R 336.1225 Health-based screening level requirements for new or modified sources of air toxics.

Rule 225. (1) A person who is responsible for any proposed new or modified emission unit or units for which an application for a permit to install is required by R 336.1201 and which emits a toxic air contaminant shall not cause or allow the emission of the toxic air contaminant from the proposed new or modified emission unit or units in excess of the maximum allowable emission rate which results in a predicted maximum ambient impact that is more than the initial threshold screening level or the initial risk screening level, or both, except as provided in subrules (2) and (3) of this rule and in R 336.1226. (2) As an alternative to complying with the initial risk screening level in subrule (1) of this rule, a person may instead demonstrate compliance with the secondary risk screening level. For the purpose of complying with the secondary risk screening level, the total allowable emissions of the carcinogen from the proposed new or modified emission unit or units and all existing emission units at the stationary source shall not result in a maximum ambient impact that is more than the secondary risk screening level. (3) If the ambient impacts of a carcinogen occur on industrial property or public roadways, as an alternative to complying with subrule (1) or (2) of this rule, a person may instead demonstrate compliance with either of the following provisions: (a) The maximum allowable emission rate of the carcinogen from the proposed new or modified emission unit or units results in ambient impacts that meet both of the following requirements: (i) The maximum ambient impact on industrial property or public roadways is less than or equal to the initial risk screening level multiplied by a factor of 10. (ii) The maximum ambient impact on all property that is not industrial or a public roadway is less than or equal to the initial risk screening level. (b) The total allowable emissions of the carcinogen from the proposed new or modified emission unit or units and all existing emission units at the stationary source result in ambient impacts that meet both of the following requirements: (i) The maximum ambient impact on industrial property or public roadways is less than or equal to the secondary risk screening level multiplied by a factor of 10. (ii) The maximum ambient impact on all property that is not industrial or a public roadway is less than or equal to the secondary risk screening level. (4) Any owner or operator who utilizes the alternative criteria provided in subrule (3) of this rule shall notify the department if a change in land use occurs for property determined to be industrial or a public roadway. The notification shall be submitted to the department within 30 days of the actual land use change. Within 60 days of the land use change, the owner or operator shall submit to the department a plan for complying with the requirements of subrule (1) of this rule. The plan shall require compliance with subrule (1) of this rule not later than 1 year after the due date of the plan submittal. (5) For the purposes of this rule, industrial property includes only property where the activities are industrial in nature, for example, manufacturing, utilities, industrial research and development, or petroleum bulk storage. The term industrial property does not include farms or commercial establishments. (6) For the purpose of subrules (1), (2), and (3) of this rule, both of the following provisions apply: (a) All polychlorinated dibenzodioxins and dibenzofurans shall be considered as 1 toxic air contaminant, expressed as an equivalent concentration of 2,3,7,8-tetrachlorodibenzo-p- dioxin, based upon the relative potency of the isomers emitted from the emission unit or units. (b) If 2 or more toxic air contaminants are present and known to result in toxicological interaction, then the interactive effects shall be considered in establishing initial threshold screening levels, initial risk screening levels, and secondary risk screening levels.