Approvals of alternate test procedures for nationwide use and specific discharges are granted by EPA. The department may approve the use of an alternate test procedure on a case-by-case basis if the criteria for approval of the alternate procedure established in s. NR 149.42 are met. If the department or the EPA approves an alternate test procedure, it shall be considered equivalent to the approved method.
Wis. Admin. Code Department of Natural Resources NR 219.05
The federal requirements for alternate test procedure approval are given in 40 CFR 136.5.