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Prepared b the Cascadia Green Building Council

March 2011

TOWARD NET ZERO WATER:

BEST MANAGEMENT PRACTICES FOR

DECENTRALIZED SOURCING AND TREATMENT


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Toward Net Zero WaterPage 2

Acknowledgements

SPONSORED By

Compton Foundation

PRIMARy AUTHORS

Joel Sisolak, Advocac and Outreach Director, Cascadia Green Building Council

Kate Spataro, Research Director, Cascadia Green Building Council

CONTRIBUTORS

Jason F. McLennan, CEO, Cascadia Green Building Council

Marin Bjork, Research Manager, Cascadia Green Building Council

Leslie Gia Clark, Cascadia Corps Volunteer

Gia Mugford, Cascadia Corps Volunteer

Samantha Rusek, Cascadia Corps Volunteer

PEER REVIEW

Morgan Brown, President, Whole Water Sstems, LLC

Mark Buehrer, P.E., 2020 ENGINEERING

Scott Wolf, AIA, Partner, The Miller/Hull Partnership, LLP

Pete Muoz, P.E., Natural Sstems International

COPyRIGHT INFORMATION

This report is the copyrighted property of the Cascadia Green Building Council, all rights reserved 2011.

This report may be printed, distributed, and posted on websites in its entirety in PDF format only and for

the purposes of education. This report my not be altered or modied without permission.


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Toward Net Zero Water Page 3

tAble of contents

ExECUTIVE SUMMARy . . . . . . . . . . . . . . . . . . 1

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . 2

CONTExT AND BACKGROUND . . . . . . . . . . . . . . 8

Histor Of Centralized Water Sstems

Current Conditions: Environmental, Social &

Economic Risks Moving Forward: A Vision for Net Zero Water

Current Barriers to Net Zero Water

BEST MANAGEMENT PRACTICES . . . . . . . . . . . .30

Integrated water management

Fitandefciency

Communit Involvement

Risk Management

Beaut and Inspiration

RAINWATER HARVESTING . . . . . . . . . . . . . . . .44

Denition Sstem Components

Technolog

Fit

Efciency

Additional Design Considerations

Additional Resources

GREyWATER RECLAMATION & REUSE . . . . . . . . .62

Denition

Sstem Components

Technolog Fit

Efciency


Additional Resources

WASTEWATER TREATMENT & REUSE. . . . . . . . . .78

Introduction

Composting Toilets. . . . . . . . . . . . . . . . . 80

Sstem Components

Technolog

Fit

Efciency


Constructed Wetlands . . . . . . . . . . . . . . . 90

Sstem Components

Technolog

Fit

Efciency


RecirculatingBiolters . . . . . . . . . . . . . . 100

Sstem Components

Technolog

Fit

Efciency

Additional Design Considerations Membrane Bioreactors . . . . . . . . . . . . . . 106

Sstem Components

Technolog

Fit

Efciency


Additional Resources . . . . . . . . . . . . . . . 114

FUTURE RESEARCH . . . . . . . . . . . . . . . . . . . 115

GLOSSARy . . . . . . . . . . . . . . . . . . . . . . . . 119

BIBLIOGRAPHy. . . . . . . . . . . . . . . . . . . . . . 122


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Toward Net Zero Water Page 1

executive summAryToward Net Zero Water is a best management practices manual on decentralized strategies for water

suppl, on-site treatment and reuse. It was conceived through an etensive literature review on the topicsof site and district-scale water sstems with a focus on best-in-class eamples from around the globe.

This manual is intended to assist developers and regulators of water sstems to better understand these

strategies and how the might be applied in American cities.

NorthAmericancommunitiesfacesignicantwater-relatedchallenges.Growingurbanpopulations

demand epanded water and wastewater services, while aging water suppl and wastewater treatment

infrastructure, most of which was designed and built in the late 19th and earl 20th centuries, approaches

end-of-life or is in need of major overhaul. This growing crisis is further eacerbated b unsustainable

water use patterns. Ever da, we use potable water within our buildings for non-potable functions such

aswashingclothesorushingtoilets,allwithlittleornoattemptatreuse.Further,alterationsinlocaland

global climate patterns pose additional risks to the health and resilience of our water sstems.

In recent ears, the green building movement has made strides to change the wa people view water

resources, raising awareness and increasing implementation of water conservation techniques. Despite

this progress, green buildings have not come far enough, fast enough to address the challenges that face

our cities water infrastructure. A widespread adoption of more integrated sstems that include suppl,

treatment and reuse of water at the building and neighborhood scale is an important strateg for increasing

the resilienc of our water sstems.

The incorporation of decentralized strategies for water suppl, on-site treatment and reuse requires a

major shift in the mindset of how buildings are conceived, designed, regulated, built and operated. Insight

into the current conditions of our water sstems and their associated environmental, social and economic

risks provides the background and contet for wh this is a necessar shift. Movement toward a soft

path for water management through decentralized and distributed-scaled sstems offer alternatives for

communities willing and/or forced to re-think their path forward.

BEST MANAGEMENT PRACTICES FOR DECENTRALIZED WATER SySTEMS

Best management practices (BMPs) for net zero water buildings emphasize closed-loop sstems, ultra-efcientmeasurestoreducesystemdemands,small-scalemanagementsystems,t-for-purposewater

use and diverse, locall appropriate infrastructure. Establishing a water balance (a numerical account of

how much water enters and leaves the boundaries of a project) is a critical step in understanding water

owson-site.Themostsuccessfuldesignstrategiesarethosethatnotonlyseekequalitybetweenwater

supplyvolumeandbuildingdemand,butalsoaddresslongtermnancialandpublichealthrisksand

provide educational opportunities for building occupants.


