Landfill operators in Pennsylvania are taking on state regulators in court to collect a refund of nearly $4 million in overpaid solid-waste tipping fees.

A dozen companies had won a previous decision in which the same court decided that a $4-per-ton fee – paid to the state – should not have been assessed on materials applied as a daily cover, usually sand. The cover materials were required by state rules. Since then, according to the companies, the state has limited how much money should be returned.

A lawyer for one of the companies said that the state took the position that landfills should have been asking for refunds each time they submitted a payment to the state.

The higher fees were placed in effect in July 2002 as part of a plan by state lawmakers to fill in a $1.3 billion hole in the budget. The dispute arose over whether alternative daily cover should be exempted by the rules. A March 2005 Commonwealth Court panel said the state should not be charging for these materials. The state Supreme Court declined to take the case and the DEP began issuing refunds. The state said they applied the rules correctly and no refunds should be issued unless a petition had been filed with the state within six months of the overpayment.