Emerging Contaminants & the Groundwater Replenishment System Shivaji Deshmukh April 18, 2007

Orange County Water District OCWD, formed in 1933, is responsible for managing and protecting the Orange County groundwater basin OCWD encompasses 229,000 acres (925 km 2 ) in the lower watershed of the Santa Ana River (SAR) Orange County groundwater basin provides water for over 2.3 million people

NON-WATERBEARING FORMATION 0 miles 1,000’ 2,000’ 3,000’ HuntingtonBeach Recharge Area Drinking Water Wells ’ Groundwater Basin Cross Section Santiago Pits OCWD Functions:  Protect Water Quality  Manage Pumping  Replenish Basin

Sources of Water for Orange County Groundwater (OCWD) provides 69% of the water used in North and Central Orange County Groundwater (OCWD) provides 69% of the water used in North and Central Orange County Imported Water (Metropolitan Water District) is water from the Colorado River and Northern California Imported Water (Metropolitan Water District) is water from the Colorado River and Northern California

OCWD Water Supply Santa Ana River 54% Reclamation 4% Local Runoff 2% Imported Water 40%

Operational Recharge Facilities Prado Dam Santa Ana River Facilities Phase I GWR System

GWR System Components Irvine Fullerton Ocean Outfall OCWD Groundwater Basin Santa Ana River N Pacific Ocean Santiago Creek OCSD Treatment Facilities Huntington Beach Advanced Water Purification Facility Pumping Facilities Seawater Intrusion Barrier Kraemer Basin GWR Pipeline Future Mid-Basin Injection/Recharge

Agency Responsibilities OCSD - Wastewater Collection, Treatment and Disposal OCWD - Manage and Protect the Orange County Groundwater Basin First Partnership in 1972 for Wastewater Reclamation Primary Treatment Secondary Treatment Advanced Water Purification Reuse Sewage Source Control OCSDOCWD

GWR System Advanced Water Purification Ultraviolet Light with H 2 O 2 Brine OCSD Outfall Backwash OCSD Plant 1 Microfiltration(MF) Reverse Osmosis (RO) Barrier OCSD Secondary Effluent Recharge Basins

Microfiltration System 86 Mgd US Filter CMF-S Microfiltration System 86 Mgd US Filter CMF-S Microfiltration System Removes bacteria, protozoa, and suspended solids Removes bacteria, protozoa, and suspended solids 0.2 micron pore size 0.2 micron pore size In basin submersible system In basin submersible system

Reverse Osmosis System 70 Mgd Reverse Osmosis System 70 Mgd Reverse Osmosis System Hydranautics ESPA-2 Membranes Hydranautics ESPA-2 Membranes Recovery Rate: 85% Recovery Rate: 85% Removes salts, viruses, organics and pharmaceuticals Removes salts, viruses, organics and pharmaceuticals Pressure range: 150 psi – 200 psi Pressure range: 150 psi – 200 psi

Ultraviolet/Advanced Oxidation System 70 Mgd Trojan UVPhox System 70 Mgd Trojan UVPhox System Low Pressure – High Output lamp system Low Pressure – High Output lamp system Removes trace organics Removes trace organics Uses Hydrogen Peroxide to form an Advanced Oxidation Process Uses Hydrogen Peroxide to form an Advanced Oxidation Process

Why Are We Concerned About Trace Organics? Some trace organics may contribute to health risks Some trace organics may contribute to health risks THMs and HAAs - associated with bladder cancer and other risks THMs and HAAs - associated with bladder cancer and other risks NDMA and other nitrosamines - powerful carcinogens NDMA and other nitrosamines - powerful carcinogens Endocrine disruption observed in fish and other aquatic animals Endocrine disruption observed in fish and other aquatic animals Traces of pharmaceuticals - any risk? Traces of pharmaceuticals - any risk? Effects of mixtures? Effects of mixtures?

What Have We Found In U.S. Waters? THMs in most drinking water systems THMs in most drinking water systems VOCs - chlorinated solvents, MTBE in many groundwaters VOCs - chlorinated solvents, MTBE in many groundwaters Pesticides, herbicides in ag/urban runoff Pesticides, herbicides in ag/urban runoff Pharmaceuticals traces in wastewater discharges Pharmaceuticals traces in wastewater discharges USGS survey of water sources, NAWQA program USGS survey of water sources, NAWQA program PPCPs, EPOCs, POPs, etc. PPCPs, EPOCs, POPs, etc.

SARWQH Study by OCWD Study of Santa Ana River recharge Study of Santa Ana River recharge Organics research by LLNL, USGS, Stanford, Berkeley, MWD Organics research by LLNL, USGS, Stanford, Berkeley, MWD Examined DBPs, Total Organic Carbon, WW marker compounds Examined DBPs, Total Organic Carbon, WW marker compounds Scientific Advisory Panel by NWRI Scientific Advisory Panel by NWRI Found no evidence of water quality or health threat from existing SAR recharge Found no evidence of water quality or health threat from existing SAR recharge

Water Factory 21 Organics testing since 1970s by Stanford and OCWD – GAC and RO Organics testing since 1970s by Stanford and OCWD – GAC and RO No problems detected until NDMA in 2000 and 1,4-dioxane in 2001 No problems detected until NDMA in 2000 and 1,4-dioxane in 2001 Treatment changed to control NDMA, dioxane Treatment changed to control NDMA, dioxane GAC eliminated GAC eliminated Flow limited to 5 MGD RO Flow limited to 5 MGD RO UV/AOP added UV/AOP added

Analytical Arms Race ppm to ppt and beyond with ever more powerful tools ppm to ppt and beyond with ever more powerful tools Pesticides and VOCs Pesticides and VOCs Pharmaceuticals, personal care products Pharmaceuticals, personal care products European and US universities, USGS European and US universities, USGS Lowest level detected becomes the new benchmark for testing Lowest level detected becomes the new benchmark for testing

Where Is The Science Leading Us? More testing for more chemicals at lower levels More testing for more chemicals at lower levels Continuing analytical arms race Continuing analytical arms race More PPCPs and PHACs More PPCPs and PHACs Nanoparticles and other persistent organics Nanoparticles and other persistent organics Detection at ppq (pg/L) levels Detection at ppq (pg/L) levels Increasing public concern Increasing public concern Regulatory and legislative confusion Regulatory and legislative confusion

What is Really Needed Now? Understanding of risk needs to catch up with analytical capabilities Understanding of risk needs to catch up with analytical capabilities AWWARF project 3085 on Toxicological Relevance AWWARF project 3085 on Toxicological Relevance Examination of what should we be testing and at what levels, based on risk Examination of what should we be testing and at what levels, based on risk Better surrogates than TOC for assessing removal of trace organics Better surrogates than TOC for assessing removal of trace organics Better understanding of relative efficacy of treatment options – e.g. MBR, SAT, NF/RO, AOP Better understanding of relative efficacy of treatment options – e.g. MBR, SAT, NF/RO, AOP