The Mact Floor

These minimum requirements for the mact emission limitation for new and existing sources are termed the maximum achievable control technology mact floor.

The mact floor.

Maximum achievable control technology mact floor means the following. The mact floor is established differently for existing sources and new sources which are defined based on the date when a neshap is proposed. 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. A statistical and analytical assessment introduction on january 30 2004 the united states environmental protection agency epa proposed maximum achievable control technology mact standards for mercury emissions from coal fired utility units.

There is a risk based component to mact standards that follows the initial technology based mact standard. 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 mact floor analysis conducted for the rule however used a 90 percent threshold thus excluding units from the mact floor analyses. 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.

1 for existing sources. 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. 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. 1 for existing sources.

Maximum achievable control technology mact floor means. An alternate emission limitation is a voluntary emission limitation that an owner or operator of a major source has agreed to achieve through the early reductions program see 57 fr 61970. Mact floor maximum achievable control technology mact floor means. Mact standards are performance criteria designed to significantly reduce air toxics emissions.

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.