55. In cases which allow it, the regional board must, before suspending, revoking or refusing to renew a permit for one of the reasons provided in subparagraphs 2, 3 and 5 of the first paragraph of section 54, issue an order in writing requiring the holder to take the necessary corrective action within the time it specifies.
If the holder fails to comply with the order, the regional board may then suspend, revoke or refuse to renew the permit.