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California Assembly Bill 99

Local control over Caltrans' pesticide use for road maintenance

AB99 would stop harmful pesticide (definition includes herbicide) use on sensitive ecosystems along highways in counties that have adopted official resolutions restricting pesticide use (like RoundUp/glyphosate). This bill would provide communities with some local control over the chemicals used by California Department of Transportation (Caltrans). Numerous counties in California have passed ordinances banning the use of synthetic pesticides for routine, non-emergency land maintenance. Caltrans, however, is exempt from local rules and is allowed to spray pesticides with far less oversight and environmental precautions.

AB99 was heard in the Environmental Safety and Toxic Materials Committee on March 28, 2023 (video of hearing available here). AB99 will be heard by the Transportation Committee on Monday April 24th.

AB99 will next be heard in front of the Transportation Committee on April 24th. The economic interests opposing this bill are strong but there is strength in numbers. If you are an organization, farm, or elected official (past and present), please show your support by signing on to one of our support letters by April 7th, 2023.


Organization support letter sign-on


Farmer and Rancher support letter sign-on


Elected official (past or present) letter sign on

Sonoma SASS was asked to provide information to the California State Assembly and participate in public hearings as an expert witness. For more information on AB99 and other educational initiatives on the benefits of managing roadsides with less chemical inputs visit


  1. Local governments do not currently have a voice over pesticides used on state highways.

  2. Caltrans has repeatedly refused to work with local jurisdictions to adopt maintenance strategies that consider residential neighborhoods, schools, sensitive environments, and organic farms along state highways. We need AB99 to provide a mechanism for Caltrans and local governments to start working together for mutually beneficial outcomes. 

  3. Caltrans’ reliance on chemical vegetation maintenance is outdated technology based on false assumptions that synthetic pesticides are safe and that using them saves money for society. 

  4. Caltrans has managed roads in Humboldt and Mendocino Counties without pesticides for non-emergency maintenance for over 35 years. Caltrans has lots of experience using alternatives such as mowing, guard rail ground coverings, grazing, and prescribed burns to keep roadsides clear and safe. 

  5. Numerous counties have passed resolutions banning various synthetic pesticides (like RoundUp/glyphosate). Caltrans is exempt from local rules and is allowed to spray pesticides with far less oversight and environmental precautions. 

  6. In Sonoma County, Caltrans typically uses thirty (30) times more concentrated pesticides per mile compared to Sonoma County Transportation and Public Works.

  7. In Sonoma County, Caltrans sprays pesticides in ditches that convey directly to the sensitive ecosystems of the Russian River and Laguna de Santa Rosa. The state water board does not allow local jurisdictions to do this, but Caltrans is exempt from these environmental protections.

  8. Caltrans’ spraying occurs during the daytime and on weekends, and Caltrans provides no advanced notification, despite frequent and documented accidental exposures to bicyclists and motorists.

  9. Chemical drift from roadside spraying has a disproportionate impact on marginalized and disadvantaged communities, including homeless communities, which are often located adjacent to state highways. 

  10. Reliance on synthetic pesticides contributes to climate change: synthetic pesticides stop soil from sequestering carbon, some pesticides release greenhouse gasses, and synthetic pesticides are manufactured from petroleum products.

  11. It is simply not true that Caltrans only uses herbicides as a last resort. Herbicides known to the State of CA to cause cancer are Caltrans’ primary maintenance tool. (see Caltrans’ Integrated Vegetation Management Plan). If it were not, Caltrans would not be afraid to transition away from using synthetic pesticides for routine, non-emergency,  road maintenance.

  12. The cost savings Caltrans claims by using synthetic pesticides does not include the cost on workers and society for chronic illnesses such as non-Hodgkin's Lymphoma and other cancers linked with RoundUp/glyphosate. They do not consider the large ecosystem costs of air and water pollution. Caltrans does not consider that they could save money by not having to purchase chemicals and train employees in safe pesticide use and report.

  13. Roadsides have the potential to be a benefit rather than a liability. Roads could function as wildlife corridors and pollinator habitats. The first step is to stop spraying them with pesticides.

  14. Pollinator highways have been shown by the University of Florida to crowd out invasive species and decrease maintenance costs while increasing ecosystem services by millions of dollars. Ecosystem services include crop pollination, which could be a boon for California almond, walnut, apple, blueberry, and pistachio farmers.

  15. There is a future paradigm that we could embrace that would benefit everyone: Caltrans, farmers, and communities, all together, if we could just see past the chemical paradigm. AB99, is the first baby step toward that big vision for our future. 

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