Sustainable Water Issues
as applied to buildings
Eric Adams
Outline for Discussion in
Design for Sustainability (1.964)
November 15, 2006
Outline
• Introduction (brief)
• Context: Boston area’s water supply
and wastewater treatment (brief)
(Is current system sustainable?)
• Water-related sustainability
measures applicable to buildings
2
Indoor Environmental
Quality
23%
22%
Materials
and Resources
Sustainable
Sites
20%
8%
Water
Efficiency
27%
Energy and Atmosphere
Figure by MIT OCW.
LEEDTM Certification Categories
3
Water and Sustainablity
• Sustainability => keeping consumption
within limits of natural replenishment
• Broader view includes
– Environmental
– Economic
– Social
4
Water vs Materials & Energy
• Largely renewable
Indoor Environmental
Quality
23%
22%
Materials
and Resources
20%
8%
27%
Energy and Atmosphere
Figure by MIT OCW.
Sustainable
Sites
Water
Efficiency
– 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
5
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
6
Water supply, wastewater,
stormwater
Potable
Central
Water
Supply
Central
Water
Treatment
Non-pot.
Landscape
Precip
Precip
Impervious
7
Boston’s Water Supply
500
479.9
479.9
200
100
1848
1864
1872
1908
1946
1980
Upper Mystic Lake
Sudbury System
Wachusett Reservoir minus
Upper Mystic Lake
Quabbin Reservoir minus
part of Sudbury System
and Lake Cochituate
Remainder of Sudbury
System Discontinued
0
Lake Cochituate
Storage Capacity (BG)
400
• 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
1
Figure by MIT OCW.
Boston’s Water Supply cont’d
Flickr image courtesy of pjmorse.
• Prim. Disinfection: O3
Res. Disinfection:
Chloramine
• Corrosion Control
• Fluoridation
• Modular for
expansion/contingency
– Filtration
• $0.34 billion
9
Million Gallons Per Day
350
System's long-term safe yield of 300 MGD (~13m3/s)
300
#
250
200
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04
# Includes temporary supply to Cambridge during construction of local water
treatment plant
MWRA Water Demand vs. System Safe Yield
Figure by MIT OCW.
Sustainable?
10
Boston’s Wastewater
Diffuser
Outfall Tunnel
In
ne
rH
arb
Deer Island
treatment plant
or
Dorchester
Bay
Fox Point
CSO treatment
facility
Moon Island
Commercial Point
CSO treatment
facility
Quincy Bay
Hingham Bay
Nut Island Headworks
(Former site of Nut
Island treatment plant)
0
• 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
5 Km
Figure by MIT OCW.
Fore River
pelletizing plant
1
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.
12
Should wastewater be returned
to watershed rather than
discharged to ocean?
13
1200
Average pounds per day discharged
Metals in MWRA Treatment Plant Discharges 1989-2002
Silver
1000
Nickel
Chromium
800
Lead
600
Copper
Zinc
400
200
0
89
90
91
92
93
94
95
96
97
Data from mwra.state.ma.us
98
99
00
01
02
14
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?
15
Stormwater (and freshwater and
stormwater)
Leaks
Central
Water
Treatment
Potable
Central
Water
Supply
Leaks
Non-pot.
Inflow
CSO
Landscape
Precip
Precip
Impervious
16
Infiltration
Combined Sewer Overflow
Figure by MIT OCW.
17
mwra.state.ma.us
Boston’s CSOs
Sewer Separation
in Reserved Channel Outfall
Tributary Areas
Pleasure Bay
Storm Drain Connection
to Outfall BOS080
15 mgd Pump Station
for Tunnel Dewatering
Pleasure Bay Storm
Water Relocation
BOS085
BOS081
BOS083
BOS084
BOS086
BOS087
BOS082
Dewatering Force Main to
BWSC Sewer System
17-Foot Diameter
tunnel
Active CSOs
Treated CSOs
Closed CSOs
Odor Control
Building
Morrissey
Blvd Storm
Drain
Figure by MIT OCW.
Figure by MIT OCW.
18
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 = $0.9 billion
Sustainable?
