40 C.F.R. § 231.7

Where a permit has already been issued, and the Administrator has reason to believe that a discharge under the permit presents an imminent danger of irreparable harm to municipal water supplies, shellfish beds and fishery areas (including spawning and breeding areas) wildlife, or recreational areas, and that the public health, interest, or safety requires, the Administrator may ask the Chief of Engineers to suspend the permit under 33 CFR 325.7, or the state, pending completion of proceedings under Part 231. The Administrator may also take appropriate action as authorized under section 504 of the Clean Water Act. If a permit is suspended, the Administrator and Regional Administrator (or his designee) may, where appropriate, shorten the times allowed by these regulations to take particular actions.