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