las vegas water reuse 2
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Water Recycling Study
Southern Nevada Regional
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Dear Valued Stakeholder:
While most people in Southern Nevada recognize the importance o maximizing our Colorado River and
local groundwater supplies, ar ewer appreciate the critical role that water recycling plays in extending
our communitys water supply. I not or the ability to recycle water, Southern Nevada would have
exhausted its available water resources many years ago.
Our community recycles water in two ways: direct and indirect. Direct reuse is a process by which
wastewater ows are treated to stringent quality standards, then used or non-potable purposes such as
irrigation. Indirect reuse, which currently represents the majority o the Las Vegas Valleys water recycling
eorts, is achieved by treating wastewater to very high levels, then returning that water to Lake Mead. For
each gallon o water returned, a credit o one gallon is created. Through this mechanism, we are able to
stretch our water resources by billions o gallons each year.
While indirect recycling is eective, additional direct reuse oers several potential benets, including
reduced energy use or water treatment and delivery. In this report, we identiy options that will allow us
to expand upon our already successul water recycling program and make optimal use o our communitys
water resources.
The Southern Nevada Regional Water Recycling Studywas developed with involvement and input rom a
diverse group o stakeholders, all o whom have a strong interest in current and uture water recycling
eorts. The report includes specic public policy recommendations with respect to water reuse.
The authors o this report believe that adoption o the principles and recommendations contained herein
will promote the optimal use o our regions scarce water supplies. Please take the opportunity to review
this document and reect upon the recommendations. I you have any questions, please do not hesitate
to contact either o us. With your guidance and support, we can protect and extend our communitys most
valuable resource and serve as a model or communities around the world.
Patricia Mulroy
General Manager
Southern Nevada Water Authority
Chip Maxeld, PE
General Manager
Clean Water Coalition
March 2009
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Purpose ofStudy
Recycled water accounts or roughly 40 percent o the
water used in Southern Nevada, making it our second
largest water resource and a critical piece o our waterresource portolio. In this study, we take a specic look at
water recycling and seek to identiy new ways to extend
our already successul water recycling programs while also
seeking new opportunities to recycle and make better use o
the water we have.
This study provides recommendations or regional policies
and goals or water recycling that both complement our water
conservation program and help provide water resources or
continued growth in a sustainable manner.
Table o Contents
Purpose o Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Water Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
All Water is Recycled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Water Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Sustainability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Setting Recycling Goals or the Future . . . . . . . . . . . . 7
Current Water Resources and Use . . . . . . . . . . . . . . . . . 8
Water Recycling Today . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Las Vegas Valley Treatment Plantsand Recycling Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
How is Recycled Water Used Elsewhere?. . . . . . . . . . 1 2
Recycling Practices Vary by Community . . . . . . . . . . 1 4
What About Graywater?. . . . . . . . . . . . . . . . . . . . . . . . .15
Stakeholder Research. . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Guiding Principles or Water Recycling . . . . . . . . . . . 1 8
Choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Weve been recycling water in Southern Nevada
or over 50 years, and oppor tunities exist
to recycle even more.
Southern Nevada Regional Water Recycling Study
www.snwa.com
www.cleanwatercoalition.com
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch2
Aquier: A geologic ormation under the ground that is
saturated with groundwater and sufciently permeable to
allow movement o quantities o water to wells and springs.
Aquier Storage and Recovery: A management strategy
in which water is treated and articially recharged to an
aquier system or later withdrawal.
Direct Potable Reuse:The introduction o reclaimed
water directly into a drinking water distribution system
(pipe to pipe).
Direct Reuse:The use o reclaimed water or nonpotable
purposes without rst discharging to a water supply source.
Graywater: Untreated used water rom bathtubs, showers,
bathroom sinks and clothes washers. Does not include water
rom toilets, kitchen sinks or dishwashers.
Indirect Reuse:The use o reclaimed water or nonpotable
or potable purposes by discharging to a water supply source,
such as resh surace water or groundwater, where it mixes,
dilutes, and may be transormed beore being removed or
reuse.
Indirect Potable Reuse:Augmenting a communitys
raw water supply with reclaimed water ollowed by an
environmental buer. The mixed reclaimed and raw water
receives additional treatment beore entering the potable
water distribution system.
