CLEVELAND (AP) — A comprehensive government study of the effects of shale gas drilling on water quality and the environment won’t be completed until 2016, a U.S. Environmental Protection Agency official said this week during an Ohio conference.

Jeanne Briskin, coordinator of hydraulic fracturing research at the EPA, said Tuesday during the conference in Cleveland that the study involves “complex research” and that the agency could have a preliminary report ready late next year, according to the Akron Beacon Journal (http://bit.ly/1bV2bba ).