Appendix W Revision: The New Era of Air Quality Modeling – SO2 Modeling Updates
Posted: March 1st, 2017
If you’ve visited ALL4’s website within the past few weeks (c’mon, don’t you visit daily?), you’ve likely seen a wealth of information regarding the U.S. Environmental Protection Agency (U.S. EPA) revisions to 40 CFR Part 51, Appendix W…
Read articleAppendix W Revision: The New Era of Air Quality Modeling – (Re)Introducing MMIF, an Alternative Option for Met Data
Posted: February 9th, 2017
As a self-described computational meteorologist, I get pretty obsessed with weather models, especially models of severe storms like hurricanes or big winter storms. If the coverage on the local news or weather networks is any indication, I don’t think I’m alone in this. My…
Read articleAppendix W Revision: The New Era of Air Quality Modeling – Introduction
Posted: January 26th, 2017
(UPDATE 1/26/17) The long awaited revisions to the 40 CFR Part 51, Appendix W (also known as the Guideline on Air Quality Models referred to as Guideline hereafter) were finally published in Federal Register (FR) on January 17, 2017. The final Guideline, which was signed by U.S. EPA…
Read article
2017 Air Quality Look Ahead
Posted: January 17th, 2017
Changes in the Wind | John Egan For over 40 years I’ve been involved in the business of environmental regulation, and more specifically air pollution control. From my early days as a field enforcement officer in Pennsylvania’s hard coal region […]
Read article
Appendix W Revision: The New Era of Air Quality Modeling – NO2 Modeling Updates
Posted: January 17th, 2017
(UPDATE 1/26/17) Air dispersion modeling of nitrogen oxides (NOX) emissions and I have a love-hate relationship. As a meteorologist, I love the process of implementing air quality modeling studies, but I hate giving bad news to clients about elevated concentrations…
Read article
Appendix W Revision: The New Era of Air Quality Modeling – AERMOD Modeling System Updates
Posted: January 17th, 2017
(UPDATE 1/26/17) I have to say, I personally was prettyyyy excited for 2017 to finally get here [and according to the internet (which is obviously never wrong), I wasn’t the only one]. Likewise, the air quality modeling team here at ALL4 has been anxiously awaiting the…
Read articleDraft MERP Guidance Has Arrived
Posted: December 12th, 2016
MERP…no I’m not referring to the word used to indicate an awkward conversation or making a sound you may hear from the likes of Kermit the Frog. I’m referring to Modeled Emission Rates for Precursors – MERPs. On December 2, 2016…
Read articleU.S. EPA Proposed 2015 Ozone NAAQS Implementation Rule
Posted: December 5th, 2016
On November 2, 2016, the United States Environmental Protection Agency (U.S. EPA) proposed an implementation of the 2015 National Ambient Air Quality Standard (NAAQS) for ozone (2015 ozone NAAQS) with requirements that would apply to states with…
Read article
A New Take on Air Dispersion Modeling: Re-Entrainment Evaluations
Posted: December 1st, 2016
Facilities are typically introduced to the world of air dispersion modeling when they are required to demonstrate that a proposed project will not exceed regulatory thresholds, such as maximum allowable air toxics screening levels or the National Ambient Air Quality Standards…
Read article
U.S. EPA Proposes Guidance on Fine Particulate and Ozone Significant Impact Levels
Posted: August 7th, 2016
UPDATE 9/7/16: The values in the tables within this article have been updated per EPA’s corrections to the draft guidance. On August 1, 2016 U.S. EPA made available for public comment draft guidance and supporting documents recommending Significant Impact Levels […]
Read article