Coeur Alaska, Inc. v. Southeast Alaska Conservation Council
The Court ruled that the Army Corps of Engineers, not the EPA, was the right agency to permit a gold mine's discharge of waste slurry into an Alaska lake, because the slurry qualified as regulated "fill material" rather than an ordinary pollutant.
The decision means mining companies and other industries can route certain waste discharges through the Corps' fill-material permitting process even when a stricter EPA pollution standard would otherwise ban the discharge outright, so long as the agencies' own definitions classify the waste as fill.
“The Act is best understood to provide that if the Corps has authority to issue a permit for a discharge under §404, then the EPA lacks authority to do so under §402.”
The Court's core holding on which agency controls permits for fill material.
How it got here: A federal district court upheld the Corps' permit; the Ninth Circuit reversed and ordered the permit vacated; Coeur Alaska and Alaska asked the Supreme Court to review that ruling.
The Case in Depth
What happened
Coeur Alaska wanted to reopen the closed Kensington Gold Mine near Juneau using a "froth flotation" process that produces a rock-and-water waste mixture called slurry. Rather than build a standard tailings pond, the company planned to pump millions of tons of slurry into Lower Slate Lake, a small subalpine lake, killing its fish and other aquatic life, and later purifying and releasing the lakewater downstream.
The question before the Court
Could a gold mining company dump waste rock-and-water slurry into an Alaska lake under a permit from the Army Corps of Engineers, instead of getting a stricter permit from the EPA?
Why it matters
Mining companies and other heavy industries gain a legal path to dispose of waste in lakes and other waters by using the Corps' fill-material permit process, even when an EPA rule would otherwise forbid the discharge entirely. Environmental groups lose a tool to block such disposal once material is classified as fill, while lakes and wetlands near mining and construction sites remain vulnerable to this kind of permanent alteration.
What changes now
The case is remanded to the lower courts for further proceedings consistent with the Court's ruling, meaning the Corps' permit for the slurry discharge into Lower Slate Lake stands and mining can proceed under it. The decision is a final merits ruling on the legal questions presented, though it does not resolve every possible future dispute over how the fill-material definition applies to other kinds of industrial waste.
What this does not decide
The Court did not decide how the fill-material definition would apply to other solid wastes, like feces, litter, or battery-manufacturing byproducts, that industries might try to reclassify as fill to avoid EPA performance standards; it left that question for future cases if it arises.
Concurrences and dissents
Concurrence — Justice Breyer
Justice Breyer emphasized that agencies have some reasonable leeway to classify material as either fill or a regulated pollutant, but stressed there are safeguards against abuse: the EPA retains veto power over Corps permits, and any EPA decision not to apply a performance standard must itself be reasonable and subject to judicial review.
Concurrence — Justice Scalia
Justice Scalia joined the Court's opinion except for its claim that it was not applying full Chevron deference to the EPA's internal memorandum. He argued the majority was effectively giving Chevron-level deference under a different name, and used the case to criticize the Court's earlier Mead decision as having created confusing, inconsistent deference rules.
Dissent — Justice Ginsburg
“Whole categories of regulated industries can thereby gain immunity from a variety of pollution-control standards.”Ginsburg's warning that classifying waste as fill could let industries dodge pollution rules.
Justice Ginsburg argued the discharge was flatly illegal under §306(e), which bars new sources from violating EPA performance standards without exception, and that nothing in §404's fill-material provision overrides that clear prohibition. She warned the majority's reading creates a loophole letting entire industries escape pollution controls simply by adding enough solid matter to raise a water body's bottom, undermining the Act's core anti-pollution purpose.
How the Court got there
The legal reasoning, step by step
- The Court first asked which agency had authority to permit the discharge at all, since the Clean Water Act splits permitting power between the EPA (for pollutants generally, under §402) and the Army Corps of Engineers (for "dredged or fill material," under §404), with §402 expressly excluding anything the Corps has authority to permit under §404.
- Because the agencies had jointly defined "fill material" by regulation to include any substance that changes a water body's bottom elevation, including mining slurry and tailings, and because the slurry here would raise the lakebed, the Court found the slurry fit squarely within the Corps' §404 authority rather than the EPA's §402 authority.
- The Court then turned to whether the Corps permit was otherwise unlawful because it conflicted with a separate EPA rule (a "new source performance standard") that bans virtually all wastewater discharges from this type of gold mine, and with the Clean Water Act's §306(e), which makes violating such a standard unlawful.
- Applying the two-step framework from Chevron for deciding when to defer to an agency's reading of an ambiguous statute, the Court found that Congress had not directly addressed whether §306 applies to discharges that qualify as fill material, since §306 doesn't mention fill and §404 doesn't mention performance standards.
- Finding the implementing regulations also silent on the conflict, the Court deferred, under the standard from Auer v. Robbins for an agency's interpretation of its own ambiguous rule, to an internal EPA memorandum concluding that its performance standard does not apply once a discharge is properly classified as fill material governed by the Corps.
- The Court concluded that this interpretation reasonably reconciled the statute's separate permitting tracks, preserved a role for EPA's standards over other discharges from the same lake, and was consistent with the agencies' past practice, so the Corps' permit was issued in accordance with law.
Doctrinal impact
Cases affected by this decision
Reaffirms Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc. (467 U. S. 837)
The Court applied Chevron's framework for deferring to agency interpretations of ambiguous statutes.
Reaffirms Auer v. Robbins (519 U. S. 452)
The Court relied on Auer's rule of deferring to an agency's reasonable interpretation of its own ambiguous regulation.