A municipal infraction which is a violation of Chapter 455B of the Code of Iowa or of a standard established by the City in consultation with the Department of Natural Resources, or both, may be classified as an environmental violation. However, the provisions of this section shall not be applicable until the City has offered to participate in informal negotiations regarding the violation or to the following specific violations:
(Code of Iowa, Sec. 364.22 [1])
1. A violation arising from noncompliance with a pretreatment standard or requirement referred to in 40 C.F.R. §403.8.
2. The discharge of airborne residue from grain, created by the handling, drying or storing of grain, by a person not engaged in the industrial production or manufacturing of grain products.
3. The discharge of airborne residue from grain, created by the handling, drying or storing of grain, by a person engaged in such industrial production or manufacturing if such discharge occurs from September 15 to January 15.