(a) An incident investigation will be initiated when:

1. (1) Routine compliance monitoring indicates a violation has occurred; or

2. (2)

   1. (A) A formal complaint is made that an alleged violative incident has occurred (filing of a written form by a complainant).
   2. (B) In cases of apparent immediate endangerment to health or the environment, the written notification may be waived, and the investigation of the alleged incident will begin immediately.