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This report contains an overview of best practices for decentralized and distributed water strategies

organized b the following subjects:

Rainwater harvesting, including strategies for potable and non-potable uses

Grewater reclamation and reuse

On-site wastewater treatment and reuse, including composting toilets

Best practices for the design and implementation of on-site stormwater management sstems and for

improvingxtureefcienciesarenotincludedinthescopeofthisreport,thoughareimportantaspectsto

achieving net zero water goals.

Each BMP chapter describes major sstem components, how the sstems work and background on

appropriatescaleandefciency.Additionaldesignconsiderationsaresuggestedforsystemsizing,location

and integration with other building sstems. Case studies of innovative projects from around the globe are

highlighted in each chapter. The additional resources section located at the end of the chapter describes

wheretondmorein-depthinformationandtechnicaldetailsondecentralizedBMPs.

FURTHER RESEARCH

The amount of research and literature available on alternative water sstems is staggering. However, more

comprehensive information and design guidance is needed on balancing available on-site water supplies,

including rainwater and reccled water, with occupant demand. More on-the-ground demonstration

projects also are needed to showcase BMPs and inform future net zero water efforts. Additional research

is needed in the following areas to support and empower the net generation of innovative water projects:

Broader evaluation of public health and safet risks

Lifeccle assessment investigating the environmental impacts associated with various strategies

Chlorine disinfection for treatment of on-site rainwater harvesting sstems

Climate change and resilienc of fresh water supplies

Occupant behavior related to water use in buildings

Presence of pharmaceuticals and other chemicals found in water supplies

Increasing water demands for urban agriculture

An etensive bibliograph of sources uncovered during the literature review is located at the end of the

report and provides a list of references for further research.


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introduction

Good, qualit water is a diminishing resource. There is growing consensus that the water

crisisacceleratedbypollution,inefcientuseandclimatechangewillsoondwarf

theenergycrisisinsignicanceandseverity.1 Alread, more than 900 million people on

this planet do not have access to safe drinking water, and 2.6 billion are not using safe

sanitation practices.2 As a species, we must generate a health relationship with water if

we want to survive and protect the biodiversit of the planet. Implementation of sustainable

water use will require the combined efforts of regulators, designers and users. This

document is intended to help regulators and designers of urban sstems understand bestpractices for creating water sstems that allow building occupants to reduce the impacts of

their use.

CURRENT CHALLENGES AND OPPORTUNITIES: WATER AND WASTE

Of all the Earths water, 97.5 percent is salt and 2.5 percent is fresh water. Of that fresh

water, onl 1 percent (.007 percent of the total water) is readil accessible for human use.

Sevent percent of the worlds water is used for agriculture, 22 percent for industr and 8

percent for domestic use. In high-income countries like the United States, approimatel

30 percent of our fresh water is used for agriculture, 59 percent for industr and 11 percent

1 Furumai, H. Rainwater and reclaimed wastewater for sustainable urban water use. Phsics andChemistr of the Earth, Parts A/B/C, 2008.

2 Corcoran, E., C. Nellemann, E. Baker, R. Bos, D. Osborn, H. Savelli (eds). 2010. Sick Water? The centralrole of wastewater management in sustainable development. A Rapid Response Assessment. UnitedNations Environment Programme, UN-HABITAT, GRID-Arendal.

Infact,asaspeciesweareapproximately65percentwateritdenesand

shapesusineverywayimaginable,physicallyandspiritually,fromourrstfew

months in the womb, when we are literall enveloped b it, to life outside the

womb, where we need to be constantl replenished with eight to ten cups of clean

water each da to survive.

Jason F. McLennan, CEO, Cascadia Green Building Council


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Introduction Page 3

for domestic use.3 Clearl, reducing demand from the agricultural and industrial sector

should be prioritized for addressing the world water crisis. However, urban water issues

willcontinuetobesignicantinanincreasinglyurbanworld.Asof2009andfortherst

time in histor, more humans live in cities than outside cities. We are an increasingl urban

species, and our water sstems are ever more important as a result.

Here in the United States, we have enjoed a half-centur of nearl universal access to

abundant supplies of potable water. But serious and sustained droughts in the south and

longbitterghtsoverwaterrightsinthewestindicatethisprivilegeisending.Future

population growth will eert more demand on water sstems while climate change is

predictedtodecreaseavailablesupplies.Recently,aGovernmentAccountabilityOfce

(GAO) surve found that water managers in 36 states anticipate water shortages b 2020.

These challenges will require a more sustainable approach to using water resources,

looking at not onl how much water is used but also the qualit of water needed for each

use.4

3 Ten Things You Should Know About Water. Circle of Blue WaterNews. N.p., October 2010.

4 Kloss, Christopher, Managing Wet Weather with Green Infrastructure: Rainwater Harvesting Policies:US EPA, 2008.


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57%

33%

10%

FIGURE I-3. TyPICAL DAILy WATER USE FOR HOTELS

Source: Kloss, Christopher. Managing Wet Weather with Green Infrastructure: Rainwater Harvesting Policies: US EPA, 2008.

While potable water is used almost eclusivel for domestic uses, Figure I-1 shows

approimatel 80 percent of demand for a tpical residential building does not require

potable water. Similar trends eist for commercial water use. Figures I-2 and I-3 provide

eamples of dail commercial water usage.

FIGURE I-1. TyPICAL DOMESTIC DAILy PER CAPITA WATER USE

Potable Indoor Dail Uses:Showers 11.6 gal.Dishwashers 1.0 gal.Baths 1.2 gal.Faucets 10.9 gal.Other uses, leaks 11.1 gal.