19
Annual CSO Events Remaining
6
4
2
0
0
10
20
Marginal Capital Cost ($ Million/Annual
Event Eliminated)
Marginal Capital Cost of Near-Surface Storage for Alewife/Mystic
River Basin
Figure by MIT OCW.
20
Central vs Distributed Systems
Advantages
• Investment/sharing
in existing
infrastructure &
professionals
• Stability under
transient water
demand/availability
• Cheap!
Disadvantages
•
•
•
•
•
•
•
Disrupts hydrology,
people
Encourages waste
High energy costs
Large sludge production
More vulnerability
Complex, hard to
monitor
21
Hard to expand
System Expansion
• Not all or nothing.
• Most urban/suburban systems are
centralized but there is room (indeed
need!) for local systems: new hookups mean greater distances & flow
rates (hence pressure losses),
implying greater marginal costs
22
Sustainability measures
Water Conservation
On-site treatment/Re-use
Potable
Central
Water
Supply
Central
Water
Treatment
Non-pot.
Landscape
Stormwater
Management
Precip
Precip
Impervious
Rainwater Collection
23
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
24
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
25
8
Frequency
6
4
2
0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
More
Ratio of actual to theoretical application
Sensor Based Irrigation Efficiency
Figure by MIT OCW.
DeOreo, et al., Boulder CO
26
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.
27
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)
28
2. Rainwater Collection/Use
Potable
Central
Water
Supply
T
Central
Water
Treatment
Non-pot.
T
Landscape
Precip
Precip
Impervious
29
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)
30
Fit for use quality/downcycling
External Supply
Class I
Rainwater
Tank
5.4
60.4
14.6
3.9
66.7
Storage Tank
Class I
- Bath
- Shower
First
phases: 25
Storage Tank
Class II
- Washbasin
Last phases: 7.8
- Laundry
- Dishwashing
Last phases: 17
Draining 52.4
- Food Prep
- Washing up
- Other
14.6
42.8
- Toilet
Storage Tank
Class III
First phases: 15.8
Draining 29.3
Class IV:
Discharge
86.7
Figure by MIT OCW.
31
Coombes, 2005
Toronto Healthy House
Figure by MIT OCW.
•
•
•
•
•
P—gutters
R—rain water cistern
S—combination filter
T—drinkable cold water tank
O—drinkable hot water tank
•
•
•
•
•
•
•
•
E—grey water heat exchanger
N—reclaimed hot water tank
U—septic tank
V—recirculation tank
W—Waterloo biofilter
X—twin combination filters
Y—reclaimed cold water tank
Z—garden irrigation
32
Toronto Healthy House
Figure by MIT OCW.
33
Figure by MIT OCW.
34
Eden Project
35
1 Rainwater Collection Roof + Site
3
None
Collection
Previous Paving
Roof+Site
Capture
site s.f.
gal
1
0
0
2
Flow loss Factor
5%
4
74,537
1,681,316
s.f.
gal
Potable
Dishwasher
s.f.
gal
gal
gal
4
201,830
7
gal
Storage
Rain water
Cistern
1,545,533 gal
No Flow
Grey water
Cistern
gal
0
Irrigation
Flushing
803,346
Available
463,950
gal
541,587
40%
gal (demand)
gal
1,005,776
gal introduced
for recharge
1.4 million gallons higher (per year)
Urinals
127,495
127,435
gal
gal
6
To City
Sewer
Plumbing
Fixtures
0
0%
Process Water
gal
gal
0
0%
reintroduced
gal
0
0%
% of supply
4
N
30%
City SewerConstructed
Flow loss Factor
Bldg
wetland
734,776 gal
gal
0
RETURN
4
Ground Water Recharge
5
Grey
Irrigation
463.950 gal
463,350 gal
Grey
10% Flow loss Factor
Grey Water Demand
15%
Overflow factor
gal
gal
gal
gal
0
0
7
Potable
Potable
Pool
M-Ro/Coad
gal
gal
0
0
gal
0
0
gal
Grey
Potable
Drinking
WC Flashing
Fountain
gal 414,092 gal
0
21,072 gal 414,032 gal
Clothes Washer
Flow loss Factor
Pre-Treatment
City Strom Sewersite
gal
201,830
Potable
Showers
0
10,890
Potable
Cistem
8
gal
gal
Potable
Sinks
0
702,813
20%
8
Catch
Basins
0
0
3
Overflow
oil/water
gal potable water demand
FLOW PATHS
0
0
394.780
2
1
N
Impervious
Area
gal (roof collection)
in.(annual)
SUPPLY
Potable Water
Rainfall
968.274
41.2
Strom Sewer
Water Flows - Yearly
1.0 million gallons lower (per year)
Water Profile Tool
www.greenroundtable.org
Figure by MIT OCW.
