The Arkansas Department of Environmental Quality (“ADEQ”) announced it is seeking comments on a new Air Quality Screening Protocol (“Protocol”).

The agency states it is proposing to update general instructions for staff in conducting screening modeling on air permit applications.

The protocol is described as general instructions for ADEQ, Office of Air Quality, Permit Branch staff, conducting screening modeling on air permit applications. The document notes that:

Modeling done in review of permit applications is generally limited to screening models to determine if additional refined modeling by the facility is necessary. This document outlines the general procedure for such a screening analysis. This is not to be used for PSD permits or other complex modeling situations.

Air quality dispersion modeling is used to estimate the probable concentration of a given pollutant at a certain geographical point. The models may use emission data along with meteorological information to produce such predictions. Additional informational components utilized are the chemistry of air emissions and topographical features in the relevant area. Changes to model components (i.e., meteorological data, etc.) will affect the resulting estimated air pollutant concentrations. The models are sometimes adjusted (i.e., “calibrated”) as better information becomes available to improve their accuracy.

ADEQ states that the protocol includes updates based on the latest infrastructure, state implementation plans, and the Clean Air Act National Ambient Air Quality Standards state implementation plan which require demonstrations for:

  • Coarse particulate matter
  • Nitrogen Oxides
  • Sulfur dioxide emission increases 100 tons per year or greater

Besides an Introduction and Background, the format of the protocol includes:

    • Non-Criteria Pollutant Control Strategy

    • Criteria Pollutants

  • Screening Procedures

  • Meteorological Data

  • Refined Modeling

  • Documentation/Files

A copy of the draft protocol can be downloaded here.