Potable Water:Water that meets all applicable ederal,
state and local requirements concerning saety or
drinking water.
Reclaimed Water:See Recycled Water
Recycled Water:Wastewater that has been treated, then
used or a benecial purpose. Also called Reclaimed Water
or Reuse Water.
Water Treatment: The act o removing contaminants
rom source water by biological processes, chemical addition,
ltration and disinection to puriy the water or it next use.
To urther the discussion about water recycling, it is
important to have an understanding o the terms and
phrases that are commonly used.
For the purposes o this study, a collection o these
terms and phrases and their associated denitions is
provided below:
Water Terminology
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Southern Nevada Regional Water Recycling Study
Water recycling is simple its nothing more than taking
water weve already used and using it again. In act, all
water is recycled, and always has been.
Through the process o evaporation, water makes its way to
mountains and rivers in the orm o precipitation (rain, snow),
runs over (or under) the earths surace and back to the ocean,
where it begins the process over again. Along
that journey, some o this water is used by plants,
animals and people, but the water is always
returned to the system. I we think about the
earths water cycle as a circular process, it would
represent a very large circle.
In Southern Nevada, we recycle water at a local
level similar to the earths water cycle, only
smaller. Water recycling means collecting the
water weve already used, treating it and using it
again here in our community.
In act, we already recycle about 40 percent o our water
here in Southern Nevada with the aid o something called a
Return Flow Credit. Return ow in Southern Nevada relies
on the concept that or every gallon o treated Colorado
River water returned to the Colorado River, we can
withdraw and use an additional gallon beyond Nevadas
base allocation. Southern Nevada is unique among major
cities that rely upon the Colorado River because our
All WaterisRecycled - Its Just a Matter of How Fast
Water Cycle
The Earths water
is constantly being
recycled.
Water recycling
means collecting
the water weve
already used,
treating it and
using it again
here in our
community.
proximity to the river allows us to very efciently recycle
water through this withdrawal and return mechanism.
Las Vegas Wetlands Park
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch
The Right Quality or the Right Use
What is water quality and how does
it afect how we meet our needs?
Water quality is a term used to describe
the characteristics o water in relation to
its intended use. Even though the water
part rom every source is the same,
water quality varies depending upon the unique biological
and chemical characteristics contained in each dierent water
source. The quality o water varies depending on what that
source contains besides just water. Regardless o the source, the
water we use is treated to ensure that it meets specic ederaland state water quality requirements .
For instance, our drinking water is treated by processes
specically designed or the water quality o our local source
waters to ensure that it meets or exceed
all ederal and state requirements ordrinking water.
Similarly, our wastewater is treated in multiple
steps beore it is returned to the environment.
In Southern Nevada, the wastewater treatment
plants are among the best in the country, combining
biological treatment, nutrient removal, chemical treatment,
ltration, disinection and neutralization o any added
chemicals. This recycled water consistently satises all
ederal and state water quality requirements or its next use.Sometimes this next use is the irrigation o parks, gol courses
or industrial uses. Recycled water not used or these needs is
returned to the Colorado River system where it is available or
our use and by others in Arizona, Caliornia and Mexico.
4
Our Level o Wastewater Treatment
Treatment plants receivewater and treat it to a
level that is appropriate
or its next use.
Water Quality
Better Treatment
Cities
Miami, FL
San Francisco, CA
Philadelphia, PA
Portland, OR
Cities
Denver, CO
New York City, NY
Houston, TX
Chicago, IL
Cities
Los Angeles, CA
Phoenix, AZ
Atlanta, GA
Dallas, TX
Cities
Las Vegas, NV
Scottsdale, AZ
Placerville, CA
El Paso, TX
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Water Quality Monitoring and TestingEnsures Public Saety
Between the various agencies responsible or managing
our water quality, hundreds o thousands o tests* are
run on our water each year in its various stages o use,
treatment and reuse. This continuous monitoring and
testing helps protect our water quality and the publics health
and saety.
Recycled water that is directly reused or returned to the
Colorado River is tested by Nevada Division o Environmental
Projection (NDEP) certied testing laboratories to ensure
that it meets requirements set orth or benecial uses.