Non-Potable Indoor Dail Uses:Clothes washers 15.0 gal.Toilets 18.5 gal.

58%

21.7%

20.3%

14%

48%

38%

FIGURE I-2. TyPICAL DAILy WATER USE FOR OFFICE BUILDINGS

Potable indoor uses

Non-potable indoor uses

Outdoor uses


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Image:Island

Wood

Students learn about on-site wastewater treatment at IslandWoods Living Machine.

Introduction Page 5

Potablewaterisoftenutilizedforpurposesthatcouldbesatisedwithlower-quality

water,suchastoiletushing,irrigationandlaundry.Statisticsalsoshowthatthevast

majorit of water is used in a one-time, pass-through manner with little attempt at reuse.

Our centralized, big-pipe infrastructure relies on an industrial model of specialization

and economies of scale.5 Though designed and managed primaril to protect the public

frompathogensandoods,thesecentralizedsystemsaretypicallyresourceandenergyintensive in their transport and treatment of water and pose serious social, environmental

and economic risks for urban American communities. Further, these sstems are riddled

withinefcienciesduetotheageandpoormaintenanceofourcitieswaterinfrastructure,

andtheirverydesigncancreateanimbalanceinwaterandnutrientowsthatdistort

hdrological and ecological regimes. According to the 2009 American Societ of Civil

Engineers Report Card, our nations water and wastewater infrastructure scored a D- with

over$255billionneededtofundupgradestothesesystemsoverthenextveyears.

In this time of growing water crisis, it is critical that we re-imagine our water sstems

in which more environmentall, sociall and economicall responsible sstem design

andoperationisconsideredalongwithpublichealthbenets.Reviewofdecentralized

infrastructure with smaller-scale integrated sstems that incorporate rainwater capture,

t-for-useon-sitetreatmentandwaterre-useisalogicalstartingpointforthisre-

imagination. These sstems are the subject of this report, which addresses best practices

for their implementation within U.S. cities that allow or are open to allowing the inclusion of

distributed sstems within the water solution for future sustainabilit.

5 Nelson, Valerie. New Approaches in Decentralized Water Infrastructure. Decentralized WaterInfrastructure, 2008


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references

Corcoran, E., C. Nellemann, E. Baker, R. Bos, D. Osborn, H. Savelli (eds). 2010. Sick Water?

The central role of wastewater management in sustainable development. A Rapid ResponseAssessment. United Nations Environment Programme, UN-HABITAT, GRID-Arendal. www.

grida.no.

Furumai, H. Rainwater and reclaimed wastewater for sustainable urban water use.

Phsics and Chemistr of the Earth, Parts A/B/C (2008): 340-346.

Kloss, Christopher, Managing Wet Weather with Green Infrastructure: Rainwater

Harvesting Policies: US EPA, 2008.

Nelson, Valerie. New Approaches in Decentralized Water Infrastructure. Decentralized

Water Infrastructure. (2008): 1-79.

Ten Things you Should Know About Water. Circle of Blue WaterNews. N.p., October 2010.

Web. October 2010. (www.circleofblue.org).


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8

11

17

20

SECTIONS

Histor of Centralized Water Sstems

Current Conditions: Environmental, Social & Economic Risks

Moving Forward: A Vision for Net Zero Water

Current Barriers to Net Zero Water


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History of centrAlized wAter systems

B the mid to late 18th centur, most large U.S. municipalities installed underground fresh

water conveance sstems. Basic stormwater sstems were installed at the end of the 18th

centur, and b the middle of the 19th centur, centralized water-carriage sewer sstems

became the standard over priv vault-cesspool sstems.

The water-carriage sstem solved some problems and created others, especiall in more

densel populated communities. Man cit residents accepted the sanitation problems

and foul odor as an unavoidable part of urban life.6 Open sewers lined the streets and

households cast their biological waste products into the streets below. Cit boosters,

wishing to clean up the urban image and attract both residents and industries, advocated

for centralized waste management and sewer sstems.

Opponents to centralized waste management and sewers argued that a source of fertilizer

would be lost, soil and water supplies would be polluted at the sstem outfalls and that

modern sewer sstems would create and concentrate disease-bearing sewer gas.7

The debate over the design of centralized sstems was split between the argument for

combined sewer sstems versus separated sewer sstems. The combined sewer sstems

used a single pipe to transport both stormwater and wastewater to a designated disposal

location, as opposed to the separated sewer sstems, which required laing two pipes.

Man cities installed combined sstems because the were less epensive to build.

6 Burrian, Steven J., Stephan Ni, Robert E. Pitt, and S. Rock Durrans. Urban WastewaterManagement in the United States: Past, Present, and Future. Journal of Urban Technolog. 7.3, 2000.

7 Ibid.

context And bAckground


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Contet and Background Page 9

It wasnt until late in the 19th centur that the relationship between wastewater and

diseasetransmissionbecamewellunderstood.Waterltrationbecamemorecommonas

studiesdemonstratedthatsandltrationprocessescouldhelplowertheinfectionrate

of waterborne illnesses such as cholera and tphoid. Using chlorine to disinfect drinking

water became prevalent in the earl 1900s. Treatment of wastewater utilizing tanks and

chemicalreactionstolter,settleandbindcontaminantsfoundinwastewaterbecamemore common b 1910-1920. Dewatering techniques were also developed, successfull

producing a b-product sold as fertilizer. As sstems developed in the 20th centur, the

unpredictableowrateofcombinedsewersystemsmadeseparatedsewersystemsthe

preferred choice for treatment plants. Man cities ended up with compound sstems

that included a combined sewer sstem in some districts and a separated sewer sstem in

newer districts. This is the legac of our urban water sstems.

