EPA Ambient Air Monitor Values Reports

Find summary reports for ambient air monitoring stations here:

Monitor Values Report AirData US EPA

NAAQS Statutory Requirements

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From 42 U.S.C. §7409 (Chapter 85, Subchapter I, Part A; CAA §109)


(b) Protection of public health and welfare 
 

(1) National primary ambient air quality standards, prescribed under subsection (a) of this section shall be ambient air quality standards the attainment and maintenance of which in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health. Such primary standards may be revised in the same manner as promulgated. 

 

(2) Any national secondary ambient air quality standard prescribed under subsection (a) of this section shall specify a level of air quality the attainment and maintenance of which in the judgment of the Administrator, based on such criteria, is requisite to protect the public welfare from any known or anticipated adverse effects associated with the presence of such air pollutant in the ambient air. Such secondary standards may be revised in the same manner as promulgated. 

40 CFR 50.2 says:

(b) National primary ambient air quality standards define levels of air quality which the Administrator judges are necessary, with an adequate margin of safety, to protect the public health. National secondary ambient air quality standards define levels of air quality which the Administrator judges necessary to protect the public welfare from any known or anticipated adverse effects of a pollutant. Such standards are subject to revision, and additional primary and secondary standards may be promulgated as the Administrator deems necessary to protect the public health and welfare. 


I expected to see language about protecting sensitive populations but didn't. The only place that language is used (that I found during this quick investigation) is at 42 U.S.C. §7408(f)(1)(C) under the heading "Information regarding processes, procedures, and methods to reduce or control pollutants in transportation; reduction of mobile source related pollutants; reduction of impact on public health."It requires "information on other measures which may be employed to reduce the impact on public health or protect the health of sensitive or susceptible individuals or groups."
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PM2.5 Implementation History and BACT Analysis

This is something I submitted to Indiana Department of Environmental Quality for the Synergy Management lime plant permit application in September 2010. The implementation history may be of general interest (though as of a couple of weeks ago, a third implementation rule was finalized). Its usefulness is limited now and rapidly diminishing, but interesting nonetheless. Don't know yet if the agency bought everything, but they at least seem to be seriously considering it.

PM2.5 Implementation Discussion

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Final 1-hr SO2 Standard and Fact Sheet

1-hr SO2 Fact Sheet

SO2 1-hr Stnd, Final 6/22/10

New NO2 Air Standards Prove Technically Challenging

This article from Trinity Consultants refers to June 28, 2010 modeling guidance from EPA (link below) that doesn't actually provide much guidance, but it does suggest an interim SIL. It also reports a SIL that NESCAUM states are using. The article discusses methods for estimating NO/NO2 ratios.

Trinity Consultants - New NO2 Air Standards Prove Technically Challenging

EPA NO2 Modeling Guidance 6/2010

NO / NO2 Ratios

Here's some background information on estimating ratios of NO and NO2:

2000 Proposed Appendix W OLM Discussion

NO2 Estimating Review

1996 EPA OLM Memo

Diesel Engine NO2 MDEQ E-mail

PM2.5 PSD Implementation

Address SILs, condensibles, precursors, significant increase thresholds, increment (none yet), etc.

Proposed Rule, September 2007

Final Rule, May 2008

EPA's Science Advisory Committee comments on potential PM standards revisions

The Clean Air Scientific Advisory Committee's Particulate Matter Review Panel supports:
-- setting secondary PM standards in terms of light extinction values rather than mass concentration values, and
-- lowering current primary PM2.5 standards

BNA article

NAAQS - Status of EPA Proposals -May, 2010

This is a summary of the status of EPA various proposals (or completed) changes to the ambient air quality standards. It's a good 'one page' summary of the numbers, proposal dates, adoption dates, etc.

NAAQS Status Table - May 2010

NAAQS/MAAQS/Increment Tables

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Up-to-date NAAQS on EPA's web site:

National Ambient Air Quality Standards (NAAQS) Air and Radiation US EPA

Here's a table of NAAQS, MAAQS, increments, SILs, SMCs, significant emission rates, etc. Last updated 5/20/2011.

Projected attainment maps for new and proposed NAAQS - 2/2010

Attached to a 3/12/2010 e-mail meeting announcement from the Montana Petroleum Association:

http://companyweb/General%20Documents/Docs%20for%20posting/NAAQS%20Update%202-23-10.ppt

PM10 & 2.5 Conformity Update, March 24, 2010

Update on implementing PM10 and PM2.5 NAAQS revisions for conformity demonstrations. Includes update on hotspot analyses requirements.

PM10-PM2.5 Conformity Rule Update, March 2010

Updated modeling guidance

Procedures for calculating the NO2 design value for comparison to the 1-hour NAAQS. Hopefully the BEEST post processor, and maybe others, will avoid the need to do this by hand.
EPA 1-hr NO2 Modeling Guidance


Excerpt from Comments of the Air and Waste Management Association's AB-3 Meteorology Committee Regarding New Dispersion Modeling Issues: PM2.5 and 1-hour for NO2 and SO2; March 12, 2010

"We now find ourselves in a unique regulatory period in which several new modeling procedures need to be established for both a newly regulated pollutant(PM2.5) and for 1-hour probabilistic standards for NO2 in spring 2010 and for SO2 in summer 2010. Associated with these pollutants and standards are important modeling issues that are not currently addressed in the Guideline. Regulatory dispersion modeling analyses have historically employed, in practice, several assumptions used to assure a conservative estimate of the modeled design concentration. Many of these assumptions are used only to simplify the analyses in the absence of more robust, scientifically sound information about the emissions sources and atmospheric conditions that affect the ambient pollutant concentrations. With the advent of several more stringent air quality standards, it is no longer practical to use redundant, overly conservative assumptions for simplicity or convenience. We encourage the development and implementation of robust methods for conducting regulatory air quality modeling analyses."

The document is here:
AWMA PM2.5 modeling comments


Here's a memo from EPA on modeling PM2.5. Basically, it "recommends" that, when modeling five years of NWS data for compliance with the 24-hr PM2.5 NAAQS, you should add the average of the first-highest 24-hr values for all five years to the 98% percentile of background measurements for three years.

2/26 & 2/24 EPA reviews and comments re. PM2.5 modeling

This supplemental EPA PM10/PM2.5 modeling memo addresses PM10 surrogacy demonstration and provides more extensive modeling guidance for PM2.5. The way I interpret it, it suggests using the highest 3-yr average across 5 years of NWS results for the annual average. For the 24-hr average, use the highest 3-yr avg. of H1H 24-hr results across 5 years of NWS model results.

March 23rd PM2.5 modeling guidance

Proposed O3 NAAQS

EPA regulatory actions summary web page
Regulatory Actions Ground-level Ozone US EPA

1/19/10 proposal in FR
http://www.epa.gov/air/ozonepollution/fr/20100119.pdf

1/19/10 proposal fact sheet
http://www.epa.gov/air/ozonepollution/pdfs/fs20100106std.pdf