Bay Area Air Quality Management District

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Moving forward.

Toward a healthy breathing environment.

Air quality in the Bay Area has improved significantly in the past few decades. The Air District’s programs have produced substantial public health benefits and saved the region millions of dollars in health-related costs. But there are still challenges to be met as population, traffic, and industry continue to grow throughout the region.

To meet these challenges and keep this momentum moving forward, the Air District will continue to fine-tune its traditional programs, while keeping up with the latest trends in air quality research and introducing new initiatives to effectively address key sources of air pollution in the Bay Area.

Particulate Matter Report

The term particulate matter, or PM, describes a diverse assortment of extremely small airborne particles from a wide range of sources that can penetrate deep into the lungs, other vital organs, and even individual cells. Health studies indicate that fine particulate matter is the air pollutant that poses the greatest overall health risk to Bay Area residents. The Air District has made substantial progress in analyzing PM and reducing PM levels in the Bay Area over the past 20 years. As a result, the region currently attains most national and state standards for PM.

To guide its ongoing efforts to reduce PM levels in the Bay Area, the Air District prepared a report in 2012 entitled Particulates Matter: Understanding PM to Protect Public Health in the Bay Area. This report:

  • describes PM and its impacts on public health, climate change, and ecosystems;
  • provides technical information about how PM is emitted and formed in the Bay Area;
  • describes progress in reducing PM levels in the Bay Area in recent years;
  • describes current regulations and programs to reduce PM emissions and concentrations;
  • identifies future technical work needed to improve the Air District’s understanding of PM; and
  • explains the importance of continuing the Air District’s efforts to reduce PM in order to protect public health and the environment.

On November 7, 2012, the Air District prepared a fine particulate emission inventory and submitted it to the U.S. Environmental Protection Agency to fulfill federal planning requirements. The PM report, which includes a PM emissions inventory, can be viewed in the Planning section of the Air District’s website at

Rule Changes

The Air District continuously evaluates and updates its air quality regulations to reflect the latest trends in research and technology.

In 2012, the Air District approved a series of amendments that strengthened the agency’s core permitting regulations by including new provisions that will further reduce emissions of fine particles and greenhouse gases from industrial sources such as refineries, power plants, and other large commercial facilities. These rule amendments fulfill federal particulate matter planning requirements, and will serve to better protect air quality in the Bay Area.

Last year, the Air District approved a pioneering rule that imposes the strictest limits in the nation on existing local Portland cement manufacturing facilities. This rule protects community health by requiring more stringent emissions limits for nitrogen oxides, particulate matter, and toxic air contaminants, such as mercury, benzene, and hydrochloric acid. It also includes new continuous emissions monitoring, recordkeeping, reporting, and operational requirements, such as dust mitigation measures.

In 2013, the Air District has approved two new rules that will further reduce particulate matter pollution and odors from foundries, forges, and metal recycling facilities. These rules are the first in California to address fugitive emissions of particulate matter and odorous substances from these kinds of metal-processing facilities. The new rules require metal-processing facilities to implement Emissions Minimization Plans, or written documents that show how these facilities plan to reduce air pollution emissions and odors. These plans must be approved by the Air District and resubmitted every five years.

This year, the Air District is also developing a rule amendment to address emissions of nitrogen oxide and carbon monoxide from boilers, steam generators, and process heaters at petroleum refineries. In addition, the agency is currently in the process of developing four new rules that further restrict fugitive dust, sulfur dioxide from coke calcining, diesel emissions from emergency generators, and refinery emissions.

Accidental Release Action Plan

Response to the August 6 incident at the Chevron refinery in Richmond, the Air District has adopted a work plan to further improve the Air District’s regulatory response and communications systems and capabilities for assisting responding agencies during significant events.

The Work Plan for Action Items Related to Accidental Releases from Industrial Facilities contains the following action items, along with a schedule for their implementation:

  • Continuing the investigation of the Chevron incident in order to take appropriate enforcement action;
  • Reviewing and updating Air District incident response procedures;
  • Evaluating enhancements to the Air District’s air quality monitoring capabilities;
  • Developing a rule that would track air emissions at refineries over time and require mitigation of any significant increases, as well as additional community air monitoring;
  • Evaluating the Air District’s incident response resources and developing amendments to the fee regulation to recover the costs of these resources;
  • Evaluating enhancements to community outreach related to incidents; and
  • Sponsoring legislation that would provide the Air District with the authority to collect more substantial penalties in order to encourage industries to take proactive measures to avoid accidental releases.

These action items are intended to reduce the potential for accidental releases in the future, to improve the Air District’s response to such releases, and to ensure that affected communities have access to the best resources and timely information. The implementation schedule for most of these items began in late 2012 and early 2013 and will continue throughout the year.

