Sustainable Water Issuesas applied to buildings

Eric Adams

Outline for Discussion inDesign for Sustainability (1.964)

November 15, 2006

2

Outline

• Introduction (brief)• Context: Boston area’s water supply

and wastewater treatment (brief)(Is current system sustainable?)

• Water-related sustainability measures applicable to buildings

3LEEDTM Certification Categories

27%

Sustainable Sites

Water Efficiency

Materials and Resources

Energy and Atmosphere

Indoor Environmental Quality

22%

23%

20%8%

Figure by MIT OCW.

4

Water and Sustainablity

• Sustainability => keeping consumption within limits of natural replenishment

• Broader view includes– Environmental– Economic– Social

5

Water vs Materials & Energy• Largely renewable

– Time scales of months to few years => we’ve had plenty of practice

– Sustainability measures driven more by extremes than averages (droughts, floods, peak demand)

• Multiple uses– Different levels of

treatment• More site specificity

27%

Sustainable Sites

Water Efficiency

Materials and Resources

Energy and Atmosphere

Indoor Environmental Quality

22%

23%

20%8%

Figure by MIT OCW.

6

A Building’s Impact on Water

• Impacts associated with occupants’ water use– Water supply– Generation of wastewater

• Impacts on hydrology– Reduced recharge, increased storm water

runoff, altered WQ– Construction, operation, demolition phases

7

PrecipPrecip

Central Water Supply

Potable

Impervious

Landscape

Non-pot.

CentralWater

Treatment

Water supply, wastewater, stormwater

1

Boston’s Water Supply

• 1795-1870: Local ponds & reservoirs

• 1875-78: Sudbury Aque-duct & Chestnut Hill Res

• 1895: Wachusett Res• 1926: Quabbin Res.• 1946-78: Pressure

Aqueducts• 1996-present:

Integrated water system improvements

• Many towns supplement MWRA with local wells

0

1848

Lake

Coc

hitu

ate

Upp

er M

ystic

Lak

e

Sudb

ury

Syst

em

Qua

bbin

Res

ervo

ir m

inus

pa

rt of

Sud

bury

Sys

tem

and

Lak

e C

ochi

tuat

e

Wac

huse

tt R

eser

voir

min

us

Upp

er M

ystic

Lak

e

Rem

aind

er o

f Sud

bury

Sy

stem

Dis

cont

inue

d1864 1872 1908 1946 1980

100

200

Stor

age

Cap

acity

(BG

)

400

479.9

500

479.9

Figure by MIT OCW.

9

Boston’s Water Supply cont’d

• Prim. Disinfection: O3Res. Disinfection: Chloramine

• Corrosion Control• Fluoridation• Modular for

expansion/contingency– Filtration

• $0.34 billion

Flickr image courtesy of pjmorse.

10Sustainable?

20085 86 87

System's long-term safe yield of 300 MGD (~13m3/s)

88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04

250

#

# Includes temporary supply to Cambridge during construction of local water treatment plant

MWRA Water Demand vs. System Safe Yield

Mill

ion

Gal

lons

Per

Day

300

350

Figure by MIT OCW.

1

Boston’s Wastewater

• 1700s-mid 1800s: Convey WW to nearest water body

• 1876 First sewer system -> Moon Is

• 1952 Nut Is TP• 1968 Deer Is TP• 1997 New Deer

Is TP

Figure by MIT OCW.

0

Hingham Bay

Moon Island

Quincy Bay

Nut Island Headworks(Former site of Nut Island treatment plant)

Dorchester Bay

Commercial Point CSO treatment facility

Fore Riverpelletizing plant

Inner Harbor

5 Km

Outfall Tunnel

Diffuser

Deer Island treatment plant

Fox Point CSO treatment facility

12

Boston’s Wastewater cont’d

• Modern 2o TP (Activated Sludge)

• 20 m3/s (ave); 50 m3/s (peak)

• Room for Expansion– AWT for Nitrogen

• 15 km ocean outfall– Contingency plan

Figure by MIT OCW.

13

Should wastewater be returned to watershed rather than

discharged to ocean?