36
2 If no water mesaure included
+1.3 Million Gallons Higher (per year)
Water Flows - Yearly
2
1
None
Flow loss Factor
5%
s.f.
gal
0
0
s.f.
gal
2
Potable
Dishwasher
gal
gal
3
gal
gal
4
gal
0
8
7
No Flow
Rain water
Cistern
gal
0
No Flow
Grey water
Cistern
gal
0
Pre-Treatment
Irrigation
Flushing
0
Available
463,950
gal
0
0%
gal (demand)
gal
0
gal introduced
for recharge
1.4 million gallons higher (per year)
To Citi
Sewer
Urinals
0
127,435
gal
gal
Plumbing
Fixtures
0
0%
Process Water
gal
0
gal
0%
reintroduced
gal
0
0%
% of supply
N
30%
Constructed
Over Loss factor
wetland
gal
0
Citi SewerBldg
1,276,362 gal
RETURN
4
Ground Water Recharge
6
Potable
Irrigation
0
gal
463,350 gal
Potable
10% Flow loss Factor
Grey Water Demand
15%
Overflow factor
5
Cistem
Overflow
gal
gal
gal
gal
0
0
7
Potable
Potable
Pool
M-Ro/Coad
gal
gal
0
0
gal
0
0
gal
Potable
Potable
Drinking
WC Flashing
Fountain
gal
gal
0
0
21,072 gal 414,032 gal
Clothes Washer
Flow loss Factor
oil/water
Citi Strom Sewersite
gal
1,681,916
Potable
Showers
0
10,890
Potable
20%
8
Catch
Basins
0
0
Potable
Sinks
0
702,813
FLOW PATHS
1
0
0
gal potable water demand
4
Roof . Site
Capture
Previous Paving
site s.f.
gal
1.740.312
3
None
Y
Impervious
Area
74,537
1,681,961
gal (roof collection)
in.(annual)
SUPPLY
Potable Water
Rainfall
0
41.2
1.0 millon gallons lower (per year)
Figure by MIT OCW.
37
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 reuse (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
38
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 -> cogeneration, effluent -> Vegetative treatment (Living
Machines) -> toilet flushing, irrigation, cooling
• Also on-site wind turbines, heat recovery, passive solar
features
39
3. Stormwater Management
Potable
Central
Water
Supply
Central
Water
Treatment
Non-pot.
Landscape
Precip
Precip
LID
BMP
Impervious
40
Effect of development: more runoff,
leaving site more quickly
(P. Shanahan)
Flow
Developed conditions
without controls
Pre-development
conditions
Time
41
Consequences
Damaged pilings
Lower water
level
Water level
Pilings
* 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
How Drops in Ground Water Damage Wooden Pilings
• Flooding
• Poor water quality
• Reduced long-term
ground water
storage
• Fluctuating ground
water table
Figure by MIT OCW.
Boston Globe May 16, 2005
42
Detention Ponds
Courtesy of Peter Shanahan.
Used with permission.
43
Detention Ponds
Courtesy of Peter Shanahan.
Used with permission.
44
Effect of site controls
(detention ponds)
Flow
Developed conditions
without controls
Developed conditions
with controls
Pre-development
conditions
Time
45
Effect of low-impact development
Flow
Pre-development
conditions
Developed conditions
with controls
Developed conditions
with LID
Time
46
Low-Impact Development
Figure by MIT OCW.
47
Vegetative Roofs
Flickr photograph courtesy of birdw0rks.
48
4. Wastewater treatment/re-use
Central
Water
Treatment
Potable
Central
Water
Supply
Non-pot.
T
T
Landscape
Precip
Precip
Impervious
49
(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
50
Small Footprint WWTPs
Sludge
Hydrocyclone
Polymer
M
Micro-sand & sludge to hydrocyclone
Microsand
M
M
M
Clarified
water
Coagulant
Raw
water
Figure by MIT OCW.
