Arkansas Ambient Air Monitoring Network: Annual Network Plan for 2025-2026

The Arkansas Department of Energy and Environment – Division of Environmental Quality (“DEQ”) submitted on August 6th to the United States Environmental Protection Agency (“EPA”) a document titled:

ARKANSAS AMBIENT AIR MONITORING NETWORK – Annual Network Plan for 2025-2026 (“Plan”).

The Plan was prepared by DEQ’s Office of Air Quality.

The Plan has previously been described as:

…the framework for the establishment and maintenance of statewide air quality surveillance (“AQS”) system.

The sampling of ambient air conditions is an important part of the process for determining whether an area is or will remain in compliance with the Clean Air Act National Ambient Air Quality Standards (“NAAQS”). EPA uses Clean Air Act authority to require state and local monitoring agencies to establish a network of air monitoring stations. They use siting and operational criteria established by the federal agency to determine compliance with NAAQS. Further, EPA requires state and local agencies to conduct an assessment of their monitoring networks periodically.

Note that the states are primarily responsible for ensuring attainment and maintenance of each NAAQS in its air quality control regions once EPA has established or revised them. Each state is then required to formulate, subject to EPA approval, an implementation plan (i.e., “SIP”) designed to achieve each NAAQS. The ability to demonstrate that the state has the capacity to adequately sample and monitor for each NAAQS is required to be demonstrated by the state.

Three primary objectives of such monitoring networks arguably include:

• Ensuring the public has access to clean air by comparing data and implementation of the NAAQS and other health indicators for toxics.
• To provide the public with timely reports and forecasts of the Air Quality Index.
• To provide information to health and atmospheric scientists to better inform future reviews and revisions to the NAAQS.

Arkansas and the other states’ monitoring network plans describe which pollutants and other parameters are used at the various ambient air monitoring sites and why they are measured at those specific locations. Also typically described are changes in the network which may include new locations along with new and discontinued measurements at existing locations. Proposed changes to the network in the near future are also addressed.

Besides the appendices, tables, and figures, the Plan components include:

• Figure 1. Map of Arkansas Ambient Air Monitoring Network
• Figure 2. Metropolitan and Micropolitan Statistical Areas of Arkansas (as of July 2023)
• Figure 3. Relative Location of Facilities Emitting Greater than or Equal to 2000 tpy SO2
• Figure 4. 2008–2023 Lead Emissions from Entergy Independence
• Figure 5. 2008–2023 Lead Emissions from Entergy White Bluff
• Table 1. DEQ Operated State and Local Air Monitoring System (SLAMS) Monitor Locations
• Table 2. DEQ Operated State and Local Air Monitoring System (SLAMS) Methods and Operation
• Table 3. U.S. Census Bureau Population Statistics for Metropolitan Statistical Areas (MSA) in Arkansas
• Table 4. Arkansas Ozone State and Local Air Monitoring System (SLAMS) Monitors Schedule and 2021–2023 Ozone Design Values (DV)
• Table 5. Arkansas Metropolitan Statistical Area (MSA) Populations and Minimum Ozone Monitors Required in State and Local Air Monitoring System (SLAMS) Network
• Table 6. Arkansas PM2.5 State and Local Air Monitoring System (SLAMS) Monitors Schedule and 2020–2023 PM2.5 Design Values (DV
• Table 7. Arkansas Metropolitan Statistical Area (MSA) Populations and Minimum PM2.5 Monitors Required in State and Local Air Monitoring System (SLAMS) Network
• Table 8. Continuous PM2.5 Air Quality Index (AQI) Monitoring Site Information
• Table 9. Arkansas PM10 State and Local Air Monitoring System (SLAMS) Monitors Schedule and 2021–2023 PM10 Annual Maximum and Three-Year Average
• Table 10. Arkansas Metropolitan Statistical Area (MSA) Populations and Minimum PM10 Monitors Required in State and Local Air Monitoring System (SLAMS) Network
• Table 11. Arkansas Core-based Statistical Areas (CBSAs) Populations and Minimum SO2 Monitors Required in State and Local Air Monitoring System (SLAMS) Network
• Table 12. Facilities Emitting Greater Than or Equal to 2000 tpy SO2
• Table 13. Current Source-Oriented Lead Waiver Status by Facility

A copy of the DEQ correspondence and attached Plan can be downloaded here.