Water Efficiency
Session 2: Agenda
1.
Sustainable Sites
2.
Water Efficiency
•
Goals / Overview
•
LEED NC Prerequisites & Credits
•
Intent & Strategies
•
LEED EB O&M Credits
•
Intent & Strategies
3.
Energy & Atmosphere
Water Overview
Using large volumes of water increases maintenance and life-cycle costs for building
operations and increases taxpayers costs for additional municipal supply and treatment
facilities.
Bolivar Waste Water Treatment Plant
Mt Eriama Water Treatment Plant
Tips from the Pros
Water efficiency measures in commercial & residential
buildings can easily reduce water usage by more than
30% or 40%.
In a typical 100,000-square-foot office building, low-flow fixtures
coupled with sensors and automatic controls can save a minimum
of 1 million gallons of water per year, based on 650 building
occupants each using an average of 20 gallons per day.
Water Use Statistics
• US daily consumption is
approximately 340 billion gallons of
fresh water per day. Annually we
extract 3,700 billion gallons more
water than we return to the natural
water system.
• The UN reports that human water
consumption has increased 6 fold in
the last century, which is double the
rate of population growth. This has
resulted in estimated extinction of
20% of fresh water species.
Endangered Humpback Chub –
Colorado River Basin
LEED Credits - Water Efficiency
LEED New Construction 1 Prerequisite, 10 points
WE P1 Water Use Reduction, 20% reduction
WE C 1 Water Efficient Landscaping, Option 1
Reduce by 50%, Option 2 (In addition to
option 1) No potable use or no irrigation
WE C 2 Innovative Wastewater Technologies
WE C 3 Water Use Reduction, 30% reduction
Water Use Reduction, 35% reduction
Water Use Reduction, 40% reduction
Req’d
2-4
2
2-4
LEED Credits - Water Efficiency
LEED for Schools 1 Prerequisite, 11 points
WE P1
Water Use Reduction, 20% reduction
Req’d
WE C 1 Water Efficient Landscaping, Option 1
Reduce by 50%, Option 2 (In addition to
option 1) No potable use or no irrigation
2-4
WE C 2 Innovative Wastewater Technologies
2
WE C 3 Water Use Reduction, 30% reduction
2-4
Water Use Reduction, 35% reduction
Water Use Reduction, 40% reduction
WE C 4 Process Water Use Reduction
1
LEED Credits - Water Efficiency
LEED Core and Shell 1 Prerequisite, 10 points
WE P1
Water Use Reduction, 20% reduction
WE C 1 Water Efficient Landscaping, Option 1
Reduce by 50%, Option 2 (In addition to
option 1) No potable use or no irrigation
WE C 2 Innovative Wastewater Technologies
WE C 3 Water Use Reduction, 30% reduction
Water Use Reduction, 35% reduction
Water Use Reduction, 40% reduction
Req’d
2-4
2
2-4
LEED Credits - Water Efficiency
LEED New Construction, Schools, Core and Shell
Referenced Standard: Energy Policy Act of 1992
It addresses energy and water use in commercial, institutional and residential facilities.
This statute became law in 2005.
Water Efficient Landscaping
Water Efficient Landscaping
Intent:
Limit or eliminate the use of
potable water or other natural
surface or subsurface water
resources available on or near
the project site for landscape
irrigation.
Water Efficient Landscaping
Reduce potable water consumption for irrigation from a
calculated mid-summer baseline case.
Water Efficient Landscaping
Reductions shall be attributed to any
combination of the following items:
– Plant species
– Irrigation efficiency
– Use of captured rainwater
– Use of recycled waste water
– Use of water treated and conveyed
by a public agency specifically for
non-potable uses
Water Efficient Landscaping
No Potable Water Use or No Irrigation
• Use only non-potable water for total
amount of water needed for irrigation
through plant selection (except for
initial watering to establish plants).
• Install landscaping that does not
require permanent irrigation systems.
