State forestry policy calls for an increase in fuels reduction efforts including the use of prescribed fire. This makes CARB’s proactive oversight of smoke forecasting, monitoring and management programs more important than ever for balancing air quality protection with fire protection and land management goals. CARB supports the State forestry policy and efforts by land managers to implement agricultural and prescribed burns. CARB strives to identify as many burn days as possible, as evidenced by historical burn day decisions found here, which in recent years have averaged around 90% of all days being permissive or marginal burn days statewide during the peak burn season. Local air districts provide final approval for each burn on the day it is scheduled to be conducted, and use CARB’s burn day advisories as a guide when deciding whether or not to approve specific burns.
For additional documents describing CARB’s prescribed fire program please visit the following links:
- CARB Informational Hearing on Prescribed Fire (July 25, 2019)
- Prescribed Fire Address to National Academy of Sciences (Sept. 24, 2020)
- Prescribed Fire Keynote Address to National Academy of Sciences (Sept. 25, 2020)
Air Quality Impacts of Prescribed Burning
Prescribed burning takes place after careful planning and under controlled conditions. Controlling where the smoke will go is an important part of every prescribed burn. If not carefully managed, the smoke – a mixture of toxic particles and gases – can be a nuisance to residents and businesses, and it can adversely impact community health. Smoke can contribute to levels of pollution that exceed health protective air quality standards. To minimize smoke impacts and protect public health, burners and air regulators work together to conduct burning under favorable atmospheric conditions.
How Prescribed Burns are Regulated
Approximately 125,000 acres of wildlands are treated each year in California using prescribed burning, and the rate of treatment is expected to rise as this tool is used more frequently to reduce the risk of catastrophic wildfires. Due to climate change, drought and other factors, today about 25 percent of the state's population – more than 11 million people – live in high-fire risk areas, including what's known as the wildland-urban interface, or the area between urban communities and wildlands. California’s smoke management program is an integrated state and local effort. The Smoke Management Guidelines, adopted by the California Air Resources Board, establish the fundamental framework for the program. Additionally, individual local air districts implement and enforce local rules and regulations. The Smoke Management Guidelines also require burners to consider alternatives to burning in planning their burn projects. However, when alternatives to burning are not feasible – due to excessive costs, technical inability, ecological needs or the potential to cause adverse environmental impacts – burning may be the only option.
Smoke Management Planning
Effective smoke management requires appropriate planning prior to conducting a prescribed burn. Before burning is allowed, a burner must complete the following planning steps:
- Register their burn with the air district;
- Obtain a burn permit from the local air district and/or fire agency;
- Submit a smoke management plan (SMP) to the air district; and
- Obtain the air district's approval of the SMP.
The SMP specifies the “smoke prescription,” which is an assessment of the air quality, meteorological, and fuel conditions of the proposed burn. Depending on the size and complexity of the burn, the SMP will contain some or all of the following information:
- Burner name and contact information
- Burn method and fuel type
- Nearby population centers
- Planned burn time
- Acceptable burn ignition conditions
- Contingency planning
- Burn monitoring procedures
- Location and size of the burn
- Expected pollutant emissions
- Smoke travel projections – including maps
- Duration of the burn
- Smoke minimization techniques
- Description of alternatives to burning
- Public notification procedures
Obtaining Burn Authorization
After the air district approves all the burn planning requirements, including the permit and smoke management plan, the burner may begin making final preparations to carry out the burn. This includes putting into place the resources needed to conduct the burn, notifying the public about the planned timing and specifics of the burn, and obtaining a final air district authorization to burn. The burner may contact the air district up to 96 hours prior to the desired burn time to obtain a forecast of the meteorology and air quality needed to safely conduct the burn. The burner will continue to work with the air district and CARB until the day of the burn to update the forecast information. Air district authorization to conduct a prescribed burn is provided to the burner no more than 24 hours prior to the burn.
Conducting Prescribed Burns
The individual who is granted the authority to burn (burn manager) is responsible for assuring that all conditions in the approved SMP and burn permit are met throughout the burn. Once the fire has been ignited, burners must make all reasonable efforts to assure the burn stays within its smoke plan prescription. If a burn goes out of its prescription, or adverse smoke impacts are observed, the burn manager will implement smoke mitigation measures as described in the SMP.