Western Pinal County Non-Attainment Area:  In July 2012 the United States Environmental Protection Agency (“EPA”) reclassified the western portion of Pinal County from “unclassified” to “non-attainment” for a particulate matter 10 microns or less in size (“PM-10”).  PM-10 are small particles that can be inhaled and become lodged in the lungs. Click here to view a map showing the new non-attainment area.   

NEW RULES:  As a result of the redesignation, Arizona and Pinal County must adopt additional regulations that will insure that the non-attainment area improves and eventually meets the National Ambient Air Quality Standards (“NAAQS”) for PM-10.  The Arizona Department of Environmental Quality (“ADEQ”) began rule making process last fall when it published a draft emissions inventory for sources in Western Pinal County that generate PM-10.  The draft inventory included paved and unpaved roads, agricultural areas and construction activity.  ADEQ received public input and is now in the process of revising the PM-10 emissions inventory.  ADEQ is also evaluating what control technologies should be incorporated into the new rules.  ADEQ should issue the new rules for Western Pinal County during the summer or fall of 2014.  When the draft is issued, ADEQ will allow a public comment period after which  ADEQ will evaluate comments, make whatever changes are appropriate and issue a final set of regulations.  Those regulations will then be submitted to the EPA for review and approval.  Once approved by EPA the regulations will become federally enforceable and part of the Arizona State Implementation Plan (“SIP). 

Current Pinal County Dust Requirements: Current Pinal County regulations generally prohibit dust generating activities without taking “reasonable precautions” to prevent fugitive dust from becoming airborne.  “Reasonable precautions” are defined as measures that will result in the least emissions by the application of  a control technology that is reasonably available considering technological and economic feasibility. 

Potential Additional Control Measures:  As part of the new PM-10 SIP rules, ADEQ will probably require additional controls relating to dust generating activities in Western Pinal County.  ADEQ has not indicated what will be required, however, it could adopt many of the dust control measures already required in Maricopa County.  Such additional requirements could include stabilizing open or vacant land, the use of specific technologies to minimize dust from dirt roads and construction sites, and best management practices for agricultural activities.  Thus, the new PM-10 SIP could increase the cost of compliance for dust related activities in Western Pinal County.  

Recommendation:  Those companies involved with dust generating activities in Western Pinal County should monitor the ADEQ SIP process and any new requirements proposed by ADEQ.  Those affected by new dust rules should submit comments on the draft PM-10 SIP when it is published by ADEQ during the summer or fall of 2014.