Air Quality History

AIR QUALITY IN THE ST. LOUIS AREA

In the eight county St. Louis area (Missouri-Illinois) overall air quality is better today than what it was at the beginning of the 20th century. However, work still needs to be done to reduce man-made ozone. Over the past ten years, air quality in the St. Louis area has steadily improved due in large part to the implementation of the following control programs: the installation of gasoline vapor recovery systems at service stations in Missouri; additional controls on industry; centralized inspection of car emissions; the use of cleaner fuels throughout the region; and a range of transportation control measures (i .e., traffic flow improvement projects, intelligent transportation system and regional ridesharing program).

In 2002, the St. Louis metropolitan area reached a significant air quality milestone. Based on 2000 -2002 air quality monitoring data, the region attained the one-hour ozone standard, as established by the U.S. Environmental Protection Agency (USEPA). On May 12, 2003, USEPA approved the request by Missouri and Illinois and the area was redesignated as in attainment of the one-hour ozone standard. This is a meaningful accomplishment that the Missouri Department of Natural Resources (MoDNR), the Illinois Environmental Protection Agency (IEPA) and local governments in the area have made. However, this is only one step on the road to cleaner air in the St. Louis area.

On April 15, 2004, the USEPA Administrator designated those areas in the U.S. which are not in attainment of the eight-hour ozone standard. These designations go into effect June 15, 2004. The St. Louis area has been designated as a moderate non-attainment area for the eight-hour ozone standard. The non-attainment area includes: in Missouri, Franklin, Jefferson, St. Charles and St. Louis Counties and the City of St. Louis; and in Illinois, Jersey, Madison, Monroe and St. Clair Counties. Under the one-hour ozone standard, Jersey County was a stand alone maintenance area.  The eight-hour ozone standard is being implemented nationally because it is a more protective, health-based standard. 

On December 17, 2004, the USEPA Administrator notified the Governors of 20 states that their states contained areas which do not meet the fine particle (less than 2.5 microns in diameter) standard.  The St. Louis fine particle matter (PM) 2.5 non-attainment area consists of: Franklin, Jefferson, St. Charles and St. Louis Counties and the City of St. Louis in Missouri; and Madison, Monroe and St. Clair Counties and Baldwin Township in Randolph County, Illinois. New control strategies resulting in additional emissions reductions will likely be necessary to achieve the new national air quality standards.
 

GATEWAY'S ROLE IN AIR POLLUTION CONTROL

Since the 1977 amendments to the Clean Air Act, the East-West Gateway Coordinating Council has been the lead air quality and transportation planning agency for the St. Louis metropolitan region.  Gateway's air quality planning efforts have focused on:

Working with the States of Missouri and Illinois on the development and implementation of Transportation Control Measures (TCMs). TCMs are physical improvements and management strategies designed to increase the use of mass transit, expand ridesharing and improve regional traffic flow which reduce hydrocarbons and carbon monoxide emissions from motor vehicles;Insuring that transportation programs and projects do not have a negative impact on air quality; and Serving as a regional clearinghouse of daily measured ozone data during the April-October ozone season and helping to maintain quality control over monitored data

OZONE FORMATION

Ozone exists in both the upper and lower atmosphere. The ozone layer of the upper atmosphere (10 -30 miles up) occurs naturally and shields the earth from harmful ultraviolet radiation. However, the ozone layer of the lower atmosphere (ground-level ozone) is manmade and creates a variety of health problems. This ozone is formed when hydrocarbons, also known as volatile organic compounds (VOC), and oxides of nitrogen (NOx) from car exhaust and certain emissions from industrial processes chemically react ,or "cook", with oxygen in the lower atmosphere in the presence of strong sunlight and high temperatures. Weather plays an important role in ozone formation. Days when ozone may form are indicated by high pressure weather systems with high temperatures (above 85o F) and low wind speeds. Temperature inversions during the warm summer months can trap pollutants close to the ground, stopping them from dispersing during the night. These weather systems are common in the St. Louis area during the months of May through early September. Changing weather patterns (especially the number of hot, sunny days) and periods of air stagnation contribute to yearly differences in ozone concentrations. 

NOx is primarily produced by the combustion of fossil fuels by motor vehicles and power plants and other industrial utility operations.

