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