Ultra-Fine Particle Study

Although they are not currently regulated as a separate air pollutant category, the Air District initiated a study of ultrafine particles, or UFPs, in 2012. UFPs are particles with diameters smaller than 0.1 microns or 100 nanometers, and their small size can lead to deeper penetration in the human body and potentially significant health impacts. The Air District’s study consists of continuous monitoring of UFPs at four air monitoring stations, preparation of an emissions inventory, air quality modeling, human exposure analyses, and an estimation of their health impacts on Bay Area residents. Because of their miniscule size, routine monitoring of UFPs has been difficult until very recently. Most UFPs are thought to be released directly to the atmosphere from combustion sources, and once their sources are better analyzed and understood, it will be possible to devise improved strategies for reducing their emissions.

Regional Commute Benefits Program

Last year, Governor Brown signed Senate Bill 1339 into law, which tasks the Air District and the Metropolitan Transportation Commission with implementing a regional commute benefits pilot program for employees who work at least 20 hours per week for an employer with 50 or more full-time employees in the San Francisco Bay Area.

This regional commute benefits requirement will give Bay Area employers the flexibility to offer employees their choice of such commute benefits as:

  • The option to pay for transit or vanpooling expenses with pre-tax dollars, as allowed by federal law;
  • A transit or vanpool subsidy up to $75 per month;
  • A free shuttle or vanpool operated by or for the employer; or
  • Their own customized commuter benefits program.

Transportation is one of the largest sources of air pollution and greenhouse gas emissions in the Bay Area. A regional commute benefits program will provide a powerful and economically viable new tool to cut traffic congestion, improve air quality, and reduce greenhouse gas emissions.

PEV Plan

In December 2012, the Air District released a regional Plug-In Electric Vehicle, or PEV, Readiness Plan for the Bay Area and Monterey Bay regions. The PEV Readiness Plan is a regional and statewide effort co-sponsored by the United States Department of Energy and California Energy Commission that seeks to identify the systems and resources that are needed to support accelerated PEV deployment, infrastructure, investment, and readiness in the region.

PEVs offer tremendous promise for reducing air pollution and greenhouse gases. In recent years, the Air District has provided more than $3 million in funding to accelerate the deployment of charging infrastructure that will be needed to support widespread PEV use in the Bay Area. That funding contributed to the deployment of more than 200 Level 2 chargers in public locations throughout the region and rebates for installation of 1,500 home chargers. In 2013, additional incentive funding for PEV deployment projects is being planned to continue the support for accelerated early-adoption of PEVs.

In 2012, the Air District also launched a new Bay Area Plug-In Electric Vehicle Ready website,, which provides valuable resources and support for current and prospective electric vehicle drivers across the region.

Bike Sharing

In 2012 and early 2013, thanks to funding from the Air District, a regional bike sharing system pilot pedaled a few laps closer to the finish line. The Air District signed a contract with Alta Bicycle Share to deploy and operate the projected regional system, which will run along the Peninsula transportation corridor in the cities of San Francisco, Redwood City, Mountain View, Palo Alto, and San Jose, and is expected to launch in August 2013.

Bike sharing is ideal for short distance point-to-point trips, providing users the ability to pick up a bicycle at any self-serve bike station and return it to any bike station located within the system’s service area. The bicycle stations will be located near transit hubs, high-density residential areas, and key destinations such as employment centers and universities, making it easier to quickly and conveniently connect to and from transit and to make short-distance trips by bike.

The pilot project is a partnership between local government agencies including the Air District, the San Francisco Municipal Transportation Agency, Sam-Trans, Caltrain, the County of San Mateo, the City of Redwood City, and the Santa Clara Valley Transportation Authority. In the Bay Area, the transportation sector accounts for more than 50 percent of overall air pollution. Significant emission reductions from this sector will help the Bay Area attain and maintain state and national air quality standards and reduce greenhouse gases.

Green Fleet Plan

In recent years, the Air District has initiated an internal Green Fleet Plan to shrink the agency’s eco-footprint. The Green Fleet Plan included the introduction of alternative fuels, use of electric and hybrid vehicles, replacement of older vehicles with more fuel-efficient ones, and “right-sizing” the fleet to ensure that vehicle specifications do not over-match requirements.

The Air District currently operates with an 81 percent green fleet, a 12 percent increase since 2010, and is moving towards the target goal of 90 percent. As of the end of 2012, the Air District managed over 111 green vehicles, including fully electric, natural gas, and hybrid sedans and SUVs. Estimated emission reductions were 85 metric tons of CO2 between 2004 and 2011.

Public Participation Plan

The Air District has prepared a draft Public Participation Plan, which includes strategies for increasing the Air District’s visibility in the community and giving residents easier access to the Air District, as well as enabling the Air District to better engage with limited English speakers about air quality issues.

In 2013, the Air District will begin workshops and public review of the draft plan, which reaffirms the Air District’s commitment to public engagement and outlines ways in which the Air District will improve public participation efforts in the future.

In 2012,

the Air District approved a series of amendments that strengthened the agency's core permitting regulations by including new provisions that will further reduce emissions of fine particles and greenhouse gases from industrial sources such as refineries, power plants, and other large commercial facilities.