Benecial uses include such things as recreation, aquatic
lie, sheries, irrigation, and source water or drinking water
supply. The Environmental Protection Agency and the NDEP
monitor the results o the tests.
Similarly, water drawn
rom the Colorado
River is tested beore
and ater treatment,
as well as at multiple
points within the
potable water
distribution system.
This ensures that it
meets or exceeds
the standards o the
Federal Sae Drinking
Water Act.
And at every point in
the cycle, the people
who are responsible or treating the water, testing its quality
and overseeing the process are certied operators and lab
analysts, licensed proessional engineers, or other similarly
qualied proessionals whose primary responsibility is the
saety o our water and the protection o the environment.
Southern Nevada Regional Water Recycling Study
Continuous monitoring and testing helps
protect our water quality and the publics
health and saety.
Water drawn rom the Colorado River
is tested beore and ater treatment.
*The water supply is analyzed or metals and inorganic compounds, radiological constituents, bacteria, viruses, protozoans (such
as Cryptosporidium and Giardia) and organic compounds.
Recycled water on its way to the Colorado River is sampled
and tested to protect water quality in the river.
Water Quality
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch
With todays increased environmental awareness and
a strong shit in values toward more sustainable living
practices, communities everywhere are reevaluating
how they use their resources.
In Southern Nevada, we also recognize that as we satisy
our present needs, we must do so in a way that does not
compromise the uture o our community.
What does it mean to be sustainable?Most people
associate it with protecting the environment. And while
it does ocus on environmental protection, sustainability
also takes in economic and social/cultural considerations.
A sustainable solution is one that represents a goodbalance between these three concerns. In the context
o water recycling, sustainable applications or its use
are evaluated in this same way. Water managers look or
opportunities to use recycled water cost eectively and in
ways where our treatment processes can eectively achieve
a high quality o water. When used in the right applications,recycled water can save energy, reduce the need or new
inrastructure, and in some instances result in an increase in
the water supply available to a community.
Sustainability
6
While it does ocus on environmental
protection, sustainability also
takes in economic and social/cultural
considerations.
Economic
Social/Cultural
Environment
Sustainability
Sustainability
Sustainable solutions
balance competing interests
EconomicGrowth and Developmen
Job Creation
Social/CulturalQuality o Lie
Community Perception
Social Values/Priorities
Environment
Pollution Prevention
Habitat Conservation
Resource Protection
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Our water resource picture is changing. The efects o
prolonged drought within the Colorado River basin
are causing stress on water resources throughout
the entire region. And the difculties caused by this
water scarcity are unlikely to go away anytime soon.
Most experts believe that the earths climate is changing,
and that one o the eects o this climate change is the
reduction in precipitation making its way into the lakes
and rivers o the Colorado River basin.
While no one knows or certain what the uture holds,
we must nd ways to make all o our water resources go
urther. Now is the time to look at how we collectively use
our shared resources and use the opportunity to set new
goals or using recycled water.
Southern Nevada Regional Water Recycling Study
The Big Picture
Setting Recycling Goals for the Future
The Study Process
In order to provide the background needed or an inormed discussion about how we use
water and how recycled water should t into our uture, this study utilized a multi-step
process.
Recommendprinciplesandgoals.
What are ourwater needs,and how dowe use ourvarious waterresources tomeet them?
How do wecurrently userecycledwater?
How isrecycled waterused in otherparts o thecountry andthe world?
How do wecompare toother places,and whatmakes senseor ourcommunity?
The eects
o prolonged
drought within
the Colorado
River basin
are causing
stress on water
resources
throughout the
entire region.
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch
Where Our Water Comes From and HowWe Use It
In order to make good decisions and set goals or using
recycled water, we need to know something about how
our water ullls our
needs. So where does our
water come rom, and
how do we use it?
Almost all o the water we
use in Southern Nevada
(nearly 90 percent)
comes rom the Colorado River, with the rest coming rom
groundwater wells. When we actor in the amount o
recycled water we use in Southern Nevada, we see that it
makes up nearly 40 percent o our total water resources.
How do we use the water we have?