Injection
Coagulation
Maturation
Tube
Settling w/ Scraper
Biological aerated Filter (BAF)
(www.vertmarkets.com)
Ballasted flocculation (BF);
(www.brentwoodindustries.com)
Figure by MIT OCW.
Integrated fixed-film activated sludge (IFAS)
(www.brentwoodindustries.com)
Membrane Bio Reactor (MBR)
(www.brentwoodindustries.com)
51
Sandino, et al., Civil Engineering, 2003
Sustainable Sewage Treatment
(R. Fenner)
Land
Area
Constructed wetlands
Reed beds
Trickling filters
Rotating
biological
contactors
Activated
sludge
systems*
Membrane
bioreactors
Energy
requirements
52
Coagulant
Flocculent
Grit
Chamber
Primary Setting Tank
Bar Screens
Sludge Treatment
and Disposal
Figure by MIT OCW.
Suspended solids removal (%)
100
80
60
40
without chemical
addition
20
0
Figure by MIT OCW.
with ferric chloride
plus polymer addition
0
20
40
60
80
100
Surface overflow rate (m/d)
TSS Percent Removal vs. Surface Overflow Rate
120
Stonecutters Island:
world’s largest and
most efficient
CEPT plant
Hong Kong uses seawater to
flush toilets
54
Figure by MIT OCW.
55
Photograph courtesy of Brett Paci.
56
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
57
The solution
• Develop a regional high pressure
district
• Construct on-site WWTP (MBR, UV,
O 3)
• Utilize a water reuse system
• Daylight Neponset River
58
0.5 MG Reuse
Water Storage Tank
0.1 MG Potable
Water Storage Tank
Emergency
Interconnection
Potable Water System
Regional Potable
Water High Service
Pressure Zone
Reuse Water
System
Off-site Water System
Improvements
Future Irrigation
Use
3-Acre
Future
Leachfield Leachfield
Gravity Sewer
4" Dosing Forceman
0.25 MGD
WWTF
4" Low Flow
Future WWTF
Expansion
16" High Flow
0.70 MG Equalization
Tank
5 MGD Wastewater
Pump Station
Sewer Forcemain
Figure by MIT OCW.
59
Projected Stadium event water use
500,000 Gal
Re-Use Tank
Untreated Wastewater
Stadium Uses
Game
All Day Concert
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.)
20,000 gal
30,000 gal
400,000 gal
600,000 gal
Total
700,000 Gal
Equalization
Tank
250,000 GPD
WWTP
Wastewater Reuse
Leach Field
Disposal
Rizzo Assoc
Figure by MIT OCW.
1
Living Machines, Inc.
• Household to small town
• Tertiary treatment
– TSS (5 mg/L)
– BOD (5 mg/L)
– NH3-N (2 mg/l)
Figure by MIT OCW.
• Landscaping & N-P water
• Anaerobic reactor ->
Closed aerated reactor ->
aerated bioreactors
(floating plant racks) ->
clarifier -> Ecological
Fluidized Beds -> disposal
60
Living Machines, Inc.
1. Anaerobic
2. Closed Aerobic
3. Open Aerobic
Toilets
4. Clarifier
5. Planted Gravel Wetland
6. Effluent Tank, UV Filter, Booster Tank
DIAGRAM OF THE LIVING MACHINE
Figure by MIT OCW.
System designed for re-use
61
Wolverton Engineering, Inc
Figure by MIT OCW.
• Household to small
town
• Concentrated in rural
South (mainly outdoor
systems)
• Mainly for discharge
back to environment,
but some re-use
• Evolved from NASA
• Septic tanks ->
rock/plant filters
(PhytoGroTM System) 62
> sand filters
The role for LCA
Influent
Effluent
Bar Screens
Cyclone
Degritter
Anoxic
tank
Primary
Clarifiers
Aeration
Secondary
Clarifiers
Sand Filters
UV
Disinfection
Dissolved Air
Flotation
Thickener
Solid Wastes
Belt Filter
Press
Anaerobic
Digesters
Biogas
Cogeneration
Plant
63