SUSTAINABLE URBAN WATER INFRASTRUCTURE SYSTEMS

Presentation, Urban Water Management: Issues and Opportunities, 2009

Universities Council on Water Resources Conference, Chicago

James P. Heaney

Dept. of Environmental Engineering Sciences

University of Florida

July 2009

Acknowledgements

• Research sponsors during the past decade:– Amer. Water Works Assn. Res. Foundation

– US EPA Edison, NJ

– National Coop. Highway Research Program

– Water Environment Research Foundation

– U.S. Army Corps of Engineers

– Florida Dept. of Environmental Protection

– SF, SWF, and St. Johns River WMDs

Graduate Student Collaborators

• University of Colorado (1991-2003)

– Lynn Buhlig, Peter Mayer, Jeff Harpring, Laurel

Stadjuhar, Beorn Courtney, Istvan Lippai, Joong Lee,

David Sample, Leonard Wright, Donald Alexander,

Derek Rapp, and Chelisa Pack

• University of Florida (2003-2009)

– Ruben Kertesz, Scott Knight, Dan Reisinger, Matthew

Rembold, Ken Friedman, Jackie Martin, Rebecca

McLarty, Miguel Morales, John Palenchar, Leighton

Walker, Camilo Cornejos and Lukasz Ziemba

Sustainable Urban Water

Infrastructure Systems• Water Supply

– National studies of the nature of urban water use

– Impact of conservation in Florida

– Dual water systems

• Waste Water– CSO and SSO control

– Reuse in Florida

• Storm Water– Characterization

– Evaluation of LID & Other BMPs

– Reuse

• System Integration

Sustainable Urban Water

Infrastructure Systems• Water Supply

– National studies of the nature of urban water use

– Impact of conservation in Florida

– Dual water systems

• Waste Water– CSO and SSO control

– Reuse in Florida

• Storm Water– Characterization

– Evaluation of LID & Other BMPs

– Reuse

• System Integration-SHOW DUBAI

Micro-Water Use Studies at the U. of Colorado

Mayer, DeOreo, and Heaney

1995-1999

• Monitored flow to each customer every 10 seconds at the water meter

• Developed software (Trace Wizard) to process these high frequency signals into water using events

• Used this method on a national AWWARF study of 1,200 homes in 12 cities

• First definitive evidence that water conservation can be very cost-effective

Trace Wizard example-Flow

measured every 10 seconds

Shower (red) and clothes washer cycles (blue)

Indoor water use is very similar across U.S.-outdoor water

use is not-AWWARF REUWS(Mayer et al. 1999)

Water Use Statistics from 1999 REUWS

Sample Persons/ Mean Indoor Outdoor

City Size house gpcd gpcd gpcd

Waterloo 95 3.1 77.5 70.6 6.9

Seattle 99 2.8 78.3 57.1 21.2

Tampa 99 2.4 100.6 65.8 34.8

Lompoc 100 2.8 104.8 65.8 39.0

Eugene 98 2.5 134.7 83.5 51.2

Boulder 100 2.4 147.9 64.7 83.2

San Diego 100 2.7 159.1 58.3 100.8

Denver 99 2.7 175.5 69.3 106.2

Phoenix 100 2.9 230.6 77.6 153.0

Scottsdale 99 2.3 233.9 81.4 152.5

Walnut Valley WD 99 3.3 163.1 67.8 95.3

Las Virgenes MWD 100 3.1 258.0 69.6 188.4

Total 1,188

Average 99.0 2.8 155.3 69.3 86.0

Standard deviation 1.4 0.3 61.0 8.2 57.7

Coef. of variation 0.01 0.11 0.39 0.12 0.67

Tampa Indoor Retrofit and

Conservation PotentialAquacraft (2004)

Pre/Post Indoor Per Capita Use in 26 Retrofit Homes

in Tampa Based on 10 Second Data

Aquacraft (2004)