Most o the water used in Southern Nevada is used at
our homes and most o that is used outdoors. I we look
beyond the water used at our homes, the remaining water
is used by companies and or services that support our
local economy and quality o lie.
How do the various uses we have or water help us
shape our water recycling goals?
The answer lies in our ability to collect water rom these
dierent uses so it can be treated and used again. I we
use the water in ways that allow us to capture it ater use
(indoor uses that send water down the drain) then we
can recycle it. But if the water cant be captured after weve
used it the rst time (such as outdoor irrigation) then we
cant recycle it.
Current Water Resources and Use
8
2008 Water Supply40%
60%
Surface and Groundwater
Recycled Water
Water Resources
Water Use
44%
15%13%
7%
5%
7%
5%4%
Residential (Single Family)
Residential (Multi-Family)
Commercial / Industrial
Resorts
Golf Courses
Schools / Government / Parks
Common Areas
Other
Recycled water
provides nearly
40 percent o
our total water
resources.
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In the end, how we satisy each need or water is not
a one-size ts all process, but rather a decision that
balances cost, resource availability, water quality and
other actors to come up with the best answer or that
water need in that community. How do we strike this
balance?Thats where setting goals comes in, and well
get to that later in this report.
Approximate Annual
Volume o Indirect
Water Recycling 186,000 acre-eet
Approximate Annual
Volume o Direct
Water Recycling
27,000 acre-eet
Gol Courses Irrigated
with Recycled Water 30
Power Plants Using
Recycled Water or
Cooling 2
Southern Nevada Regional Water Recycling Study
Our Current Water Recycling Practices
Did you know that we have been recycling water in
Southern Nevada or over hal a century and or over
20 years it has been a part o our strategic water
resource plan?
Most o the water that goes down our drains (sinks, showers,
toilets) is ultimately returned to the Colorado River, but not
until it has been treated and tested to make sure that it is
clean enough to be returned to the water cycle (reer to the
water cycle on page 3). But some of the water that has been
treated comes back to our community (without going to the
river) or benecial use. While we dont use this recycled water
or drinking, we are able to use it to meet many o our other
water needs.
Recycled water is currently used or gol course, green belt and
median irrigation, cooling water or power plants, water or
dust control, and other minor uses. And it is important to note
that while many o our gol courses use recycled water, not all
do. The same is true or the other applications in which we use
recycled water a combination o recycled water and potable
waters are used to meet their overall needs. Some water needs
are minimized through conservation as well.
Water RecyclingToday
Return Flow Credit
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Southern Nevada Regional Water Recycling Study
5
6
7
4
9 8
12
3
NorthLas Vegas
Las Vegas
Clark County WaterReclamation District
Henderson
SunriseStation
Power Plant
Las Vegas Wash
Clark StationPower Plant
Silver BowlSoccer Field
Complex
MedianLandscaping
AlongBoulder Hwy
McCarran IntlAirport
Return Flow toLake Mead
PalmMortuaryCemetery
(Irrigated withRecycled
Water)
159
215
15
15
159
93
215 93
95
160
160
215
515
515
0 1 2 3 40 5
miles
Treatment Plants
Power Plants
Wetlands Park
Golf Courses that currently use
reclaimed water (30)
Legend
City of Henderson
City of North Las Vegas
City of Las Vegas
Clark County Water Reclamation
District Service Area
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch
In Some Places, Water Recycling MayNot Be the Best Answer
Water recycling is oten more expensive than treating
and discharging wastewater and relying on
non-recycled sources to meet water needs.
Communities that have an abundance o
water resources that exceed their needs
oten dont recycle, primarily because the
cost o building and operating the treatment
and distribution systems required to supply
recycled water just isnt justied.
Many Communities UseRecycled Water or Irrigation
The single most common use or recycled
water is or outdoor irrigation. The typical
water customer who buys recycled water
or irrigation uses it to water gol courses, public median
landscapes, and certain types o agriculture. While
the recycled water treated or irrigation is not suitable
or drinking, the water needs o many plants can be
satised by recycled water as long as careully managedwatering practices are in place.
School and Parks
Using recycled water or irrigating landscaping at schools,
ball elds and parks is given careul consideration becauseo the increased potential or human
contact with the recycled water.