OZONE HEALTH EFFECTS

In large doses, ozone can cause headaches, fatigue, shortness of breath, coughing, wheezing and eye, nose and respiratory tract irritation. It impairs lung function and limits the ability to exercise, especially in the very young and the very old. Prolonged exposure to ozone can aggravate chronic heart disease, chronic respiratory ailments, decrease resistance to infection and trigger asthma attacks.

PEOPLE SENSITIVE TO OZONE Children at Play Outdoors  Adults Who Work Outdoors during the Summer Months People with Respiratory Disease Healthy People Who Exercise Outdoors The Elderly

When the air quality is poor, people should exercise indoors. If they must exercise outdoors, the early morning and evening hours are best. Those suffering from asthma or other respiratory ailments should stay indoors.  At the end of this section is a list of things individuals can do to improve air quality.

PM FORMATION

Particle matter (PM) is a mix of solid particles and liquid droplets suspended in the air. Fine PM is considered to be less than or equal to 2.5 microns in diameter (about 1/30 the width of a human hair ). Fine PM is made up of a variety of components including acids, organic chemicals, metals, dirt, or dust particles. Many manmade and natural sources emit PM directly or emit other pollutants which have a chemical reaction in the atmosphere to form PM. Fine PM can be emitted directly from the  combustion of fuel (power plants, motor vehicles, wood burning), fires and certain industrial activities . Other particles may be formed indirectly from the chemical change of gases, such as sulfur dioxide , nitrogen oxides and volatile organic compounds, in the air. Fine PM can also be formed individually when these gases react with sunlight and water vapor. PM can affect human health and is a source of haze which reduces visibility.

PM HEALTH EFFECTS

Fine PM is able to penetrate and lodge in deep areas of the lungs. Health effects include: irritation of the eyes; sore throat; coughing; chest tightness; and shortness of breath. PM may also trigger asthma. People most at risk from exposure include those with asthma, heart or lung disease, children and the elderly. Children and adults who are active outdoors may be at increased risk because during physical activity, people breathe faster and more heavily, taking more particles deeper into their lungs.

When air quality is poor, if your outdoors activity involves prolonged or heavy exertion, reduce your activity time or substitute another activity that involves less exertion. Furthermore, attempt to plan outdoor activities for days when PM levels are low.

NATIONAL AMBIENT AIR QUALITY STANDARD

One-Hour Ozone Standard

The one-hour National Ambient Air Quality Standard (NAAQS) for ozone is 0.12 parts per million (ppm ). The one-hour standard is exceeded whenever the hourly average value of any monitor is recorded as 0.125 ppm or greater on any day. Based on 2000-2002 air quality monitoring data, the St. Louis metropolitan region attained the one-hour ozone standard in 2002. On May 12, 2003, the U.S. Environmental Protection Agency (USEPA) determined that the St. Louis area had met the one-hour ozone standard. It redesignated the area as in attainment of this standard and approved each State's Maintenance State Implementation Plans (SIP). The anti-backsliding provisions of the Clean Air Act require that emissions reductions committed to in the Maintenance SIPs are to remain so that the area can continue to attain the one-hour ozone standard through 2014 or until eight-hour ozone SIPs are approved by USEPA.

The one-hour ozone standard will be in effect until June 15, 2005. The area has to stay in attainment of the one-hour standard until this date.

Eight-Hour Ozone Standard

In 1997 after a lengthy evaluation and review process, USEPA revised the NAAQS for ozone. The change was made to protect the public from adverse health effects resulting from longer periods of exposure to ozone. With the eight-hour ozone standard, a concentration-based measurement approach will replace the current exceedance approach. An area will be considered to attain the eight-hour ozone standard when the three year average of the annual fourth highest daily maximum eight-hour ozone concentration as measured at each monitor is less than or equal to 0.08 ppm.

On April 15, 2004, the USEPA Administrator designated those areas in the U.S. which are not in attainment of the eight-hour ozone standard. These designations go into effect June 15, 2004. The St. Louis area has been designated as a moderate non-attainment area for the eight-hour ozone standard. The non-attainment area includes: in Missouri, Franklin, Jefferson, St. Charles and St. Louis Counties and the City of St. Louis; and in Illinois, Jersey, Madison, Monroe and St. Clair Counties. Under the one-hour ozone standard, Jersey County was a stand alone maintenance area. Both Missouri and Illinois will be required to prepare new eight-hour ozone SIPs.