Wastewater treatment became widespread

after the introduction of federal funding

with the Water Pollution Control Act of

1948. The WPC Act provided planning,

technicalservices,researchandnancial

assistance b the federal government to

state and local governments for sanitar

infrastructure. The WPC Act was amended

in 1965, establishing uniform water qualit

standards and creating the Federal Water

Pollution Control Administration authorized

to set standards where states failed to do

so. In 1970 the Environmental Protection

Agenc (EPA) was created.

In 1972, the Clean Water Act was passed

to limit pollution of freshwater sources.

In 1974, the Safe Drinking Water Act

was adopted to regulate public water

systems.Itspeciedwhichcontaminants

must be closel monitored and reportedto residents should those contaminants

eceed maimum allowable levels. Since

the 1970s, federal, state and municipal

governments have closel monitored

American drinking water sstems. For1885ScienticAmericanMagazinefeaturingalargeinfrastructureprojectin New york Cit.


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decades federal funding for water suppl and sanitation was provided through grants to

local governments. After 1987, the sstem was changed to loans through revolving funds

that have favored big-pipe infrastructure.

Increased water qualit standards and regulation, coupled with advancements in water

treatment and deliver and wastewater disposal sstems, have dramaticall improved

human health in American cities. These sstems have also altered human settlement

patterns b allowing communities to grow beond the carring capacit of their local

eco-sstems as water-on-demand and waste-be-gone sstems became standard.

Thesesystemshaverequiredlargeenergyandnancialinputstomanufacture,installand

operate.Now,thisaginginfrastructureisanancialburdenformunicipalities.

Cities across America must face big decisions about how the will continue to meet the

water and wastewater needs of their growing communities while continuing to protect

public health. The business-as-usual approach is to rebuild and epand the eisting

sstems without considering alternative solutions. In evaluating alternatives, it isimportant to understand the associated environmental, social and economic risks of each

option. As communities risk bankruptc in order to maintain aging infrastructure, prudent

consideration of decentralized and distributed sstems is crucial to help address the

nancialresiliencyofourcommunities.

Centralized water treatment facilit.


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current conditions: environmentAl, sociAl &economic risks

Centralized water collection and treatment sstems have greatl improved overall public

healthbyprovidingaccesstoafresh,cleanwatersupply.Despitethesebenets,thescales

andmethodsatwhichthesesystemscurrentlyoperateposesignicantenvironmental,

socialandnancialrisks.

ENVIRONMENTALdp aa h h h ah

The ecological impacts of large dams and water treatment projects have become a growing

environmentalconcern.Disruptingthenaturalowofrivers,streamsandgroundwater

percolation have far-reaching effects on a watersheds ecological health. At its healthiest,

a freshwater sstem maintains a state of dnamic equilibrium, ielding crucial ecological

servicesbyprovidinghabitat,barrierstotoxins,nutrienttransportationandlter

functions.8 To maintain this equilibrium, mechanisms allow the ecosstem to control

eternal stresses or disturbances within a certain range of responses thereb maintaining

a self-sustaining condition.9 Big pipe sstems quickl move large volumes of water from

one watershed to another. This movement can cause the groundwater table to drop at the

source, creating a sstem imbalance. The disruption of a watersheds equilibrium can

consequentl cause high nutrient and pollutant concentrations in areas previousl devoid

of such contaminants, compromising the qualit of the ecological services these sstems

provide.10 Large water infrastructure projects strain the resilience of these comple

watershed sstems, making this ver precious resource vulnerable.

P a a

Most sewer sstems were designed as Combined Sewer Sstems, where wastewater and

stormwaterowintoonepipeontheirwaytobetreated.Itistypicalforsewersystemsto

bedesignedforpeakowloadssothateventhelargeststormwatereventcanbetreated

throughthesystem.However,manyoldercombinedsewersystemsaresubjecttoows

abovetheircapacityduringheavyrains.TheuseofaCombinedSystemOverow(CSO)was

an economical wa to prevent sewage backups into homes and businesses b releasing

overowwastewaterandstormwaterintoadjacentbodiesofwater.11 The CSO is an obvious

8 Federal Interagenc Stream Restoration Working Group (FISRWG) Stream Corridor Restoration;Principles, Processes and Practices. Washington, D.C.: FISRWG, 1998.

9 Ibid.

10 PacicStatesMarineFisheriesCommissionandtheOregonFisheriesCongress,WhenSalmonAreDammed., 04 Apr 1997. Web. 7 Sep 2010.

11 KingCounty.CombinedSewerOverow(CSO).PublicHealth-Seattle&KingCounty.KingCounty,03 Feb 2010. Web. 8 Sep 2010.


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danger to the health of our waterwas. Due to the rigid infrastructure of the big pipe

system,itisdifculttorespondtotheseuctuationsandconcentrationsofcontaminants.12

The big pipe sstem leaves little room for quick, economical upgrades, as the

infrastructure is a long A to B treatment sstem. With this in mind, change in capacit

over long periods of time can prove problematic. As Rose George eplains in The Big

Necessity, Wet weather discharge is normal. Its how the sstem works, whether people

know it or not. Sewer designers calculate their sstem capacit to cope with storms and

oods.NewYorkssewers,builtindrier,lessgloballywarmedtimes,werebuilttocome

with a maimum of 1.75 inches of rain falling in an hour. But times and the weather have

changed. As we continue to see shifts in rainfall and snowmelt due to climate change,

our sewer sstems capacit to handle increasing loads will be both an environmental and

economic concern.

