Water Challenges Water Challenges --Past, Present, and FuturePast, Present, and Future

Perry L. McCartyPerry L. McCartyDepartment of Civil and Environmental EngineeringDepartment of Civil and Environmental Engineering

Stanford UniversityStanford University

Water Supply and Distribution

Listed by the National Academy of Engineering as among the Greatest Engineering Achievements of the 20th Century

50 Years Ago -

The arrival of new problems - bring a paradigm shift

Cuyahoga River, Cleveland, Ohio -1952 - “Burn on, Big River, Burn on”

Photographer - James Thomas

San Francisco - 1971 Oil Spill

National Geographic magazine photographs

TorontoToronto

ChicagoChicago Los Angeles CountyLos Angeles County

San JoseSan Jose

Aerobic - Activated Sludge Treatment

ABS Synthetic Detergents – 1950s

Photographer - Bruce M. Wyckoff

Whittier Narrows, CA1962 Wastewater Reuse

1962

1965 - South Lake TahoeAdvanced Wastewater Treatment

1968 - Direct Potable Reuse, Windhoek, Namibia

Orange County, California1976 - Water Factory 21

Super Fund - 1980

Global Annual Production of Synthetic Organic Material (Source UNEP, 1987)

0

100

200

300

1920 1940 1960 1980 2000Mill

ion

Tons

per

Yea

r

Emerging Chemicals of Concern

• Perchlorate (ClO4-)

• Nitrosodimethylamine(NDMA)

• 1,4-Dioxane• Fire retardants– PBDE– Perfluoros

• Pharmaceuticals• Endocrine disrupters– Fish Feminization

Worldwide Problem

• Over 1 billion people lack access to safe drinking water

• 2.4 billion lack access to adequate sanitation facilities

• In 1998, 2.2 million people estimated to have died of diarrhealdiseases

• Millions suffer from parasitic worm infections

“…Supreme Court ruled that carbon dioxide and other so-called greenhouse gases

are air pollutants…”Wall Street Journal, April 3, 2007

New York TimesApril 3, 2007

San Jose Mercury NewsApril 3, 2007

Wall Street JournalApril 3, 2007

An Inconvenient Truth

Question

What is impact of wastes and waste treatment

on greenhouse gas emissions?

Global Warming PotentialCO2 = 1

310Nitrous Oxide (N2O)

21Methane (CH4)

1Carbon Dioxide (CO2)

GWPGas

Global Anthropogenic Greenhouse Gas Emissions

US EPA, Global Mitigation of Non-CO2 Greenhouse Gases, June 2006, EPA 430-06-005

CO2

76%

CH4

15%

N2O8%

Other 1%

Anaerobic Digestion, Elsevier (1981)

Anaerobic Pathways to Methane Formation

Anaerobic Treatment

Anaerobic Treatment in China

2000 Non-CO2 Emissions -% of Total CO2eq

US EPA, Global Mitigation of Non-CO2 Greenhouse Gases, June 2006, EPA 430-06-005

0

5

10

15

20

25

World USA

Perc

ent

FossilFuels

Wastes

OtherAgricul-

ture

EntericFerment

Rice

2000 Waste CH4+N2O Emissions -% of Total CO2eq

US EPA, Global Mitigation of Non-CO2 Greenhouse Gases, June 2006, EPA 430-06-005

0

1

2

3

4

5

World USA

Perc

ent

Waste-Water

Manure

SolidWastes

CH4

N2O

1.8

1.0

1.3

2.1

0.90.6

TUESDAY, NOVEMBER 6, 2007 SAN JOSE MERCURY NEWS

SAN JOSEMERCURY NEWS

TUESDAY,NOVEMBER 6, 2007

Water-Related Energy Consumption in California (2001)

California Energy Commission, CEC-700-2005-001-SF (2005)

0

5

10

15

20

25

30

35

1 2

% o

f CA

Ene

rgy

Usa

ge

Electricity Natural Gas

Heating &Cooling

End UseT & T

kWh/Million Gallons for Urban Water in California

12,7003,950Total

2,5002,500Wastewater Treat.

