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SUSTAINABLE WATER RESOURCES AND URBAN REUSE
TECHNOLOGY
SUSTAINABLE WATER RESOURCES AND URBAN REUSE
TECHNOLOGY
Lecture 10
DEFINITIONS
Wastewater domestic wastewater =sewage =all
wastewater industrial wastewater = process wastewater
Greywater domestic wastewater except toilet
wastewater, or domestic wastewater except toilet & kitchen
wastewater Reclaimed Water
derived from sewage treated to a standard satisfactory for
intended reuse Biosolids
sludge not “solid waste”
Water Issues Water Use
Reduce, Reuse, Recycle Rainwater Harvesting Greywater systems Blackwater systems Reclaimed water
Wastewater Reduce, Reuse, Recycle
Stormwater Maintain natural hydrologic period of site Use natural systems to buffer flows
Sustainable Global Resources
“...The ability to provide for the needs of the present without detracting from the ability to
serve the needs of the future...”
Availability and Sustainability of Resources
Minimize Resource Degradation Minimize Resource Depletion Maximize Resource Efficiency
WATER SERVICE AREA MAP
Existing Conditions Private Wells and Septic Systems
9,251 Private Wells(Over 98% Used for Irrigation)
Minimal number of private septic systems Relatively Low Per Capita Demand
District Goal of < 150 GPCD Current City Average of 124.4 GPCD
(80 GPCD Household) Consumptive Use Permit Modification
Existing Conditions
Designation as Priority Water Resource Caution Area Groundwater not sufficient
to meet future water demands
Alternative water supplies will be needed to meet future water demands
Planning Assumptions Unknowns
Amount of future groundwater allocation Financially and technically feasible
alternative water supply source Assumptions
Fresh groundwater allocations limited Brackish groundwater allocations allowed Flagler County Cooperators will identify
financially and technically feasible alternative water supply sources
Future Conditions-Palm Coast
0
5
10
15
20
25
30
2007 2012 2017 2022 2027
MG
D
Finished Water Demand
Groundwater
Brackish
Alternatives
212,295
137,963
RECLAIMED WATERSITES
MGD
Alternative Water Supplies Brackish Groundwater
Water Treatment Plant #3 Capability Part of District Permit Modification
Flagler County Cooperators Group Develop countywide water supply plan Identify feasible alternative water
supply source Surface Water Options Saltwater / Desalination
Conservation/Reuse Practices Continue water conservation program
Water treatment technologies Water use monitoring Indoor conservation programs Water efficient landscape ordinance Irrigation design requirements Customer and employee education
Required to install reclaimed water distribution system
Required to connect to reclaimed system
Sustainable Water Resources
“...As the common denominator in virtually every ecosystem, water resources serve as the cornerstone
of human society and sustainment...”Problem: Regional water demands exceeding hydrologic
regenerationCause: Regional population growth and over development Climatic and hydro-geologic forcesEffect: Increasing water resource overdraft and withdrawal Increasing waste discharge and resource contamination
Population Increase vs. Water Demand
“...Use of potable water in Florida increased a factor of 6 in the last 90 years with 25% of the increase occurring in the last 25 years...”
•Figure 1 Current and projected water demand vs. population growth in Florida
1950 1960 1970 1980 1990 2000 2010 2020
Years (decades)
0
3
6
9
12
15
18
21
Po
pu
latio
n (
mil
lio
ns)
1950 1960 1970 1980 1990 2000 2010 2020
Years (decades)
0
500
1000
1500
2000
2500
3000
3500
4000
Wit
hd
ra
wa
l (
MG
D)
Urban Water Recycling and Reuse
“...In select commercial applications 75% or more of all potable water used serves toiletry fixtures alone...”
•Figure 2 Wastewater flow in typical commercial and residential structures
34% Toilets
23% Laundry
12% Cooling& HVAC
25% Lavs &Shower
6% Irrigation
75% Toilets &Urinals
15% Lavs &Irrigation
10% Cooling &HVAC
(Residential)(Commercial)
On-site Greywater Recycling and Reuse
“...Type A dual distribution and greywater recycling will achieve maximum benefit in residential structures where the greywater reused is roughly equivalent to the non-potable demand...”
•Figure 3 Type A greywater riser diagram
Shower
ShowerW.C.
W.C.
Lav. Lav.
Lav.
Lav.
WasherWasher
SinkSink
Waste (blackwater) to sewer
Non-fecal (graywater) to on-site treatment
Graywater wet-vent
Soil stack
On-site Wastewater Reclamation and Reuse
“...In commercial structures, the recovery of all wastewater for treatment and reuse is required using Type B dual distribution...”