14

Metals in MWRA Treatment Plant Discharges 1989-2002

0

200

400

600

800

1000

1200

89 90 91 92 93 94 95 96 97 98 99 00 01 02

Ave

rage

pou

nds

per d

ay d

isch

arge

d

Silver

Nickel

Chromium

Lead

Copper

Zinc

Data from mwra.state.ma.us

15

Boston’s Wastewater cont’d• Aggressive Source

Control• Sludge recycling at

Quincy– New England

Fertilizer Co.– Bay State Fertilizer

Co.• Total cost: $3.8

billion

Sustainable?

16

PrecipPrecip

Central Water Supply

Potable

Impervious

Landscape

Non-pot.

Leaks

Infiltration

Inflow CSO

CentralWater

Treatment

Leaks

Stormwater (and freshwater and stormwater)

17

Combined Sewer Overflow

mwra.state.ma.us

Figure by MIT OCW.

18

Boston’s CSOs

Pleasure BayStorm Drain Connection to Outfall BOS080

15 mgd Pump Stationfor Tunnel Dewatering

Dewatering Force Main to BWSC Sewer System

Pleasure Bay Storm Water Relocation

17-Foot Diameter tunnel

Odor Control Building

BOS087

BOS086BOS084

BOS083

BOS082

BOS081BOS085

Sewer Separation in Reserved Channel OutfallTributary Areas

Morrissey Blvd Storm Drain

Active CSOsTreated CSOsClosed CSOs

Figure by MIT OCW.Figure by MIT OCW.

19

CSOs (cont’d)

• 85% reduction in CSO volume since 1988 (3.3 -> 0.5 bgy).

• 95% of CSO will receive some treatment (4 plants)• Not 100% because marginal cost of CSO storage/

treatment increases as event frequency decreases• And stormwater will never be clean • Boston Harbor & Charles River will never be

completely swimmable• Total cost = $0.9 billion

Sustainable?

20

Marginal Capital Cost of Near-Surface Storage for Alewife/Mystic River Basin

00

2

Ann

ual C

SO E

vent

s R

emai

ning

10Marginal Capital Cost ($ Million/Annual

Event Eliminated)

20

4

6

Figure by MIT OCW.

21

Central vs Distributed Systems

• Investment/sharing in existing infrastructure & professionals

• Stability under transient water demand/availability

• Cheap!

• Disrupts hydrology, people

• Encourages waste• High energy costs• Large sludge production• More vulnerability• Complex, hard to

monitor• Hard to expand

Advantages Disadvantages

22

System Expansion

• Not all or nothing.• Most urban/suburban systems are

centralized but there is room (indeed need!) for local systems: new hook-ups mean greater distances & flow rates (hence pressure losses), implying greater marginal costs

23

PrecipPrecip

Central Water Supply

Potable

Impervious

Landscape

Non-pot.

CentralWater

Treatment

Water Conservation

StormwaterManagement

Rainwater Collection

On-site treatment/Re-use

Sustainability measures

24

1. Water Conservation

• Mainly for non-potable and landscaping flows

• Low flow faucets, shower heads• Low flow, dual flush toilets, waterless

urinals, separation/dry toilets• Smart irrigation (and landscaping)• Greatest potential for institutional

sources

25

Smart Irrigation• 30-70% of residential water use is for

landscaping; homeowners over-water by 2X

• Method of delivery– Drip irrigation

• Timing/quantity– Timers – Local weather reports– Rainfall, solar sensors (theoretical ET)– Moisture sensors

26DeOreo, et al., Boulder CO

Sensor Based Irrigation Efficiency

00 0.2

Ratio of actual to theoretical application

0.4 0.6 0.8 1.0 1.2 1.4 More

2

4

Freq

uenc

y6

8

Figure by MIT OCW.

27

Boston Globe August 2, 2006

• Opened March 2005; Design by Hellmuth, Obata and Kassabaum• Annual water savings: 1.7 million gallons• Storm water filtration reduces pollution to Boston harbor

Figure by MIT OCW.

28

Synthetic Lawns• E.g., Residential Field Turf• No water (or mowing, fertilizer,

pesticides…)• Drains through turf to underground

pipes (permeability approaches grass)• Comparable cost to sod• Trace metals, pathogens vs nutrients,

pesticides• Aesthetics? (Monet effect)

29

PrecipPrecip

Central Water Supply

Potable

Impervious

Landscape

Non-pot.

