1. What is air pollution?
Air pollution is the presence of substances - both gases and particles - in the air in amounts that are harmful to the health or comfort of humans or animals, or can cause damage to plants or materials (properties). This is usually the result of industrial processes and/or vehicle activities.
2. What is the federal Clean Air Act?
The federal Clean Air Act of 1970, which was amended significantly in 1990, requires that the U.S. Environmental Protection Agency (EPA) study the effects of air pollution on human health and the environment, and to establish appropriate ambient air quality standards.
3. What are the criteria pollutants?
There are six criteria pollutants: ozone, carbon monoxide, particulate matter, sulfur dioxide, nitrogen dioxide and lead.
4. For what criteria pollutants is the Houston-Galveston-Brazoria region in nonattainment?
Ozone is the only criteria pollutant for which the eight-county Houston-Galveston-Brazoria area currently fails to meet the national air quality standard.
5. Are there any other non-attainment areas in Texas?
The other non-attainment areas are: Beaumont-Port Arthur, Dallas-Fort Worth and El Paso.
6. How is Ozone being formed?
Ozone is formed as a consequence of chemical reactions in the atmosphere where the reactants are nitrogen oxides and volatile organic compounds in the presence of light.
7. What are the health effects of Ozone?
Ozone poses health problems for children, the elderly, asthmatics and even healthy adults.
• It can cause acute respiratory problems.
• It can aggravate asthma, emphysema and bronchitis.
• It can lead to hospital admissions and emergency room visits.
• It can impair the immune system.
8. What is a State Implementation Plan (SIP)?
It is a specific plan required by the Clean Air Act to achieve the national air quality standards in all non-attainment areas. The SIPs are developed by the states (with local inputs) and submitted to U.S.EPA for approval. After approval, the SIPs and all associated control measures are enforceable at both the state and federal levels.
9. What is the status of Houston air quality now?
For the 1 hour ozone standard, the classification is "severe". It has an approved SIP and the attainment date was 2007. At this time the HGB region is still in nonattainment.
For the 1997 eight-hour ozone standard, the classification is "severe". The SIP is due by the end of 2009 and the attainment date is 2019.
10. What are the federal control strategies for mobile sources?
Vehicle emission standards: The use of catalytic converters and fuel injection started in the late 1960s. Starting in 2004, all the new vehicles have to comply with the Tier 2 emission standards (0.07gr/mile of NOx), this standard is for regular gasoline passenger vehicles as well as for gasoline and diesel sport utility vehicles and light duty trucks. The standard will reduce NOx emitted from new cars by 77%, and NOx emitted by sport utility vehicles and light duty trucks by 95 percent.
The Heavy Duty Diesel rule effective in 2007 will reduce NOx emissions by 95 percent and particulate matter by 90 percent through a phase-in approach.
Cleaner Fuels-gasoline: Since 1995, reformulated gasoline (RFG), a conventional gasoline blended to burn cleaner and evaporate less, has been the only gasoline available for sale in the non-attainment area. Beginning in 2000, more stringent RFG standards (Phase II RFG) replaced RFG in the Houston-Galveston-Brazoria area. Phase II RFG cut an additional 27 percent of VOCs and 7 percent of NOx.
Beginning in 2004, refineries and importers are required to meet corporate average gasoline standards of 120 ppm sulfur, with a maximum of 300 ppm. By 2006, refiners produced gasoline that averages no more than 30 ppm sulfur, with a maximum not to exceed 80 ppm.
Cleaner Fuels-diesel: Since October 1994, federal law has allowed a maximum of 500 ppm sulfur diesel fuel in on-road vehicles. This rule has had only a minimal impact on NOx reductions, but it has resulted in larger reductions in sulfur and particulate matter.
Starting on September 1, 2006 on road diesel fuel sold at retail stations are required meet the 15 ppm new sulfur standard. As a result of this program each new truck and bus has been more than 90 percent cleaner than current models. Resulting in a 90 percent and 95 percent reduction in PM and NOx emissions respectively.
