(a) No cessation order or notice of violation issued under this part may be vacated because of inability to comply.

(b) Inability to comply may not be considered in determining whether a pattern of violations exists.

(c) Unless caused by lack of diligence, inability to comply may be considered only in mitigation of the amount of civil penalty under part 845 of this chapter and of the duration of the suspension of a permit under § 843.13(c).