CentralWater

Treatment

T

T

2. Rainwater Collection/Use

30

Rainwater collection systems

• Order of increasing quality requirements– Landscaping, (rain

barrels, SmartStorm)– Non-potable water (e.g.,

new MIT buildings)– Potable water (Toronto

Healthy House)

31

Fit for use quality/downcycling

Coombes, 2005

Rainwater Tank

Storage Tank Class I

- Laundry- Dishwashing

Storage Tank Class II

Storage Tank Class III

Class IV:Discharge

86.7

External SupplyClass I

- Food Prep- Washing up- Other

- Bath- Shower

- Washbasin

- Toilet

60.4

5.4 66.7

Draining 52.4

Draining 29.3

14.63.9

14.6

42.8

Last phases: 7.8

Last phases: 17

First phases: 15.8

First phases: 25

Figure by MIT OCW.

32

Toronto Healthy House

• P—gutters••••

•••••••

R—rain water cisternS—combination filterT—drinkable cold water tankO—drinkable hot water tank

E—grey water heat exchangerN—reclaimed hot water tankU—septic tankV—recirculation tankW—Waterloo biofilterX—twin combination filtersY—reclaimed cold water tank

• Z—garden irrigationFigure by MIT OCW.

33

Toronto Healthy House

Figure by MIT OCW.

34

Figure by MIT OCW.

35

Eden Project

36

Rainfall968.274

41.2

Potable Water

394.780gal (roof collection)in.(annual)

gal potable water demand

N NoneImpervious

Area00

site s.f.gal gal gal

gal

gal

gal gal

s.f. s.f.00

74,5371,681,316

Previous Paving Roof+SiteCapture

Potable Potable PotableDishwasher Sinks Showers

Potable

010,890

00

0

0%

0%

40%

0

0%

0

541,587 0 0

0702,813

galgal

galgal

galgal

gal gal gal

gal

gal

gal

galgal

Clothes Washer

5%20%

Flow loss Factor

Flow loss Factor

Flow loss Factor

Storage No FlowRain water

CisternGrey water

Cistern1,545,533

803,346

201,830 0

Overflow

15%

Irrigation Flushing Plumbing Fixtures

Process Water

Available463,950 gal (demand)

oil/water

CatchBasins

Pre-Treatment

City Strom Sewer-site

201,830gal introducedfor recharge

Constructed wetland

N30% City Sewer-

Bldg734,776

Overflow factor

To City Sewer

reintroduced0 gal

% of supply

10%

Potable Potable Grey

GreyGreyPotable

M-Ro/Coad Pool Irrigation

WC Flashing Urinals

0

0

0 463.950

414,092 127,495

0 0 463,350gal gal

galgalgal

galgal

galgal

galgal

gal

DrinkingFountain

Grey Water Demand

1,005,776

Ground Water Recharge

1

1

2

2 3

3

4

7

78

8 5 6

4

4

Cistem

Water Flows - YearlySU

PPLYFL

OW

PATH

SR

ET

UR

N

1.4 million gallons higher (per year) 1.0 million gallons lower (per year)

414,032 127,43521,072

Strom SewerCollection

Flow loss Factor

4

Rainwater Collection Roof + Site1

Water Profile Tool www.greenroundtable.org Figure by MIT OCW.

37

Rainfall0

41.2

Potable Water

1.740.312gal (roof collection)in.(annual)

gal potable water demand

Y None NoneImpervious

Area74,537

1,681,961site s.f.gal gal gal

gal

gal

gal gal

s.f. s.f.00

00

Previous Paving Roof . SiteCapture

Potable Potable PotableDishwasher Sinks Showers

Potable

010,890

00

0

0%

0%

0%

0

0%

0

0 0 0

0702,813

galgal

galgal

galgal

gal gal gal

gal

gal

gal

galgal

Clothes Washer

5%20%

Flow loss Factor

Flow loss Factor

Flow loss Factor

No Flow No FlowRain water

CisternGrey water

Cistern0

0

0 0

Overflow

15%

Irrigation Flushing Plumbing Fixtures

Process Water

Available463,950 gal (demand)