11. What are the state control strategies for mobile sources?
Texas emission reduction program (TERP): This program is designed to provide economic incentives, rebates and grants for various plans for improving air quality throughout the state. These projects can be improvements to on-road diesel and non-road diesel emissions, infrastructure development programs, qualifying fuel projects, demonstration projects, energy efficiency programs and new technology programs.
Transportation Control Measures (TCMs): The Clean Air Act Amendments of 1990 require regions in non-attainment areas to make commitments to implement TCMs. H-GAC and the transportation project-implementing agencies have committed to a number of TCMs for on-road mobile source emissions. These include HOV lanes, arterial traffic flow improvements, park and ride lots, transit service improvements, bicycle facilities, area-wide rideshare programs, computerized transportation management systems and light rail.
Voluntary Mobile Emission Reduction Programs (VMEPs): Since 1997 EPA adopted a policy to allow credit in the SIP for voluntary mobile emission reduction programs, and in this way encourages innovation and investment in effective local programs. The voluntary programs are the following:
• Vehicle Scrappage: This measure intends to replace or repair high emitting light duty gasoline vehicles. From January 2006 thru June 2009, there have been 11,543 repairs and 10,891 retire/replacements in the HGB region.
• Smoking vehicle program/Clean Air Action: This program is a citizen outreach strategy designed to encourage the proper maintenance and repair of cars, trucks and buses with excessive emissions, and promote public awareness regarding the harmful emissions and air pollution caused by these vehicles.
• Clean Cities/Vehicle Programs: Under these programs, emission reductions from vehicle fleets are realized through clean vehicle purchases and retrofits of EPA-approved voluntary retrofit packages.
• Commute Solutions: This measure combines regional commute alternatives, such as mass transit, vanpooling, teleworking and cash in lieu of paid parking.
• Regional computerized traffic signal system: This measurement aims to reduce vehicle congestion on local streets through signal timing.
• Locomotive emission reductions: A memorandum of agreement (MOA) had been signed with Union Pacific, Burlington Northern and Santa Fe Railroads to achieve emission reductions through various controls. This MOA was for a previous SIP.
• Commercial Marine: Memorandums of agreement have been signed with Texas Waterway Operators and Texas Department of Transportation for emission reductions through various controls. This MOA was for a previous SIP.
12. What is transportation conformity and how is it linked to the SIP?
Transportation conformity is the process that links the State Implementation Plan (SIP) with the regional roadway planning, which occurs in the Regional Transportation Plan (RTP) and the Transportation Improvement Program (TIP).
13. What are Transportation Control Measures or TCMs?
The TCMs are actions included in the SIP to adjust traffic patterns or reduce vehicle use to reduce air pollutant emissions. Examples: HOV lanes, bicycle facilities, park and ride lots and traffic flow improvements (grade separations and signal timing).
14. What is the budget test?
The projection of roadway and transit emissions must be less than the mobile vehicle emission baseline established by the State Implementation Plan.
15. What is the latest emission model for transportation?
16. What can I do to improve air quality?
Reduce use of solvents, reduce use of energy, keep vehicles in good repair, use alternative commuting options, select low emission vehicles, reduce unnecessary trips, postpone polluting activities on high ozone days, reduce emissions from off-road sources.
17. How much does air pollution cost?
Air pollution is very costly for our society. The costs include expenses for increased health care, property damage as well as decreased in quality of life. Some of these costs are being paid indirectly through increase in insurance premiums and decrease in productivity.
The reduction of air pollution is also costly to our society. These costs include installation, operation, maintenance, monitoring and record keeping of emission control systems. Some of these costs are also paid indirectly through increased costs of consumer products and loss of business opportunities.
18. What is the most recent budget to which HGB region needs to conform?
In the Reasonable Further Progress SIP, the budget for 2008 is 186.13 tons/day of NOx and 86.77 tons/day of VOCs. These numbers represent the emissions needed to demonstrate reasonable further progress.
19. How does Mobile6 compare to the California model EMFAC2002?
MOBILE6 and EMFAC2002 are similar in that they both provide estimates of current, past and future emissions from onroad motor vehicles. The two models are based on common sets of current empirical data, developed from research studies, surveys and hundreds of vehicle emissions tests conducted by federal, state and local agencies as well as private industry. Each model is a core element for SIP development under the Clean Air Act, EMFAC for California and MOBILE6 for the rest of the nation.
