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 article
Draft 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UPDATE 9/7/16: The values in the tables within this article have been updated per EPA’s corrections to the draft guidance. On August 1, 2016 U.S. EPA made available for public comment draft guidance and supporting documents recommending Significant Impact Levels […]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
Critical Timelines for the SO2 Data Requirements Rule
Posted: January 19th, 2016
We are now approaching the “home-stretch” of the SO2 Data Requirements Rule (DRR). State agencies were due to provide U.S. EPA with a list of the affected facilities where SO2 air quality will be characterized on January 15, 2016. The next critical…
Read article
It’s a Cluster#$%&…Top Challenges Facing Facilities Subject to SO2 Data Requirements Rule
Posted: September 10th, 2015
For a while now ALL4 has been writing about the Sulfur Dioxide (SO2) Data Requirements Rule (DRR), including our most recent update on the final SO2 DRR. For those who are new to the process…
Read article
Sulfur Dioxide (SO2) Data Requirements Rule (DRR): The Final Rule
Posted: August 19th, 2015
On August 10, 2015, the U.S. Environmental Protection Agency (U.S. EPA) submitted the final version of the DRR (40 CFR Part 51, Subpart BB) for the 2010 one (1)-hour sulfur dioxide (SO2) National Ambient Air Quality Standards (NAAQS). The final rule looks pretty familiar…
Read article