PITTSBURGH (AP) — Pennsylvania plans to do a major study of radiation levels in oil and gas industry wastewater and byproducts.

The Department of Environmental Protection says in a release Thursday that Gov. Tom Corbett ordered the study.

The agency says the study will look at the levels of naturally occurring radioactivity in underground water that comes back to the surface after drilling, as well as radiation levels during the transportation, storage and disposal of drilling wastes.

The agency says some radiation monitors at landfills have been triggered by drilling waste, but that so far information shows very low levels of natural radioactivity. The new study is expected to take 12 to 14 months.