Cal. Code Regs. tit. 23 § 2918
On April 15, 2008, the State Water Resources Control Board (State Water Board) adopted Resolution No. 2008-0025, a statewide Water Quality Control Policy (Policy) that authorizes compliance schedules in NPDES permits that implement Clean Water Act § 301(b)(1)(C). The Policy supersedes all existing provisions authorizing NPDES compliance schedules with the exception of:
A discharger who seeks a compliance schedule must demonstrate to the satisfaction of the applicable Water Board that additional time is needed to implement actions such as designing and constructing facilities or implementing new or significantly expanded programs and securing financing, if necessary, to comply with a more stringent permit limitation specified to implement a new, revised, or newly interpreted water quality objective or criterion in a water quality standard. Any compliance schedule must require compliance as soon as possible. The Policy specifies that, in general, the duration of the compliance schedule may not exceed ten years from the date of adoption, revision, or new interpretation of the applicable water quality standard. However, an extended compliance schedule may be established in a permit for a permit limitation that implements waste load allocations specified in a TMDL.
Cal. Code Regs. Tit. 23, § 2918