Impact/Purpose:

The objective of this task is to provide data and tools to support implementation of PM NAAQS. Specifically, this task will provide:

(1) Monitoring methods to determine compliance with NAAQS.

(2) Atmospheric chemistry models to enhance air quality models used for development, evaluation, and adjustment of State Implementation Plans (SIP).

(3) Receptor modeling tools and applications to identify sources contributing to air pollution in non-attainment areas to support development, evaluation, and adjustment of SIPs.

Description:

The Clean Air Act requires EPA to set National Ambient Air Quality Standards (NAAQS) for six criteria pollutants (lead, carbon monoxide, sulfur dioxide, nitrous oxides, ozone, and particulate matter). After setting NAAQS, there are several activities required to implement the standard including conducting ambient monitoring to identify areas of the country that exceed NAAQS levels, i.e., non-attainment areas, and developing and evaluating State Implementation Plans (SIP) that identify needed actions to improve air quality in non-attainment areas. Research is often needed to reduce the uncertainty and improve the effectiveness of these implementation activities. The Human Exposure and Atmospheric Sciences Division (HEASD) with the National Exposure Research Laboratory (NERL) conducts research to support implementation of NAAQS in the areas of atmospheric measurement methods, atmospheric chemistry, and receptor modeling for source apportionment. The most significant uncertainties currently exist in the implementation of NAAQS for particulate matter (PM).

Current PM NAAQS implementation activities center on the NAAQS promulgated in 1997 and the upcoming 2006 NAAQS promulgation. The 1997 NAAQS for PM introduced new standards for PM less than 2.5 micrometers in diameter (PM2.5 or fine PM). Non-attainment areas for PM2.5 NAAQS have been identified and State Implementation Plans (SIPs) are to be submitted by 2008. In September of 2006, EPA will most likely promulgate NAAQS for PM between 10 and 2.5 micrometers in diameter (PM10-2.5 or coarse PM). The HEASD contributes to the implementation of these NAAQS by (1) developing and evaluating the ambient monitoring methods used to measure compliance, (2) characterizing key atmospheric chemical processes that are incorporated into source-oriented models, and (3) developing and applying receptor-oriented models to identify sources contributing to air pollution.

For the 1997 NAAQS, HEASD is developing and applying atmospheric chemistry models and receptor modeling tools that will be used to understand the relationships between sources and ambient air concentrations to develop, evaluate, and adjust effective control strategies. More specifically, HEASD is developing a secondary organic aerosol chemistry model for the CMAQ model, conducting a peer review of and releasing EPA receptor modeling tools, and applying EPA receptor modeling tools to support the development of a SIP for St. Louis.

For the upcoming 2006 PM NAAQS, HEASD is working to evaluate and develop measurement methodologies that will be used to measure compliance. For coarse PM, HEASD is developing the Federal Reference Method (FRM) which is the standard method used to measure compliance. In addition, for both coarse and fine PM, HEASD is developing revised testing requirements and acceptance criteria for Federal Equivalent Methods (FEM) that may also be used for measuring compliance. The FRM and the revised acceptance criteria for FEMs will be included in the monitoring provisions associated with the promulgated 2006 PM NAAQS. Together, HEASD's research in support of the 1997 PM NAAQS and the upcoming 2006 PM NAAQS will improve the implementation of these NAAQS and, ultimately, lead to improved public health.

Record Details:

Record Type:PROJECT

Start Date:10/01/2005

Projected Completion Date:09/01/2008

OMB Category:Other

Record ID: 151763

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Project Information:

Progress :Monitoring Methods

Comprehensive field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 in ambient air. These field studies included five separate PM10-2.5 monitoring approaches, including continuous as well as integrated samplers. These approaches were evaluated during six comprehensive field campaigns conducted at four separate sampling sites (Gary, IN, Phoenix, AZ, Riverside, CA, and Birmingham, AL). Results from the field campaigns showed that the inter-manufacturer precision among the integrated samplers was typically excellent. The results of the field campaigns and the subsequent data analysis were summarized in a written report and submitted to the CASAC Ambient Air Monitoring Methods (AAMM) Subcommittee for review. In written comments submitted to the Agency, the Subcommittee expressed a consensus that the study design was well conceived and that the difference method provided the most fundamental basis of comparison upon which to evaluate candidate PM10-2.5 samplers. The Subcommittee also recognized that noted performance issues with the candidate samplers needed to be addressed and that subsequent field evaluations of second generation instruments would be required. ORD has been working with the manufacturers in an effort to identify and address noted deficiencies in their respective sampler performance.

In cooperation with OAQPS, ORD has also been developing draft specifications for Class III PM2.5 samplers, which are designed to provide unattended, continuous operation and provide test results with time resolutions of 1 hour or less. Draft testing requirements and acceptance criteria have been developed for Class III instruments. The draft provisions have been submitted to the State, Local, and Tribal monitoring organizations for review and comment. Associated draft 40 CFR Part 53 documents have also been prepared as an integral part of the 2006 PM rulemaking.

Atmospheric Chemistry Models

HEASD has carried out laboratory studies and short term field studies to identify the key chemical reactions controlling the organic and nitrate concentrations in PM2.5 and conducted laboratory studies to evaluate the proposed SOA chemistry model.

Receptor Modeling

HEASD has release EPA PMF 1.1 on a public website and has conducted hands-on receptor modeling training sessions in Chicago, IL and San Francisco, CA. In addition, HEASD has provided technical support to numerous users of receptor models. Finally, HEASD submitted a proposal under the Advanced Monitoring Initiative (AMI) for a receptor modeling application to support development of the SIP for St. Louis.

Relevance :This task will directly support implementation of 1997 and upcoming 2006 PM NAAQS. This task produces the fundamental measurement methods needed to identify those areas of country with ambient PM concentrations that exceed the NAAQS (i.e., non-attainment areas) and to measure future compliance and progress toward improvements in air quality in these areas. In addition, the revised testing requirements and acceptance criteria for candidate PM FEM will allow the broader introduction of semi-continuous sampling methods into the Nation's ambient air monitoring networks. This type data will support monitoring objectives in addition to compliance including providing more highly resolved data for future health, exposure, and source apportionment studies. The atmospheric chemistry and receptor modeling research results and products developed under this task will enhance activities to bring non-attainment areas into compliance with the PM NAAQS by providing methods, measurements, and models to identify sources of PM that contribute to an area's non-attainment status and to develop, evaluate, and adjust control strategies (i.e., SIPs) to improve air quality in those non-attainment areas. Ultimately, by enhancing the implementation activities for the PM NAAQS, this task will lead to risk mitigation activities that will improve air quality, reduce the number of non-attainment areas in the country, thereby reducing exposures to PM and improving public health.

Clients :AMD, OAQPS, Regions, State, Locals, Tribes

Project IDs:

ID Code :21179

Project type :OMIS