The Mact Floor

Maximum achievable control technology mact floor means the following.

The mact floor.

1 for existing sources. The mact floor for new sources is equivalent to the level of hap emission control achieved by the best controlled similar source and the mact floor for existing sources is the average level of hap emission control achieved by the top 12 percent of that industry group s currently operating sources. 1 for existing sources. Mact standards are performance criteria designed to significantly reduce air toxics emissions.

I the average emission limitation achieved by the best performing 12 percent of the existing sources in the united states for which the administrator has emissions information excluding those sources that have within 18 months before the emission standard is proposed or within 30 months before. The mact floor is established differently for existing sources and new sources which are defined based on the date when a neshap is proposed. Scope and methodology the audit objectives were to identify efficiencies that could be implemented to accelerate the mact standards development process and to evaluate the agency s method of determining the mact floor for emission standards. There is a risk based component to mact standards that follows the initial technology based mact standard.

Epa s proposed mact floor standards for mercury emissions from coal fired utility units. Maximum achievable control technology mact floor means. The mact floor analysis conducted for the rule however used a 90 percent threshold thus excluding units from the mact floor analyses. Mact floor maximum achievable control technology mact floor means.

I the average emission limitation achieved by the best performing 12 percent of the existing sources in the united states for which the administrator has emissions information excluding those sources that have within 18 months before the emission standard. Under the 1990 caaa epa was mandated to set technology based standards based on maximum achievable control technology mact for the source categories specified under 112 d. To find which maximum achievable control. For existing sources the mact floor must equal the average emissions limitations currently achieved by the best performing 12 of sources in that source category if there are 30 or more existing sources.

The court ruled that if a source is to be considered in a subcategory then the source needs to be accounted for in setting the mact floor.