EMFAC2002 is tailored specifically to represent the many diverse regions of California. As a result, EMFAC2002 addresses regional variations in fleet composition, travel patterns, applicable regulations, temperatures and other factors. Each vehicle technology group has populations with emission rates specific to five separate regimes (normal, moderate, high, very high and super emitters), allowing a stronger resolution of emission factors within groups and a highly detail emission inventory over 45 model years using California conditions.
On the other hand, MOBILE6 can estimate emission factors for any calendar year between 1952 and 2050, the emission rates are specific for two regimes (normal and high emitters), and many variables affecting vehicle emissions can be specified by the user.
20. What are the Highway Performance Monitoring System (HPMS) adjustment factors?
The HPMS is a national level highway information system that includes data on the extent, condition, performance, use and operating characteristics of the Nation's highways. In general, the HPMS contains administrative and extent of information on all public roads.
The HPMS was originally developed in 1978 as a continuing database, and it has been modified several times to reflect changes in coverage, highway systems, legislation, national priorities, new technologies and to consolidate reporting requirements.
21. How are the adjustment values from HPMS being used in Mobile6?
The HPMS is used to adjust the link-based VMT when calculations. This is applied in an attempt to tie the model to real-world conditions.
22. What is the difference between conformity and ozone attainment?
Conformity is a process in which mobile sources have to show that they meet emission budgets in the SIP. The SIP purpose is attaining the National Ambient Air Quality Standards, which is achieved through a series of strategies for point, area, and mobile sources. These strategies are directed to reduce NOx and VOCs which are the precursors of ozone.
23. What is the relationship between transportation and air quality?
Air quality issues play a major role in metropolitan planning. MPOs in air quality nonattainment and maintenance areas are required to ensure that emissions from transportation investments will not cause new violations or affect an area's schedule to attain the air quality standards. Therefore, MPOs need to have a clear idea of what the requirements are. Air pollution is caused by the interaction of topography, weather, and human influences on the environment, such as manufacturing, use of petroleum-based products like gasoline, and even small business activities, such as dry cleaning.
24. What are the major sources of pollution?
Sources of air pollution can be classified as stationary, area, or mobile sources.
• Stationary sources include relatively large, fixed facilities such as power plants, chemical process industries and petroleum refineries.
• Area sources are small, stationary, nontransportation sources that collectively contribute to air pollution and include such sources as dry cleaners and bakeries, surface coating operations, home furnaces and crop burning.
• Mobile sources include on-road vehicles such as cars, trucks, and buses; and off-road sources such as trains, ships, airplanes, boats, lawnmowers and construction equipment.
Houston-Galveston-Brazoria 8-county Nonattainment Area
Modeled values from the TCEQ 2005 base line emission inventories (February 2009)
| VOC (tpd)
|| NOx (tpd)
| Point Sources
(elevated, low level and tanks)
| Area Sources
| On-Road Mobile Sources
| Off-Road Mobile Sources
The key transportation-related pollutants are ozone precursors, carbon monoxide (CO), and particulates (PM-10 or PM-2.5 or particles smaller than 10 microns or 2.5 microns, respectively).The ozone precursors are pollutants that combine to form ground-level ozone, which in turn is part of smog. Ozone precursors are volatile organic compounds (VOCs) and nitrogen oxides (NOx).These pollutants all emanate in part from on-road mobile sources and cannot exceed certain specified levels in a given region.
Nonattainment areas are geographic areas that do not meet the federal air quality standards, and maintenance areas are areas that formerly violated but currently meet the federal air quality standards. If no violations of air quality standards have been found, the area is considered to be in compliance or attainment with federal air quality standards. The Clean Air Act (CAA) of 1990 identifies the actions States and MPOs must take to reduce emissions from on-road mobile sources in nonattainment and maintenance areas.