However, extensive study and many
years o use at schools and parks in
other communities show that this is
a responsible use o recycled water.
Because recycled water for irrigation
is not treated to a potable standard,
signage and specially colored piping and
sprinkler heads identiy it as recycled and
instruct people not to drink it.
Recycled Water Can Be Usedto Supplement Groundwater
In some communities, the groundwater aquier is their main
water resource. They draw the groundwater rom wells
and use it to meet the community water needs. But where
groundwater supplies are limited, and when the need or
groundwater exceeds what can be replenished naturally,recycled water can be used to replenish the groundwater
supply and help these communities maximize their
groundwater resources.
2
The typical water customer who buys recycled
water or irrigation uses it to water gol courses,
public median landscapes, and certain types o
agriculture.
Silver Bowl Park
How is Recycled Water Used Elsewhere?
Aquier Storage and Recovery
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Prevention o Seawater Intrusion IntoPotable Aquiers
For coastal communities that rely heavily on groundwater,
pumping groundwater rom aquiers near the ocean can
result in a lowering o the water table and an inux o
seawater into the same aquiers they rely on or drinking
water. In these communities recycled water injected into
the ground can help increase groundwater pressure and
prevent the migration o seawater into the potable aquier.
Industrial Uses
Many businesses use water or manuacturing and
industrial processes, and or some o these uses, recycled
water is a viable option to meet their needs. Common
industrial uses or recycled water
include evaporative cooling
towers, washing o aggregates or
concrete, soil compaction and dust
control, commercial laundries and
car washes. For industrial uses, the
specic water quality requirements
or each use are evaluated, and
requirements or supplemental
treatment (i needed) are identied.
Indirect Potable Reuse
Southern Nevada is one o many communities that indirectly
augment drinking water supplies with recycled water. Whileour current eorts augment
our surace water supply
(the Colorado River), some
communities use recycled
water to stretch surace
and/or groundwater
supplies. Other examples
include Orange County,
Caliornia, the greater Denver metropolitan area that includes
Aurora, Colorado, and Atlanta, Georgia. Indirect Potable Reuse
is practiced internationally as well.Singapores national water
agency currently ullls 15 percent o total water demands
with recycled water, with a small proportion o this percentage
contributing to indirect potable reuse.
Direct Potable Reuse
At the most aggressive end o the water recycling spectrum is
the concept o taking recycled water, treating it to the same
potable standards that would apply to any other source water,and then placing it directly into a potable water distribution
system without the benet o buering or dilution rom
another body of water. Because of the increased public health
risk and public perception difculties associated with such an
approach, direct potable reuse
applications are extraordinarily
rare, and are not permitted by
state or ederal regulations in
the United States. In act, only
one documented instance o a
municipal water system utilizing
this approach could be identied
Windhoek, Namibia.
Southern Nevada Regional Water Recycling Study
Recycled Water can be used to satisy industrial
cooling water needs.
Recycled water is used
in Southern Nevada
to supplement surace
water supplies as
Indirect Potable Reuse.
How is Recycled Water Used Elsewhere?
Seawater Intrusion Barrier
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch
Diferent Places, Diferent Practices
I you look at the range o
water recycling practices usedelsewhere, and then compare
them with the water recycling
practices we currently use in
Southern Nevada, youll notice
some diferences.
Why do recycled water use
practices dier rom place
to place?Simple the water
recycling practices each areauses are balanced responses
to the water needs, available supplies, water rights/
regulatory ramework and the costs associated with
meeting the water needs o these individual communities.
Because the constraints and challenges of supplying water
to these various communities are dierent, the waterrecycling practices adopted may dier as well.
Even within Southern Nevada, recycling practices vary or
the individual communities in the region. For instance,
most o our communities are located such that they can
recycle water indirectly via return ow to the Colorado
River. But for those communities where return ow to the
Colorado River is impractical, a dierent set o recycled
water priorities may be in order. The inability to return
recycled water to the Colorado in these communitiesplaces a greater value on direct uses o recycled water such
as irrigation and industrial uses, and oers the opportunity
to engage in other orms o indirect recycling such as
Aquier Storage and Recovery.
