(a) Each operator shall identify and ensure, by contract or other approved means, the resources necessary to remove, to the maximum extent practicable, a worst case discharge and to mitigate or prevent a substantial threat of a worst case discharge.
(b) An operator shall identify in the response plan the response resources which are available to respond within the time specified, after discovery of a worst case discharge, or to mitigate the substantial threat of such a discharge, as follows: ----------------------------------------------------------------------------------------------------------------
Tier 1 Tier 2 Tier 3----------------------------------------------------------------------------------------------------------------High volume area..................... 6 hrs.................. 30 hrs................. 54 hrs.All other areas...................... 12 hrs................. 36 hrs................. 60 hrs.----------------------------------------------------------------------------------------------------------------