA citizen suit claims.  Still, that the claims fit squarely into existing CWA jurisprudence doesn’t mean that they’re not new and important.

There’s no doubt that another front has been opened in the battle over alleged plastic pollution.

Another Study Regarding the Health Impacts of PM Emissions From Power Plants: What Impact Will It Have On Regulation and Litigation?

An article in Science published last week indicates that the mortality risk from exposure to PM2.5 from coal-fired electric generating units is roughly twice as high as the risk posed by PM2.5 from other sources.  According to the article, there were roughly 460,000 excess deaths in the United States from 1999-2020 resulting from exposure to PM2.5 from coal-fired EGUs.  Prior models would have indicated roughly half that number. 

I’m not qualified to opine on the technical merits of the study, but it does suggest a number of implications.  First, in significant part, this is a good news story.  A substantial majority of the excess mortality occurred prior to 2008; as coal-fired EGUs increasingly installed scrubbers to control sulfur dioxide emissions, excess mortality declined rapidly, by more than 85%.  Given that much of the world, particularly India and China, will still be relying on coal for some time, regulators in countries still utilizing coal for energy production should insist on state-of-the-art sulfur dioxide controls.

Second, as the authors suggest, in the United States, EPA may want to consider a more refined measurement than total PM2.5 in its setting of National Ambient Air Quality Standards.  NAAQS that reflect the risks posed by the specific chemical constituents of PM2.5 would seem to be in order.

Finally, I wonder whether this research might revive public nuisance litigation over PM2.5 emissions.  In 2010, I rightly predicted the end of public nuisance claims aimed at emissions alleged to be causing risks at concentrations below NAAQS levels.  While I cheered that result at the time, my cheering was premised on the notion that public nuisance law is a very blunt instrument, particularly compared to specific NAAQS standards that go through a thorough scientific vetting process.

I still would rather rely on EPA’s process for setting NAAQS standards than judicial review under a vague public nuisance standard.  However, I can imagine plaintiffs, particularly in EJ communities, bringing public nuisance claims where EPA has not addressed the risks posed by specific constituents of PM2.5 emissions.  And I can also imagine judges being responsive to such claims, where the evidence indicates that the overall PM2.5 NAAQS does not adequately protect against the risks posed by specific constituents of PM2.5 emissions.

Is Litigation the Solution to Plastic Pollution?

Earlier this week, New York State Attorney General Letitia James filed suit against PepsiCo.  At the core of the case are allegations that PepsiCo.’s widespread use of single-use plastics has created or contributed to a public nuisance in the Buffalo River. 

I don’t doubt that plastic-related conditions in the Buffalo River constitute a public nuisance.  Without diving into the facts, it seems totally plausible.  However, that doesn’t mean that PepsiCo. is necessarily liable for the nuisance.  More importantly, even if PepsiCo. might be found liable for a public nuisance, that doesn’t mean that such litigation is the best way to solve the problem posed by single-use plastics.

I recognize that there are historical examples of the use of litigation to prod Congress and/or regulatory agencies to enact legislation or promulgate regulations to address pollution problems.  What seems different today is that it does not seem at all likely that this litigation, or others like it, will succeed in prodding Congress into action.  In short, this litigation seems to be trying to fill the gap left by a failure to legislate or regulate, rather than as a prod to legislation and regulation.

Does anyone think that this litigation can result in a comprehensive and appropriate solution to the problem of plastic waste?  On the other hand, those who would complain about activist judges can hardly complain when judges provide the only potential pathway towards a remedy.  When Congress takes a pass, it’s difficult to complain when those harmed seek a judicial remedy.

And whether it’s PepsiCo. and plastics or DuPont and PFAS or some other manufacturer of some other useful compound alleged to cause adverse impacts, my advice would be to prepare for more litigation.  Whether such litigation succeeds or not, nuisance cases will be more than just a nuisance for defendants.

Ubi jus ibi remedium.  You can look it up.

What Will Be the Real Consequences of an EPA Decision to List PFAS as Hazardous Substances Under CERCLA?