77.0

38.5

0

10

20

30

40

50

60

70

80

Gal

/Cap

/Day

Indoor

Baseline Post-Retrofit

Indoor use

decreased

by about

50%

Summary Trends in Indoor Water Use

• More efficient water using fixtures, especially toilets and clothes washers, and better leak management should reduce indoor water use from 70 to 40 gpcd over the next 25 years

• Base wastewater flows should likewise decrease

• May have additional clogging problems in sanitary sewer systems due to lower flows

Outdoor Water Use is Increasing in

Many Areas

Trends in Outdoor Water Use

• Case study of long-term trends in

Gainesville, Florida

• Alachua County Tax Assessor’s database

includes fields for sprinkling systems and

pools for residential customers

• We linked customer level water use billing

data to tax assessor’s database

• Pools add about 5 gpcd to water use

Trends in Outdoor Water Use for Irrigation

Trends in Outdoor Water Use for Irrigation

Residential Water Use as a Function of % of

Homes with Sprinkling Systems

Options for Reducing Outdoor

Water Use

• Reduce irrigated area

• Plant more drought tolerant species- xeriscaping

• Use soil and/or rain controllers to operate the

sprinkling systems to minimize water use, e.g.,

supply 60% of ET, not 100%

• Restrict irrigation to fewer days per week

• Discourage use of in-ground irrigation systems

• Raise the price of water

Do New Homes Use Less Water?

• Ongoing national study of water use in

homes that were built before and after

1/1/2001

• Is water use decreasing because new

homes are more water efficient?

Jacksonville, FloridaAquacraft (2008)

Avg. Annual

Use (kgal)

Non-

Seasonal

(kgal)

Seasonal

(kgal)

Pre-2001 86.9 44.6 42.3

Post-2001 123.0 51.0 71.9

%change 41.51% 14.4% 70.0%

Year BuiltAvg. Lot Size (sf)

# of Bedrooms

Avg. # of Residents

% Reporting outdoor irrigation

% with irrigation system

% with swimming

pool

Average value of owned

homepre 1972 10240 3.1 2.3 79.0 59.2 15.0 $228,214post 2003 13124 3.7 2.7 98.2 82.1 15.8 $311,647

Results for Jacksonville

• Newer houses use 41.5% more water

– Indoor water use increased by 14%

– Outdoor water use increased by 70%

• 30% increase in lot sizes

• Higher % of irrigation systems

Conclusions on Water Supply

• Average indoor water demand can be reduced

by over 30% by retrofitting toilets, clothes

washers, faucets, and fixing leaks

• Outdoor water use is increasing due to more

lawn area per capita, use of automatic sprinklers

and higher application rates

• Much of outdoor water supply needs could be

met by reclaimed wastewater and stormwater

Demand Management Success Story-SeattleSlides Courtesy of Al Dietemann

0

20

40

60

80

100

120

140

160

180

200

1930

1935

1940

1945

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

An

nu

al

MG

D

Actual Annual

5-Year Moving Average

Firm Yield

Total and Billed Annual Average Consumption Per CapitaSeattle Regional Water System: 1975-2006