Hh a, a a aa

According to the US Environmental Protection Agenc (EPA), approimatel 3 percent of ournational energ consumption is used solel for the purpose of providing safe drinking water

and sanitation services. In California, water-related energ use consumes 19 percent of the

states electricit, 30 percent of its natural gas and 88 billion gallons of diesel fuel ever

ear and this demand is growing.13

Currentl the average person living in the United States uses between 65 to 78 gallons

ofwaterperdayfordrinking,cooking,bathing,ushingandyardwatering.14 Though the

need for conservation in our water habits is inarguabl a concern, the means b which we

transport our water in urban areas from suppl sources and to remote treatment facilities

is in need of equal attention. The big pipe sstem has created an etensive network of pipes,

pumps and tanks to accommodate this transportation, all of which need to be maintained.

Overtime,cracksturntoleaksthat,duetothesizeoftheselargesystems,canbedifcult

to locate and repair. The United States suffers about 240,000 water main breaks annuall

and the countr loses approimatel 6 billion gallons a da enough water to suppl the

entire state of California.15 This constant need for maintenance leads to increased water

waste as well as the potential for groundwater and surface water contamination.

12 Slaughter, S. Improving the Sustainabilit of Water Treatment Sstems: Opportunities for Innovation.Solutions. 1.3 2010.

13 California Energ Commission, Californias Water Energ Relationship: Final Staff Report, 2005.

14 PacicInstitute,WaterFactSheetLooksatThreats,Trends,Solutions.,2008.

15 Urban Land Institute, Infrastructure 2010: Investment Imperative. Urban Land Institute, 2010.


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protection, operator training, funding for water sstem improvements and public

information requirements, ensuring better water qualit.

Contaminants become regulated when the occur in the drinking water suppl and are

considered a threat to public health. There are four tpes of known contaminants that are

tested for which can be broken down into four groups: Microbial Pathogens, Organics,

Inorganics and Radioactive Elements.

Though much has been done to prevent risks of contaminants entering our drinking water,the size and age of our water infrastructure makes the risk of alternate point contamination

difculttoassess.Inaddition,investigationsconductedinthelastveyearssuggestthata

substantial proportion of waterborne disease outbreaks, both microbial and chemical, are

attributable to problems within distribution sstems.

In an effort to improve water qualit deliver, the National Academies Water Science

andTechnologiesBoardhasidentiedwaystoassesstherisksassociatedwiththe

contamination of a large water distribution sstem. These methods include the utilization

of pathogen occurrence data, the surveillance of waterborne disease outbreak, and the

eecution of an epidemiolog stud that isolates the distribution sstem component.

Increased consumption of pharmaceuticals and hormones has led to the presence of

these chemicals in our water stream. In 2008, the American Associated Press investigated

thelevelsofpharmaceuticalsindrinkingwater,ndingthatover46millionAmericans

consume water that tested positive for trace pharmaceuticals. The effects of these trace


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pharmaceuticals are not et known as water qualit standards do not currentl test for

them. Research conducted in Europe b poisons epert and biologist Francesco Pomati is

preliminar but warrants further investigation. Pomati eposed developing human kidne

cells to a water miture containing 13 drugs that mimicked the levels in Italian rivers. He

found that cellular growth was slowed b up to one-third the speed of uneposed cells.19

Testing for the presence of pharmaceuticals and more research on the effects of thesemitures is needed.

Hah aaph a

Major catastrophe or malfunction of a big pipe sstem leaves its service population

vulnerable to contamination or without access to potable water. In 1975 a valve failure

combinedwithheavyrainscontributedtorisingoodwatersinTrentonandHamilton

townships in New Jerse, leaving residents with a shortage of water for ten das. Though

heav rains were present, the culprit of the shortage was a simple mechanical failure.

Hurricane Katrinas disastrous legac in New Orleans was accelerated due to thecatastrophic failure of the levee sstem. This severe storm also affected a number of

water sstems in cities across the region. The EPA estimated that more than 1,200 drinking

water facilities and 200 wastewater treatment facilities were affected.20Foroodedareas,

sewage treatment is one of the last services to get back on line, as these plants often eist

in the lowest ling areas. The big pipe sstem offers large solutions to a large population

but when failure occurs, it is time consuming for the sstem to become operational. A one-

point source of treatment also offers one point for concentrated contamination in the event

of a catastrophe.

eq

Waterinfrastructurethatissizedtoaccommodateowcapacitiesprojected20-30years

into the future is costl to a communit. As discussed in the economic section of this

chapter, these high initial costs ma result in a disparit in water qualit depending on a

recipients proimit to the centralized sstem. This disparit could affect the qualit of

communit planning and negativel impact development choices.

d a /a a

The big pipe paradigm moves our water from tap to treatment to tap again with little

user knowledge of what happens in between. The instant deliver of clean water is aconvenience that we take for granted. This convenience also disconnects us from an

19 Donn, Jeff, PHARMAWATER-RESEARCH: Research shows pharmaceuticals in water could impacthuman cells, Associated Press, n.d. Web. 7 Sep 2010.

20 Copeland, C. Hurricane-Damaged Drinking Water and Wastewater Facilities: Impacts, Needs, andResponse, Congressional Research Service, Librar of Congress, 2005.


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understanding of our watershed sstem and

where our water comes from, also affecting

our understanding about how to best care of

this resource.

