As the U.S. Supreme Court heads into its final two argument sessions of the year, the justices have at least two potentially major cases with unsettled backgrounds that could derail when and how the court issues any final rulings.

The term's biggest environmental challenge—County of Maui v. Hawaii Wildlife Fund—has been wrought with a series of twists and turns in recent weeks over whether the dispute has been, or will be, resolved before the justices hear arguments next week. A new lawsuit was filed in Hawaii state court this week over who has authority to enforce a presumptive settlement that would end the litigation.

In the other case, the first major gun rights challenge in more than a decade, the two sides feuded in recent months over whether there was still a controversy for the justices to resolve. Lawyers for New York City, which was sued over regulations that restrict the movement of firearms, had urged the justices to take the case off the argument calendar after the city said it had amended its laws in favor of the challengers. But the high court in October denied the request, saying the justices would consider whether there's still a live controversy when they hear the case in December.

It's not unusual for one or more cases to wash out either before or shortly after oral arguments in the Supreme Court. Last term, the justices removed a veteran's case, Gray v. Wilkie, from its February argument calendar—just shy of three weeks from the argument date—because of a suggestion of mootness by the government.

The Hawaiian case raises a significant question that pits mainly environmental groups against industry. The Trump administration's Justice Department added to the controversy when it abandoned the legal position—favoring environmental groups—long held by the Environmental Protection Agency.

The justices are asked if the Clean Water Act requires a permit when pollutants are conveyed to navigable waters by a "nonpoint source"—in this instance, by groundwater. The case has attracted 29 amicus briefs, an indication of the high stakes for all parties, many of whom have drawn upon advocates from Big Law, including Mayer Brown; Kirkland & Ellis; Beveridge & Diamond; Gibson, Dunn & Crutcher; Hogan Lovells; Crowell & Moring; and Baker Botts.

In the Hawaii case, the justices received a series of letters in early October informing the court of a settlement approved by the county in September and a dispute over whether the mayor had to agree to it as well. The corporation counsel, who represents both the county and the mayor and who was ordered to enforce the agreement, insisted that the mayor needed to sign off on the settlement and the withdrawal of the high court case. The mayor has continued to refuse to do so.

The chair of the Maui County Council wrote to the Supreme Court on Oct. 9 to request dismissal or postponement of the Nov. 6 arguments.

Moana Lutey, the corporation counsel for Maui County, wrote on the same day to the justices: "Please accept my sincerest apologies" for the council member's letter. "I was unaware that this letter was going to be sent to you," Lutey wrote. She added: "I am able to represent to this court that the County of Maui is not requesting a delay or dismissal of this matter. Any alleged conflict involving the county charter is a matter that may be addressed independently."

David Henkin of Earthjustice, who will argue on behalf of the Hawaii Wildlife Fund, said he is prepared to answer any questions the justices may have about the settlement issue. "Whether a settlement has been reached is ultimately a question for the Hawaii courts," he said, adding that the issue does not affect the legal merits of the high court case.

Elbert Lin of Hunton Andrews Kurth

His opposing counsel, Elbert Lin, partner in Hunton Andrews Kurth, was not available to comment. Lin, formerly the West Virginia state solicitor general, joined the firm in 2017. Lin, now based in Richmond, Virginia, had led West Virginia's fight against the Obama administration's Clean Power Plan. The Hunton team also includes partner Michael Shebelskie.

Maui County first contracted with the predecessor firm Hunton & Williams in 2013 for $250,000, government records show. Subsequent amendments, including $500,000 for litigation in the U.S. Supreme Court, pushed the total contract to $4.3 million.

An environmental advocacy group and several Maui residents filed the new state lawsuit against Maui's mayor. The plaintiffs, represented by Anthony Ranken of Anthony Ranken & Associates in Wailuku, asked the court for a declaratory judgment that the county council has the exclusive authority to accept the proposed settlement and it is binding on the county and legal counsel.

If the Supreme Court case is not withdrawn, they argue, it will result in a decision that is "beyond the control of the county" and may cause damage to offshore coral reef ecosystems, beaches, water quality and recreational activities.

The justices have scheduled 30 minutes of argument time for next Wednesday. The U.S. solicitor general's office was granted 10 minutes to participate at the hearing. Lin is scheduled to argue for Maui County.