Restrictions applicable to existing installations

No person may discharge into the ambient air from any single source of emission whatsoever, with the exception of existing incinerators, any air contaminant which exhibits an opacity greater than forty percent except that a maximum of sixty percent opacity shall be permissible for not more than one six-minute period per hour. Provided, however: 1. In consideration of public health and welfare, when it becomes both technically and economically feasible, the source shall comply with visible air contaminant restrictions as outlined in section 33.1-15-03-02 when directed by the department. 2. Any existing source which has installed control technology capable of complying with the visible air contaminant restrictions applicable to new installations shall comply with section 33.1-15-03-02 when directed by the department. 3. If any party is aggrieved by the department's decision as referenced in subsections 1 and 2, that party may request a hearing before the department to review such decision. Such hearing must be conducted according to North Dakota Century Code chapter 28-32. If a hearing is requested, the requirements of section 33.1-15-03-02 are not effective until ordered by the department at the conclusion of the hearing process.