SOUTH PORTLAND, Maine (AP) A Maine city’s ordinance prohibiting bulk loading of crude oil onto tankers does not violate the U.S. Constitution.

That was the ruling of a federal court that had been considering South Portland’s “Clear Skies” ordinance on Friday. Portland Pipe Line Corp. challenged the ordinance on the grounds that it violated clauses of the Constitution that give Congress sole power over foreign and interstate trade.

The Portland Press Herald reports the ordinance blocked the company from reversing the flow of its 236-mile underground pipeline. The pipeline has carried foreign crude from harbor terminals in South Portland to Canadian refiners for decades.

The ruling followed a four-day June trial in U.S. District Court in Portland. South Portland’s City Council banned bulk loading of crude oil on the city waterfront in 2014.