•Figure 4 Type B wastewater reclamation riser diagram
Reuse Systems Flow Analysis
•Table 1 Conventional vs. reuse systems flow and waste discharge analysis
System Piping TreatmentReuseApplications
WaterSavings
SewageReduction
Conventional Base None N/A 0 0
Type A Dual distribution Filtration Water closet 31,500GPD 27,750GPDDual sanitary Adsorption Irrigation (42% of total) (46% of total)
Chlorination
Type B Dual distribution Biochemical Water closet 36,000GPD 33,400GPDSingle sanitary Filtration
AdsorptionIrrigation (48% of total) (56% of total)
Chlorination
Reuse Systems Economic Analysis
•Table 2 Conventional vs. reuse systems economic analysis
System specific costs Conventional System Type A System Type B System
Initial cost increase n/a $355,000.00 $689,235.00Operational & maintenance $ 6,300.00 $ 20,700.00 $ 27,384.00Economic life 20 years 20 years 20 yearsInterest rate 12% 12% 12%Amortized annual cost n/a $ 47,526.00 $ 92,273.00Potable water cost $182,410.00 $109,520.00 $ 72,890.00Wastewater treatment cost $ 56,700.00 $ 34,125.00 $ 22,650.00
Totals $245.410.00 $211,871.00 $215,197.00
Water Reuse Alternatives
“...34% to 90% of all potable water used in most residential and commercial structures is used by non-potable fixtures...”
Toilet and urinal flushing Irrigation Mechanical make-up and trap priming Washdown Fire suppression Ornamental and aesthetic impoundments Environmental impoundments and wetlands
restoration Indirect groundwater and aquifer recharge
Water Reuse Mechanics
“...The overall concern for the distribution of non-potable resources is predicated on the economics and reliability of protecting the user from accidental access, contact,
or ingestion...”
Maximum obtainable separation distances Pressure differentials Air-gap separations and cross-connections Back-flow prevention devices Color coding and material differentiation Identifications and warning signatures Aesthetic reuse water dyes
Cross-connection and Back-flow Prevention
•Figure 6 Minimum separation distances and back-flow check valve assembly
Potable
1' - 0"
Non-potable
3' - 0" Minimum
Float check
Check seat
Air inlet port
Reuse Identification Signatures
•Figure 7 Sample reclaimed water use identification signature
CAUTIONRECLAIMED WATER
DO NOT DRINK
NOTICE
CONTACT BUILDING MANAGEMENT
BEFORE PERFORMING ANY WORK
ON THIS WATER SYSTEM
Purple pipes
Reuse Water Quality Objectives and Standards
•Table 3 Recommended water quality objectives for non-potable reuse
Condition Acceptable Limits Condition Acceptable Limits
Biochemical Oxygen Demand, mg/L 15-20 pH, LSI 5-8Total Suspended Solids, mg/L 15 Alkalinity, mg/L 250Chlorine Residual, mg/L 1 Hardness, mg/L 150Fecal Coliform, per 100mL <2.2 Chlorides, mg/L <300Total Coliform, per 100mLTurbidity, NTUNitrate, mg/L
32
<5
Chemical Oxygen Demand, mg/LAmmonia, mg/LPhosphate, mg/L
80-10025<5
Greywater Characterization and Treatment
•Figure 8 Water quality characteristics and passive treatment alternatives for domestic greywater
Urban Water Conservation
“...Efficiency of water use has not been the hallmark of fixture design, as the water to waste ratio in a conventional water closet is nearly
80:1...”
Water consumption in typical residential environments can be reduced between 19% - 44% using low-flow fixtures
Low volume toilets reduce water use 50% or more per flush Aerated shower and lavatory fixtures reduce flow rates from
4.5gpm to 1.5gpm or less Passive irrigation techniques and Xeriscapingtm reduce water
use a further 15%-40% Pressure reducing valves (PRV) reduce water pressures from
80psi to 35-40psi
Waterless Urinals
The Waterless Company
Composting Toilets
Phoenix, Inc.
Flow Bypass
Rainwater Harvesting
System for House in Oregon
http://www.eng.warwick.ac.uk/DTU/rainwaterharvesting/
Recommendations
“...Complete wastewater reclamation and reuse has demonstrated the greatest potential toward maintaining
sustainable water resources...”
Central utility cores Large point loads and densities of occupants Primarily occupied by adults Controlled access to reuse fixtures and
distribution systems Designated and trained maintenance
personnel
Conclusion
Water resource depletion is directly proportional to population growth and resultant water demand
Water resource contamination is directly proportional to water resource overdraft and resultant wastewater discharge
Hydro-geologic and climatic detriment such as saltwater intrusion and drought place further burden on an already stressed ecosystem
Water reuse, recycling, and conservation will reduce water demands 40%-90% in urban environments, reduce wastewater discharge accordingly, reduce saltwater intrusion, and reduce the impact of regional drought.
