Pesticides and Toxins

West Marin is a unique environment with an exceptional community working for clean air, pure waters, healthy ecosystems, a diverse and thriving native flora and fauna, and the preservation of a rural, community spirit.  Prevention of unnecessary pesticide use is critical for the residents and sensitive ecosystems of West Marin.

EAC is a proud council member of the West Marin Mosquito Council (WMMC). The WMMC is a community group composed of representatives of our local public utilities and environmental groups focused on the use of pesticides in West Marin. 


West marin mosquito council

In 2004, West Marin was annexed into the Marin Sonoma Mosquito & Vector Control District.  Vector Control Districts have very broad power to abate vectors (CA Health and Safety Code Division 3, Section 2040-2055 and Division 3, Section 2060-2067). The residents of West Marin reacted to the proposed use of toxic chemicals being introduced to the environment to abate mosquitoes.

In response to 80% of Bolinas voters approved a poll to direct Bolinas Community Public Utility District (BCPUD) to take measures to protect against the use of pesticides within BCPUD boundaries, the Bolinas Lagoon and its watershed.

Residents of greater West Marin supported this approach and the original advisory committee expanded in 2006 and became the West Marin Mosquito Control Coordinating Council (WMMCCC). The expanded council consists of 18 representatives from West Marin unincorporated villages, special districts, state and national parks, and organic and environmental organizations.

In 2006, a non-toxic protocol was signed limiting the methods used to control mosquitoes in West Marin to education, prevention (physical and mechanical) and biologic treatments approved for certified organic farms.

The introduction of toxic pesticides and herbicides into the environment threatens aquatic and terrestrial wildlife, human health, our local economy, organic farms and gardens. The West Marin Mosquito Council Agreement ensures the precautionary principle is in effect by limiting the introduction of toxic pesticides and herbicides into our environment. The agreement is a model for other communities in Marin County and beyond.

The original agreement was updated and renewed in 2007 and in 2009 was extended for a period of five years (2014). The agreement expires in June 2016 and is currently being negotiated by representatives of the West Marin Mosquito Council and the Marin Sonoma Mosquito and Vector Control District.

wmmc and vector control - 2016 agreement renewal

May 9, 2016, the WMMC voted on an agreement renewal with six supported votes, two opposed, and one abstained.

The WMMC renewed an agreement with the Marin Sonoma Mosquito and Vector Control District (MSMVCD).  Since the fall of 2015, representatives of the WMMC and MSMVCD participated in renegotiation meetings with former District Four Supervisor Steve Kinsey. 

The WMMC agreement restricts the MSMVCD’s use of pesticides, limiting the toolbox of over twenty-two mosquito pesticide treatments to five.  The Organic Materials Review Institute (OMRI) approves four of the five pesticides listed in the current agreement.

Negotiations were challenging, as the MSMVCD required the addition of the known estuarine and marine invertebrate toxin, methoprene, to the list of acceptable pesticides to control mosquito populations. The inclusion of methoprene has been introduced to replace Agnique MMF, the one non-OMRI approved pesticide on the 2006 agreement.

Agnique MMF is currently in use to abate the pupa life-stage of mosquitoes.  With the discontinuation of Agnique MMF, the MSMVCD would like to replace it with methoprene, as Altosid Briquets to be applied to problematic septic tanks that are not properly screened and sealed. Several WMMC members are opposed to this inclusion.

Additionally, several members of the WMMC would like the inclusion of the San Geronimo Valley into the agreement to ensure a watershed based on the flow of the San Geronimo and Lagunitas Creeks into Tomales Bay. At this time, the WMMC understands the MSMVCD is currently using a variety of the 22 mosquito treatment pesticides to treat mosquitoes in the San Geronimo Valley. This is concerning, as it may negatively affect the health of the residents, sensitive ecosystems, and species like the red-legged frog, salmon, and aquatic invertebrates.

Tomales Bay Watershed includes the San Geronimo Valley, which is currently not included in the WMMC and MSMVCD agreement to limit the use of pesticides.

Tomales Bay Watershed includes the San Geronimo Valley, which is currently not included in the WMMC and MSMVCD agreement to limit the use of pesticides.

Improperly sealed and covered septic tanks are responsible for the majority of mosquito breeding problems in West Marin.

Improperly sealed and covered septic tanks are responsible for the majority of mosquito breeding problems in West Marin.

EAC’s Position

As one of the environmental WMMC members, EAC must consider the environmental impacts introduced pesticides have on residents and sensitive ecosystems.

  • The use of pesticides, including methoprene—that are not OMRI listed—are incompatible with the protection of West Marin’s community health, watersheds, organic farms, and wildlife.
  • Inclusion of the San Geronimo Valley is critical for a healthy Tomales Bay watershed. Based on the challenges in the current negotiations, the San Geronimo Valley may have to be achieved after an agreement is reached with WMMC. EAC will continue to work on this issue to ensure that the San Geronimo Valley will be included in the future.
  • Prevention needs to be addressed. Public outreach, education, and prevention program to seal and screen septic tanks in West Marin villages is important to reduce the number of mosquitos in our area.

EAC is adamantly opposed to the addition of methoprene, and will cast a no vote on any agreement renewal including methoprene (Altosid Briquets).