Pesticides and Urban Water Quality in California. A Stormwater Perspective Dave Tamayo, Environmental Specialist Sacramento County Stormwater Program Chair, CASQA Pesticides Subcommittee Western Region IPM Ant Workshop Riverside, CA August 20, 2008

Acknowledgements  Kelly Moran, TDC Environmental  San Francisco Estuary Project  Laura Speare, SF Estuary Project  Geoff Brosseau, CASQA  Bill Johnson, Tom Mumley SFRWQCB  CASQA Pesticides Subcommittee  Loren Oki, Jay Gan. Univ of California

Why do Stormwater Programs care about pesticides?

Clean Water Act liability for pesticide toxicity  303d listing  TMDLs  Permit provisions  Citizen suits Off with their heads!

Phase Out Reduced Diazinon Levels in Chollas Creek (San Diego) Source: City of San Diego, Chollas Creek TMDL Source Loading, Best Management Practices, and Monitoring Strategy Assessment, prepared by Weston Solutions, September 2006.

Bay Area Diazinon & Chlorpyrifos Use Decreased from Pounds of Active Ingredient

BUT… Application of Bay Area Pyrethroids Use Almost Tripled Between 2001 & 2004 (as measured in permethrin equivalents) Estimated use of study list pyrethroids in the San Francisco Bay Area (permethrin equivalents)

We’ve got problems right now: Pyrethroids are causing widespread toxicity in California urban waters.  Main problem—sediment toxicity  Some water column samples toxic  Widespread toxicity found in urban California streams –Urban>>Agricultural areas Hyalella azteca (amphipod)

Locations of pyrethroid detections and associated toxicity

SWAMP Pesticide Sampling Sites

Pyrethroids observed by region Holmes et al 2008

Figure: Holmes et al 2008 Pyrethroid Toxicity is Statewide

Pyrethroid Toxicity in Urban Creeks is Severe  Pyrethroids detected in almost 100% of urban creek sediment samples  Multiple pyrethroids contribute to toxicity –Bifenthrin, cyfluthrin & cypermethrin biggest  Majority of tested creeks have toxicity  Direct connection to urban runoff shown  # Toxic units (TUs) varies – 20 TU found –Many samples >10 TU Photo courtesy California Water Board Source: Publications by Weston et al., urban runoff program data and California Water Board data.

We need to get off the pesticide merry-go-round.

Where Are More Pesticides Used in California? Photo courtesy USGS

Urban Pesticide Facts  >900 registered pesticide active ingredients  >11,000 registered pesticide products  At least half of California pesticide use is in urban areas –Technically, 75% is urban –About half of urban use is chlorine & sodium hypochlorite

Which Pesticide Uses Are Most Important for Water Quality?

Urban Runoff Carries Pesticides to Creeks Figure courtesy SF Bay Regional Water Board, based on U.C. IPM Project drawing

Toxicity Matters: Permethrin Equivalents San Francisco Bay Area Study List Pyrethroids Urban Uses, 2003 by Active Ingredient By Permethrin Equivalents

Almost 90% of Toxicity in California Pyrethroids Use is in Urban Areas Estimated use of study list pyrethroids in California, 2004 (permethrin equivalents)

All User Groups Apply Pyrethroids Outdoors in the SF Bay Area Estimated use of study list pyrethroids in the San Francisco Bay Area, 2004 (permethrin equivalents)

Myth: Public outreach is the solution.  Outreach is expensive  10-20% behavior change  Regulatory action needed

Progress: Pre-construction termiticides  Label changes to reduce chance of sediment runoff University of Hawaii Termite Project

Progress: Structural Pest Control Board New Regulations (pending OAL approval)  Progressive definition of structural IPM  IPM training required to get most licenses  IPM Continuing Education requirements for all licensees  Establish statewide IPM Certification program  Allow promotion of IPM environmental benefits

Whose job is it, anyway? This is what EPA says: “When EPA approves a particular pesticide for registration, the Agency has assessed the chemical and found that, when used according to label directions, it does not pose unreasonable risk to public health and the environment.”

Contact Dave Tamayo, Environmental Specialist County of Sacramento Stormwater Program Co-Chair, CASQA Pesticides Subcommittee

Whose job is it, anyway? CA Department of Pesticide Regulation  Cannot change EPA label  Establish use restrictions  Pesticide use reports  “Environmental certification”  Re-evaluation