0

20

40

60

80

100

120

140

160

1801975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

Gallo

ns p

er

Pers

on

per

Day

Billed

Consumption

Total

Consumption

Per

Average Single Family Use

is 66 gallons per person/day

Impact of All Forms of Conservationon Past and Forecast Water Demand-Seattle

0

25

50

75

100

125

150

175

200

225

250

1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030

An

nu

al M

GD

Unattributed Savings

Transitory Savings

Conservation Programs

Plumbing Code

Rate Impacts

System Operation Improvements

1990 Forecast with No

Conservation

Actual

Demand

2007 Forecast with

Conservation

Trends in Urban Water

Infrastructure• Water Supply

– National studies of the nature of urban water use

– Impact of conservation in Florida

• Waste Water– CSO and SSO control

– Reuse in Florida

• Storm Water– Characterization

– Evaluation of LID & Other BMPs

– Reuse

• System Integration

Nature of Wastewater Flows-

Boulder, Colorado

• Dry weather flow is expected to decrease from

about 70 to 40 gpcd over the next 25 years

• Could have a situation where the majority of

wastewater flows are I/I

Combined and Sanitary Sewer

Overflows

Sources of Infiltration/Inflow in

Sanitary Sewers

\

VSF100iF3.CDR

LeakyBuildingLateral

FoundationDrainConnectedto BuildingLateral Exfiltration

fromStorm Drain

Sanitary SewerLEGEND

Cracked orBroken Pipe

Red Lettering is Infiltration

Deteriorated orMisaligned Joint

Faulty LateralConnection toSanitary Sewer

Illicit CatchBasin Connection

ManholeCover withHoles

Blue Lettering is Inflow

Storm Drain

DeterioratedManhole

FaultyManholeFrame/ChimneySeal

Root Penetration

RoofVent Downspout

Area Drain

Service LineCleanout(uncapped)

DrivewayDrainStairwell

Drain

FoundationDrain

Floor Drain

Ways to Control Infiltration/Inflow

• Repair leaking pipes

• Add more storage at the wastewater

treatment plant to capture excess flows

• CSO/SSO controls can be very expensive

• Ideally, the total wastewater flow is equal

to the indoor water use

Water Reuse in Florida

– Encouraged and promoted as State

objectives

– 660 MGD of reclaimed water to reuse

• Represents 65% of domestic wastewater

• 465 facilities with 1.3 BGD reuse capacity

• Florida reuse goal: 1 BGD by 2010

Water Reuse in SE Florida

Palm Beach

County

Broward

County

Miami-Dade

County

Boynton-Delray

Boca Raton

Broward/North

Hollywood

Miami-Dade/North

Miami-Dade/Central

Image from Google Earth

–Account for approximately 1/3 of

state’s population

–Generate 39% of state’s

wastewater

–Account for less than 10% of

state’s reuse capacity

–Send 285 MGD treated effluent to

ocean outfalls (20.6% of state’s

wastewater)

–State is encouraging reuse to meet

the projected future growth in

demand for water

Potential Users of

Reclaimed Water

–Pink areas indicate potential open

space areas for reuse irrigation, e.g.,

golf courses

–Built-out areas such as Miami-Dade

County have fewer potential reuse

sites

Satellite Wastewater Treatment

Systems for Reuse• Divert wastewater en route to the central

treatment plant near a good point of use

• Treat wastewater & return solids to sanitary sewer

• Send treated water to nearby reuse site

• Provides extra hydraulic capacity for the central plant

• Makes reuse more cost-effective because piping and pumping costs are greatly reduced

• Membrane bioreactors are being used for satellite treatment

Supply and Demand for Reclaimed Water-

Mismatch Between Supply & Demand-

Seasonal Storage is Needed

0

0.5

1

1.5

2

2.5

1 3 5 7 9 11

Month

Mo

nth

ly F

low

as

a F

ra

cti

on

of. .

Av

era

ge M

on

thly

Flo

w

Reclaimed Water Supply

Irrigation Demand

Reuse of Reclaimed Water is a Cost-

Effective Option for Many Florida Cities

• Irrigation demand is highly variable depending on whether the water use is metered and/or whether irrigation is restricted.

• Inclusion of dual water systems in new developments can be an attractive option for more sustainable systems

• Need to monitor groundwater quality to assure that adverse effects are avoided

• Need to meter reclaimed water use to discourage wasteful usage

Trends in Urban Water

Infrastructure• Water Supply

– National studies of the nature of urban water use

– Impact of conservation in Florida

• Waste Water– Optimal size of service area

– CSO and SSO control

– Reuse in Florida

• Storm Water– Characterization

– Evaluation of LID & Other BMPs

– Reuse

• System Integration

Stormwater

• Urban stormwater varies in relative

importance because of climatic variability

• Water budgets indicated that annual urban

runoff was about 20 % of water use for

Denver while it was about 100% of water

use for New York City

Urban stormwater per capita increased

dramatically during the 20th century

• More automobiles which require more streets and parking and create additional pollutant sources