The CAA and Title 23 U.S.C. both require that transportation and air quality planning be integrated in areas designated by the U.S. Environmental Protection Agency (EPA) as air quality nonattainment or maintenance areas. In fact, in nonattainment and maintenance areas, federal funding and approval for transportation projects is only available if transportation activities are consistent with air quality goals through the transportation conformity process. The transportation conformity process includes a number of requirements that MPOs must meet (see section below on transportation conformity).
An area can be nonattainment for one pollutant and in compliance for another. Transportation conformity is required for all ozone, carbon monoxide, nitrogen dioxide and particulate matter nonattainment and maintenance areas.
25. What is the role of the MPO in air quality issues?
The challenge for MPOs in nonattainment and maintenance areas is to decide on a mix of transit and highway investments that, combined with measures such as Inspection and Maintenance (I/M) programs or reformulated gasoline, will keep emissions within the allowable limits from the emission budgets allowed in the SIP.
According to the CAA, transportation plans, TIPs, and projects cannot:
• Create new violations of the National Ambient Air Quality
• Increase the frequency or severity of existing violations of the standards; or
• Delay attainment of the standards.
MPOs are encouraged to participate in air quality planning and to identify transportation strategies that will help reduce emissions from on-road mobile sources of pollution.
Though not required, many MPOs have developed public education and communications programs to inform the public of the connection between transportation and air quality in their respective regions, and to encourage the public to make travel choices that will benefit air quality.
26. What is transportation conformity and how does it relate to the NAAQS?
The transportation conformity process is a way to ensure that transportation projects meet air quality goals in order to be eligible for federal funding and approval. Whenever a long-term transportation plan or TIP is approved or updated, the MPO must make sure that all plans and programs comply with the conformity requirements.
The CAA requires that each State environmental agency develop a plan called a State Implementation Plan (SIP).The SIP shows how the State will meet the National Ambient Air Quality Standards (NAAQS) for each type of air pollutant, according to the schedules included in the CAA. Pollutants are usually measured in parts per million (ppm) of ambient air, and standards vary by type of pollutant.
For each source category (stationary, area, or mobile), the SIP assigns emission reduction targets of the pollutant. For on-road mobile sources, the emission reduction target is further refined into a motor vehicle emissions "budget" — emissions limits for motor vehicle emissions sources. As a nonattainment area gets closer to its attainment date (e.g., 2007, 2010, 2019), the motor vehicle emissions budget may decrease.
Vehicle emissions reductions programs (e.g., the use of reformulated gasoline or implementation of Inspection and Maintenance [I/M] programs); changing how we travel (e.g., ride sharing or use of transit); or transportation projects that reduce congestion (e.g., signal synchronization programs) can all help areas meet emission reduction targets for on-road mobile sources. MPOs should be actively involved with the State in setting the motor vehicle emissions budgets. Transportation officials need to educate themselves about the options and trade-offs available to them, so they can balance the need for transportation investment with the need to achieve healthful air.
Motor vehicle emissions budgets can be revised. However, doing so requires revising the SIP, which can be a complicated and lengthy process. MPOs should participate in the SIP revision process if it is undertaken.
27. What is a conformity determination and who makes it?
Transportation conformity on transportation plans and TIPs is demonstrated when projected regional emissions for the Plan and TIP do not exceed the region's motor vehicle emissions budgets. A conformity determination is a finding by the MPO policy board, and subsequently by FHWA and FTA, that the transportation plan and TIP meet the conformity requirements. While the MPO is ultimately responsible for making sure a conformity determination is made, the conformity process depends on federal, state, and local transportation and air quality agencies working together to meet the transportation conformity requirements.
If transportation control measures (TCMs) are part of the SIP, the MPO must provide an assurance that TCMs are being implemented on schedule each time it updates its plan and TIP.
A necessary part of the transportation and air quality planning process is consulting with other involved agencies on critical issues and providing opportunities for public participation. MPOs must inform the public that they are going to make a conformity determination, make all relevant documents reasonably available, and give adequate time to review the documents and supporting materials.
28. What plans, programs, and projects are subject to transportation conformity requirements?
The MPO's 20-year transportation plan and TIP must meet the conformity requirements. This includes all projects that are expected to be funded or that will require an approval by FHWA/FTA at any point during the life of the plan or TIP.