Last week, Inside EPA (subscription required) reported that EPA will reopen CERCLA cleanups due to the presence of PFAS on a case-by-case basis.  The article reported on the gnashing of teeth among the regulated community at the prospect of seeing a significant number of sites reopened.  As a card-carrying member of the regulated community, I am prone to teeth-gnashing as well.  And I agree with my friend Jeff Porter, who was quoted by Inside EPA as saying that reopening Superfund sites due to PFAS could have “monumental implications.” 

Taking that as a given, I still think it’s useful to try to get past the gnashing of teeth and delve into the details a bit.

First, while I’m sympathetic to concerns about listing a class of PFAS as a hazardous substance and to concerns about listing many individual compounds about which we know very little, I am very skeptical about challenges to the listing of PFOA and PFOS, which is EPA’s currently pending proposed rule.  The odds that a court, even in the person of a very conservative judge, is going to find that EPA was arbitrary and capricious in listing PFOA and PFOS are slim to none.

It would be better for the regulated community to develop cogent and credible arguments against cleanup standards in the parts per quadrillion range than to challenge the threshold listing decision.

Second, the monumental implications of reopening Superfund sites are going to be unavoidable.  The Inside EPA article focused on EPA’s authority to require additional work if the remedy is not protective.  I think that PRPs might well have defenses to claims that EPA can require additional work to address PFAS.

However, what Inside EPA did not discuss is the standard reservation of rights for “unknown” conditions.  Use of the unknown conditions reopener by EPA would require EPA to assert new claims, but this does seem to be exactly why the unknown conditions reopener exists, and I think we’re going to see a lot of such cases, unless settling defendants decide to address PFAS under an existing consent decree even though there might be grounds to dispute EPA’s authority to require additional work.

Which brings me to what’s really at issue here.  CERCLA is a terribly written statute that has led parties to spend millions of dollars without much evidence at all that the cleanups provide significant benefit.  And EPA has significant powers of coercion under the statute.  EPA’s repeated willingness to use its powers of coercion is part of the reason why there is such opposition to the listing proposal.  It’s why the original Sackett decision happened.  And it’s part of the explanation for growing opposition to the modern administrative state.

So I advise the regulated community to get used to the idea of PFAS as hazardous substances under CERCLA and to the likely need to remediate PFAS at Superfund sites thought to be closed, but I also advise EPA to avoid sowing the wind, lest it end up reaping the whirlwind.

Oil and Hazardous Substances; Never the Twain Shall Meet

Late last month, in Munoz v. Intercontinental Terminals Company, the 5th Circuit Court of Appeals held that the liability provisions of CERCLA and the Oil Pollution Act do not overlap and that, consequently, where oil and hazardous substances commingle, the sole remedy is under CERCLA.

As the Court correctly noted, it has long been the case under CERCLA that petroleum commingled with hazardous substances is subject to CERCLA jurisdiction as a hazardous substance.  However, it is not obvious why there cannot be any overlap between the liability provisions of CERCLA and the OPA.

In Munoz, a fire occurred at a tank farm.  There were tanks containing hazardous substances and other tanks containing oil.  Based on the facts recited in the opinion, it appears that all of the tanks were surrounded by a single combined secondary containment area.  As a result of the fire, the proverbial chemical soup accumulated in the containment area and, when containment was breached, the soup flowed into the Houston Ship Channel.

I don’t doubt that the chemical soup should be considered a hazardous substance subject to jurisdiction under CERCLA, but does that necessarily mean that the oil lost its status as “oil” such that it was no longer subject to jurisdiction under the OPA?  Consider the following hypothetical, which seems totally plausible.  Many tank farms have separate containment areas for each tank.  What should the outcome be if there’s a large tank farm with one tank containing waste TCE and another tank some distance away that contains oil?  If they both have releases that breach secondary containment, and the TCE and oil each separately enter the water, that would seem to constitute two separate spills, one subject to CERCLA and one subject to the OPA.

But what happens over time, when the two releases merge?  Does the oil magically lose its status as oil, so that the combined release is subject only to CERCLA?  What happens to the part of the release closer to shore that remains pure oil.  Is that still subject only to the OPA?

As far as one can tell from the opinion, the plaintiffs in Munoz did not present this question to the Court.  The Court in any case did not address it.  Perhaps the next plaintiffs will read this blog and present the question to the next appellate court that must decide this issue.

