The Department of Environmental Protection says in a Friday statement that tests done after the Feb. 11 fire showed radiation levels weren't above normal "background" levels at three locations near the well pad.
Naturally occurring radiation is present in many Pennsylvania rock formations, including those that contain Marcellus Shale natural gas.
DEP has also completed air quality sampling at the site and started soil sampling this week. Those results will be made available when analyses are completed.
The southwestern Pennsylvania fire killed a worker and later spread to a second well at the site. The fires were extinguished after about a week.