Temporary irrigation systems used for
plant establishment are allowed (if
removed within 18 months of
installation).
Tips from the Pros
Tree gators are a non-permanent irrigation system
that can help establish plants.
Hose bibs for hand-watering may also be acceptable as non-permanent irrigation.
Water Efficient Landscaping
Potential Technologies and Strategies:
• Perform a soil/climate analysis to design
landscaping with native/adapted plants to
reduce/eliminate irrigation.
• Use high efficiency irrigation-Drip
irrigation can use 30% less water than sprinklers.
• Zone irrigation based on terrain & vegetation.
• Use harvested building or storm water for
irrigation.
• Use soil moisture tensiometers or rain sensors controls.
Water Efficient Landscaping
Variables used in calculations:
Landscape coefficient: Volume of
water lost via evapotranspiration,
depends on species, micro climate
and planting density.
Species factor: Accounts for
variation of water needs by different
species rated by high average and
low.
Water Efficient Landscaping
Density factor: The number of plants and the total
leaf area of the landscape, sparsely planted areas
have lower evapotranspiration rates than densely
planted areas.
Microclimate factor: Environmental conditions
specific to the landscape, including temperature,
wind and humidity.
Water Efficient Landscaping
Evapotranspiration rate: he
amount of water needed to grow
a certain reference plant
expressed in millimeters or
inches.
Irrigation efficiency: Based on
the type of irrigation used and
the corresponding efficiency.
Review Question
A project practices water efficiency
by reducing the potable water used
for irrigation by 50%. How could the
project achieve additional water
efficiency?
Review Question
A project practices water efficiency by reducing the potable water used for
irrigation by 50%. How could the project achieve additional water efficiency?
Answer: Either eliminate the need for irrigation
altogether OR use only non-potable water.
Innovative Wastewater Technologies
Intent:
Reduce generation of
wastewater and potable water
demand, while increasing the
local aquifer recharge by:
• Reducing the use of potable water for
building sewage conveyance.
• Treat of wastewater onsite to tertiary
standards. For LEED, treated water must
be infiltrated or used onsite.
Innovative Wastewater Technologies
Potential Technologies & Strategies
To reduce use of potable water:
• Specify high-efficiency fixtures and
dry fixtures such as composting
toilets and waterless urinals,
• Harvest stormwater or building
greywater (sinks, showers) for
sewage conveyance.
Innovative Wastewater Technologies
Potential Technologies & Strategies
To treat wastewater
onsite:
• Implement on-site
wastewater treatment
systems (constructed
wetlands, high efficiency
filtration system, living
machines).
Innovative Wastewater Technologies
Living Machines: Whole systems approaches to treating
wastewater. They are accelerated versions of the water
treatment facilities, incorporating helpful microbes, plants,
snails and fish into diverse, self-organizing and responsive
communities. Living machines are site-specific, biological
solutions that re-route waste streams into resources.
Ben & Jerry’s
Water Use Reduction
Intent:
Maximize water efficiency within buildings to
reduce the burden on municipal water supply
and wastewater systems.
Achieve (in comparison with a baseline set
for the project) through high efficiency flow
and flush fixtures per the Energy Policy Act
of 1992.
EPAct regulated fixtures include lavatories,
toilets, urinals, showers and kitchen sinks.
Water Use Reduction
Projects can achieve up to 40% water use
reduction without occupants even noticing
they are using “high efficiency” fixtures.
Specify fixtures to meet the following criteria:
• Lavatories – 0.5 GPM aerators and auto
on/off set to 12 sec (rather than baseline 2.5
GPM).
• Urinals – 0.5 GPF or 0.125 GPF(rather than
baseline 1 GPF).
Water Use Reduction
• Toilets – 1.2 GPF (or dual-flush)
(rather than baseline 1.6 GPF).
• Kitchen Sinks – 1.8 GPM (rather than
baseline 2.5 GPM).
