POTABLE REUSE: When Are We Going to Drink It?

Bahman SheikhBahman.sheikh@gmail.com

April 28, 2010

Presentation Outline

• Demand for Water and Supply• Evolution of Water Recycling• Direct or Indirect?• Who Is Drinking Recycled Water?• Who Failed to Implement Potable Reuse• Advantages of Potable Reuse• Energy Use, Cost Comparisons• Obstacles to Potable Reuse• What Are We Waiting For?

Evolution of Water Reuse:

to Direct Potable Reuse

to Indirect Potable Reuse

to Groundwater Recharge

to Industrial Reuse

to Landscape Irrigation

From Agricultural Reuse

Crops Grown with Recycled Water76%

1.0%

1.8%2.3%

4.8%1.1%

ArtichokesStrawberries

Lettuce

CeleryBroccoliCauliflower

Israel, Dan Region Project

Direct or Indirect

• Definitions• Water Quality Differences– Direct; Nearly Pure Water– Indirect; Blended with Runoff, Groundwater

• Role of the Environmental Buffer– Psychological Barrier– Regulatory CYA– Technological Reasons:

• Storage• Quality Control

• Which Will It Be?

Successful Potable Reuse Examples

• Unplanned Potable Reuse along Major Rivers• Windhoek• Alexandria, Virginia• Singapore• Orange County Groundwater Replenishment• Los Angeles County Seawater Intrusion Barriers• LA, Montebello Forebay Groundwater Recharge• El Paso, Texas• Chanute, Kansas 1956-57• Denver DPR Demonstration Study 1985-88

Failed Potable Reuse Projects

• San Diego “Repurified Water”– Senatorial Candidate’s Populism– “Toilet-to-Tap”– “Effluent of the Affluent”

• City of Los Angeles “East Valley Project”– Mayoral Candidate’s Demagoguery– San Fernando Valley Separatist Movement

• Livermore “Pure Water Revival”– Anti-Growth Opposition– Disingenuous Water Quality Claims

Advantages of Potable Reuse• Lower Distribution System Costs• Higher Water Quality– Removal of Microconstituents (aka CECs)– Removal of Salts– Improvement of Existing Water Sources

• Greater Reliability of Supply Resource• Stoppage of Effluent Discharge to Environment

Obstacles to Potable Reuse

• Public Perception– Alternative Supplies– Costs– Water Quality– “Yuck” Factor

• Political Will• Up-Front Costs• Regulatory Hurdles• “Unknowns”

Recycled Water

Groundwater Pumping

Brackish Water Desal

Imported Water (N CA)

Ocean Water Desal

0 1,000 2,000 3,000 4,000 5,000

Energy Use, kWh/AF

SOURCE: Inland Empire Utilities Agency

Cost Comparisons

Reverse Osmosis Cost Trends

0

1

2

3

4

5

1950 1960 1970 1980 1990 2000

Year

$/cu

bic

met

er

Reverse Osmosis Technology

Micro Filtration

Bacteria

Pathogens

Virus

SaltWater

Water

Reverse Osmosis

Sulaibiya, Kuwait Orange County, CA

Singapore

Drinking Water Purified from Wastewater

What Are We Waiting for?• The Right Time Is NOW!

– We Have the Technology– The Price Is Right– Our Mindset Is Not There Yet

• Political Will Is Lacking• Perceptions Are Out of Touch with Reality

– Quality Is Far Better than Conventional Potable Supplies– Public Education / Outreach Is Lacking– Need to Get Over the Fear Factor, Yuck Factor, Unknown…

• Crisis Atmosphere Would Push Potable Reuse– Drought (Atmospheric, Legal, Climate Change)– Population Explosion– Competing Demands for Water