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Lead in Air

SIP Toolkit - Glossary

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Glossary of terms for lead implementation in Plain English

1978 Lead NAAQS 1.5 micrograms per cubic meter (µ/m3), National Ambient Air Quality Standard for lead based on Pb-TSP indicator and averaged over a calendar quarter.

2008 Lead NAAQS - 0.15 µ/m3, National Ambient Air Quality Standard for lead based on Pb-TSP indicator and a three-month rolling average. Pb-PM10 data may be used in limited instances, including to show nonattainment.

Attainment Demonstration: An analysis submitted by a State to show that there will be sufficient emission reductions for the area to attain the air quality standard by the statutory attainment date.

Attainment Date: Under Subpart 5 of the CAA, the nonattainment area attainment date for lead areas is 5 years following designations (determination of areas that fail to meet the lead national air quality standard).

Contingency Measures: Additional control measures to reduce pollution that go into effect if an area fails to attain the air quality standard, or fails to meet reasonable further progress (RFP) or incremental progress toward meeting the air quality standard. The measures are implemented without further action by the State or EPA. These measures are also implemented within 60 days of a determination by EPA of failure to attain, or failure to meet RFP.

Designations: Determinations by the state and EPA concerning what areas are nonattainment (not meeting the air quality standard), attainment (meeting the air quality standard) or unclassifiable (not enough data to determine whether the air quality standard has been met) following a new or revised air quality standard for a pollutant.

Emission Inventories: A comprehensive inventory of actual pollution emissions by the State from sources that are within a nonattainment area as a part of the SIP. The emissions inventory provides an indication of the amount of pollution being emitted in the nonattainment area from one or more sources. EPA suggests a threshold for consideration of sources emitting 0.5 tons per year (tpy) lead or more.

General Conformity: Federal Agencies must show that they do not contribute to violations of air quality standard by either increasing frequency or severity of existing violations or otherwise delay attainment of the air quality standards for the area. The most recent regulations for general conformity apply to the revised Lead air quality standard. Transportation Conformity does not apply to the Lead NAAQS.

Infrastructure plan: a state-wide plan to attain, maintain and enforce the NAAQS.

National Ambient Air Quality Standards (NAAQS): The Clean Air Act requires EPA to set two types of NAAQS for ‘criteria’ air pollutants. Primary standards are setto protect public health with an adequate margin of safety. Secondary standards are set to protect public welfare and the environment (visibility, wildlife, crops, vegetation, national monuments and buildings).

Reasonable Available Control Measures (RACM) including Reasonable Available Control Technology (RACT): Control measures (measures that reduce pollution) that are technologically feasible and economically cost effective to implement for sources in a nonattainment area to reduce air pollution.

Reasonable Further Progress (RFP): Annual incremental pollution reduction in a nonattainment area to help assure the attainment of the NAAQS by its statutory attainment date. For lead nonattainment areas, RFP is to be achieved by implementing an emissions reduction compliance schedule outlined in the SIP.

Prevention of Significant Deterioration (PSD) and nonattainment New Source Review (NSR) permitting programs for lead: The CAA requires States to submit, as a part of the Infrastructure SIP, provisions for permits for construction and operation of new or modified stationary sources.

State Implementation Plan (SIP): The SIP is comprised of the following parts: New Source Review, Infrastructure SIP, attainment demonstration using computer modeling ((New Source Review (NSR), Control Measures (RACM/RACT), Reasonable Further Progress (RFP), Contingency Measures and Emission Inventories), the attainment date and general conformity.

Violation of the 2008 lead NAAQS: Any three-month rolling average exceeding 0.15 µ/m3. As described in Appendix R of 40 CFR part 50, a violation can be based on either Pb-TSP or Pb-PM10 data and only three months of data are necessary to produce a valid violation.


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