Connecticut Issues RFP for 2 GW of Offshore Wind

Earlier today, the Connecticut Department of Energy & Environmental Protection (“DEEP”) issued an RFP for up to 2 GW of offshore wind. The RFP solicits bids to enter into long-term power purchase agreements for energy, renewable energy certificates (RECs), and related environmental attributes. Responses to the RFP will be evaluated by various state agencies and the electric distribution companies (“EDCs”), with the ultimate selection to be made by the Commissioner of DEEP.… More

New Report Details Massachusetts Whole-of-Government Approach to Climate Crisis

Yesterday, Massachusetts Climate Chief Melissa Hoffer issued a report detailing how “to implement the Healey-Driscoll Administration’s whole-of-government approach to addressing the climate crisis.” The report identifies trends, barriers, and gaps in Massachusetts climate policy, establishes guiding principles for whole-of-government climate action, and offers recommendations to strengthen the “climate-related practices and policies of executive department agencies.” The recommendations represent a roadmap for the state to implement its climate goals while enhancing public health,… More

Department of Energy Chooses Seven Regions for $7 Billion in Hydrogen Hubs Funding

This morning, the Department of Energy decided how it will allocate up to $7 billion of Bipartisan Infrastructure Law (“BIL”) funding set aside for establishing regional Hydrogen Hubs. (For more information on the Hubs, see our post HERE).

The funding could be critical to jump-starting the country’s clean hydrogen economy.  It will support projects for clean hydrogen production, distribution, and end-use within the Hub regions.  The goal is to drastically reduce greenhouse gas emissions—particularly for hard-to-decarbonize sectors of the economy that will make use of the low-carbon hydrogen the Hubs will produce.  Those hard-to-decarbonize sectors include manufacturing steel, cement, and industrial chemicals, as well as the production of sustainable fuels for air travel, heavy-duty trucking, and maritime shipping.

The following Hubs were selected for funding:

  • Mid-Atlantic Hydrogen Hub (Mid-Atlantic Clean Hydrogen Hub (MACH2); Pennsylvania, Delaware, New Jersey) – up to $750 million.
  • Appalachian Hydrogen Hub (Appalachian Regional Clean Hydrogen Hub (ARCH2); West Virginia, Ohio, Pennsylvania) – up to $925 million.
  • California Hydrogen Hub (Alliance for Renewable Clean Hydrogen Energy Systems (ARCHES); California) – up to $1.2 billion.
  • Gulf Coast Hydrogen Hub (HyVelocity Hydrogen Hub; Texas) – up to $1.2 billion.
  • Heartland Hydrogen Hub (Minnesota, North Dakota, South Dakota) – up to $925 million.
  • Midwest Hydrogen Hub (Midwest Alliance for Clean Hydrogen (MachH2); Illinois, Indiana, Michigan) – up to $1 billion.
  • Pacific Northwest Hydrogen Hub (PNW H2; Washington, Oregon, Montana) – up to $1 billion.

The Hubs announcement reaffirms the Biden administration’s commitment to clean hydrogen as a key climate solution.  Yet it is in many ways just the beginning for the clean hydrogen industry and serves as a critical reminder that several questions remain unanswered regarding how the Hubs and other hydrogen incentives will function.

The selected Hub proposals themselves will need to be developed further.  Hub funding is to be doled out in four phases, according to the Department’s Notice of Funding Opportunity.  Those phases will be punctuated by Go/No-Go reviews, in which the Department will assess project performance, adherence to project schedule, whether milestone objectives have been met, the Hub projects’ continuing ability to meet cost-sharing and contingency requirements, and whether Hub projects have been adequately implementing community benefit programs.  The first phase—“Detailed Project Planning”—will require, among other things, the “completion of preliminary engineering, construction, and commercial scale designs” and the accomplishment of other milestones intended to show that the Hub is “technologically, financially, and legally viable, with buy-in from relevant local and community stakeholders.”

The federal government must also decide how it will implement other hydrogen programs that will be critical to the Hubs’ success.  The one that immediately comes to mind is the Hydrogen Production Tax Credit in the Inflation Reduction Act.  Treasury and IRS have delayed issuing guidance on how that credit will be implemented, leaving many to wonder what production processes will qualify and how the agencies will determine whether lifecycle GHG emissions thresholds for clean hydrogen are met.