ECONOMICcapa paa

The nature of the big pipe paradigm

necessitates large amounts of

infrastructure, which requires increased

maintenance as the sstem ages. Population

growth places additional strain on older

sstems, with increased densit demanding

increased infrastructure in urban andrural areas. According to John Crittenden

of Georgia Tech Universits Brook Bers

Institute for Sustainable Sstems, We

epect in the net 35 ears to double the urban infrastructure, and it took us 5,000 ears

to get to this point. So we better do that right. We better have a good blueprint for this as

we move to the future, so that we can use less energ, use less materials, to maintain the

life that we have become used to.21 The man costs of this increase in infrastructure and

maintenancearebeingconsideredbytheEPA,theGovernmentAccountabilityOfce,the

Water Infrastructure Network and others as the project a wastewater funding gap of $350billion to $500 billion over the net 20 ears.

c a

If the average person living in the United States uses between 65 to 78 gallons per da,

29percentofthishigh-qualitywaterisusedforushingtoilets.22 This means that on a

dailybasis,everyAmericanushesapproximately19gallonsofpotablewaterdownthe

drain. The big pipe sstem is designed to combine all grades of water and to treat it to the

same level regardless of how it will be used. This wa of piping water creates ecessive

waste with economic consequences. With the operational costs for treatment to potable

21 IEEESpectrumPodcasts.DecentralizedWaterTreatmentismoreefcient,exibleandresilient.Web. 7 Sep 2010.

22 Urban Land Institute, Infrastructure 2010: Investment Imperative. Urban Land Institute, 2010.

Up to 80 percent of sstem costs can be attributed to collection and conveance ofwater.


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standards being on average $2 per 1,000 gallons, both consumers and producers could be

spending much less b reducing potable water demands. 23

iq & p

High initial costs of big pipe sstems take into consideration the future capacit of the

treatment facilit. Communities that do not have the resources to cover these initial

epenses ma opt to connect onl certain portions of their communit to centralized water,

leaving parts of the population without access to the same standard of clean water. In

addition, the total cost of big pipe sstems ma not be full realized in some areas where

local water is scarce, such as the desert southwest. This misrepresentation of the actual

costofprovidingwatertotheseremoteareascangivetheillusionofabundanceofanite

resource.

moving forwArd: A vision for net zero wAter

The gap between projected demand and funding for drinking water infrastructure has been

estimated b the U.S. EPA to be as much as $267 billion over the 20-ear span between

2000 and 2020. The situation for wastewater infrastructure is similar and Congress is not

expectedtollthisgap.24

In April 1997, the U.S. EPA concluded that decentralized sstems can protect public

health and the environment, tpicall have lower capital and maintenance costs for rural

communities, are appropriate for varing site conditions and are suitable for ecologicall

sensitive areas when adequatel managed.25

Decentralized infrastructure could be second onl to improved agricultural use in

addressingthenationswatersustainabilitychallenges,butchangecanbedifcult.Many

forms of decentralized sstems have long proved to be effective for improving water (and

energ) sstem performance, but recognition of this potential has been slow to gain ground.

Distributed sstems operate at the margins of engineering practice, and construction of

big-pipe infrastructure continues.26

23 US EPA. Funding Decentralized Wastewater Sstems Using the Clean Water State Revolving Fund.Washington, DC: US EPA, June 1999.

24 Etnier, Carl, Richard Pinkham, Ron Crites, D. Scott Johnstone, Mar Clark, Am Macrellis, OvercomingBarriers to Evaluation and Use of Decentralized Wastewater Technologies and Management. London: IWAPublishing, 2007.

25 US EPA, Decentralized Wastewater Treatment Sstems: A Program Strateg. Cincinnati: U.S. EPAPublications Clearinghouse, 2005.

26 Nelson, Valerie. New Approaches in Decentralized Water Infrastructure. Decentralized WaterInfrastructure. 2008.


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Urban water and waste sstems management has been driven b technological, end-of-

pipe problem solving. The current dominant paradigm has evolved in a stepwise fashion,

andthelongevityandinvestmentnancial,structuralandsocialintothesesystems

has locked man communities into an approach with rapidl diminishing returns. The

compleit of challenges and dnamic nature of modern cities requires an integrated

approach that supports adaptabilit and innovation. Movement toward a soft path forwater management with decentralized and integrated technical sstems and distributed

andexiblemechanismsofcoordinationandcontroloffersawayforwardformany

communities willing or forced to challenge their status quo.

THE WATER PETAL OF THE LIVING BUILDING CHALLENGEThe soft path for water management emphasizes closed-loop

systems,ultra-efcientmeasurestoreducedemand,small-scaled

managementsystems,t-for-purposewateruseanddiverse,locally

appropriate and commonl decentralized infrastructure.27

ThispathwayisreectedintheintentoftheLivingBuildingChallengev2.0sWaterPetal:

TheintentoftheWaterPetalistorealignhowpeopleusewaterandredenewaste

in the built environment, so that water is respected as a precious resource. Scarcit

of potable water is quickl becoming a serious issue as man countries around the

world face severe shortages and compromised water qualit. Even regions that have

avoided the majorit of these problems to date due to a historical presence of abundant

fresh water are at risk: the impacts of climate change, highl unsustainable water use

patterns,andthecontinueddrawdownofmajoraquifersportentsignicantproblems

ahead.

The Living Building Challenge Water Petal includes two imperatives. The primar focus of

this report is on meeting the demands of the Net Zero Water Imperative:

One hundred percent of occupants water use must come from captured precipitation

or closed-loop water sstems that account for downstream ecosstem impacts and

thatareappropriatelypuriedwithouttheuseofchemicals.

This prerequisite requires water sstems to be primaril closed-loop, recirculating water

back to its source for eventual re-draw. This report includes best management practicesand technologies for catchment and use of rainwater, on-site reuse of grewater and on-

site treatment of sewage or blackwater. Case studies provide real-world eamples of how

these distributed sstems have been designed and implemented.

