Status of Air Quality Standards for Criteria Pollutants EPA Region 2 Air Programs Branch Bob Kelly, Regional Air Modeler.

Status of Air Quality Standardsfor Criteria Pollutants

EPA Region 2

Air Programs BranchBob Kelly, Regional Air Modeler

Questions

• How does EPA sets air quality standards?

• What are the “criteria pollutants” for air?

• What is the status of revisions to the air quality standards?

Overview of NAAQS Reviews

• The Clean Air Act calls for national ambient air quality standards (NAAQS) for pollutants that “may reasonably be anticipated to endanger public health and welfare… from numerous or diverse mobile or stationary sources”

Overview of NAAQS Reviews

• "Primary" standards protect public health with an adequate margin of safety;

• "Secondary" standards protect public welfare and the environment (crops, vegetation, wildlife, buildings & national monuments, visibility)

Overview of NAAQS Reviews

• EPA has set NAAQS for six common air pollutants: ground-level ozone, particulate matter, carbon monoxide, lead, nitrogen dioxide, and sulfur dioxide

Overview of NAAQS Reviews

• The Act requires EPA to review the scientific criteria and these standards at least once every five years, with advice from the Clean Air Scientific Advisory Committee (CASAC)

Different Considerations Used in Setting and Achieving NAAQS

• Setting the Standards

• Health Effects• Environmental

Effects

• Achieving the Standards

• Costs• Time to attain the

standards

Administrator sets the standard using scientific criteria (hence the “criteria document”), including an adequate margin of safety, protecting against hazards that science has not come to conclusion about or not yet identified.

Review Process for NAAQS

Air Quality Standards have several parts:

• Indicator

• Averaging time period

• Concentration of the standard

• How many times can it be exceeded?

National Ambient Air Quality StandardsPollutant Standard(s)Carbon Monoxide 9 ppm (10 mg/m3) 8-hour1

35 ppm (40 mg/m3)1-hour1

Lead 1.5 µg/m3 Quarterly Average

Nitrogen Dioxide 0.053 ppm (100 µg/m3) Annual (Arithmetic Mean)

Particulate Matter (PM10) 50 µg/m3Annual2 (Arithmetic Mean)150 ug/m324-hour1 

Particulate Matter (PM2.5) 15.0 µg/m3Annual3 ( Arithmetic Mean)65 ug/m324-hour4 

Ozone 0.08 ppm 8-hour5 0.12 ppm1-hour6

Sulfur Oxides 0.03 ppm Annual (Arithmetic Mean) 0.14 ppm24-hour13-hour10.5 ppm (1300 ug/m3) (Secondary Standard)

All are Health-based “Primary” Standards, except as noted.

Footnotes to Table of Standards1 Not to be exceeded more than once per year.2 To attain this standard, the expected annual arithmetic mean PM10 concentration at each monitor within an area must not exceed 50 ug/m3.3 To attain this standard, the 3-year average of the annual arithmetic mean PM2.5 concentrations from single or multiple community-oriented monitors must not exceed 15.0 ug/m3.4 To attain this standard, the 3-year average of the 98th percentile of 24-hour concentrations at each population-oriented monitor within an area must not exceed 65 ug/m3.5 To attain this standard, the 3-year average of the fourth-highest daily maximum 8-hour average ozone concentrations measured at each monitor within an area over each year must not exceed 0.08 ppm. 6 (a) The standard is attained when the expected number of days per calendar year with maximum hourly average concentrations above 0.12 ppm is <= 1, as determined by appendix H.   (b) The 1-hour NAAQS will no longer apply to an area one year after the effective date of the designation of that area for the 8-hour ozone NAAQS. The effective designation date for most areas is June 15, 2004. (40 CFR 50.9; see Federal Register of April 30, 2004 (69 FR 23996).)

• Larger particles (> PM10) deposit in the upper respiratory tract

• Smaller, inhalable particles (≤ PM10) penetrate into the lungs

• PM10-2.5 are thoracic coarse PM

• PM2.5 go deeper than PM10-2.5

• Smallest particles (ultrafines, PM0.1) may enter bloodstream

• Deposited particles may accumulate, react, be cleared or absorbed

Particulate Matter

Particulate Matter• First set in 1971 as Total Suspended Particulates –

annual and 24-hr std• Revised in 1987 as PM 10 • Revised in 1997 as PM 10 and PM 2.5• 1987 PM 10 standard still in use – new PM 10 standard

stayed by Supreme Court Ruling

• Latest: Final Criteria Document October 2004• 2nd draft of EPA staff paper at CASAC

• Next Step: Clean Air Science Advisory Council reviews draft staff paper April 2005

• Propose standards, if needed, December 2005• Final Rule by September 27, 2006

Draft Staff Paper Recommendations for PM

•Provisional staff recommendations, not EPA policy

•PM 2.5 – Annual 15ug/m3 and 24-hr 35 to 25– Annual 14 to 12 and 24-hr 40 to 35

•PM 10-2.5- 24-hour equivalent to present PM10

standard = 65 to 85ug/m3- Support standard as low as 30 to 35- Annual standard may be supported

-Secondary PM 2.5 of 30 to 20ug/m3 over 4 to 8 hours for visibility.

Ozone

• First set in 1971 - 1-hour standard• Revised in 1979• Present Standard: 8-hour average

standard set 1997• 1- hour standard expires June 2005• Status of Review: 1st Draft Criteria

Document 2005• Comment period closes May 2, 2005• Criteria document final February 2006

Sulfur Dioxide

Set in 1971

Affirmed in 1996

States to review monitored 5 minute concentrations above concern level of 0.6 ppm and act at endangerment level of 2.0 ppm

Lead

First set in 1978

Most recent Criteria Document completed in 1986, supplemented in 1990

EPA started review in 2004

Projected to have final Criteria Document by February 2007

Nitrogen Dioxide

Set in 1971

Reviewed in 1996

EPA declined to set short-term standard

Carbon Monoxide First set in 1971 Standard retained 1994Most recent Criteria Document completed in 2000

Non-methane hydrocarbons

Not a health standard, set as target to meet ozone health standard

Revoked in 1980s.

Public Awareness of Air Quality

• NJDEP stations mostly automated

• NJ has provided pollution data and forecasts via phone message, TV and now the Internet

• EPA/State collaboration: near-real-time pollution data for PM and ozone via AIRNOW at: epa.gov/airnow/