Wis. Admin. Code Department of Natural Resources NR 151.006
Maximum extent practicable applies when a person who is subject to a performance standard of subchs. III and IV demonstrates to the department's satisfaction that a performance standard is not achievable and that a lower level of performance is appropriate. In making the assertion that a performance standard is not achievable and that a level of performance different from the performance standard is the maximum extent practicable, an applicant shall take into account the best available technology, cost effectiveness, geographic features, and other competing interests such as protection of public safety and welfare, protection of endangered and threatened resources, and preservation of historic properties.
Wis. Admin. Code Department of Natural Resources NR 151.006