27 Chanan, A., J. Kandasam, S. Vigneswaran, and D. Sharma. A Gradualist Approach to AddressAustralias Urban Water Challenge. Desalination. 249.3. 2009.


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The second imperative under the Living Building Challenge Water Petal focuses on

Ecological Water Flow:

One hundred percent of storm water and building water discharge must be managed

on-site to feed the projects internal water demands or released onto adjacent sites

formanagementthroughacceptablenaturaltime-scalesurfaceow,groundwater

recharge, agricultural use or adjacent building needs.

This report addresses on-site wastewater treatment but does not provide best

managementpracticesspecictothedesignandimplementationofstormwatersystems.It

alsodoesnotprovideguidanceforimprovingxtureefciencyorinstitutingotherdemand

management strategies such as real cost pricing or public education. Other topics not

discussed here but ver relevant to the success of these projects include the creation of

regulator environments that allow and incentivize such sstems, and the implementation

of strategies that ensure proper long-term sstem operation.

TheOmegaCenterforSustainableLivinginRhinebeck,NewYork,isoneoftherstprojectscertiedundertheLivingBuildingChallenge.Theprojectisawastewaterltrationfacilitydesignedtoreusetreatedwaterforirrigationandserveasateachingtool for campus educational programs. Image: Farshid Assassi courtes of BNIM Architects


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TOWARD GREATER EMBRACE OF DECENTRALIZED SySTEMSIn her 2008 article New Approaches in Decentralized Water Infrastructure, Valerie

Nelson offers three steps toward greater embrace of decentralized water sstems:

1. Incorporation of water concerns into the green building movement and funding of

communit demonstration projects.

2. Support for a multi-faceted conversation about sustainable water infrastructure

with public bureaucrats and managers, sstem designers, entrepreneurs, activists

and the public.

3. Serious restructuring of water institutions and policies, including an integration

ofplanning,funding,andregulationsacrossthecurrentlysegmentedeldsof

water, stormwater and wastewater; an epanded role for the private sector in

technologydevelopment,systemsmanagementandnance;acloserlinkbetween

professional practice and communit participation; and careful management andstimulus of continuous innovation and reform.

Nelsonsapproachrequirestheremovalofsignicantregulatory,nancialandcultural

barriers to decentralized sstems.

current bArriers to net zero wAter

A variet of challenges eist for net zero water projects that seek to use best practices

around water conservation, rainwater harvesting, grewater and blackwater reuse indistributed and on-site sstems.

REGULATORy BARRIERSThe compleit of navigating the regulator sstem around such sstems at the local,

state and national levels presents the largest obstacle for project teams seeking approval

for net zero water projects. Currentl, water is regulated across multiple jurisdictions

and agencies: plumbing codes enforced b local or state building departments; local and

state public health agencies regulating water suppl and waste treatment; departments

of environmental qualit and protection regulating stormwater management, reclaimedwater, and on-site wastewater treatment; and wetland and shoreline protection that ma

involve approvals from local, state and national agencies such as the Corps of Engineers.

Some states such as Colorado have water rights laws governing rainwater harvesting,

whileotherssuchasCaliforniaandArizonahaveprovisionsspecictogreywaterreuseor

water-efcientxturesandappliances.


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Regulator barriers to net zero water projects stem from the current bias for centralized

water suppl and wastewater treatment and the associated lack of an authoritative bod

with appropriate powers to operate, manage and regulate decentralized approaches.

Particularl in urban and suburban areas where development codes and public health

regulations require connections to public utilities, small-scale decentralized sstems

frequentlylackanyclearlydenedregulatorypathwaysforapprovalsandinsteadrelyonindividualprojectteamswiththewillornancialmeanstonavigatetheregulatory

sstem. Often, the regulations that do eist at the local, state and national levels overlap

orconictwitheachother,andsometimestherearegapswherenoregulatoryprovisions

are currentl in place. Project teams are tasked with a length or costl variance process to

seek approvals for net zero water strategies, costs that are rarel recoverable to a project

team.Furthermore,case-by-caseapprovalsareseldomdocumentedforthebenetof

future projects or to guide future code updates.

Often overlooked are the code and regulator barriers that eist in local land use and

development codes and in covenants, conditions and restrictions (CCR) declarations of

communit associations. For instance, cisterns for rainwater collection sstems can

conictwithsetbackandheightrestrictionsprohibitingtheiruseforretrotapplications

thattendtowardabove-groundstorage.Likewise,landscapingrequirementscanconict

with low-impact development strategies. Such was the case in a communit in Marland


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where disconnecting downspouts and creating rain gardens to manage stormwater on-site

wasinconictwithregulationsthatrequiredmowingoftheraingardensiftheyexceeda

certainheightlimitationtoavoidmunicipalnesandpenalties.28 Other eamples include

development codes that require connections to municipal utilities as a condition of building

permit issuance, and neighborhood-scale water sstems that cross site boundaries or

public right of was that are often not supported b an codes.

Man regulator agencies are responding to net zero water strategies, though often in

disjointed and incremental was. For eample, the International Association of Plumbing

andMechanicalOfcials(IAPMO)theagencyresponsibleforthedevelopmentofthe

Uniform Plumbing and Mechanical Codes has released a green supplement outlining

voluntaryprovisionsforwaterefciencyandwaterreusestrategiesthatjurisdictionscan

adopt. Additionall, local and state jurisdictions are beginning to open up legal pathwas

for using grewater and rainwater for non-potable uses. But despite these and other

efforts, regulator resistance persists against on-site potable water sources other than

wells, reuse of water for purposes other than subsurface irrigation, non-proprietar on-

sitetreatmenttechnologiessuchasconstructedwetlandsandwaterlessxturessuchas

composting toilets.

