Accepting comments from July 1, 2021, through August 2, 2021.
The Idaho Department of Environmental Quality (DEQ) seeks public comment on revisions to the State of Idaho Guideline for Performing Air Quality Impact Analyses (modeling guideline) that describes methods and procedures for performing air impact modeling analyses required for issuance of air quality permits.
The revision changes air pollution emission-based threshold levels that, when exceeded, trigger the requirement to perform air impact modeling analyses for facilities seeking a permit to construct (PTC) from DEQ.
Performing air impact modeling analyses is resource-intensive for both permit applicants and DEQ. Where facilities have low air pollutant emissions, site-specific impact modeling analyses may not be necessary to conclude that applicable standards will not be violated. DEQ developed a series of thresholds to trigger when impact modeling is needed to confidently evaluate compliance with standards. These thresholds and guidance on their use are provided in Section 3 of the modeling guideline.
DEQ reevaluated the thresholds presented in the modeling guideline and revised those thresholds. A summary of DEQ’s reevaluation is presented in a technical memorandum and the new thresholds are provided in a revised Section 3 of the modeling guideline. DEQ’s revised Section 3 of the modeling guideline and the supporting technical memorandum are available for review on DEQ’s website.
Written comments on the revised modeling applicability thresholds presented in the modeling guideline will be accepted through August 2, 2021, at 5 p.m. MST. After consideration of comments received, the thresholds may be amended or adjusted in the future, in which case, DEQ may provide for additional public comment depending on the significance of the changes.
Submit comments electronically on DEQ’s Public Comment Opportunities page or by mail or email:
1410 N Hilton Street
Boise, ID 83706
State of Idaho Guideline for Performing Air Quality Impact Analyses