Also signed on April 15 was Part 1 of the eight-hour ozone implementation rule. It went into effect on  June 15, 2004.  The implementation rule provides direction as to what a state will have to do so that a non-attainment area will be come into compliance with the eight-hour ozone standard and when. Items covered in Part 1 include: non-attainment area classifications; the transition from the one-hour ozone standard to the eight-hour ozone standard; anti-backsliding; revocation of the one-hour ozone standard; dates for the various non-attainment area classifications to reach the eight-hour standard; how to receive an extension of the attainment date; and emissions reductions. Part 2 of the implementation rule, is scheduled to be published in Spring 2005, will address: Reasonably Available Control Technology; rate-of-progress provisions including specific control measures or strategies by classification; demonstration of attainment process; computer modeling requirements; and New Source Review.

East-West Gateway has until June 15, 2005 to conduct an air quality Conformity Determination on its long range Transportation Plan based on the eight-hour ozone standard. The Conformity Determination demonstrates that transportation projects and programs contained in the Transportation Improvement Program and Transportation Plan will not have a negative impact on air quality in the region. (See Conformity Determination section) This Conformity Determination was adopted by the Board of Directors on March 30, 2005.

Because St. Louis is a moderate non-attainment area, Missouri and Illinois have to submit their eight -hour ozone SIPs to USEPA by June 15, 2007. The attainment date for the St. Louis area is June 15, 2010. However, as controls need to be in place before the start of the ozone season which is in April, 2009 is a critical year.  

To attain the eight-hour ozone standard, the three year average of the annual fourth highest daily maximum eight-hour ozone concentration as measured at each monitor has to be less than or equal to 0.08 ppm. Missouri and Illinois calculate eight-hour averages based on monitored data, track the four highest eight-hour averages per monitor during the ozone season and identify excursions of the eight-hour standard. An excursion of the eight-hour ozone standard is considered to occur whenever an eight-hour average of values from a monitor is calculated to be 0.085 ppm or greater on any day. The number of excursions does not indicate whether a monitor will or will not be in attainment.

PM 2.5 Standard

USEPA has a standard for large size or coarse particulate matter (PM 10). In 1997, after a lengthy evaluation and review process, USEPA added a fine particulate (PM 2.5) national standards. The change was made to protect the public from adverse health effects of particles less than 2.5 microns in diameter. The PM 2.5 standard is based on averaging air quality measurements both annually and on a 24-hour basis. The annual standard is 15 micrograms per cubic meter and is met when the three-year average of the annual arithmetic mean is less than 15.05 micrograms per cubic meter. The 24-hour standard is 65 micrograms per cubic meter and is met whenever the three-year average of the annual 98th percentile of values at designated monitoring sites is less than or equal to 65 micrograms per cubic meter.

Based on 2000-2002 PM 2.5 information from Missouri and Illinois, the Blair Street monitor in the City of St. Louis and the monitors in Alton, Wood River, Granite City, East St. Louis and Swansea in Illinois violate the annual PM 2.5 standard. However, the St. Louis area is in attainment of the 24-hour part of the PM 2.5 standard.

On December 17, 2004, the USEPA Administrator notified the 20 Governors that their states contained areas which do not meet the fine particle (less than 2.5 microns in diameter) standard.  The St. Louis PM 2.5 non-attainment area consists of: Franklin, Jefferson, St. Charles and St. Louis Counties and the City of St. Louis in Missouri; and Madison, Monroe and St. Clair Counties and Baldwin Township in Randolph County, Illinois. Both Missouri and Illinois will be required to prepare new PM 2.5 SIPs.

USEPA is preparing the PM 2.5 implementation rule. It will provides guidance on what should be included in the PM 2.5 SIP.

Missouri and Illinois are to submit their respective PM 2.5 SIPs to USEPA by April 5, 2008. The St. Louis area is required to be in attainment of the PM 2.5 standard by April 5, 2010.  

East-West Gateway has until April 5, 2006 to conduct an air quality Conformity Determination on its long range Transportation Plan based on the PM 2.5 standard. Conformity Determination is to demonstrate that transportation projects and programs contained in the Transportation Improvement Program and Transportation Plan will not have a negative impact on air quality in the region. (See Conformity Determination section)