Also, any regionally significant projects (as defined by the conformity rule), even those that are not federally funded or approved, must be included in the regional emissions analysis of the transportation plan and TIP. Regionally significant projects include, at a minimum, all principal arterial highways and all fixed-guideway transit facilities
Finally, certain projects in CO and PM nonattainment and maintenance areas must be assessed for expected concentration levels ("hot spots") of carbon monoxide and particulates.
29. How frequently must a transportation conformity determination be made and what happens if the MPO cannot make a conformity determination on time?
A conformity determination must be made on the transportation plan and TIP at least once every four years. Each time the MPO updates its transportation plan or its TIP (except for minor amendments), a conformity determination is required. A conformity determination is also required not more than 24 months after a SIP or a SIP revision is approved or found adequate by EPA.
If an MPO cannot meet the transportation conformity requirements (i.e., is in a conformity lapse), then only certain types of projects may proceed until the requirements are met.
The MPO has two choices if it cannot make a conformity determination: 1) it can change the mix of projects in the transportation plan/TIP in an attempt to meet the conformity requirements or 2) it can request a SIP revision of the motor vehicle emissions budget.
Under the metropolitan transportation planning requirements of SAFETEA-LU, projects in air quality nonattainment and maintenance areas cannot be approved, funded, or implemented unless those projects are included in a conforming long-range transportation plan and TIP. This means that the funding necessary to implement the long-range transportation plan is reasonably expected to be available over the 20-year plan period, and that funding for the first two years of the TIP is available or committed.
30. What funding is available for air quality improvement programs and projects?
Under the CMAQ program, States receive funding based on the severity of pollution and the population by county of each nonattainment and maintenance area. Additional funding is given to areas that violate both the ozone standard and the carbon monoxide standard. Each state receives CMAQ funding and then allocates funds, at the State's discretion, to the air quality nonattainment and maintenance areas.
31. How much money does the MPO receive each year in CMAQ funding?
Each year, the amount of funding any individual MPO receives varies depending on the following factors: severity of pollution, population, whether both the ozone standard and the CO standard are violated, and the State's method for allocating the funds. The FHWA posts the annual population numbers in each nonattainment and maintenance area, and the weighting formula for the apportionments of CMAQ funding, on its website at:
32. What types of projects are funded with CMAQ funding?
CMAQ funding is reserved for projects that reduce congestion and improve air quality. Typical projects include transit improvements, shared-ride services, traffic flow improvements, pedestrian and bicycle programs, construction of high-occupancy vehicle (HOV) lanes, I/M programs and transportation demand management strategies. Guidance on the CMAQ program can be found at: ww.fhwa.dot.gov/environment/cmaqpgs/index.htm
33. Who decides which projects receive CMAQ funding?
Decisions must be coordinated through the MPO planning process and are made collaboratively by the MPO and state, subject to federal eligibility guidelines. These guidelines are quite flexible, in order to promote innovation.
34. What other sources of federal funding are there for air quality improvement projects?
The Surface Transportation Program (STP) in SAFETEA-LU allows states to use certain funds (known as "flex" funds) for a variety of projects, including transit, transportation demand management and other strategies that will help to reduce emissions.
The FTA provides funding for public transit projects, including fixed rail transit, rail modernization, buses and bus facilities (including the purchase of alternatively fueled buses) and other public transit projects. Other sources of funding include programs administered by the EPA and the U.S. Department of Energy; in many areas, state and local funding programs are in place.
Additional sources of information:
www.fhwa.dot.gov/environment/cmaqpgs/index.htm gives a basic explanation of conformity, provides policy guidance and a brochure about CMAQ, outlines policy, and gives helpful links.
environment/4805_5136_ENG_HTML.htm provides information on CMAQ, Transportation and Air Quality Impacts of Transit Projects, and a description of the FTA General Noise Assessment Spreadsheet.
www.fhwa.dot.gov/hep/index.htm is a helpful source of information on funding programs.
www.energy.gov/engine/content.do?BT_CODE=EF_SS6 is a consumer oriented
site hosted by the Department of Energy on how to save fuel, and provides a helpful example of how MPOs can educate the public about air quality.