The Environmental Protection Agency says contractors with a natural gas company will pump a mixture of brine and mud into a well in Oklahoma to try to stop propane from spewing into the air.
The EPA is on the scene of the leak at a fuel-storage plant outside of Medford that prompted a voluntary evacuation of the town's 1,000 residents.
City Manager Dea Kretchmar says 10 to 15 percent of residents have left town, most staying with friends or family. Two people checked into a shelter in nearby Wakita after the evacuation advisory was issued Thursday.
The leak started Tuesday at the ONEOK (WUHN'-ohk) plant. ONEOK spokeswoman Megan Washbourne says crews are working to fix the leak, but they don't know when it will be contained.