4
Recycling Practices Vary by Community
Southern Nevadas Constraints and Challenges Vary with the Region
Community can
Return Water toColorado River
Recycling EortsEmphasizeIndirect Recycling
Community cantReturn Water toColorado River
Recycling Eorts
Emphasize DirectRecycling
Colo
rado
Riv
er
Supply
Retu
rnFlow
Gro
undwater
Gro
undwater
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Both graywater and recycled water have a common ideabehind them, which is to use water more than once. But if
you look back to the denitions rom page 2, youll see there is
a critical dierence. Recycled water has been treated to a high
standard to make it sae or many uses, whereas graywater
receives no treatment at all.
A recent publication rom the World Health Organization
noted the potential implications o graywater on public health.
Because graywater has the potential to transmit disease,
graywater systems are typically required to be designed to
avoid human contact through the use o subsurace irrigation
systems. This potential risk o disease is accepted in some
communities as the trade-o or the reduced demand on
their water supply. In Southern Nevada, however, graywater
use would not reduce demand on our water supplies since
our current practice o recycling it returns the water to our
supply source. In either case, graywater users dont use
less water than non-graywater users. Since the graywater
used would have otherwise been sent to a wastewater
treatment acility and recycled, no water is saved. In act,
a recent analysis o water use data or graywater users
in Western Australia yielded data that indicates just the
opposite. Data showed that homeowners who installed a
graywater reuse system and subsurace irrigation system
actually increased domestic water consumption. More
investigation is planned by Australian water managers
to understand the reasons underlying this surprising
result, but they currently suspect that homeowners
are rationalizing that they can use more potable water
because they are making irrigation water.
Our current potable and recycled water practices yield
the same or better use o the water while avoiding
the potential human health risks associated with
graywater.
Southern Nevada Regional Water Recycling Study
As graywater is contaminated with
ecal coliorms [an indicator o ecal
contamination] and some chemical pollutants
rom bathing and laundry, microbial and
chemical contamination o graywater poses
a potential risk to human health, and so it is
important to recognize that graywater does
have the potential to transmit disease.
Overview o Graywater ManagementHealth Considerations, World Health
Organization, 2006.
What About Graywater?
Graywater and Recycled Water Are Notthe Same
The rebates or alternative water sources...
appear to be very eective. The exception
appears to be graywater reuse
systems that are associated
with an increase in
consumption o scheme water.
Waterwise Rebate Scheme
Review 2007, Data Analysis
Australia Pty Ltd, April 2008.
Recycled water has been treated to a
high standard to make it sae or many
uses, whereas graywater receives no
treatment at all.
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch
Community Leaders Weigh In
To understand the values, priorities and concerns o
Southern Nevadans about how we use water and howrecycled water ts into the picture, ace-to-ace interviews
with 49 community leaders were conducted.The community
leaders interviewed included representatives rom
government, development, business, green industry
and others. As a part o the interviews, a short overview
o water resource issues relevant to Southern Nevada was
provided, which was then ollowed by a 19-question, open-
ended survey to gauge views on various water issues in our
community. This survey and its results can be ound on both
the SNWA and CWC websites.
While an in-depth analysis o the interview results and
surveys would be too lengthy to include in this study, several
strong themes were evident in the discussions.
Saety o Recycled Water
Saety was one o the most prevalent themes
ound across the various opinions o thecommunity leaders. Because recycled water is
made by treating wastewater, multiple measures
are in place to protect public health. Nevada
has strict regulatory controls that govern the
production and use o recycled water. Local
agencies are responsible to see that the public
health and saety is protected
through adherence to these
regulations. There have beenno documented cases o
human illness in Southern
Nevada caused by contact with
recycled water.
Cost/Benet oRecycled Water
When asked various questions
related to the expansion o recycling practices to meet
certain water needs in Southern Nevada, one o the prevalent
themes voiced by most participants was the cost o the
recycled water in comparison to the benets it oers. Most
participants elt that i recycled water was a cost-eective
means to meet certain water needs when compared to
other water sources, then its use could be expanded and still
represent a net benet to the community.