1,2001,200Water Distribution

100100Water Treatment

8,900150Supply & Convey

SouthNorth

California Energy Commission, CEC-700-2005-001-SF (2005)

Rene Dubois

“Think globally, act locally”

2005 - U. S. Anthropogenic Greenhouse Gas Emissions

Source: US EPA, Inventory of U. S. Greenhouse Gas Emissions and Sinks:1990-2005, Draft, February 20, 2007

Passenger Car8.7%

Question

How can we reduce energy consumption and

greenhouse emissions from wastewater treatment?

2007 Google-Map Data ©NAVTEQTM

Palo Alto Wastewater Treatment Plant

• Primary settling

• Aerobic BOD removal

• Nitrification

• Sludge incineration

San Jose Wastewater Treatment Plant

• Primary settling

• Aerobic BOD removal

• Nitrification

• Sludge digestion

Sunnyvale WTPSunnyvale WTPStabilization PondsStabilization Ponds

2007Google-Map Data ©NAVTEQTM

2007Google-Map Data ©NAVTEQTM

PrimaryTanks

Influent

2007Google-Map Data ©NAVTEQTM

StabilizationPonds

PrimaryTanks

Influent

2007Google-Map Data ©NAVTEQTM

StabilizationPonds

PrimaryTanks

Influent

Flotation

2007Google-Map Data ©NAVTEQTM

Nitrification

Flotation

StabilizationPonds

PrimaryTanks

Influent

2007Google-Map Data ©NAVTEQTM

Filtration

Nitrification

Flotation

StabilizationPonds

PrimaryTanks

Influent

2007Google-Map Data ©NAVTEQTM

Disinfection

Filtration

Nitrification

Flotation

StabilizationPonds

PrimaryTanks

Influent

2007Google-Map Data ©NAVTEQTM

Effluent

Disinfection

Filtration

Nitrification

Flotation

StabilizationPonds

PrimaryTanks

Influent

2007Google-Map Data ©NAVTEQTM

PrimaryTanks

Digesters

2007Google-Map Data ©NAVTEQTM

Flotation

PrimaryTanks

Digesters

2007Google-Map Data ©NAVTEQTM

COCO22 + CH+ CH44

Flotation

PrimaryTanks

Digesters

2007Google-Map Data ©NAVTEQTM

DryingBeds

COCO22 + CH+ CH44

Flotation

PrimaryTanks

Digesters

5O25CO2+2H2O+NH3Soluble

C5H7O2NBOD

ParticulateC5H7O2N

BOD Conversion to Algae

Cogeneration at Sunnyvale Wastewater Treatment Plant

CO2 & N2O Release in Nitrification

NH3 + 202 + NaHCO3 = NaNO3 + 2H2O + CO2

CO2

PowerAir

Plus trace of N2O

CO2 Equivalents (1000 kg/day)Treatment of 10,000 kg BOD5 /day

6.212.229.0Total

(6.6)(3.3)2.2Energy Usage

1.22.82.8Nitrification

1.41.1CH4 Loss (1%)

6.85.4CH4 Oxidation

3.42.6Digestion-CO2

20.4Incineration

3.63.6BOD Removal

Algae + Digestion

Aerobic + Digestion

Aerobic + Incineration

Energy Costs - US$1000/yearTreatment of 10,000 kg BOD5 /day

(366)(97)236Total

(378)(299)Excess Power

122458CO2 Penalty

178178Oxygen Supply

Algae + Digestion

Aerobic + Digestion

Aerobic + Incineration

CO2 penalty = US$20/tonC

Water Reuse in Monterey County

Monterey RegionalWater Pollution Control Agency

• Largest wastewater recycle in U.S. for irrigated crops• Irrigates 12,000 acres• 34.2 billion gallons produced since 1997

Water Reuse in Monterey County

Conclusions for Sustainability

• A reevaluation of waste treatment alternatives is needed because of climate change concerns

• Methane from wastes must be contained

• Desired alternatives are those that reduce both greenhouse gas emissions and power consumption

• Anaerobic treatment is likely to be an attractive component of the alternatives

• Wastewater is a resource for water, energy, and plant nutrients

Rene Dubois

"Trend is not destiny"

Ancient Chinese Proverb

"Unless we change our direction, we are likely to end up where

we are headed"

Thank you!Thank you!