Air Quality Review

Air quality in San Francisco varies throughout the city depending on location, weather, and land uses. While many areas of San Francisco have good air quality, areas close to freeways, ports, or industrial activities generally have more air pollution. Consistent exposure to high air pollution may lead to preventable health problems, such as increased illness and premature death from asthma, bronchitis, emphysema, pneumonia, coronary heart disease, abnormal heart rhythms, congestive heart failure, and stroke.

The San Francisco Planning and Public Health departments, along with the Bay Area Air Quality Management District, prepared a Citywide Air Quality Health Risk Assessment in 2020. The assessment identifies areas of the city with unhealthy levels of air pollution. The assessment included emissions from stationary pollutant sources, such as wastewater treatment plants, backup generators, and gas stations; mobile sources, which included cars, trucks, and rail activity; and maritime sources, which included ferries and shipping vessels and other port-related activities. The Citywide Health Risk Assessment was used to create the air pollutant exposure zone, or APEZ map, where air modeling indicates higher levels of air pollution. Most of the air pollution in the city comes from cars and trucks on city roads and highways.

• San Francisco Citywide Health Risk Assessment: Technical Support Documentation, September 2020

The Planning Department developed the Air Quality and Greenhouse Gas Analysis Guidelines to present our approach to analysis of air quality and greenhouse gas impacts and provide substantial evidence to support that approach, pursuant to the California Environmental Quality Act (CEQA). The purpose of the guidelines is to assist both department staff and consultants in the preparation of air quality and greenhouse gas analyses that are useful, consistent, and legally sound.

• Air Quality and Greenhouse Gas Guidelines, July 2024
• Air Quality and Greenhouse Gas Guidelines with Appendices, July 2024

The City and County of San Francisco has long been a leader in protecting residents' public health. The City identifies areas with higher levels of air pollution in the APEZ. Since 2008, San Francisco Health Code article 38 requires new residential construction projects in the APEZ to install enhanced ventilation in buildings to protect residents from the health effects of poor air quality. In addition, through the environmental review process, many construction projects in the APEZ are required to use the cleanest available construction equipment to reduce air quality impacts.

• Air Pollutant Exposure Zone Handout, December 2020

The APEZ story map describes the main differences between the prior (2014) and current (2020) iterations of APEZ maps and allows users to search a location to determine if it is in one or both versions of the APEZ map:

• Air Pollutant Exposure Zone Story Map

For those who live within the APEZ, or those concerned with the health effects from outdoor air pollution, the Planning Department developed a guide to learn about purchasing a portable air cleaner. These devices, when used properly, have the ability to remove up to 90 percent of the harmful particles present in indoor air and improve air quality inside of a home.

• Protecting your Health from Outdoor Air Pollution, December 2020

The California Air Resources Board requires owners of construction equipment to register all pieces of off-road construction equipment included in their fleets, such as bulldozers, excavators, and compactors. Since the mid-1990s, the federal and state governments have required manufacturers to make cleaner construction equipment over time. As a result, reductions in harmful emissions from older models of off-road diesel construction equipment to the current models have proven to be as much as 96 percent. Electric off-road equipment, while currently rare, is becoming more widely available in California, and has no tailpipe emissions.

The planning department has been tracking the availability of clean construction equipment since 2010 using data from the California Air Resources Board.

• Off-Road Construction Equipment Vehicle Inventory, October, 2023

The data demonstrates a more than four-fold increase in the amount of clean construction equipment available since 2010. Moreover, approximately three-quarters of construction equipment in the Bay Area meets the most health-protective off-road diesel standards or is electric. Many projects that are located within San Francisco’s APEZ are required to use the cleanest available construction equipment to reduce air quality impacts.

In addition to enforcement of article 38, the creation of the APEZ, and requiring the use of cleaner construction equipment, the City has undertaken ongoing activities to reduce air pollution emissions and lessen air pollution exposure. Some of these activities include:

• All-Electric Construction Ordinance: In 2020, the City adopted an all-electric new construction ordinance, which prohibits the installation of gas piping systems, and requires that all indoor and outdoor space-conditioning, water heating, cooking, and clothes drying systems in new construction be all-electric.
• Greenhouse Gas Reduction Strategies: The City has developed multiple plans and programs to reduce the city's contribution to global climate change and meet long-term climate stabilization goals. In 2021, ordinance 117-02 established City’s “0-80-100-Roots" framework, which defines climate and sustainability goals in four key areas: zero waste (“0% zero waste”), transportation (“80% low-carbon trips”), energy (“100% renewable energy”), and carbon sequestration (“Roots”).
• The City's 2021 Climate Action Plan: is the most recent plan, which charts a pathway to achieve net-zero greenhouse gas emissions while addressing racial and social equity, public health, economic recovery, and community resilience. In 2023, the planning department published an update to the City’s greenhouse gas reduction strategy to reflect the new climate action plan.
• Transportation Demand Management Program: In February 2017, the City adopted an ordinance to establish a transportation demand management program, requiring development projects to provide on-site amenities that support sustainable modes of transport and reduce single-occupancy driving trips associated with new development.
• Construction Dust Control Ordinance: In July 2008, the City adopted an ordinance to reduce the quantity of dust generated during site preparation, demolition, and construction work in order to protect the health of the general public and onsite workers, minimize public nuisance complaints, and to avoid orders to stop work by the Department of Building Inspection.
• Clean Construction Ordinance: In April 2007, the City adopted an ordinance requiring public projects to reduce emissions at construction sites starting in 2009. In March 2015, the City expanded the existing ordinance to require public projects to further reduce emissions at construction sites in certain areas with high levels of background concentrations of air pollutants.
• Bicycle Strategy: The San Francisco Bicycle Strategy, created in 2013, contains specific proposed near-term bicycle route network improvement projects for a safe, interconnected bicycle network that supports bicycling as an attractive alternative to private auto use.
• Better Streets Plan: The Better Streets Plan, adopted in 2006, created a unified set of standards, guidelines, and implementation strategies to govern how the City designs, builds and maintains its pedestrian environment. The plan promotes streets designed to promote walking, cycling, and transit use over single occupancy vehicle use, which will reduce local air pollution and San Francisco's contribution to global climate change.

For additional information on the Planning Department’s air quality review process, please contact Josh Pollak at josh.pollak@sfgov.org