On-road motor vehicles are the major source of air pollutant emissions contributing to violations of most air quality standards. Projects that affect the capacity or location of major roads or other elements of the transportation system can cause both adverse and beneficial air quality impacts. The impact is often positive, a capacity or alignment change may improve traffic flow enough, at least for a period of time, to reduce pollutant emissions compared to existing conditions or no-build alternative.
On-road motor vehicles are the major source of air pollutant Aq for conformity contributing to violations of most air quality standards. Projects that affect the capacity or location of major roads or other elements of the transportation system can cause both adverse and beneficial air quality impacts.
The impact is often positive, a capacity or alignment change may improve traffic flow enough, at least for a period of time, to reduce pollutant emissions compared to existing conditions or no-build alternative.
In the long term, overall emissions from motor vehicles will drop due to improved vehicle emission controls, but future traffic growth will, to some degree, counteract these reductions.
For some pollutants, vehicle-related emission controls may not have a major effect; for example, re-entrained road dust emissions are roughly proportional to vehicle miles traveled. Also, short-term emissions from construction processes and equipment may be an issue if not adequately accounted for in existing regional air quality plans and regulations.
Environmental Protection Agency U. EPA administers the FCAA, sets the specific air quality and emissions standards, and delegates certain responsibilities to other federal agencies and to the states. EPA sets and Aq for conformity both primary health and secondary welfare standards for the six "criteria pollutants" - carbon monoxide, lead, nitrogen dioxide, ozone, sulfur dioxide, and particulate matters PM10 and PM2.
Most air toxics originate from human-made sources, including on-road mobile sources, non-road mobile sources such as airplanesareas sources e.
MSAT are compounds emitted from highway vehicles and non-road equipment. All federal air toxics are incorporated into the California lists by reference. In addition, California regulates a large number other substances not currently on the federal list. Key California-only air toxics for consideration in transportation projects include diesel exhaust particulate matter and naturally occurring asbestos.
Note that not all of the ARB toxics programs apply to transportation projects; consult with technical or Legal staff before getting into a lot of detail. EPA has designated planning areas throughout the country. Areas are classified as being in "attainment" for a given pollutant if they meet the prescribed standards.
If an area does not meet the standard, it is designated as a "nonattainment" area for that pollutant. Areas that were previously designated as non-attainment areas but have now met the standard with U. EPA approval of a suitable air quality plan are called "maintenance" areas.
The FCAA requires that states produce improvements in air quality over time.
This means reducing air pollution to healthful levels in nonattainment areas and developing controls to ensure the air remains healthful in subsequent years.
The State Implementation Plan SIP process is the means by which states develop a collection of regulations and plans to demonstrate this effort to the federal government. The projects included in these plans and programs must be consistent with or conform to the approved SIP, and hence the requirements of the FCAA.
This process is called "Transportation Conformity. For more about how air quality is addressed at the planning stage, see the SER, Vol. It also applies if projects are determined to be regionally significant as defined at 40 CFR A further demonstration of transportation conformity—at the project level—is required if a project is located in a nonattainment or maintenance area.
The basic demonstration of conformity consists of showing that the project is listed in and consistent with a conforming RTP and TIP. Emission reduction measures may be required to ensure that the project will not cause or contribute to new violations of a standard.
Caltrans cannot approve a project that would cause or contribute to violation of a federal air quality standard. See the attachment at the bottom of this memo.
Although state air standards for some pollutants are more stringent than federal standards, there is no conformity process under the state law. Over time, as air quality improves under the federal conformity process, it is expected that there will be progress in meeting state standards as well.
The California Air Resources Board ARB is responsible for establishing state air quality standards and enacting regulations for statewide air pollution control programs, and for submitting the SIP to the U.
Local air pollution control districts and air quality management districts directly regulate stationary and some area sources of emissions, but not mobile sources, under the structure set up by the CCAA.
The following is a brief breakdown of the most common pollutants. Ozone impacts are regional in nature and cannot be ascribed to any single project. Ozone is formed by reactions, in the presence of sunlight and heat, primarily between organic compounds and nitrogen oxides.
These precursor compounds are emitted by all combustion sources, and in many regions mobile sources including motor vehicles are the major source. Ozone violations most often occur in summer April-Octobersince strong sunlight and heat are necessary for its formation.Air Quality Conformity Analysis Report York MPO TIP and LRTP National Ambient Air Quality Standards (NAAQS) Addressed: The York, PA Annual PM Maintenance Area.
Background on Transportation Conformity Transportation conformity is a way to ensure that federal funding and approval are awarded to transportation activities consistent with air quality goals. Air Quality Conformity Report Report Contents This document includes a summary of the methodology and data assumptions used for the conformity analysis.
As shown in Exhibit 1, attachments containing additionaldetail have been provided with the document. In addition, modeling input and output files have been reviewed by Region III and the EPA. RTP July Amendment – Air Quality Conformity Determination 2 from Massachusetts monitoring stations, the EPA sent a letter on December 16, , proposing that only Dukes.
The air quality conformity analysis reflects an assessment of the regionally significant, non-exempt transportation projects included in both the TIP and the LRTP.
This document replaces the previously approved conformity demonstration of the TIP and LRTP, and. TRANSPORTATION-AIR QUALITY CONFORMITY ANALYSIS FOR PLAN BAY AREA and AMENDED TRANSPORTATION IMPROVEMENT PROGRAM FINAL SUPPLEMENTAL REPORT JULY Metropolitan Transportation Commission.