Roadside Pesticide Spraying in Sonoma County

Hey Bob,

Who ever is spraying will likely need a permit. If there is a chance any of the pesticides will reach surface waters they will need to apply to the RWQCB to be covered by the state wide aquatic pesticide permit.  If Stephen or anyone else want to stop this practice they should contact the discharger.  They can also do sampling and if these pesticides or their breakdown products reach surface waters they can sue under the CWA.



They are spraying because of the fire hazard. I believe that this fire hazard should be handled by mowing these areas and using the material for compost rather than spraying.

I think that Highway 12 is a state highway and therefore it would be maintained by Cal Trans crews which would be state crews. These crews would not be under the control of our County Public Works Road Department unless they were some how contracted by the State.  I don’t think that our Supervisor has any direct control over this issue however he could probably register a more effective complaint to the State then we could. I will try to check with the County to verify who the lead agency is.

In the 1980’s I was licensed in all 5 categories of pesticide use and was assigned the task of purchasing, and tracking the herbicide applications for the sanitation division of Sonoma county Public Works.  This thankless and dubious distinction was assigned to me because I was the only one in my department who could pass the applicator test. From personal experience I agree with you that the broad based dispersal of these herbicides is a very bad idea. Far too much of this material is being sprayed in Sonoma County by all manner of agencies and private parties.

If Roundup or associated spreader sticker carriers are measurable as runoff in an irrigation ditch as a point source it might be subject to the Clean Water Act. I will discuss this with Jack.  The timing of this spraying was not likely to have been a political decision. It would have been based on the ambient temperature, wind, likelihood of rain, and crew scheduling considerations. Roundup requires 6 hours of warm dry weather to be effective.  Spraying cannot be done if the wind creates any produce drift. Rain would obviously wash the product off of the vegetation rendering it ineffective.  All of those elements are critical to the application of weed killers.

Bob Rawson

Caltrans appears to have started spraying road verges again. This is noticeable either side of the Fulton Rd/Hwy 12 interchange. It seemed to start almost immediately after the supervisor election.

Is RoundUp now less toxic to aquatic life now that it was a year ago?


Hi Folks–

The use of pesticides is not limited to Conventional ag practices or spraying programs against pests such as Glassy-winged sharpshooter or Light Brown Apple moth.  PG&E’s contractors are using a toxic mixture of several chemical formulations for control of annual, perennial and woody plants growing at the base of poles and within utility line right-of-ways, according to Californians for Alternatives to Toxics (see below).


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