BART Overview Lee Alter Western Governors’ Association WRAP SSJF Meeting Denver, CO February 18, 2004

WRAP Emissions (13 Contiguous States) SO2 NOx PM10 1996 2018 Note: Emissions do not include wind-blown dust or EPA’s proposed Tier IV off-road engine standards. Natural gas compressors span the point and area source categories.

WRAP Point Source Emissions (1996) Not all these categories are BART-eligible.

What Is BART? An emission limitation based on the degree of reduction achievable through the application of the best system of available continuous emission reduction for each pollutant. When determining BART, states and EPA must take into consideration: The costs of compliance, The energy and nonair quality env. impacts of comp., Any existing controls at the source, The remaining useful life of the source, and The degree of visibility improvement which may reasonably by anticipated to result.

To Whom Does It Apply? To BART-eligible sources emitting any pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any mandatory Class I Federal area. A BART-eligible source is that portion of a facility which: Belongs to any one of 26 source categories, Was in “existence” on 8/7/77, Was not in “operation” before 8/7/62, and Has the potential to emit > 250 tpy of any visibility impairing pollutant (SO2, NOx, PM, VOC, NH3).

Alternatives to BART within the RHR Must include all BART-eligible sources Must provide for greater reasonable progress Emissions analysis (tonnage and distribution) If significant change in distribution, then a dispersion modeling analysis to show that: On average, areas show greater progress, and No area experiences a decrease in visibility May phase in reductions over the entire planning period (2018) rather than 5 years May contain elements to address geographic enhancements

WRAP BART Efforts Help identify BART-eligible sources ($100,000) Objectives Provide direct assistance to some states and tribes to identify BART-eligible sources Coordinate approach among all states and tribes Identify and track status of sources in the region Challenges Operation and existence dates Reconstructed and modified units Data availability Proposals due today

WRAP BART Efforts Resources available to help determine which BART-eligible sources should be subject to BART ($100,000) Not necessary if pursuing an alternative to BART Possibly ... Determine emission reductions attributable to BART Can be done on a category-wide basis if pursuing an alternative to BART Develop an alternative to BART Review EPA revisions to BART regulations and guidance and comment where appropriate

IMPROVE Monitoring Data (2002) Percent Light Extinction Due to Ammonium Sulfate on the 20% Worst Days

IMPROVE Monitoring Data (2001) Percent Light Extinction Due to Ammonium Nitrate on the 20% Worst Days Percentages are higher when natural sources of haze are excluded On some of the hazy days on the CP, nitrate is 40 - 60 %

IMPROVE Monitoring Data (2002) Percent Light Extinction Due to Ammonium Nitrate on the 20% Worst Days

Point Source NOx Emissions (1996) 763 plants > 100 tpy These account for 94% of SS emissions ~150 are power plants