sustainable urban water infrastructure systems
TRANSCRIPT
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
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5-Year Moving Average
Firm Yield
Total and Billed Annual Average Consumption Per CapitaSeattle Regional Water System: 1975-2006
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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
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1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030
An
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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
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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