Key issues must be resolved particularly regarding how “green” hydrogen—hydrogen produced via electrolysis using renewable energy—will be credited.  Treasury and IRS are considering stakeholder comments regarding how hydrogen projects planning to use power from the electric grid will attribute that power to renewable resources, such as wind and solar.  Some propose an annual matching requirement, while others are advocating for a more stringent hourly matching requirement, which would, in effect, require hydrogen producers to match their power consumption on an hourly basis to renewable power being generated during the same time.  Other requirements under consideration include additionality—that hydrogen should be produced drawing only from new sources of renewable power, rather than preexisting resources—and regionality—that hydrogen producers must attribute their power to renewable generation occurring within their specific region.

Department of Energy must also decide how to allocate the remaining up to $1 billion in Hubs funding it has set aside for demand-side projects, that is, projects that will use the clean hydrogen the Hubs produce.  For the Hubs to function successfully, hydrogen producers and distributors will need off-takers seeking a reliable supply of clean hydrogen.

We may soon get answers to the outstanding questions.  Some reporting suggests that the Hydrogen Production Tax Credit guidance could be released before the end of the year.  The Hubs funding decision could add pressure to get that guidance out sooner rather than later, as many hydrogen projects could be relying on obtaining the credits and other incentives to be economical.

Chevron Is (Still) Not a Left-Wing Plot

Last week, a number of Democratic Senators filed an amicus brief in Loper Bright Enterprises v. Raimondo, arguing that the Supreme Court should not overrule Chevron.  The first heading under the argument section of the brief is that:

CHEVRON … IS UNDER ATTACK IN THIS CASE BY PRO-CORPORATE SPECIAL INTERESTS

My first point is to ask whether, as a matter of strategy, an argument based on opposing “pro-corporate special interests” is likely to succeed before a SCOTUS that is largely sympathetic to corporate interests.

My second point is to emphasize, as I’ve noted in the past, that Chevron is not a left-right issue.  The Trump administration pursued a number of regulatory initiatives based on statutory interpretations that heavily relied on Chevron deference.

Chevron, at its heart, is not even really about deference to agency interpretation.  The real issue about Chevron is whether Congress has authority to enact statutes that enshrine broad principles, while leaving the Executive Branch to fill in the details.  In other words, the opposition to Chevron is really just a back-door argument about the non-delegation doctrine.  It’s an attack on Congress masquerading as an attack on the deep administrative state.

Biden Expands Consideration of Social Cost of Carbon by Federal Agencies

On September 21, 2023, the Biden administration outlined plans to expand federal agencies’ consideration of the social cost of carbon—a metric for the economic cost of each additional ton of carbon dioxide emitted to the atmosphere. This announcement tilts the balance of cost-benefit analyses in favor of activities that reduce greenhouse gas emissions, and it could have widespread effects for entities that receive federal funding or are subject to federal regulation.… More

Establishing Standing in Citizen Suits Under the Clean Air Act: Breathing Polluted Air May Not Suffice

Earlier this month, Judge William Young dismissed for lack of standing claims brought by the Conservation Law Foundation alleging that bus companies violated anti-idling regulations.  The opinion is important, because it does not make life easy for citizen plaintiffs and it provides something of a roadmap for defendants to follow in challenging plaintiffs’ standing.

The Court addressed both the injury in fact and traceability requirements.  Because the Court found that plaintiffs could not establish an injury in fact that was traceable to defendants’ conduct, it did not need to reach the redressability criterion.

First, with respect to injury in fact, the Court noted the following:

  • The “particularity” requirement means that the harm suffered by the plaintiff must be specific and different in kind than that suffered by the general populace.
  • The Court declined to follow other cases in which courts have held that merely breathing contaminated air constitutes injury in fact.

This Court holds that the requirement of an actual injury — one that is concrete and particularized — necessitates more than just breathing in polluted air.  Without any associated physical side effects, recreational or aesthetic harm, or well-grounded fear of health effects, this Court is not satisfied that breathing may constitute an Article III injury.

