HARRISBURG — A consultant says rig workers' failure to use enough pressure-control devices led to a natural gas well blowout in central Pennsylvania last month.

Consultant John Vittitow's report being released today also criticizes the drilling crew's lack of training and testing of equipment.

Vittitow was to appear with Pennsylvania Department of Environmental Protection Secretary John Hanger to discuss his report.

Hanger hired Vittitow to investigate the June 3-4 blowout, which blasted explosive gas and toxic wastewater into the air for 16 hours before control was restored.

No one was injured and the gas did not ignite.

It happened during finishing work on a Marcellus Shale well owned by Houston-based EOG Resources Inc. in rural Clearfield County.