California State Implementation Plan
Introduction
Federal clean air laws require areas with unhealthy levels of ozone, particulate matter, carbon monoxide, nitrogen dioxide, and sulfur dioxide to develop State Implementation Plans (SIPs). These comprehensive plans outline how an area will achieve national air quality standards. SIPs are not single documents but rather a collection of plans, programs, rules, regulations, and controls. Many of California's SIPs rely on strategies like vehicle emission standards, fuel regulations, and limits on emissions from consumer products.
California's Air Resources Board (CARB) is the lead agency for SIP development. Local air districts and other agencies contribute to SIP elements, which are reviewed and approved by CARB. Approved SIP revisions are then submitted to the U.S. Environmental Protection Agency (EPA) for final approval. California's SIP is complex due to its large population and diverse geography. The state has a long history of air pollution issues and has implemented numerous measures to improve air quality.
Background
The Clean Air Act (CAA) requires areas with unhealthy levels of certain pollutants to develop SIPs. The 1990 amendments to the Clean Air Act set deadlines for attainment based on the severity of an area's air pollution problem. EPA has established the National Ambient Air Quality Standards for six "criteria" air pollutants - which are widespread common pollutants known to be harmful to human health:
- Carbon monoxide pollution
- Lead air pollution
- Nitrogen oxide pollution
- Ozone pollution
- Particulate matter pollution
- Sulfur dioxide pollution
SIPs provide a plan for implementation, maintenance, and enforcement of the NAAQS in each state. SIPs in states with areas that do not meet the NAAQS must include additional requirements to reduce air pollution in those “nonattainment” areas.
The contents of a typical SIP fall into three categories:
- State-adopted control measures which consist of either state statues and regulations or source-specific requirements (such as orders and consent decrees);
- State-submitted "non-regulatory" components (see list of examples below);
- Additional requirements promulgated by EPA to satisfy a mandatory requirement in Section 110 or Part D of the Clean Air Act.
Applicable laws and regulations
- CFR 52.220
- CAA Section 107 (a)
- CAA Section 110 (h)(1)
- CAA Section 110 (k)
- CAA Section 110 (n)
- CAA Section 110 (o)
- CAA Section 113
- CAA Section 172 (c)
- CAA Section 182 (c)
- CA Health and Safety Code Division 26 , Part 1, Chapter 2
- CA Health and Safety Code Division 26, Part 4, Chapter 3, Article 5
- CA Public Resources Code Division 13
- CA Code of Regulations Title 2, Division 6, Chapter 7; Article 1
- CA Code of Regulations Title 13, Division 3
- CA Code of Regulations Title 17, Division 3
Related definitions
“Ambient air quality standards” are established protections designed to prevent the harmful effects of air pollution on human health and the environment.
The “California Air Resources Board (CARB)” is the regulatory agency that oversees all efforts to control air pollution and conserve air quality standards in the state.
Key to remember
Federal clean air laws require areas with unhealthy levels of ozone, particulate matter, carbon monoxide, nitrogen dioxide, and sulfur dioxide to develop State Implementation Plans (SIPs). California’s comprehensive plan outlines how the CARB will achieve national air quality standards.
Real-world example
In March (2024) CARB reached a settlement agreement with technology company, for $16,196,120 for violating regulations aimed at reducing nitrogen oxides, a criteria air pollutant under NAAQS. The regulation aims to reduce the pollutants from off-road compression-ignition engines. CARB identified three emissions violations: incomplete reporting, incorrect test procedures not and the production of large spark-ignition engines not included in CARB’s certification authorizing sale of the engines in the state.