Rapid City Regional Hospital Inc. has petitioned the South Dakota Public Utilities Commission to join five area industrial companies in fighting the proposed Black Hills Power rate increase.

It joins Dakota Panel, GCC Dacotah, the Sanford Underground Laboratory at Homestake, Rushmore Forest Products and Spearfish Forest Products in saying the rate increase would harm them by increasing their cost of business at a time they are already under economic stress.

The businesses have filed petitions to intervene in the case.

Hospital officials told the Journal in October the rate hikes would mean about a 30 percent increase -- or about $600,000 more -- in power bills for the hospital and its affiliated clinics and other buildings, which pay about $2 million a year to Black Hills Power.