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 km2) 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 miles0 miles

1,000’1,000’

2,000’2,000’

3,000’3,000’

HuntingtonHuntingtonBeachBeach

Recharge AreaRecharge Area

Drinking Water WellsDrinking Water Wells

55 1010 1515 2020

0’0’

Groundwater Basin Cross Section

Santiago Pits

OCWD Functions:Protect Water QualityManage PumpingReplenish Basin

Sources of Water for Orange County

GroundwaterGroundwater (OCWD) provides (OCWD) provides 6969%% of the water used in North of the water used in North and Central Orange Countyand Central Orange County

Imported WaterImported Water (Metropolitan (Metropolitan Water District) is water from the Water District) is water from the Colorado River and Northern Colorado River and Northern California California

OCWD Water Supply

Santa Ana

River

54%

Reclamation 4%

Local Runoff 2%

Imported

Water 40%

Operational Recharge Facilities

Prado Prado DamDam

Santa Ana River FacilitiesSanta Ana River Facilities

Phase I GWR SystemPhase I GWR System

GWR System Components

Irvine

Fullerton

OceanOceanOutfallOutfall

OCWDOCWD

Groundwater BasinGroundwater Basin

Santa Ana River

N

Pacific Ocean

Santiago Creek

OCSDOCSDTreatmentTreatmentFacilitiesFacilities

HuntingtonBeach

AdvancedAdvancedWater PurificationWater PurificationFacilityFacility

Pumping Pumping FacilitiesFacilities

SeawaterSeawaterIntrusionIntrusion Barrier Barrier

Kraemer BasinKraemer Basin

GWR PipelineGWR Pipeline

Future Mid-BasinFuture Mid-BasinInjection/RechargeInjection/Recharge

Agency ResponsibilitiesAgency Responsibilities

OCSD - Wastewater Collection, Treatment and OCSD - Wastewater Collection, Treatment and

DisposalDisposal

OCWD - Manage and Protect the Orange County OCWD - Manage and Protect the Orange County

Groundwater Basin Groundwater Basin

First Partnership in 1972 for Wastewater ReclamationFirst Partnership in 1972 for Wastewater Reclamation

Primary Treatment

Secondary Treatment

Advanced WaterPurification ReuseSewage

SourceControl

OCSD OCWD

GWR System Advanced Water PurificationGWR System Advanced Water Purification

Ultraviolet Ultraviolet Light with Light with

HH22OO22

Brine Brine OCSD OutfallOCSD Outfall

Backwash Backwash OCSD Plant 1OCSD Plant 1

MicrofiltrationMicrofiltration(MF)(MF)

Reverse Reverse OsmosisOsmosis

(RO)(RO)

BarrierBarrier

OCSD OCSD Secondary Secondary

EffluentEffluent

Recharge Recharge BasinsBasins

Microfiltration System

86 Mgd US Filter 86 Mgd US Filter CMF-S Microfiltration CMF-S Microfiltration SystemSystem

Removes bacteria, Removes bacteria, protozoa, and protozoa, and suspended solidssuspended solids

0.2 micron pore size0.2 micron pore size In basin submersible In basin submersible

systemsystem

Reverse Osmosis System

70 Mgd Reverse 70 Mgd Reverse Osmosis SystemOsmosis System

Hydranautics ESPA-2 Hydranautics ESPA-2 MembranesMembranes

Recovery Rate: 85%Recovery Rate: 85% Removes salts, Removes salts,

viruses, organics and viruses, organics and pharmaceuticalspharmaceuticals

Pressure range: 150 Pressure range: 150 psi – 200 psipsi – 200 psi

Ultraviolet/Advanced Oxidation System

70 Mgd Trojan 70 Mgd Trojan UVPhox SystemUVPhox System

Low Pressure – High Low Pressure – High Output lamp systemOutput lamp system

Removes trace Removes trace organicsorganics

Uses Hydrogen Uses Hydrogen Peroxide to form an Peroxide to form an Advanced Oxidation Advanced Oxidation ProcessProcess

Why Are We Concerned About Trace Organics?

Some trace organics may contribute to health Some trace organics may contribute to health risksrisks

THMs and HAAs - associated with bladder THMs and HAAs - associated with bladder cancer and other riskscancer and other risks

NDMA and other nitrosamines - powerful NDMA and other nitrosamines - powerful carcinogenscarcinogens

Endocrine disruption observed in fish and Endocrine disruption observed in fish and other aquatic animalsother 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 systemsTHMs in most drinking water systems VOCs - chlorinated solvents, MTBE in many VOCs - chlorinated solvents, MTBE in many

groundwatersgroundwaters Pesticides, herbicides in ag/urban runoffPesticides, herbicides in ag/urban runoff Pharmaceuticals traces Pharmaceuticals traces

in wastewater dischargesin wastewater discharges USGS survey of water USGS survey of water

sources, NAWQA programsources, NAWQA program PPCPs, EPOCs, POPs, etc.PPCPs, EPOCs, POPs, etc.

SARWQH Study by OCWD

1994-2004 Study of 1994-2004 Study of Santa Ana River rechargeSanta Ana River recharge

Organics research by LLNL, Organics research by LLNL, USGS, Stanford, Berkeley, USGS, Stanford, Berkeley, MWD MWD

Examined DBPs, Total Examined DBPs, Total Organic Carbon, WW marker Organic Carbon, WW marker compoundscompounds

Scientific Advisory Panel by Scientific Advisory Panel by NWRINWRI

Found no evidence of water Found no evidence of water quality or health threat from quality or health threat from existing SAR rechargeexisting SAR recharge

Water Factory 21

Organics testing since 1970s by Organics testing since 1970s by Stanford and OCWD – GAC and ROStanford and OCWD – GAC and RO

No problems detected until NDMA in No problems detected until NDMA in 2000 and 1,4-dioxane in 20012000 and 1,4-dioxane in 2001

Treatment changed to control NDMA, Treatment changed to control NDMA, dioxanedioxane

GAC eliminated GAC eliminated Flow limitedFlow limited

to 5 MGD ROto 5 MGD RO UV/AOP addedUV/AOP added

Analytical Arms Race

ppm to ppt and beyond with ever more ppm to ppt and beyond with ever more powerful toolspowerful tools

Pesticides and VOCsPesticides and VOCs Pharmaceuticals, Pharmaceuticals,

personal care productspersonal care products European and US European and US

universities, USGSuniversities, USGS Lowest level detected Lowest level detected

becomes the new becomes the new benchmark for testingbenchmark for testing

Where Is The Science Leading Us?

More testing for more chemicals at lower levelsMore testing for more chemicals at lower levels Continuing Continuing analytical arms raceanalytical arms race More PPCPs and PHACs More PPCPs and PHACs Nanoparticles and other Nanoparticles and other

persistent organicspersistent organics Detection at ppq (pg/L) levelsDetection at ppq (pg/L) levels Increasing public concernIncreasing public concern Regulatory and legislative Regulatory and legislative

confusionconfusion

What is Really Needed Now?

Understanding of risk needs to catch up with Understanding of risk needs to catch up with analytical capabilitiesanalytical capabilities

AWWARF project 3085 on Toxicological AWWARF project 3085 on Toxicological RelevanceRelevance

Examination of what should we be testing and at Examination of what should we be testing and at what levelswhat levels, based on risk, based on risk

Better surrogates than TOC for assessing Better surrogates than TOC for assessing removal of trace organicsremoval of trace organics

Better understanding of relative efficacy of Better understanding of relative efficacy of treatment options – e.g. MBR, SAT, NF/RO, treatment options – e.g. MBR, SAT, NF/RO, AOPAOP