1. (a) If an acceptable ambient level in 15A NCAC 02D .1104 is exceeded because of emissions of two or more facilities and if public exposure is such that human health may be adversely affected, the Commission shall require the subject facilities to apply additional controls or to otherwise reduce emissions. In considering whether human health may be adversely affected, the Commission shall consider one or more of the following:

   1. (1) an emission inventory;
   2. (2) ambient monitoring;
   3. (3) modeling; or
   4. (4) an epidemiological study.
2. (b) The allocation to the facilities of additional controls or reductions shall be based on their relative contributions to the pollutant concentrations unless the owners or operators agree otherwise.

3. (c) The owner or operator of a facility shall not be required to conduct the multi-facility ambient impact analysis described in Paragraph (a) of this Rule. This type of analysis shall be done by the Division. In performing its analysis, the Division shall:

   1. (1) develop a modeling plan that includes the elements set out in 15A NCAC 02D .1106(h);

   2. (2) use for the source modeling parameters:

      1. (A) the modeling parameters used by the owner or operator of the source in his or her modeling demonstration; or
      2. (B) parameters contained in or derived from data contained in the source's permit if a modeling demonstration has not been done or if a needed parameter has not been used in the modeling demonstration;
   3. (3) use a model allowed by 15A NCAC 02D .1106(e);
   4. (4) use the time periods required by 15A NCAC 02D .1106(f); and
   5. (5) only consider impacts of a facility's emissions beyond the premises of that facility.

History Note: Authority G.S. 143‑215.3(a)(1); 143‑215.107(a)(3),(5); 143B‑282;
Eff. May 1, 1990;
Amended Eff. July 1, 1998;
Readopted Eff. July 1, 2018.