oil/water

CatchBasins

Pre-Treatment

Citi Strom Sewer-site

1,681,916gal introducedfor recharge

Constructed wetland

N30% Citi Sewer-

Bldg1,276,362

Overflow factor

Over Loss factor

To Citi Sewer

reintroduced0 gal

% of supply

10%

Potable Potable Potable

PotablePotablePotable

M-Ro/Coad Pool Irrigation

WC Flashing Urinals

0

0

0 0

0 0

0 0 463,350gal gal

galgalgal

galgal

galgal

galgal

gal

DrinkingFountain

Grey Water Demand

0

Ground Water Recharge

1

1

2

2 3

3

4

7

78

8 5 6

4

4

Cistem

Water Flows - Yearly +1.3 Million Gallons Higher (per year)

SUPPLY

FLO

W PAT

HS

RE

TU

RN

1.4 million gallons higher (per year) 1.0 millon gallons lower (per year)

414,032 127,43521,072

If no water mesaure included2

Figure by MIT OCW.

38

One Bryant Park(Bank of America Bldg NYC)

• Cook and Fox, 54 stories, $1billion, const. start: 2008

• First LEED platinum skyscrapper• Rainwater, condensate, groundwater &

greywater collection, treatment and re-use (flushing, cooling)

• Waterless urinals• Zero discharge to storm sewer (irrigation

instead)• Also:

– On-site wind turbine, heat pumps– Low-e glass and daylight dimming lights\– Displacement ventilation, filtering– Digest cafeteria scraps -> CH4– 90% recycling of construction debris,

blast furnace slag in place of cement

39

9900 Wilshire Bldv(luxury condos in Beverly Hills)

• Architect: Richard Meier; 252 units, average = 3300 sq ft.• First LEED Gold condo development in West• On-site WW treatment: 1) methane from sludge -> co-

generation, effluent -> Vegetative treatment (Living Machines) -> toilet flushing, irrigation, cooling

• Also on-site wind turbines, heat recovery, passive solar features

40

PrecipPrecip

Central Water Supply

Potable

Impervious

Landscape

Non-pot.

CentralWater

Treatment

BMP

3. Stormwater Management

LID

41

Effect of development: more runoff, leaving site more quickly

(P. Shanahan)

Time

Flow Developed conditionswithout controls

Pre-developmentconditions

42

Consequences

•••

•* Wood pilings bathed in ground water do not rot.

** If water level drops, the wood is exposed to oxygen, allowing fungi and bacteria to attack

Water level

Pilings

Damaged pilingsLower water

level

How Drops in Ground Water Damage Wooden Pilings

FloodingPoor water qualityReduced long-term ground water storageFluctuating ground water table

Boston Globe May 16, 2005

Figure by MIT OCW.

43

Detention Ponds

Courtesy of Peter Shanahan.Used with permission.

44

Detention Ponds

Courtesy of Peter Shanahan. Used with permission.

45

Effect of site controls(detention ponds)

Time

Flow Developed conditionswithout controls

Pre-developmentconditions

Developed conditionswith controls

46

Effect of low-impact development

Time

Flow

Developed conditionswith LID

Pre-developmentconditions

Developed conditionswith controls

47

Low-Impact Development

Figure by MIT OCW.

48

Vegetative Roofs

Flickr photograph courtesy of birdw0rks.

49

PrecipPrecip

Central Water Supply

Potable

Impervious

Landscape

Non-pot.

T

CentralWater

Treatment

T

4. Wastewater treatment/re-use

50

(On-site) Wastewater Treatment

• Order of increasing quality requirements– Recharge to GW or discharge to surface

water– Landscaping/irrigation– Non-potable water

• Natural or mechanical– Large area vs High Energy

51

Small Footprint WWTPs

Integrated fixed-film activated sludge (IFAS) (www.brentwoodindustries.com)

Ballasted flocculation (BF); (www.brentwoodindustries.com)

Membrane Bio Reactor (MBR) (www.brentwoodindustries.com)

Biological aerated Filter (BAF) (www.vertmarkets.com)

Sandino, et al., Civil Engineering, 2003

M M M M

HydrocyclonePolymer Micro-

sand

SludgeMicro-sand & sludge to hydrocyclone

Clarified water

MaturationCoagulationInjection

Raw water

Coagulant

Settling w/ ScraperTube

Figure by MIT OCW.

