The Pennsylvania Department of Environmental Protection announced plans Tuesday to more uniformly enforce Marcellus Shale natural-gas drilling regulations after an internal study found inconsistences among different regions.

The announcement by DEP Secretary Michael Krancer drew a subdued response.

"Every DEP secretary that I recall has tried to do this," said Louis D'Amico, president of the Pennsylvania Independent Oil and Gas Association, who nonetheless welcomed the effort.

Jan Jarrett, president of Citizens for Pennsylvania's Future, said DEP "has expended substantial time and resources tracking down minor inconsistencies in notices of violations," but said government's efforts could be better spent enforcing regulations that affect public health and the environment.

DEP said that 324 of 4,157 Marcellus inspections over five months this year uncovered one or more violations. Nearly 10 percent of inspections in the north central region resulted in a violation, compared to less than 4 percent of inspections in the southwest region.