More than seven years after Pennsylvania officials requested that the disposal of radium-laden fracking wastewater into surface waters be restricted, a new study finds that high levels of radioactivity persist in stream sediments at three disposal sites. Radioactivity at these sites is 650 times higher than at unaffected sites upstream. The contamination comes from conventional, or non-fracked, oil and gas wastewater, which, under current state regulations, can still be treated and discharged into streams.