In a unanimous ruling, justices upheld a 2015 Environmental Court decision that concluded the Costco expansion was permissible under Vermont's Act 250 land-use laws.

The feud has pitted Vallee, owner of R.L. Vallee, Inc., which owns dozens of gas stations across Vermont under the Maplefields name, against the national corporation.

Costco secured several permits to add gas pumps and reconfigure its parking lot in Colchester, but Vallee, who owns a gas station close to the Colchester Costco, appealed to the Environmental Court and eventually the state's highest court.

Vallee argued that the gas pumps would worsen traffic at the busy intersection off Interstate 89 in Colchester and endanger local wetlands.

Costco accused Vallee of using the land-use process to stifle competition. 
R.L. Vallee, Inc. is one of four companies that have been targeted with a class action lawsuit alleging that they have been fixing gas prices in Chittenden, Franklin and Grand Isle counties for years.

The 2015 lawsuit also mentions Vallee's efforts to quash new gas stations at the Costco in Colchester and a Walmart in St. Albans.

"The defendants have cynically misused, sometimes in concert, Vermont environmental laws to obstruct the entry of low-cost gasoline providers and to extract unreasonable covenants that prevent or limit competition," says the complaint, filed by the law firms Bailey & Glasser and the Burlington Law Practice.

Vallee has denied the accusations. Vallee's attorney, Jon Anderson of Burlington, did not immediately respond to a message.

Vallee is an influential player in Vermont Republican politics. He served as Vermont’s Republican national committeeman between 1999 and 2004, raised money for George W. Bush, and served for two years as Bush's ambassador to Slovakia.

Vallee Decision