HARRISBURG — A Pennsylvania State Police crackdown last week on commercial vehicles hauling wastewater from Marcellus Shale gas drilling sites resulted in hundreds of citations and 208 trucks taken off the road.

Police today announced the results of a three-day enforcement effort that was focused on Bradford, Clearfield, Susquehanna, Tioga and Washington counties.

Troopers issued 959 citations, most commonly for violations related to brakes, lights or permits. Sixty-four drivers were placed out of service. Police conducted 1,135 inspections.

About two-thirds of the vehicles taken off the road were hauling wastewater from wells, and some of the others were also related to the horizontal fracturing drilling technique known as "fracking."

During a previous "Operation FracNET" effort in June, 250 trucks and 45 drivers were idled, and 669 citations were issued.

Marcellus Shale natural gas drilling requires massive amounts of water. Some of it returns to the surface and must be hauled away.