Water Conservation Case Studies
In Our Backyard…. City of Atlanta
City of Savannah
Atlanta Water Department Low Income “Care and Conserve”
Program
Plumbing repairs to reduce water waste
Fixture replacement (w/ ultra low-flow fixtures)
Direct payment assistance when funds are available
Information and instruction on water conservation
Atlanta Water Department Xeriscape “Water Wise
Landscaping” Program Site audits Evaluate the current landscape for water
use needs/patterns. Deliver water conservation literature &
water saving devices for indoor and outdoor use.
Provide one-on-one instruction in the basic principles of Xeriscaping
Savannah’s Savings Strategies
Conduct unaccounted for water audits Leak repair programs and meter
calibrations Fire protection and looping
improvements Alternate water sources for irrigation –
5 MGD of reclaimed water Water conservation program Conversion of light industrial &
commercial groundwater use to surface water
Savannah’s Water Conservation Program
Public outreach and education Mascot, “Less Waters” Indoor/Outdoor Water Conservation kits Water Wisdom video Water Sourcebooks to schools
Plumbing retrofit program for residential homes has saved approximately 1.113 MG/year.
Plumbing retrofit for public housing complexes has saved approximately 3 MG/year.
Savannah’s Bottom Line Customer base in last 17 years increased by
17% Total water production from all city wells has
remained constant over the last 17 years Total water leaks reduced by 65% from 3,242
leaks in 1981 to 1,131 leaks in 2000 Looping lines requires less system flushing
In 1999, 21.8 MG was needed to maintain water quality in 800 miles of distribution system
In 2000, only 15.0 MG was needed
Dwelling Units vs. Pumpage
50000
55000
60000
65000
70000
75000
80000
Dw
ellin
g U
nit
s
7500
8000
8500
9000
9500
10000
Pu
mp
ag
e in
MG
19881989199019911992199319941995199619971998199920002001
YearDwelling units Pumpage
Dwelling Units vs Pumpage
Beyond the Backyard Examples
Irvine Ranch Water District City of Albuquerque City of Cary Arizona’s Public Awareness
Campaign
Irvine Ranch Water District Connections: 85,000 and Population: 266,000 Conservation Budget: $700,000 – $2 million
(funded through the excessive use penalties)
Conservation Rate StructureConservation Rate Structure Based on water budgets for all customers Penalties for excessive use Landscape water use has decreased approx.
50% (over 650,000 gallons per year)
Irvine Ranch Water District Other Conservation ProgramsOther Conservation Programs
• Rebates/low interest loans for irrigation system and landscape upgrades
• Monthly performance reports for 4,000 dedicated landscape meters
• Monthly notification letters to the highest water wasters
• Monthly conservation tips and suggested irrigation schedules provided as bill inserts
• 80% of landscape accounts are reclaimed water
Irvine Ranch Water District More Conservation ProgramsMore Conservation Programs
• Water Conservation Demonstration Garden• School education program• Residential garden workshops• Participation in the Orange County
Landscape Performance Certification Program
• Participate in regional ULFT programs, CII rebate and Landscape Education programs
Irvine Ranch Water District Conservation StudiesConservation Studies
• X-Ray Film Processor Study – Initial savings are 98% • Supermarket Cooling Systems Study• Residential Run-off Reduction Study – Testing a
real-time water based irrigation controller. Initial data showing a 70% reduction in runoff.
• Pressure Optimization Study – Testing pressure levels for reducing “misting” and breaks in irrigation systems
• National Sub-metering Study• Strawberry Reclaimed Water Study – Initial savings
are nearly 1 MGY
City of Albuquerque Population Served: 483,000 Conservation GoalsConservation Goals
• 30% reduction over 10 years ( 1995 -2005) Reduction in total production from 250 gpcd to 175 gpcd
• Achieved 23% savings by 2001• Gpcd = 205 in 2001, down from 216 in
2000Residential only per capita for 2001 = 144 Residential only per capita for 2001 = 144
gpcd, down 27% from the baseline of 198 gpcd, down 27% from the baseline of 198 gpcdgpcd
City of Albuquerque Conservation ProgramsConservation Programs
• 2000 letters to customers with more than 10% increase in usage since 1994
• Commercial water audit program • Free residential surveys to SF & MF customers• Toilet rebate program – 43,000 replacements to
date• Xeriscaping – 286 customers rebated for
383,180 square feet of xeriscape conversions• Water-waste inspectors – visited 3000+ sites
and issued more than 400 water-waste violations
City of Albuquerque More Conservation ProgramsMore Conservation Programs
• “Take the Plunge” media campaign• Outdoor Watering Time of Day restrictions –
April to September• Water Recycling – over 3.4 MGY • Audit of unaccounted for water loss
– Washing machine rebates -$100 for high Washing machine rebates -$100 for high efficiency machinesefficiency machines
City of Cary Population has doubled in last 10
years 75% residential, 21% commercial
customers 1998 average daily retail water
demand 8.6MGD 2028 projected is 26.7
Cary’s Response Benefit-Cost Analysis Model Conservation measures chosen with
B/C greater than 1.0 10 year plan to reduce retail water
production by 4.6 MGD (16% by 2028)
Emphasis on measures to reduce peak-day demand during high-volume summer months
Cary’s Program Water Reclamation Facility for 4.6 MGD Conservation Rate Structure New Homes Points Program Residential Audits Landscape Water Budgets Landscape and Irrigation Codes Toilet Flapper Rebates Public Education
WATER SHORTAGE WATER USE RESTRICTIONS
PHASE I & IISWFMD
Our water supply comes from RAIN Our water supply comes from RAIN
Two Seasons…Wet & DryTwo Seasons…Wet & Dry
70% of annual rain falls during summer Replenishes lakes and underground aquifers
Two Seasons…Wet & DryTwo Seasons…Wet & DryHighest demands during dry winter/spring
• Tourists• Seasonal Residents• Agriculture
Sunshine State…or Water State?Sunshine State…or Water State?
