Caltrans statement on herbicide spraying along Route 84


To Whom It May Concern:

RE: Herbicide Spraying along Route 84 in San Mateo County

March 10, 2015

Thank you for bringing your concerns about Caltrans' herbicide spraying operations along Route 84 and the potential effects on the environment.

The goal of the herbicide spraying is to provide fire risk control in the safest, most efficient manner available. Caltrans follows best practices for vegetation management to provide a safe work environment for our Maintenance workers and the traveling public, and to protect the environment.

In collaboration with San Mateo County to create fire safe zones, there is a Memorandum of Understanding (MOU) Establishing the San Mateo County Weed Management Area (Dec 11, 2000). The purpose of this MOU is to "cooperate and coordinate activities necessary to prevent the introduction, establishment and spread of noxious weeds in San Mateo County".

Caltrans has a vegetation control program with safety standards that dictate how we perform weed abatement along the many miles of freeway that we service in the nine Bay Area counties.

We have evaluated mowing as an alternative to herbicide application and have determined that it is not feasible to implement this activity in a manner that is safe. Limited sight distance around the curves along Route 84 is a major safety concern. Safe locations for mowing equipment to be dropped off and loaded safely are not available along Route 84, and a mowing operation is stationary, requiring additional resources (signage, lane closures, flagman). Mowing can also cause resprouting from seeds spread with the mower blades. The ideal situation would be to mow and apply herbicide to the cut stems where the open wound can absorb the herbicide. Without the option to mow, we have to depend on the hot weather for the stomatas to open on herbicide application. In general, the use of herbicides is more effective and efficient. Herbicide application guarantees the eradication of the noxious weeds and promotes fire safety and can be done quickly. Mowing along Route 84 could take four to six weeks to complete, if it were safe to do so.

Caltrans is mindful of the environment with applying herbicides. This has been our practice yearly along Route 84. The use of herbicides will vary between 2 feet to 6 feet from the edge of pavement and we will maintain a 25 to 50 foot buffer from all drains, creeks and waterways. The types of chemicals used are registered by the Environmental Protection Agency (EPA). In California, pesticides undergo additional scrutiny before being labeled for use in this state.

To further ensure the procedures that Caltrans have in place fully comply with EPA standards, a certified Qualified Applicator will be on site (a Qualified Applicator certificate is issued by the Department of Pesticide Regulation to handle/spray Restricted Danger/Poison material). Even though Caltrans does not spray Restricted Danger/Poison material, the certification/training gives our employees the knowledge to handle/spray all pesticides in a safe manner. The Qualified Applicator supervises the whole spray operation from loading to the end of disposing/ cleaning the containers and spray rig and is equipped to handle emergencies in case accidents happen whether through spill or pesticide exposures. Properties displaying "No Spray Sign' will not be sprayed, and no spraying will take place in the towns of La Honda or San Gregario.

Community Outreach Performed:

• Community Advisory sent out on February 25, 2015 to residents and media.

• Caltrans distributed flyers within the project limits from post mile 1.0 to 14.93. Flyer was given to the community center in La Honda.

• Updated Community Advisory sent out on March 3, 2015 to residents and media for 1 week postponement.

• Updated Community Advisory will be sent out today to residents and media for 1 week postponement. (weather permitting)

• Response letter to e-mails sent out on March 10, 2015 to residents.

The advisories informed residents that the following chemicals and procedures are proposed for application along Route 84 for effective vegetation control:


• Matrix SG @ 3 oz/acre at 50 gal dilution

• Milestone @ 5 oz/acre at 50 gal dilution

• EsplAnade 200 SC @ 5 oz/acre at 50 gal dilution


• Spray in the morning to reduce temperature inversion

• Proper 8004 nozzle and 40 psi to reduce drift

• Do not spray in driveways and mailbox congregations

• 50 feet buffers from creeks and waterways

• Do not spray in any standing water including puddles

• Do not spray in City limits of La Honda and San Gregorio

An Advanced Warning Vehicle will be used to warn the traveling public about the slow traffic ahead due to the on-going herbicide spraying operation.

Given the best practices in place for the choice of chemicals, the amount applied, methods of application, and the successes of previous years, the weed abatement along Route 84 using herbicide spraying will not pose a threat to the environment.

This two day herbicide spraying operation takes place once a year.

If you have any further questions or concerns, please contact Public Information Officer Gidget Navarro at (510) 286-5574.

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