(a)  If an acceptable ambient level in Rule .1104 of this Section is exceeded because of emissions of two or more facilities and if public exposure is such that the commission has evidence that human health may be adversely affected, then the Commission shall require the subject facilities to apply addition controls or to otherwise reduce emissions.  The type of evidence that the Commission shall consider shall include one or more of the following:

(1)           emission inventory,

(2)           ambient monitoring,

(3)           modeling, or

(4)           epidemiological study.

(b)  The allocation of the additional reductions shall be based on the relative contributions to the pollutant concentrations unless the owners or operators agree otherwise.

(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 of  Air Quality.  In performing its analysis, the Division shall:

(1)           develop a modeling plan that includes the elements set out in Paragraph (f) of Rule .1106 of this Section;

(2)           use for the source modeling parameters, the modeling parameters used by the owner or operator of the source in his modeling demonstration, or if a modeling demonstration has not been done or if a needed parameter has not been used in the modeling demonstration, parameters contained in, or derived from data contained in, the source's permit;

(3)           use a model allowed by Paragraph (c) of Rule .1106 of this Section;

(4)           model for cavity effects and comply with the modeling requirements for stack height set out in Rule .0533 of this Section;

(5)           use the time periods required by Paragraph (d) of Rule .1106 of this Section; and

(6)           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.