• Larger houses on larger lots that increase runoff quantity and pollutant loads

• More contemporary urban area is devoted to parking than to human habitat and commercial activities

• Low density urbanization generates over three times as much stormwater runoff per family than did pre-automobile land use patterns

Recent Stormwater Trends

• Significant growth in “green developments”

that are more energy and water efficient

• Significant increase in use of low impact

development concepts

• Trend towards higher density mixed use

developments that reduce the dependency

on automobiles

Wet Weather Source

Characterization

• Smaller storms account for bulk of annual

runoff

• Directly connected impervious areas

(DCIA) are the key cause of urban

stormwater quality problems

• Focus on smaller storms and DCIA

BMP Taxonomy

• More than 75 BMPs

• BMPs can be classified into about 10 major functional categories, e.g., filtration systems

• BMPs can be classified into two major categories

– Surface storage/treatment, e.g., ponds.

– Subsurface storage/treatment, e.g., soil systems.

Centralized vs. Decentralized Storage

Conventional vs. LID

Roadways, Paved

Surfaces and Turf Used to

Collect, Convey and

Concentrate Runoff

Conventional site design increases

runoff for nearly all storms

LID Retrofit-Seattle

On-site Controls at Heritage Oaks

BMP Performance

• Stormwater BMPs should be viewed as being ubiquitous within the urban area. Thus, control can be achieved by manipulating the rainfall-runoff-transport relationship as well as installing a downstream control.

• LID controls are much more complex to analyze because they are so much more numerous and diverse and they tend to rely on more complex infiltration processes

• EPA SWMM 5.0 can evaluate BMPs by altering parameters such as infiltration rates to represent the expected impact of a BMP

Stormwater Reuse Systems

• In many parts of the country enough stormwater can be collected to satisfy average irrigation demands

• Storage of stormwater may be necessary to meet seasonal irrigation demands

• Stormwater may not be of acceptable quality for reuse without treatment

• Aggressive wastewater reuse programs in Florida highlight the need for joint utilization of stormwater and reclaimed water storage areas

Trends in Urban Water

Infrastructure• Water Supply

– National studies of the nature of urban water use

– Impact of conservation in Florida

• Waste Water– CSO and SSO control

– Reuse in Florida

• Storm Water– Characterization

– Evaluation of LID & Other BMPs

– Reuse

• System Integration

Energy-Water Nexus

• Cities are looking at more energy-intensive supply options to satisfy its future demands, e.g.,– Desalination

– Piping surface water supplies to other areas

• Rising energy costs and climate change concerns favor less energy intensive options, e.g., 19% of California’s energy use is for transporting and treating water

• Improved water use efficiency can be a cost-effective and reliable part of the solution to the need for sustainable solutions to balance supply and demand

• Decentralized urban water systems are less energy intensive

• Some newer energy options such as bio-fuels require major increases in water demand and generate additional wastes

One Month Supply of Water for

Typical Florida Family

• 12,000 gallon tank

• Weight = 50 tons

• Cost of water is about

$30-60/month

• 2/3 of cost is to transport

the water

• Major use of expensive

energy

• Most of the water is used

for landscape irrigation

Catalysts for Future Urban Systems

• The utter devastation of Hurricane Katrina and the failure of the flood control and public health infrastructure

• Intensified competition for water supplies including provision of water for natural systems

• Decaying infrastructure that needs to be rehabilitated or replaced

• More aggressive regulation of stormwater quality

• Desire for more sustainable infrastructure that is not as resource dependent

• Need to reduce energy use

• Need to rejuvenate our economy

Masdar, UAE-City of the Future?

• 50,000 people

• No cars

• Solar powered

• Desalination

• 60% less water use

• Maximize reuse

• 1st phase completed

in 2009