• Showers – 1.5 to 1.8 GPM (rather
than baseline 2.5 GPM).
Process Water Use Reduction
Water-using systems other than lavatories, toilets, urinals, showers and kitchen sinks
are considered “process water.”
Examples of process water use include:
• Clothes washers
• Dishwashers with racks
• Cooling towers
• Ice machines
• Industrial processes
Tips from the Pros
Definitions:
Potable water
• Water suitable for drinking. Meets or exceeds EPA
standards.
Greywater
• Multiple definitions (Uniform Plumbing Code,
International Plumbing Code, State and local codes)
“untreated household waste water which has not come
into contact with toilet waste.” (UPC)
Tips from the Pros
Blackwater
• Does not have one widely accepted definition.
• State and local codes may consider wastewater
from kitchen sinks, showers or bathtubs as
blackwater.
• Wastewater from toilets is always considered
blackwater.
Integrated Water Management
$
VS.
Can the design process be integrated?
LEED Credits – Water Efficiency
Existing Buildings Operations & Maintenance
1 Prerequisite, 14 points
WE P1
Minimum Indoor Plumbing Fixture and
Fitting Efficiency
Required
WE C 1
Water Performance Measurement
1-2
WE C 2
Additional Indoor Plumbing Fixture and
Fitting Efficiency
1-5
WE C 3
Water Efficient Landscaping
1-5
WE C 4
Cooling Tower Water Management
2
EBOM: Water Use
Minimum Indoor Plumbing Fixture and Fitting
Efficiency
Intent: To ensure that the building seeking certification has reached a certain level of
water efficiency.
Requirement:
Reduce fixture potable water usage to a level equal-to-or-below the water baseline,
which is a percentage of the water usage.
Divides plumbing systems into 2 groups:
•Completed in 1994 or later
•Completed before 1994
Uniform Plumbing Codes (UPC) 2006 or International Plumbing Codes (IPC)
2006.
Water Performance Measurement
Intent:
To inform decision making regarding operations and retrofits by measuring water
consumption.
Requirements:
Have permanently installed water meter(s) measuring total potable water use (entire
building and grounds). Data should be recorded regularly and summarized monthly and
annually.
Strategies:
Have a building wide water meter or series of water meters measuring all water delivered
to the building.
Water Performance Measurement
Requirements:
Have in place permanently installed metering for one or more of the following
subsystems:
•
Irrigation
•
Indoor plumbing fixtures
•
Cooling towers
•
Domestic hot water
•
Other process water
Additional Indoor Plumbing Fixture and Fitting
Efficiency
Intent:
To further increase water efficiency in existing buildings.
Strategies:
Retrofit with high-efficiency fixtures:
• Lavatories
• Urinals – 0.5 GPF or waterless
• Toilets – dual flush
• Kitchen Sinks
• Showers
Water Efficient Landscaping
Intent:
To reduce the consumption of water needed for landscape purposes.
Strategies:
•
Replace existing vegetated species with native, adapted, and drought
resistant varieties.
•
Install moisture meters around the soil to inform watering schedule.
•
Remove irrigation system (hand watering is allowed).
Cooling Tower Water Management
Intent:
To ensure that the building management team is aware of the proper operating
procedures required to maintain a cooling tower.
Cooling Tower Water Management
Requirements:
Chemical Management
Implement a water management plan for the cooling tower that addresses chemical
treatment, bleed-off, biological control and staff training as it relates to cooling tower
maintenance.
Water Management
Improve water efficiency by installing & maintaining a conductivity meter and automatic
controls to maintain proper concentration.
Cooling Tower Water Management
Intent:
To further reduce potable water consumption during cooling tower operation.
Requirements:
Use cooling tower makeup water from non-potable
sources.
Examples of nonpotable water sources: stormwater, air-conditioning condensate,
swimming pool filter backwash, cooling tower blowdown, pass-through cooling water,
recycled treated wastewater, municipally reclaimed water.
Questions on Water Efficiency?