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Environmental
Air Quality Introduction
Massport is conducting a comprehensive air quality monitoring study in the vicinity of Logan Airport. The program will collect air quality data in Winthrop and Boston over approximately a two-year period at 11 locations. The work plan for this study can be viewed by clicking here.
Air emissions associated with Logan Airport operations include three primary sources: (1) aircraft; (2) ground service equipment (GSE); and (3) motor vehicles. Although a range of other sources including fuel storage, heating and cooling, also contribute to air emissions at Logan, aircraft are the largest single source of emissions.
Four principal air pollutants are emitted by aircraft: carbon monoxide (CO), volatile organic compounds (VOC), oxides of nitrogen (NOx), and particulate matter (PM10 and PM25 ). Ambient air quality standards exist for CO, sulfur dioxide (SO2), PM10, PM25 and nitrogen dioxide (NO2), one of the NOx compounds. There are no standards for VOCs; however, VOCs are precursors to ozone (O3) for which an air quality standard has been established.
Air Quality Standards
The Clean Air Act as amended by the Clean Air Act Amendment of 1990 (CAAA), federal and state regulations, and the National Ambient Air Quality Standards (NAAQS) govern air quality issues at Logan Airport. The Massachusetts State Implementation Plan (SIP) promulgated pursuant to and in compliance with the CAAA, also govern air quality issues at the airport. The NAAQS and the SIP are discussed briefly below.
The U.S. Environmental Protection Agency (EPA) has established air quality standards for outdoor (ambient) air to protect the public's health and welfare with a margin for safety. The National Ambient Air Quality Standards (NAAQS) are summarized in Table 1, below. Concentration units for the NAAQS shown in Table 1 are given in parts per million (ppm) and micrograms of pollutant per cubic meter of air (B5g/m3 ). The one hour value for NO2 is a MA Department of Environmental Protection (DEP) policy guideline (not a regulatory standard) that is only applicable to major stationary sources emitting over 250 tons per year of NO2. Although it is not applicable to Logan in a regulatory sense since Logan is a mobile rather than a stationary source, Massport has used the guideline value in the past in airport air quality assessments.
Eastern Massachusetts is currently classified as a nonattainment area for the one hour NAAQS for ozone, however seven of the nine DEP monitoring stations in eastern Massachusetts and all of those in Middlesex County, have measured no violations of the NAAQS since 1996.
| Massachusetts and National Ambient Air Quality Standards (NAAQS) |
| Averaging | Standard |
| Parameter | Time | ug/m3 | ppm |
| CO | 8 Hour 1 | 10,000 | 9 |
| 1 Hour 1 | 40,000 | 35 |
| NO2 | Annual | 100 | 0.05 |
| 1 Hour 2 | 320 | 0.17 |
| PM10 | Annual | 50 | - |
| 24 Hour 3 | 150 | - |
| PM25 | 24 Hour 3 | 65 | - |
| SO2 | Annual | 80 | 0.03 |
| 24 Hour 1 | 365 | 0.14 |
| 3 Hour 1 | 1,300 | 0.50 |
| Lead | Calendar Quarter | 1.5- |
| Ozone | 1 Hour 5 | 235 | 0.12 |
| Ozone (Proposed 1997) | 8 Hour 6 | 157 | 0.08 |
Source: 40 CFR 50 |
1 Not to be exceeded more than once a year.
2 DEP NO 2 Policy Guideline level not to be exceeded more than one day per year.
3 98th percentile (PM2.5) (99th percentile PM10) 24-hour concentrations in a year (average over three years).
4 Three year average of annual PM2.5 arithmetic needs.
5 Daily 1-hour ozone maximum not to be exceeded more three times in a three year period.
6 Three year average of annual 4th highest daily maximum 8-hour ozone concentration.
State Implementation Plan (SIP)
EPA requires states to develop SIPs for all nonattainment areas. The SIP establishes the control strategies, emissions limitations and time tables to achieve and maintain compliance with NAAQS. In 1998, DEP amended the SIP for ozone, which describes the Federal and State measures that Massachusetts considers necessary in order to meet the 1-hour ozone standard (0.12 ppm). This plan commits Massachusetts to meet the 1-hour standard as quickly as possible, but no later than November 2007.
After years of planning analysis, legal proceedings and negotiations, EPA recently implemented a new nationwide 8-hour ozone standard (0.08 ppm averaged over 8 hours). The new 8-hour standard is intended to provide a greater level of public health protection by reducing emissions of ozone-causing pollution. Studies have indicated that longer-term exposure to lower levels of ozone can affect human health. In April 2005 (one year from issuance of the new 8-hour standard), the 1-hour standard was phased out. The 8-hour designations took effect on 15 June 2004, and the MA Department of Environmental Protection (DEP) will be required to revise the State Implementation Plan (SIP) by April 2007.
There have been no violations of this standard since the area had been designated as attainment/maintenanceb in 1999. Because the data demonstrate no violation of the standard, EPA has proposed that Massachusetts submit a request to be redesignated as an attainment/maintenance area.
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