South Florida’s average yearly rainfall is 52 inches per year
Almost 45 inches “lost” to evaporation and transpiration
Rainfall during 2006 was just 40.75 inches (almost a foot below normal)
52” rainaverage52” rainaverage
40.75” rain in 2006
40.75” rain in 2006
Water Shortage RestrictionsWater Shortage Restrictions
Prohibits wasteful and unnecessary water use
Identifies specific water use limits
Each phase corresponds to the overall reductions needed to stretch available supplies
Essential public health & safety services are not restricted
Beyond year-round Water-Use GuidelinesBeyond year-round Water-Use Guidelines
Local governments have year-round ordinances in place prohibiting daytime watering
To keep up-to-date on restrictions in your area call the hotline
WATER SHORTAGE RESTRICTIONSNOW IN EFFECT
Current Water Restriction in Your Area
Phase I: moderate Phase II: severe Phase III: extreme Phase IV: critical
Water shortage phases require an increasingly larger reduction in water use.
Landscape Irrigation Limits (LESS than 5 acres)
Phase I limited to watering 3 days a week Phase II limited to watering 2 days a week
• New landscaping less than 30 days old Mon. to Fri. 2 a.m.- 8 a.m.
Hand watering with automatic shut-off nozzle anytime
Landscape Irrigation Limits (MORE than 5 acres)
Phase I limited to watering 3 days a week Phase II limited to watering 2 days a week
• New landscaping less than 30 days old Mon. to Fri. 12:01 a.m.- 8 a.m.
Hand watering with automatic shut-off nozzle anytime
Washing Cars, Boats and Equipment
Wash cars, boats and equipment only on your watering days 4-8 a.m. and 5-7 p.m.
Must be done on or drain to a non-paved surface
Use an automatic shut-off nozzle or low volume pressure cleaner
Applies to all sources of water except RECLAIMED!
Water-use restrictions DO apply to all sources from public utilities, private wells and all surface waters such as canals, lakes, ponds and rivers.
Water restrictions DO NOT apply to the use of 100%
reclaimed water (reuse)
Restrictions are mandatory
Restrictions are mandatory
Synchronize your sprinkling scheduleSynchronize your sprinkling scheduleFollow water restriction limitsFollow water restriction limits
Set your automatic system to allowable water-use restrictions
Use a rain switch on automatic systems Set automatic timer according to home
address 3 days a week maximum in Phase I 2 days a week maximum in Phase II
Rain switch adjusts watering schedule for you to prevent over watering
Synchronize your sprinkling schedule with natureSynchronize your sprinkling schedule with nature
Prevent OVERWATERINGPrevent OVERWATERING Do not water immediately before,
during or after it rains Use your designated watering days
only when areas show signs of stress When footprints remain visible in the
grass When grass blades begin to curl When color changes from green to blue-
gray
How to help drought-proof your lawnHow to help drought-proof your lawn
Water early in the day– best before sunrise
Water deeply / less frequently
Keep mower blades sharpand raise the blade
Don’t fertilize until summer rains
Tips for inside the homeTips for inside the home It’s easy to reduce your water
use Change your habits:
Turn off the faucet when brushing your teeth or rinsing vegetables
Take shorter showers Install low-flow toilets/showerheads Don’t use toilet as a waste basket Wash full laundry and dish loads Repair leaky fixtures
No Pain…Lots of GainNo Pain…Lots of GainDo the Math…
One drop per second from a leaky faucet =
2,700 gallons per year!
In a city of 10,000 homes =
27,000,000 gallons per year!
YOU can make a difference
For more water conservationtips and informationvisit www.sfwmd.gov/conserveor call our Water Conservation
HOTLINE: 800-662-8876