R307-403-5. Offsets: Particulate Matter Nonattainment Areas

  (1) PM₁₀ Nonattainment Areas. (a) In addition to the general offsetting requirements of R307-403-4, as they apply to new major sources and major modifications as defined in R307-403-2(10)(b), new sources which have a potential to emit, or modified sources which would produce an emission increase equal to or exceeding the tonnage total of combined PM₁₀, sulfur dioxide, and oxides of nitrogen listed below which are located in or impact a PM₁₀ Nonattainment Area as defined in R307-403-5(1)(e), shall obtain an enforceable offset as defined in R307-403-5(1)(b) and R307-403-5(1)(c).

  (b) For a total of 50 tons/year or greater, an offset established at a ratio of 1.2:1 of the emission increase is required.

  (c) For a total of 25 tons/year but less than 50 tons/year, an offset established at a ratio of 1:1 of the emission increase is required.

  (d) For the offset determinations required in R307-403-5(1)(b) or R307-403-5(1)(c), PM₁₀, sulfur dioxide, and oxides of nitrogen shall be considered on an equal basis. In areas where offsets are also required for PM_2.5, and/or ozone, the most stringent emission offset ratio for oxides of nitrogen required by R307-403 or R307-420 shall apply.

  (e) For the purpose of determining whether the owner or operator which proposes to locate a source outside a nonattainment area is required to obtain offsets, the maximum allowable impact on any nonattainment area is 1.0 microgram/cubic meter for a one-year averaging period and 3.0 micrograms/cubic meter for a 24-hour averaging period for any combination of PM₁₀, sulfur dioxide and nitrogen dioxide.

  (2) PM_2.5 Nonattainment Areas.

  (a) In addition to the general offsetting requirements of R307-403-4, new major sources or major modifications to existing sources which are located in, or would impact a _PM2.5 nonattainment area as defined in R307-403-3(1), shall obtain an enforceable offset as defined in R307-403-5(2)(d) through (f).

  (b) a major source is:

  (i) in a moderate nonattainment area, any stationary source of air pollutants which emits or has the potential to emit 100 tons per year or more of direct PM_2.5, or any individual PM_2.5 precursor as defined in R307-403-1(4)(c).

  (ii) in a serious nonattainment area, any stationary source of air pollutants which emits or has the potential to emit 70 tons per year or more of direct PM_2.5, or any individual PM_2.5 precursor as defined in R307-403-1(4)(c).

  (iii) any physical change that would occur at a source not qualifying under R307-403-5(2)(b)(i) or R307-403-5(2)(b)(ii) as a major source, if the change would constitute a major source by itself.

  (c) For the purposes of determining what is a significant emission increase or a significant net emission increase and therefore a major modification, significant means a rate of emissions that would equal or exceed 10 tons per year (tpy) of direct PM_2.5, 40 tpy of sulfur dioxide, 40 tpy of nitrogen oxides, or 40 tpy of volatile organic compounds (VOC). In PM_2.5 nonattainment areas where ammonia has not been exempted as a PM_2.5 precursor, the rate of emissions that is significant is specified in R307-403-1(4)(b).

  (d) Any increase in emissions that has been determined to require offsets shall be offset at a ratio of no less than 1:1. If the quantity of offsets is determined to be a non-whole number, the offset required shall be rounded up to the next whole number.

  (e) If offsetting requirements for PM₁₀ and/or ozone are also triggered, the most stringent emission offset ratio required by R307-403 or R307-420 shall apply.

  (f) Offsets may not be traded between pollutants.