Health and Saety o Graywater
Ninety percent o the people interviewed elt that our
current systems o potable and recycled water were more
benecial than graywater systems. Because graywater is
untreated, it contains pathogens and contaminants that pose
a public health risk, and this potential risk to public health
and saety was central to the discussions and concerns on
graywater. Recent developments among
builders who specialize in sustainable
building practices have led to proposals to
incorporate graywater systems in homesand major commercial developments, but
graywater systems are currently not permitted
by Southern Nevada building codes. Seventy-
nine percent o those interviewed thought
health and saety would be one o the greates
challenges in utilizing graywater systems.
6
Stakeholder Research
Seventy-nine
percent o those
interviewed thoughthealth and saety
would be one o the
greatest challenges
in utilizing
graywater systems.
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch
Goals Need a Sustainable Framework
Since one o the key objectives o this study is the
establishment o goals or uture water recycling practicesin Southern Nevada, we need to dene the guiding
principles that any such goals would ollow. With the insight
provided through interaction with community leaders, we
have the ability to establish principles that can be adopted
by the entities who manage our water resources.
8
Taken together, these principles provide a ramework
rooted in sustainability or establishment o water recyclinggoals. And because these principles speak to the values o
the community, they are robust enough to help us make
good decisions about recycled water in the uture when
our circumstances (how we use water, how much water we
have, etc.) may be dierent than they are today.
Sae
Treated to provide a high
degree o assurance that
public health and saety
is saeguarded.
Efective
Shown to be an eective
means o maximizing the
water resources available
to Southern Nevada.
Sustainable
Demonstrated to represent
the best balance o the
environmental, economic,
and social/cultural benets.
Efec
tiveS
afe
Sustainable
Guiding Principles:
Recycled Water resources should be developed and used in applications that are:
Guiding Principles for Water Recycling
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With a set o principles in place that will result in balanced choices or our communities, we developed a menu o recycled
water options that make sense or Southern Nevada. They include:
Southern Nevada Regional Water Recycling Study
IndirectReuseasReturn
Flow
Useofrecycledwaterviadisc
hargetotheColoradoRivera
ndsubsequent
reuseinSouthernNevadahas
beeninpracticefornearly40
years,and
remainsoneofthemosteffec
tivetypesofrecycledwateru
seavailableto
ourcommunity.
Public/CommercialLandscapeIrrigation
Thiswouldincludeirrigation
ofpublicmedians,landscapingaroundpublic
orcommercialbuildings.Some
publicandcommerciallandsca
pesand
mediansinSouthernNevada
alreadyuserecycledwater.
GolfCourseIrrigation
Representingthemajorityof
directlyrecycledwaterusein
Southern
Nevada,golfcourseuseisap
roven,successfulpractice.
SchoolYardIrrigation
Whilerecycledwaterisnotc
urrentlyusedforirrigationat
schoolsin
SouthernNevada,u
secouldbeexpandedtoschoo
lsifsupportedbylocal
communities.
ParkIrrigation
Useofrecycledwateratpubli
cparksinSouthernNevadais
limited,and
usecouldbeexpandedtomor
eparksifsupportedbylocalc
ommunities.
IndustrialUses
Useofrecycledwaterforpow
erplantcooling,dustcontrol
and
constructionwaterisalready
practicedinSouthernNevada
.Additional
potentialindustrialusesforre
cycledwatermaybeviablein
Southern
Nevada.
AquiferStorageandRecovery
Useofrecycledwatertosupp
lementexistinggroundwatersupplieshas
recentlybeenprovidedforby
changestoNevadaregulation
s.Useof
recycledwaterforthispurpo
secouldbedevelopedifsuppo
rtedbylocal
communities.
Choices
RecycledWaterMenu
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Southern Nevada Water Authority Clean Water Coalition Black & Veatch0
Expand return fow to the Colorado River to increase Nevadas credit or subsequentwithdrawal.
We already recycle roughly 40 percent o the all the water we use in Southern Nevada by returning it to the Colorado River
or use again. Continuing eorts to reduce irrigation uses (which cannot be captured or recycled) mean that an increasing
proportion o our water is available or indoor uses that can be captured and recycled. This practice is sae, has been
practiced in Southern Nevada or over hal a century, maximizes our water resources, and makes good use o existing
inrastructure. By taking measures to expand this practice, we can gain urther benet rom a limited resource while
saeguarding the environment.