  • The court did find that two CLF members had established injury in fact, through statements that they recreated less due to concerns about air pollution near the defendants’ bus stops.

The real nail in the plaintiffs’ standing coffin was the Court’s conclusion that CLF could not establish that any injuries that its members suffered were in fact traceable to pollution from defendants’ idling buses.

  • At bottom, the Court found that CLF had failed “to show a sufficiently direct causal connection between the challenged action and the identified harm.” The CLF members said that they were bothered by vehicle exhaust, but the declarations did not establish that the exhaust that bothered them came from illegally idling buses.

These connections between the members’ injuries and the Bus Companies’ conduct are just too attenuated to satisfy the second prong of the standing inquiry. In an urban environment, a span of a mile or two contains numerous vehicles and bus stops. In such an environment, the injuries alleged cannot be conclusively linked to the excessive idling by the Defendants. Allowing suit against the Defendants for anyone suffering the most minor of injuries who has occasionally traveled within two miles of any bus stop could mean that every resident of the greater Boston area has standing to sue the Bus companies. This Court cannot find that this aligns with the Supreme Court’s guidance on standing.

What’s the lesson here?  At a certain level, it may be simply that size matters. If the defendant is a major stationary source and there’s modeling information about concentrations resulting from the source that are likely impacting potential plaintiffs, it’s going to be easier to establish standing than it was in this case.  Either way, whether you are a potential plaintiff or a potential defendant, this case warrants careful reading.

Does EPA Have Authority to Promulgate Cumulative Risk Assessment Guidance?

Last week, Inside EPA (subscription required) reported that the Texas Commission on Environmental Quality has basically informed EPA that EPA may not promulgate guidance on cumulative risk assessments because of questions about its legal authority to require CRAs. 

If EPA plans to interpret such environmental regulations as providing EPA with the authority to require that states consider CRAs in its decision making, including CRAs that may include nonchemical stressors, then TCEQ requests that EPA conduct rulemaking to implement regulations applicable to state programs that include CRAs as criteria allowed for consideration in permitting and other regulatory decisions.

Without such rulemaking, TCEQ has no authority to consider CRAs and CIAs in decision making where they are not required in statute or rule. Guidance is non-binding, often not media-specific, and no substitute for rulemaking, which would provide state agencies with authority to consistently apply CRAs and CIAs in decision making as contemplated by EPA.  (Emphasis added.)

I freely confess from my ivory tower located in deep-blue Massachusetts that I don’t always agree with the TCEQ.  But on this issue, I support TCEQ’s position, at least insofar as it calls for EPA to undertake a rulemaking to implement CRAs.  If EPA believes in the value and importance of cumulative risk assessment, then it should have the courage of its convictions and do a rulemaking.  Because if there’s one thing that’s certain, it’s that, if EPA does promulgate CRA guidance, such guidance will be implemented as though were in effect a binding regulation.

For what it’s worth, I support integrating cumulative risk assessments (and cumulative impact assessments) into federal and state agency decision-making, notwithstanding the difficult methodological issues that need to be resolved to make CRAs a reliable tool. I’m also skeptical that TCEQ would actually support a CRA rulemaking.  I fully expect that TCEQ would challenge a rulemaking, just as they are challenging issuance of guidance.

Still, they’re right about the guidance part!

EPA Must Consult With Other Agencies Before Issuing Water Quality Criteria: Is This an Example of Congressional Use of Behavioral Economics?

Last month, Judge John Hunderaker held that the Endangered Species Act requires EPA to consult with the Fish and Wildlife Service and the National Marine Fisheries Service before issuing recommended water quality criteria.  He also vacated EPA’s 2016 chronic freshwater criterion for cadmium.  The case is potentially important for a number of reasons. 

First, it’s a thorough analysis of standing in cases where the plaintiffs claim a procedural injury – here, EPA’s failure to consult with FWS and NMFS before issuing new recommended water quality criteria.

Second, there is an extensive discussion regarding what constitutes agency “action” subject to judicial review.  EPA argued that promulgation of recommended water quality criteria is not an action because it does not dictate what states must do; they are free to promulgate WQC that differ from EPA’s recommendation.

