Air Quality Bureau

San Juan County Early Action Compact for Ozone (2003)

Open House/Public Forum for Ozone in San Juan County Presentations from November 6, 2002 public meeting (Adobe Acrobat Format)

Presentation by Ralph Gruebel - NM Environment Department
Presentation by Barbara Toth - NM Department of Health
Presentation by Roger Polisar - NM Environment Department

The Ozone Task Force is a group of stakeholders addressing ozone levels in San Juan County. Information on the Four Corners Ozone Task Force

Overview

The Air Quality Bureau operates two monitoring stations in San Juan County that measure ozone, a colorless gas that can cause respiratory distress and other health impacts at elevated levels. Since the installation of these monitors, we have measured concentrations that approach one of the federal health-based standards. These measurements were unexpectedly high for a rural area. Most areas with high ground-level ozone concentrations are densely-populated cities. If ozone concentrations in San Juan County exceed the federal ozone standards, the New Mexico Environment Department would have to implement a plan to reduce air pollution in order to protect public health. This plan would affect businesses and individuals in San Juan and possibly adjacent counties. This would have a significant economic impact for the area, so we are focusing resources to determine causes and solutions to this problem so that the ozone concentrations in San Juan County will not increase.

We have developed a team to study this issue, and we welcome participation from any interested party in the state. As our research progresses, we will update this page with data and analyses. If you have questions or you want to become involved with this issue, please contact Rita Bates, Planning and Policy Section Manager, (505) 476-4304.

What is Ozone and what are its health effects? (Links to EPA website)

Ozone is produced naturally in trace amounts in the atmosphere. Ozone is also formed when industrial emissions, automobile emissions and residential emissions of nitrogen oxides and volatile organic compounds mix together. Ozone in the upper layers of the atmosphere (the stratosphere) is essential to screen and absorb the sun's radiation; however, ozone in the lower atmosphere (the troposphere) can cause harmful health effects. Tropospheric ozone is increasing worldwide. In rural areas, ozone concentrations are generally lowest in the early morning hours and peak during the afternoon. Ozone concentrations vary seasonally; highest concentrations generally occur during the summer months. Ozone can be transported over long distances.

What is going on in San Juan County?

The New Mexico Environment Department monitors ambient ozone levels at various locations within New Mexico. These monitoring sites provide information about ozone levels throughout the state. In the Farmington area ozone is monitored at two sites, one west of Farmington near PNM San Juan Generating Station and one north of Bloomfield near the Bloomfield Gas Corridor. Ozone is an EPA-designated criteria pollutant and the new ozone National Ambient Air Quality Standard (NAAQS) is a three-year average of the fourth-highest 8-hour concentration that is not to exceed 0.084 ppm. The previous NAAQS for ozone was a 1-hour standard of 0.124 ppm, not to be exceeded more than once per year. The monitors near Farmington were initially sited to gain air quality data for dispersion modeling input to predict nitrogen dioxide concentrations from industrial sources in San Juan County. Elevated ozone concentrations are generally not recorded in rural areas. Usually areas with ozone concentrations that exceed the standards are highly urbanized, for example, Houston or Los Angeles.

One-hour maximum ozone concentrations in San Juan County were historically moderately high compared to other areas of the state, but never approaching or exceeding the NAAQS. EPA promulgated the new 8-hour ozone standard in 1997; however, due to court challenges it has not yet been implemented. EPA has recently concluded a court-mandated analysis of the standard and has issued notice that the standard should remain as proposed in 1997. Implementation guidelines from EPA will likely be received by the states in the very near future. The Environment Department is in the process of analyzing monitoring data to determine which areas of the state may have monitored ozone concentrations near or above the new 8-hour standard. For the year 2000, the fourth-highest 8-hour averaged concentrations near Farmington were 0.079 ppm at the monitor near PNM and 0.080 ppm at the monitor near the Bloomfield Gas Corridor. In light of the fact that these measured concentrations of ozone are higher than concentrations in other parts of the state (including Albuquerque) and near the NAAQS, the Environment Department has formed a team of staff members to research and analyze these elevated ozone concentrations in San Juan County.

What does this mean?

The 1963 Clean Air Act was the first modern environmental legislation passed by Congress. The act requires EPA to develop National Ambient Air Quality Standards (NAAQS) and empowers states to create regulations to ensure that all areas of the state meet these standards. The NAAQS are set for the most common and widespread air pollutants: nitrogen dioxide, sulfur dioxide, ozone, carbon monoxide, lead and suspended particulate matter. The standards are concentrations of air pollution above which the EPA has determined that serious health and welfare consequences could occur. If concentrations are below the NAAQS, there are no expected adverse effects to humans and the environment. The EPA must review the NAAQS periodically to determine if recent research supports the standard or indicates that the standard should be revised. In 1997, EPA determined that the 1-hour ozone standard should be removed and an 8-hour ozone standard should replace it. The state of New Mexico is required to adopt a plan to monitor air pollution and implement regulations to maintain or reduce air pollution to levels below the NAAQS.

If the three-year average of the fourth-highest 8-hour concentration of ozone exceeds the NAAQS in San Juan County, EPA could designate the area as "non-attainment" for ozone. EPA would require New Mexico to submit a plan to bring the area back into attainment with the standard. Typical plans include controls on sources of nitrogen oxides and volatile organic compounds, as these pollutants are precursors to the formation of ozone. Sources of nitrogen oxides and volatile organic compounds include mobile sources, such as cars; industrial combustion sources, such as engines and boilers and other facilities, such as painting and coating operations. The non-attainment designation would require a federal permitting program for new and modified large industrial sources in San Juan County that emit volatile organic compounds and nitrogen oxides This permitting program requires more stringent controls called "Lowest Achievable Emission Rate" (LAER), emissions offsets for increased emissions of nitrogen oxides and volatile organic compounds, certification of compliance and visibility analyses. Unlike the Best Available Control Technology requirements for larger sources with emissions in areas designated as attainment, LAER does not allow industrial facilities to take into account the economic cost of controls in determining the control level required for a new or modifying source of air pollution. Given the many oil and gas sources in San Juan County that emit these pollutants, a non-attainment designation would have a significant impact in the area. The Department will continue to monitor and research ambient ozone levels and trends near Farmington to plan for any changes in the attainment status of the area.

Where can I get more information?

We plan to publish additional information on this web page as the analysis progresses. For now we have a few files which are of interest. If you have questions, please contact Rita Bates, Planning and Policy Section Manager, (505)476-4304.