Two companies seeking to advance the use of vehicles powered by compressed natural gas (CNG) by business fleets will host an educational workshop on April 20 in Grimes. NatGas Services LC of Ankeny and Black Hills Energy, a unit of Rapid City, S.D.-based energy company Black Hills Corp., say the ecologically friendly fuel has the potential to lower fleet owners’ transportation costs substantially. By the end of May, the companies plan to open the state’s first public CNG refueling location will be located at Krueger’s BP Amoco on Iowa Highway 141. The fuel will be priced at $1.99 per gasoline gallon equivalent. The workshop will be held 9 a.m.-1 p.m. at the Grimes Community Center at 410 S. Main St. There is no charge to attend the event, but reservations are required by April 13. To RSVP or for more information, contact Deb Harre at (515) 964-6799 or email her at deb@natgasservices.com