Category: AERMOD

  • Be Explicit, But Don’t Double Count

    Be Explicit, But Don’t Double Count

    To demonstrate compliance with the NAAQS, you need to account for ALL emission sources. The impact of those sources that is not already included in the monitored background concentrations need to be explicitly included in your dispersion modeling analysis. How do you determine which sources are included in the monitored values and which ones are […]

  • Give Yourself Flexibility

    Give Yourself Flexibility

    Golfers typically use a variety of clubs: a putter, a driver or two, and a pitching wedge. You could get by with just one club, but why limit yourself. When representing, say, a boiler in your dispersion modeling analysis, why represent the boiler in just one way if it can burn a variety of fuels. […]

  • Modeling The Unplanned

    Modeling The Unplanned

    Unplanned events happen. Things break. Equipment fails. If the unexpected incident triggers 30 TAC 101.201 of the “emission event rules” then you may be required to perform dispersion modeling. On July 14th, 2021 at noon CDT, join us for a FREE LIVE webinar as we explain the nuances and details to be aware of to […]

  • If At First You Don’t Succeed, Refine

    If At First You Don’t Succeed, Refine

    To simplify, and expedite an air quality analysis (AQA), a rough first pass is typical when performing dispersion modeling. If the first pass doesn’t show compliance, additional refinements are in order. When trying to demonstrate compliance with the NO2 1-hour NAAQS, there are quite a few refinement options available. On July 7th, 2021 at noon […]

  • NOx Shouldn’t Mean No

    NOx Shouldn’t Mean No

    When the 1-hour nitrogen dioxide (NO2) NAAQS became effective in 2010, demonstrating compliance with the NO2 NAAQS, became a whole lot more difficult. Passing the annual standard was almost no problem at all, but the 1-hour standard was a bit problematic. On June 30th, 2021 at noon CDT, join us for  a FREE LIVE webinar […]

  • Dispersion Modeling Simplified – Bits and Pieces

    Dispersion Modeling Simplified – Bits and Pieces

    When we say something is complicated, what does that really mean? In grad school, I had a final that had just two problems. The first problem was, from basic principles, derive the full (no simplifications) Navier-Stokes equations. The second problem was to derive the full vorticity equations and identify what each term means. In high […]

  • EPA Proposed updates to AERSURFACE

    EPA Proposed updates to AERSURFACE

    I typically start my articles with a personal story that somehow relates to the topic at hand. The story is meant to draw you in so that an otherwise really dry subject seems a little bit interesting and relatable. For this article, I have decided not to do that because the issues involved are too […]

  • New NK Tools Online

    New NK Tools Online

    Most of you have heard of Ring, the wifi-enabled digital video camera and doorbell home security system. When the company was starting out and showing signs of growth, the founder and CEO made a pitch to potential investors on the TV show Shark Tank. The purpose of the pitch was to take the 6-figure company […]

  • A Modern Approach to Dispersion Modeling

    A Modern Approach to Dispersion Modeling

    Knowledge and Skills Obsolescence in the Air Quality Sector As technology advances, the collection of human knowledge expands and the skills necessary for living in a functioning society eventually get replaced with new ones that did not exist before. Thousands of years ago, the time for the sum total of human knowledge to be replaced […]

  • Dispersion Modeling Audits: Using NK Tools

    Dispersion Modeling Audits: Using NK Tools

    Neil Armstrong and Buzz Aldrin landing and walking on the moon was quite an achievement. Though the ultimate goal was to put humans on the moon, the steps to get to that end point didn’t exactly resemble the final product. The beginning stages of the preparation for the moonshot were very crude, clumsy, and addressed […]