1 update ocean desalination feasibility studies karl seckel assistant general manager

1

Update

Ocean Desalination Feasibility Studies

Karl Seckel Assistant General Manager

2

South Orange County ChallengesSouth Orange County Challenges

Region is 95% dependent on imported water to meet potable demand

Single water treatment plant and two pipelines supply imported water to more than 500,000 residents and businesses

Limited groundwater, surface water

Emergency outage of the imported water delivery system could cause significant problems for residents, businesses, and the economy

3

Planned Reliability Improvements Planned Reliability Improvements

System Reliability Improvements

– Lined and covered reservoirs

– Interconnections

– Ocean desalination

Supply Reliability Improvements

– Water recycling

– Water use efficiency/conservation

– Groundwater recovery projects

– Ocean desalination

4

Planned Reliability Improvements (cont’d)

Planned Reliability Improvements (cont’d)

Ocean desalination is one part of the solution – and provides two benefits:

– A reliable local water source

– Emergency water supply during outages of the imported delivery system

Camp Pendleton Ocean Desal

Dana Point Ocean Desal

Orange County Cross Connector

Groundwater EmergencyService

Coastal Junction Pump Connection IRWD to South County Pump Station

IRWD to JTM P

PP

D

D

Diemer Filtration Plant

GW

Coastal Pipeline to SD County

Central PoolAugmentation Project Alignments

P

P

Lake Mathews

Projects Further Out in Time:

Camp Pendleton Ocean Desal

Central Pool Augmentation Project

Coastal Pipeline to SD County

Orange County Cross $30 25+ ConnectorGW Emergency $15 15Service

Coastal Junction $2 20Pump Connection

IRWD to JTM $16 50

IRWD to SCPS $23 50

Dana Point Ocean Desal $? ?

Total $166 135±(1)

(1) Project Capacities are not all additive

Cost Capacity Component $M CFS

SOUTH ORANGE COUNTYWATER RELIABILITY PROJECTS

SOUTH ORANGE COUNTYWATER RELIABILITY PROJECTS

Upper & Lower $80 32Chiquita Reservoirs

Upper Chiquita Reservoir

Lower Chiquita Reservoir

6

Dana Point Ocean DesalinationDana Point Ocean DesalinationSubsurface Intake System No entrainment/impingement impacts

Reduces ocean construction impacts

Improved chance for permitting approval

Pretreatment – natural sand and gravel filtration could eliminate need for costly pre-filtration step

Questions to be Answered: Capacity of intake system

Which technology to use for well intake

Power source for treatment plant

Use of existing outfall system for brine discharge

7

Working with Federal, State and Local AgenciesWorking with Federal, State and Local Agencies U.S. EPA U.S. Bureau of Reclamation U.S. Fish and Wildlife Service U.S. Army Corps of Engineers California Department of Water Resources California State Lands Commission California Department of Parks and Recreation California Department of Fish and Game California Coastal Commission San Diego Regional Water Quality Control Board County of Orange City of Dana Point South Coast Water District Metropolitan Water District of Southern California

8

Phase 1 Exploratory Test Boring SitesPhase 1 Exploratory Test Boring Sites

Bore Hole//Monitoring Well

Bore Hole

Future Desalination Site

SOCWA Outfall

B3

B1

B2/M1

B4/M2

9

Dana Point Phase 1 Hydrogeology ConclusionsDana Point Phase 1 Hydrogeology Conclusions

The permeability of the aquifer formation looks promising

Need information on the formations under ocean floor

Further testing needed to:

– Estimate production capacityof the aquifer

– Analyze water quality

10

Phase 2 Near Shore Test Drilling ApproachPhase 2 Near Shore Test Drilling Approach

Ocean SurfaceLand Surface

Fres

h W

ater

200 to 250 feet ±

Slant test well

Infiltration

Drill Rig

Ocean Bottom

Main Aquifer 40 to 130 feet ±

Salt

Wat

er

23o

Temporary Vault

11

Full Scale Slant Well ConceptFull Scale Slant Well Concept

Subsurface Slant Wells & Collector

Intake System SOCWA Outfall

Future Desalination Plant Site

12

Slant Well Intake System ConceptSlant Well Intake System Concept

P

OceanDesal Plant

gravity flow intocaisson forocean water intake

screened slant wellburiedbeachcaisson or pipecollector

pumpto plant

ocean surface

tunneled pipeline

1500 feet± from beach

pressuredifferential

Drill Rig

ocean floor

beach

land

natural filtration

13

Questions or Comments?

Karl Seckel Assistant General Manager