I. No person shall operate any device or process at a stationary source that emits a regulated toxic air pollutant without a temporary or operating permit issued by the department in accordance with this chapter or RSA 125-C, provided, however, that no permit or permit application shall be required for any device or process at a stationary source exempted under N.H. Rev. Stat. § 125-I:3, III, or whose uncontrolled emissions of regulated toxic air pollutants do not exceed ambient air limits at or beyond the compliance boundary and for which no other permit is required under RSA 125-C.
II. Existing devices or processes emitting regulated toxic air pollutants at a stationary source in operation as of the effective date of the rules adopted by the commissioner under N.H. Rev. Stat. § 125-I:6, II shall comply with either:
(a) The rules adopted by the commissioner relative to air toxics, including but not limited to rules establishing ambient air limits, in effect immediately prior to the effective date of this section for a period of 3 years following the effective date of this section at which time such stationary sources shall comply with the rules adopted under this chapter relative to regulated toxic air pollutants; or
(b) Rules adopted under this chapter relative to regulated toxic air pollutants at any time, but no later than 3 years following the effective date of this section.
III. All new and modified devices or processes emitting regulated toxic air pollutants at a stationary source shall comply with the rules adopted under this chapter relative to regulated toxic air pollutants.
IV. If the department revises the list of regulated toxic air pollutants or their respective ambient air limits or classifications under N.H. Rev. Stat. § 125-I:4, II and III, and as a result of such revision any source of regulated toxic air pollutants is required to obtain or modify a permit under the provisions of N.H. Rev. Stat. Chapter 125-I or RSA 125-C, the stationary source shall have 90 days following publication of notice of such final revision in the New Hampshire Rulemaking Register to file a complete application for such permit or permit modification. The department shall include as conditions in any permit issued as a result of a revision to the list of regulated toxic air pollutants a compliance plan and a schedule for achieving compliance based on public health, economic and technical considerations, not to exceed 3 years. Failure to comply with any such compliance plan or schedule of compliance shall be subject to the enforcement provisions of N.H. Rev. Stat. § 125-I:8.
V. A person or persons having ownership or control of a stationary source may demonstrate compliance with this chapter and any rules adopted under this chapter by air dispersion analysis or such other techniques as the department designates pursuant to rules adopted by the commissioner in accordance with RSA 541-A. In addition, the department shall establish in rules adopted by the commissioner pursuant to N.H. Rev. Stat. Chapter 541-A one or more methodologies by which any stationary source can determine, through testing, calculation, or other methods without air dispersion modeling, whether the existing or proposed emission of any regulated toxic air pollutant will result in an exceedance of an ambient air limit at the source’s compliance boundary.