More than a year after hearing arguments in a Carmel mining-regulation case, the Indiana Supreme Court decided Thursday that municipalities can regulate mining and don't have to rely on a zoning process to do so.

The unanimous decision came in City of Carmel v. Martin Marietta Materials, Inc., No. 29S04-0611-CV-469. Justice Frank Sullivan authored the ruling in Carmel's favor after considering the validity of a 2005 city ordinance exerting control over the 50-year-old mining operation by regulating issues such as the mine's hours of operation and intensity at which it could set off blasts.

Marietta argued that Carmel was overstepping its jurisdiction because it didn't follow proper procedure in passing the mining regulation ordinance. Hamilton Superior Judge William Hughes had prohibited the city from enforcing the ordinance, and the Court of Appeals agreed in 2006.

Justices heard arguments in January 2007. In Thursday's ruling, the court pointed to Marietta's prevailing argument as a "fairly technical one" and said the company wrongly interpreted the General Assembly's intent in passing a law to regulate mining activities solely through the zoning process.

"But the fallacy in Martin Marietta's argument is its contention that when a unit exercises its police power, at least with respect to mining, the unit is compelled to utilize the zoning process," Justice Sullivan wrote, noting that municipalities must use a process called the 600 Series Procedures allowing a planning commission to first review and make recommendations on a zoning amendment. "But beyond that, a unit may, but is not required to, use the zoning process to regulate mining. In the alternative, the City may proceed as it did here."

This holding is consistent with the "home rule" philosophy, Justice Sullivan wrote, and in that thought Indiana Code 36-8-2-4 and the Home Rule Act authorize the city council to "regulate mining without diminishing the authority of zoning procedures with respect to dictating what type of land use is permitted and where."

The court also noted that the Carmel ordinance doesn't unlawfully delegate legislative authority to an administrative official, as Marietta had also contended.

While no direct impact exists from this state appellate ruling, a federal suit remains pending in U.S. District Court in Indianapolis. Filed by Marietta in 2006, the suit accuses Carmel Mayor Jim Brainard of using his political power to stop the company from expanding its mining operation. That suit, Marietta v. Brainard, remains open but is wrapped up in settlement conferences, according to the court docket.