However, as the Court noted repeatedly its opinion, the statute requires states that wish to vary their WQC from EPA’s recommendations to explain the basis for their decision to reject EPA’s recommendation.  That matters, because it imposes costs on states and “nudges” their behavior in the direction of adopting EPA’s recommendations.

And so we come to my real reason for posting about this case.  Without using the words “behavioral economics” or talking about “nudges” or “choice architecture”, the Court made clear that Congress, in enacting what the Court referred to as the “adopt-or-explain requirement”, had established a specific choice architecture for states deciding whether to adopt EPA’s recommended WQC and had purposefully nudged states in the direction of adopting EPA’s recommended WQC.  Moreover, as the Court noted, the nudge works, because states overwhelming choose to adopt EPA’s criteria.

Stakeholders can argue that the statute incorporates much more of a shove than a nudge and can reasonably take the position that Congress shouldn’t be nudging – or shoving – states in that direction.  Regardless, it important to recognize that it is possible in a federal system for Congress to provide incentives to states to take particular actions, while still leaving the ultimate decision to state authorities.

Energy Department Launches Hydrogen Interagency Task Force, But Few Details Emerge on Status of Federal Hydrogen Programs

[This post is part of our Hydrogen Blog Series. Read the rest of the series here.]

The Department of Energy (“DOE”) held a webinar on Friday, August 18, 2023 on the U.S. government’s national hydrogen strategy.  The main announcement was the formation of the Hydrogen Interagency Task Force, or “HIT,” but the webinar was otherwise light on details regarding the status of key federal hydrogen programs,… More

Guidance Is Still Not the Same as Regulation

Earlier this week, the 10th Circuit Court of Appeals vacated EPA’s disapproval of Wyoming’s regional haze plan for the PacifiCorp’s Wyodak power plant.  The basis for the disapproval was an issue near and dear to my heart.  In rejecting Wyoming’s SIP, EPA repeatedly pointed to Wyoming’s failure to comply with EPA’s guidelines for determining Best Available Retrofit Technology, even though the guidelines were not enforceable regulations. 

The role of the BART guidelines is a curious one.  Congress required in the Clean Air Act that EPA develop guidelines for determining BART.  Moreover, the CAA provides that, with respect to powerplants with a total capacity great than 750 megawatts, the BART guidelines are binding.  However, Congress did not make the BART guidelines mandatory for facilities below the 750 MW threshold.

To me, that Congress made the BART guidelines binding for large facilities, but not for small facilities, makes it obvious that EPA cannot enforce the guidelines against small facilities.  It’s actually a weaker situation for the enforcement of guidance than if Congress had said nothing at all and EPA had just developed the BART guidelines on its own.

However, EPA did not see it that way, and the 10th Circuit opinion is replete with citations to EPA’s rule that reflect a conclusion by EPA that the failure to “comply” with the BART guidelines was a fatal flaw in Wyoming’s regional haze SIP.  For example:

In the final rule, the EPA noted that it had “proposed to disapprove the State’s [Wyodak] determination because the State neglected to reasonably assess the costs of compliance and visibility improvement in accordance with the BART Guidelines.”

It is important to note that the decision was not some radical repudiation of EPA authority.  The opinion is in fact quite measured both in its tone and its conclusion:

Certainly, the guidelines are helpful while not binding, and ordinarily no problem presents itself when the EPA references them in reviewing Wyoming’s SIP. The problem arises, however, when the EPA’s rejection of the state’s BART determination—supposedly for unreasonable cost and visibility analyses—is grounded in a strict application of the nonbinding guidelines. The EPA’s final rule confirms that the agency treated the guidelines as binding for Wyodak and disregarded the state’s broad discretion under the Clean Air Act.

Moreover, the Court did not rule that EPA had to accept the Wyoming SIP.  It merely remanded with an order the EPA reconsider the Wyoming SIP, “giving proper deference to the state and without treating the guidelines as binding.”

Sounds reasonable to me.

The case is clearly further grist for my anti-guidance mill.  The evidence is inescapable that, when agencies promulgate guidance – even when with the best intentions – it is inevitable that they will ultimately come to treat the guidance as though it were a binding regulation.  And that’s not how the administrative process is supposed to work.