Expand the use o Recycled Water in the Las Vegas Valley where large tur andindustrial demands exist.
The use o recycled water to ulll the needs o large tur irrigation and industrial applications are the most common direct
water recycling applications in practice today. The technologies and practices to use recycled water or these needs are
proven and more than adequate to protect public health and saety. Though the use o recycled water or these needs
does not lessen the demand on Southern Nevadas water resources overall, sustainable uses o this type or recycled
water can still oer a net benet to the public. Such benets may include energy savings, decreased demand or new
inrastructure, and reductions in the nutrients being added to the Colorado River.
Maximize the use o Recycled Water in areas o Southern Nevada where return fow
to the Colorado River system is not practical, including the testing o aquier storage
and recovery.
The geography o Southern Nevada is such that not all o our communities are able to return recycled water to the
Colorado River. In communities where indirect recycling is impractical, direct water recycling becomes even more valuable
since it has the eect o increasing the water supply. And in order to make water recycling more efcient and cost eective
in these same communities, testing o an indirect method such as aquier storage and recovery is recommended.
Develop a Salt Management Strategy to address the accumulation o salts that are
detrimental in Recycled Water.
One o the side eects o the use o recycled water is the accumulation o salts in the ground. Because our recycled water
has a concentration o total dissolved solids (TDS a means o measuring salt concentration) that is roughly twice that o
Colorado River water, using recycled water or irrigation (our most common use) can be detrimental to the very plants we
are trying to support. Further, the very successul conservation programs used in Southern Nevada have reduced indoor
water use which also contributes to higher TDS. The development and adoption o a regional Salt Management Strategy
could eliminate barriers to urther use o recycled water.
Applying the guiding principles and considering the many uses or recycled water,seven recommendations are oered:
Recommendations
1
2
4
3
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Continue to advance the research o the health and saety implications o
Recycled Water.
The saety o public water systems is understandably one o oten voiced concerns when discussing the use o recycled
water. And because recycled water has been a resource drawn on by communities across the globe or many years,
a signicant body o research has lead to well-tested regulations and best practices or recycled water use. But as
the science o water quality continues to improve, opportunities to advance the research on the health and saety
implications o recycled water continue to be identied.
Prohibit the use o treated or untreated Graywater in the Las Vegas Valley, and
prohibit its use outside o the valley where there is reasonable potential or return
fow to the Colorado River system or other Water Recycling programs.
As it stands today, graywater systems are not permitted in Clark County. Unlike recycled water, which is highly treated
and regulated, graywater receives no treatment, which introduces the potential to transmit disease. Further, because
Southern Nevada has the ability to recycle water both directly and indirectly, the use o graywater would not result in
water savings. Southern Nevada water managers will continue to promote and regulate water quality and efciency
measures in homes and businesses.
Educate the public about our local water cycle and the benets o Recycled Water.
An inormed public is better able to participate in public policy discussions and decision making processes, but
much o the discussion about water resources in Southern Nevada requires knowledge that our residents may not
have. Community leaders interviewed as a part o this study share our desire to educate the community about
recycled water. A public outreach eort to provide the residents o Southern Nevada with the inormation needed to
understand our local water cycle and how reclaimed water is a part o that cycle would be a benet to the community.
Southern Nevada Regional Water Recycling Study
Recommendations
5
7
6
Conclusion: The recommendations ofered in this study support Southern Nevadasexisting recycled water programs and ofer opportunities to expand them
as well as to promote new recycled water uses. These recommendations
and the guiding principles that support them are complementary to
the regions conservation eforts and provide sustainable solutions to
make the best use o Southern Nevadas water resources. Through these
practices, and through continued eforts to involve Southern Nevadans in
the discussion o our water resources and how best to use them, we can
maintain the reliable water supply that has helped make our community
a great place to live.
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This Study was commissioned by the Southern Nevada Water Authority and the Clean Water Coalition. It was conducted
by Black & Veatch, a global water resources and engineering frm, and supported by a group o subconsultants and subject
matter experts. The study began in late 2007 and was completed in early 2009.
For more inormation please contact,
Want More Inormation?
www.snwa.comwww.cleanwatercoalition.com
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