The opinion upholds a ruling last year by Southwest District Judge Dan Greenwood, who said the sole authority for zoning rests with the commission, which regulates energy development in the state.
Environmental Driven Solutions sued Dunn County in 2013 for denying zoning for storage tanks on property adjacent to the treatment facility, sparking the dispute. Three other oil-producing counties filed documents supporting of Dunn County.
Dunn County officials said the site in question was zoned as "rural preservation," which does not allow for salt water storage tanks.
The justices said in an opinion released Tuesday that state law clearly trumps the county's zoning requirements.