Pending EPA Health Advisory for PFOA and PFOS Board of Directors May 18, 2016

What are PFOA and PFOS ? PFOA = Perfluorooctanoic Acid (C8HF15O2) PFOS = Perfluoroctane Sulfonate (C8HF17O3S) Key ingredients/byproducts in the production of: Consumer Products: Teflon, Scotchgard, Stainmaster, Gore-Tex Polymers for aircraft and electronics Paper packaging and wrappers for food (e.g., microwave popcorn bags) Fire fighting foams Initially developed in 1940s Phase out in USA began in 2000s

PFOA & PFOS properties Very stable, resistant to degradation Resistant to water, grease, and stains (lipophobic) Newer & more sensitive laboratory technology has revealed widespread occurrence in environment Found in groundwater near manufacturing sites EPA review of animal testing & human epidemiological studies indicate exposure to PFOA & PFOS above certain levels may result in Cancer (e.g., kidney) Liver effects (e.g., tissue damage) Developmental effects on fetuses and infants

EPA Health Advisory Health Advisories are non-enforceable drinking water levels that are intended to provide technical guidance to state regulators, public health officials, and water utilities EPA Provisional Health Advisories issued in 2009 Developed for short-term (weeks to months) exposure PFOA = 400 ng/L (parts per trillion) PFOS = 200 ng/L (parts per trillion)

EPA Health Advisory, cont. New Pending EPA Lifetime Health Advisory Under development since 2009 preliminary value released Scheduled to be publically released tomorrow, May 19th Release possibly accelerated due to Flint water crisis and recently discovered PFOA/PFOS groundwater contamination in NY, VT, NH Will account for short-term exposure to sensitive sub-populations Likely to be set < 100 ng/L (parts per trillion) for combined PFOA + PFOS Likely EPA recommendations to accompany public release for utilities with PFOA/PFOS concentrations above the Health Advisory Confirm testing results and assess sources Inform consumers Limit exposure (e.g., via use of alternative sources, blending, treatment)

PFOA & PFOS Occurrence in Orange County PFOA & PFOS testing required nationally by EPA via Unregulated Contaminant Monitoring Rule (UCMR) 3 program OCWD laboratory developed required capability to fulfill testing requirements for all Producers serving >10,000 people PFOA reporting limit : 20 ng/L (parts per trillion) PFOS reporting limit: 40 ng/L (parts per trillion UCMR3 testing completed between 2013-2015 135 samples collected (e.g., wells, reservoirs, blending points) 5 Producers had detections related to groundwater All results below 2009 Provisional Health Advisories (200 & 400 ng/L)

Current OCWD Actions Assess sources Reviewing potential local industrial sites Sampled Santa Ana River and MWD-OC 28 (results due next week) Review GWRS data 2012 research study: PFOA & PFOS not detected in GWRS Final Product Water 2014 OCWD testing: PFOA & PFOS not detected in GWRS Final Product Water Confirms studies showing reverse osmosis is effective treatment Assess extent via future testing at select OCWD monitoring wells Coordination with potentially affected Producers

Coordination with Potentially Affected Producers Meetings and calls between EPA, CA DDW, Producers, and OCWD Coordination on clear communications for likely inquires from public & media Producers have plans in place or have already begun blending and/or use of alternative sources (e.g., shut off wells with detections) Specific future actions depend on lifetime Health Advisory concentration

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