Wis. Admin. Code NR § 506.18
The department may deny, suspend or revoke the operating license of a solid waste disposal facility as provided in s. 289.31(1), Stats., for failure to pay fees required under ch. 289, Stats., or for grievous and continuous failure to comply with the approved plan of operation under s. 289.30, Stats., or, if no plan of operation exists with regard to the landfill, for grievous and continuous failure to comply with any requirement of chs. NR 500 to 538. Any failure to comply with any such requirement or condition on 5 or more days within any 30 successive calendar days and which consists of action or inaction which may cause pollution as defined in s. 281.01(10), Stats., or which may otherwise create nuisance conditions, is a grievous and continuous failure to comply with the requirement or condition.
Wis. Admin. Code Department of Natural Resources § NR 506.18