We feel it is appropriate to hold such hearings in Oklahoma, as our State is no stranger to such exceptional events. It seems we truly get more than our fair share. In just the past few years, Oklahomans have experienced drought, floods, fires, a major tornado and a tragic bombing. A prime example of an exceptional event in Oklahoma and its relationship to air pollution is a vivid and integral part of our State's history. The extreme meteorological conditions associated with the Dust Bowl Days of the late 1920s and early 1930s were responsible for the loss of millions of tons of topsoil and the resultant air pollution, which devastated the environment and economy in our area of the country. We can only imagine what the particulate loadings to the atmosphere were back then, but I would surmise that present day National Ambient Air Quality Standards were greatly exceeded.
And exceptional events continue to affect us today. Dust storms and wildfires, which can greatly contribute to air pollution, still occur with some regularity; likewise, periods of drought, dominant high-pressure ridges, and abnormal wind patterns can greatly exacerbate various air pollution levels.
Let's examine a recent exceptional event that had environmental impacts on Oklahoma. During the spring of 1998 there were numerous significant forest fires in Mexico and Central America's Yucatan Peninsula. These fires made national news and produced an air pollution episode that was a truly extraordinary event and beyond the control of state and local air pollution control agencies. It was definitely documented that besides causing high particulate levels and haze, these fires were also responsible for high levels of ozone. Air pollution from these fires affected many areas of the United States, but the haze and particulates were so severe that during the episode, areas of Texas and Louisiana were issued health advisories. Those fires began in early spring, and were not extinguished until in the summer.
On May 11, 1998 abnormally elevated ozone values were observed in the Oklahoma City area. These values were higher than expected because they occurred on a day with relatively high wind speeds and mild temperatures, conditions not normally conducive to ozone formation. In fact on May 11 the Edmond, Moore, Oklahoma City, and Goldsby sites experienced 8-hour maximum ozone values that became the 4th highest ozone values for the entire year. It is these fourth highest values that are the critical ones used in the calculations to determine an area's attainment status. And all this was occurring about the time of the height of the fires' impact on Texas and the Gulf Coast. Later after reviewing ambient data, investigating meteorological conditions, observing pollution levels throughout our part of the country, and making use of extensive satellite photography, it became apparent to our Air Quality Division that the Mexican fires were the most probable cause for the elevated ozone values in the Oklahoma City area on May 11. During 1998 and 1999 the DEQ worked diligently with the Environmental Protection Agency to try to exclude data from the extraordinary event when determining our attainment status. Using available satellite photography, we felt we had some very convincing evidence that the plume from the Mexican fires impacted central Oklahoma on May 11 and met EPA's exclusion criteria. Nevertheless, we were unable to convince EPA of our position.
(VISUAL DEMONSTRATION ON PROXIMAL SHOWING PLUME IMPACTING OKLAHOMA CITY AREA)
Even more recent exceptional events have influenced air pollution concentrations observed in Oklahoma. This year, one of our monitoring stations in Tulsa experienced ozone concentrations that caused a violation of the 1-hour ozone standard. This was the first violation of the one-hour ozone standard experienced in Oklahoma in many years. In fact, it is the only violation of the standard that has occurred since additional SIP control measures were required in 1988 and our nationally copied ozone alert programs were implemented in the early 1990s. Nevertheless, four exceedances occurred at the site over the last three years: three of the exceedances surprisingly occurring during the Labor Day weekends of 1998 and 2000. Coincidentally, during both these weekend periods, the Tulsa area found itself under extremely abnormal meteorological conditions, which we feel qualify as exceptional events.
On September 4, 1998 the day of one of the ozone exceedances in question, the high temperature in Tulsa was 107 degrees F. an all-time record for the day and 14 degrees above the normal daily high. In fact, this day was the hottest day of the hottest summer since record keeping began in 1895! The only comparable period was the "Dust Bowl Era" which peaked in 1931! The reason for this extraordinary heatwave was primarily an abnormally long lasting high-pressure ridge that dominated the region. Such high-pressure ridges are accompanied by light surface winds and "sinking" air which traps pollutants. According to the National Oceanic and Atmospheric Administration (NOAA), northeastern Oklahoma can expect two or fewer stagnation cases per year and less than ten total days of air stagnation. In 1998 we set an all time record for Oklahoma air stagnation with 33 days!
The two Tulsa exceedances on Labor Day weekend of this year occurred on September 1 and 2. The high temperature in Tulsa on September 1 was 108 degrees F. which was another all-time record for the day and 14 degrees above the normal high. The high temperature of September 2, 107 degrees F, was the highest on that date since 1939. These hot days followed the driest month since 1896. Stagnation days were again much more prevalent than normal during this period. The particular air stagnation event, which immediately preceded the Labor Day weekend 2000 high ozone values, was in its 12th and 13th consecutive days when the high value occurred.
Clearly, the truly exceptional weather conditions that occurred in the Tulsa area during the Labor Day weekends of 1998 and 2000 significantly contributed to our ozone violation. As you are aware, ozone is formed by unique photochemical reactions between volatile organic compounds, oxides of nitrogen, and sunlight. High temperature and stagnant conditions accelerate the process. Since we feel that these abnormal conditions are completely beyond our scope of control, we will be requesting that the EPA exclude data collected on the days in question when determining the areas attainment/nonattainment status for the 1-hour standard.
As you can see, exceptional events have uniquely impacted environmental planning in Oklahoma. The Clean Air Act requires the States to monitor their air sheds for specific criteria pollutants. The concentrations observed are then compared to health standards. If the standards are exceeded, then control plans must be developed and implemented. The problem arises when data collected are skewed by exceptional events whose occurrence is almost always infrequent or outside the control of the regulatory agency. Declaring an area a nonattainment area using data collected during an exceptional event just doesn't make good sense. EPA must make its guidelines on how to exclude such data as clear and concise as possible, and yet be flexible enough to accept valid scientific arguments. Specifically, we feel that EPA guidance on exceptional events particularly relating to ozone needs revision, especially allowing abnormal stagnation events and inversions to be considered the exceptional events they in truth are. We feel that draft guidance published by the Agency in 1994, though never finalized, goes a long way in meeting this objective. We believe this draft guidance is much more appropriate than the Agency's official 1986 version because it provides a mechanism for "flagging" extreme weather events.
We further contend that it is the affected State, not EPA, that is in the best position to determine whether an event is considered exceptional or not. It is also our suggestion that the Clean Air Act be amended to specifically exclude air quality monitoring data shown to be influenced by truly exceptional events when determining compliance with the National Ambient Air Quality Standards.
Thank you, Mr. Chairman.