This post was originally published on SCOTUSblog. Reprinted under Creative Commons license CC BY-NC-ND 3.0.

Less than two months after oral argument, in its first interstate groundwater case, the Supreme Court unanimously decided that Mississippi must rely on a doctrine known as equitable apportionment if it wants to sue Tennessee over the shared Middle Claiborne Aquifer. In an opinion by Chief Justice John Roberts, the court squarely rejected Mississippi's claim that Tennessee is stealing Mississippi's groundwater, noting that it had "'consistently denied' the proposition that a State may exercise exclusive ownership or control of interstate waters."

The Supreme Court's decision

As expected, the court's opinion in Mississippi v. Tennessee is short — 12 pages, half of which recount the long history of the case. Nevertheless, in this first opinion about states' rights to interstate aquifers, the court made three important decisions that are likely to guide …

This post was originally published on SCOTUSblog. Reprinted under Creative Commons license CC BY-NC-ND 3.0.

Mississippi v. Tennessee is not only the Supreme Court’s first oral argument of the 2021-22 term, but it is also the first time that states have asked the court to weigh in on how they should share an interstate aquifer. The court’s decision could fundamentally restructure interstate groundwater law in the United States for decades — or the case could be dismissed immediately on the grounds that Mississippi has failed to allege the proper cause of action.

The case will be argued on Monday, and it will be the court’s first in-person argument in a year and a half. In March 2020, the justices stopped meeting in person due to the coronavirus pandemic, and since then, all arguments have been conducted by phone. But the justices are returning to …

This is the first of of a two-part post. Part II is available here.

Last week, the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers announced that the regulations defining “waters of the United States” under the Federal Water Pollution Control Act (better known as the Clean Water Act) are once again going to change.

The importance of that announcement is best demonstrated through a quick recap of the chaos that has dominated this element of Clean Water Act jurisdiction. In the 1980s, the EPA and Army Corps finally agreed on a regulatory definition of “waters of the United States,” a phrase that Congress had used in its 1972 overhaul of the Federal Water Pollution Control Act to define “navigable waters.” The phrase is also one of the key jurisdictional terms defining the waters to which the restructured law applies.

“Waters of …

This is the second of of a two-part post. Part I is available here.

In the first part of this post, I briefly touched on the chaotic history of the EPA and Army Corps' definition and regulation of "waters of the United States" under the Clean Water Act. I also pointed out that this definition and its varying interpretations across courts and administrations can have significant impacts on water pollution prevention and the protection of our nation's waterways. With the Biden administration tackling a redo of the "waters of the United States" rule, court challenges are sure to follow. In this post, I'll explore three approaches to the rule that might help it survive judicial review.

This post is part of a series of essays from the Environmental Law Collaborative on the theme "Environmental Law. Disrupted." It was originally published on Environmental Law Prof Blog.

How much do presidents really matter to the United States' participation in international environmental law?

Fairly obviously, presidential turnovers in the United States are absolutely critical to how the United States conducts its international relations. President George W. Bush's pursuit of Middle Eastern terrorists in the wake of 9/11, including wars in Iraq and Afghanistan, represents a far different engagement with the rest of the world regarding international terrorism than President Obama's reliance on drones and attempts to bring American troops back home. In turn, President Obama's engagement with the rest of the world on climate change, including committing the United States to the Paris Accord, represents a radically different path than the one President Trump …

Climate change is having significant effects on the ocean. Sea levels are rising. The ocean is becoming warmer, and because the ocean absorbs chemically reactive carbon dioxide, its pH is dropping. Hurricanes, typhoons, and other coastal storms are becoming stronger on average. Marine species are on the move, generally shifting toward the poles and, to a lesser extent, deeper. Coral reefs are dying. 

Clearly, the climate impacts on the ocean are cause for concern. Between 2013 and 2016, the ocean along United States' west coast experienced a three-year surge of hot water that National Geographic dubbed "The Blob that Cooked the Pacific." Perhaps most fittingly, on Halloween 2018, Nature published a new study indicating that the ocean is warming 60 percent more per year than the Intergovernmental Panel on Climate Change (IPCC) had projected. 

So, yes, there is cause for serious concern. And it's not …

Last week, the U.S. Environmental Protection Agency (EPA) finalized new National Ambient Air Quality Standards (NAAQS) for ozone pursuant to the federal Clean Air Act. See 42 U.S.C. § 7409. The new regulation reduces both the primary and secondary NAAQS for ozone from 0.075 to 0.070 parts per million (ppm) (or from 75 to 70 parts per billion) averaged over eight hours in order to better protect human health, welfare, and the environment. The new regulation has not yet been published in the Federal Register, but it is available from the EPA.

NAAQS are one of the Clean Air Act’s primary mechanisms for protecting human health and the environment from air pollution. Such protections begin with the EPA Administrator designating criteria pollutants—pollutants that, when emitted into the air, “cause or contribute to air pollution which may reasonably be anticipated to endanger …

On Monday, June 9, 2014, the U.S. Supreme Court decided CTS Corp. v. Waldburger, --- U.S. ---, --- S. Ct. ---, 2014 WL 2560466 (June 9, 2014), a case that posed the seemingly simple legal question of whether the federal Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA,” also known as Superfund), 42 U.S.C. §§ 9601-9675, preempts state statues of repose. Behind that legal question, however, lies the issue of whether the plaintiffs landowners do or should have a state-law remedy for the fact that CTS Corporation contaminated their properties with toxic chemicals as part of its electronics business between 1959 and 1985.

CTS sold the property in 1987, and the plaintiffs brought suit in 2011, alleging a state-law nuisance claim. North Carolina, the state where the properties are located and where the suit was filed, has a 10-year statute of repose. CTS argued that the statute of …

There is no question but that the Clean Water Act has led to enormous improvements in water quality throughout the United States. Funding for publicly owned treatment works (POTWs) has largely eliminated the use of the nation's waterways for the disposal of raw sewage. Most point source discharges are now subject to permitting and technology-based and/or water-quality based effluent limitations.

There is also no question that the Clean Water Act is a statute that is still evolving to address water quality challenges that have become visible once the turbidity of sewage and point source discharges had been largely cleared away. The collection and discharge of stormwater, for example, has evolved from being largely unaddressed, to being the subject of much litigation and court decisions, to being incorporated explicitly into the Act through congressional amendments that imposed permitting requirements on significant stormwater discharges. Even so, stormwater details …