Figure by MIT OCW.

52

Sustainable Sewage Treatment (R. Fenner)

Land Area

Energy requirements

Constructed wetlands

Reed beds

Trickling filters

Rotating biological contactors Activated

sludge systems*

Membrane bioreactors

GritChamber

Bar Screens

Coagulant Flocculent

Sludge Treatment and Disposal

Primary Setting Tank

TSS Percent Removal vs. Surface Overflow Rate

0 20 40

Surface overflow rate (m/d)

60 80 100 1200

20

Susp

ende

d so

lids

rem

oval

(%)

40

60

without chemical addition

with ferric chloride plus polymer addition

80

100

Figure by MIT OCW.

Figure by MIT OCW.

54

Hong Kong uses seawater to flush toilets

Stonecutters Island: world’s largest and

most efficient CEPT plant

55Figure by MIT OCW.

56Photograph courtesy of Brett Paci.

57

Gillette Stadium: Water and sewer issues

• Water supply – Limited municipal supply (100 gpm) vs.

Peak demands (3,500 gpm) – Summer water bans– No municipal water allowed for irrigation

• Wastewater disposal– 30 yr old treatment system– No municipal sanitary sewers

58

The solution

• Develop a regional high pressure district

• Construct on-site WWTP (MBR, UV,O3)

• Utilize a water reuse system• Daylight Neponset River

59

0.5 MG ReuseWater Storage Tank

0.1 MG PotableWater Storage Tank

Emergency Interconnection

Regional PotableWater High Service

Pressure ZoneOff-site Water System

Improvements

Future Irrigation Use

5 MGD WastewaterPump Station

0.25 MGDWWTF

Future WWTFExpansion

3-AcreLeachfield

Future Leachfield

4" Low Flow

16" High Flow0.70 MG Equalization

Tank

4" Dosing ForcemanGravity Sewer

Sewer Forcemain

Potable Water System

Reuse Water System

Figure by MIT OCW.

1

Projected Stadium event water use

Rizzo Assoc

Selected Toilets(65%)

260,000 gal 390,000 gal

Potable Water Uses (35%)(Sinks, Showers, Ect.)

120,000 gal 180,000 gal

Potable Water Losses (5%)(Washdown, Ect.)

Total 400,000 gal 600,000 gal

20,000 gal 30,000 gal

Stadium Uses Game All Day Concert

700,000 GalEqualization Tank Wastewater Reuse

Unt

reat

ed W

aste

wat

er

250,000 GPDWWTP

Leach FieldDisposal

500,000 GalRe-Use Tank

Figure by MIT OCW.

60

Living Machines, Inc.• Household to small town• Tertiary treatment

– TSS (5 mg/L)– BOD (5 mg/L)– NH3-N (2 mg/l)

• Landscaping & N-P water• Anaerobic reactor ->

Closed aerated reactor -> aerated bioreactors (floating plant racks) -> clarifier -> Ecological Fluidized Beds -> disposal

Figure by MIT OCW.

61

Living Machines, Inc.

System designed for re-use

Toilets

6. Effluent Tank, UV Filter, Booster Tank

1. Anaerobic 2. Closed Aerobic 3. Open Aerobic

4. Clarifier

5. Planted Gravel Wetland

DIAGRAM OF THE LIVING MACHINEFigure by MIT OCW.

62

Wolverton Engineering, Inc

•

•

•

••

Household to small townConcentrated in rural South (mainly outdoor systems)Mainly for discharge back to environment, but some re-useEvolved from NASASeptic tanks -> rock/plant filters (PhytoGroTM System) -> sand filters Figure by MIT OCW.

63

Bar Screens Cyclone Degritter Primary

Clarifiers

Anoxic tank

AerationSecondary Clarifiers

Sand Filters UV Disinfection

Dissolved Air Flotation Thickener

Anaerobic Digesters

Cogeneration Plant

Belt Filter Press

Influent Effluent

Solid Wastes

Biogas

The role for LCA