In order to create support for net zero water projects, a major shift from our current

regulator framework is necessar. A more holistic approach to regulating water and waste

is needed at all agenc levels in order to support innovative projects and drive future policies.

Muchlikethe1995EnergyPolicyActthatmandatedmaximumowratesforplumbing

xtures,morestringentnationalstandardsareneededtocurbwastefulwaterusebehaviors.

State and local building codes, land use codes and development standards must align tocomprehensivel address on-site water suppl, use, reuse and treatment practices with

clearlydenedrolesandresponsibilitiesforpermitting,operationsandmaintenanceofthese

sstems. Most importantl, water regulations established to protect risks to public health

will need to be assessed and updated to full account for current environmental, social and

economic risks related to centralized water sstems, creating new standards in support of

more integrated water sstems at the site and neighborhood scales.

FINANCIAL BARRIERS

Net zero water projects rel upon on-site or distributed sstems for water suppl andtreatment otherwise managed at the municipal level b publicl-owned utilities. As such,

the cost burden for suppl and treatment sstems as well as their ongoing operation,

maintenance and replacement needs are shifted from the utilit to the individual project

28 Eisenberg, David, Sonja Persram. Code, Regulator and Sstemic Barriers Affecting Living BuildingProjects, Seattle: Cascadia Green Building Council, 2009.


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owner.Whilethiscancreatenancialbarriersforprojectowners,uniqueopportunitiesexist

for utilities to develop fee structures and incentives to support the transfer of capital cost,

epense and revenues to offset an owners upfront investment in on-site water sstems. 29

A project owners upfront investments in rainwater harvesting sstems, water-conserving

xtures,dualplumbingforwaterreuse,andon-sitetreatmentsystemscancreate

burdensomenancialbarriers.Evenwhenlifecyclecostsaretakenintoaccount,

articiallylowutilityratesforwaterandwastewaterservicestranslatetolongpayback

periods, since not all utilities use full cost pricing to establish rates for water and

wastewater services.

Full cost pricing factors into account all costs past and future, operations, maintenance

and capital costs into utilit prices and can encourage conservation and reuse strategies

emploed b net zero water projects. Utilities can also utilize alternative pricing structures

to encourage conservation such as block rates that increase the per-unit charge for

services as the amount used or generated increases, or surcharge rates imposed on

above-average water use.30

Robustnancialincentivesatthelocalandstatelevelscanhelpoffsetnancialbarriers

for net zero water projects. Eamples include New york Cits Comprehensive Water Reuse

29 Paladino and Compan, Inc. Onsite Wastewater Treatment Sstems: A Technical Review. Seattle:Seattle Public Utilities, 2008.

30 US EPA. About Water & Wastewater Pricing. Sustainable Infrastructure. US EPA, 08 Apr 2010.

TABLE C-1: TRANSFERRING COSTS AND BENEFITS FROM UTILITy TO OWNER

CAPITAL COSTS ExPENSES REVENUE

Utilit

New central

treatment facilities

Water deliverinfrastructure

Operations and

maintenance

Insurance

User fees

(rates and permits)

Sstem development charges(utilit connection fees)

New connections,

repairs and rebuildsTaes

Costs, Expenses, and Revenue Shifted from the Utility to the Owner

Owner

Onsite treatmentsstem

Dual plumbing

Collection sstems

Operations andmaintenance

Insurance

Reduced water use

and discharge fees,reduced permitting fees

Reduced connection fees

Repairs and rebuilds Grants/incentives

Source: Onsite Wastewater Treatment Sstems: A Technical Review prepared b Paladino & Co. 2008 for Seattle Public Utilities


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Incentive Program, which provides project owners a 25 percent discount on water services

for reducing demand on the cits infrastructure for water suppl and wastewater services. 31

Likewise, some state agencies offer regulator compliance credits, smaller impact fees

andstreamlinedorsimpliedpermitprocessesforprojectsmanagingstormwateron-site

using low-impact development techniques. While man low-impact development projects

have demonstrated 15-80 percent lower capital costs for project owners in comparison

to conventional methods,32municipalitiescanprovidefurthernancialincentivesthrough

reductions in stormwater discharge fees.

Federalfundingcanalsohelpoffsetnancialbarriersfornetzerowaterprojects.The

American Recover and Reinvestment Act of 2009 provided $4 billion for the Clean Water

State Revolving Fund. Of that, 20 percent of each states capitalization grant can go toward

GreenReserveprojects,whicharedenedasgreeninfrastructure,energyefciency

projects,waterefciencyprojectsorinnovativeenvironmentalprojects.TheU.S.EPA

describes decentralized wastewater sstems as being well positioned for funding underthe Green Reserve projects. In addition, Section 319 of the Clean Water Act provides the

statutor authorit for EPAs Non-point Source Program. According to the U.S. EPA, most

states have non-point source management plans that allow for the use of Section 319

funds for decentralized wastewater sstem projects and decentralized sstem technolog

demonstration projects.33

Financial barriers for distributed water sstems can be directl related to the regulator

barriers noted above. Backup or redundant connections to municipal water and wastewater

utilities ma be required b codes even when a net zero water project is designed

and operated not to use them. Composting toilets sometimes require backup sewer

connectionsandassociatedplumbing,creatinganancialdisincentiveforprojectowners

to even consider their use. Likewise, capacit charges are established b utilities to recoup

sunk costs for large investments in centralized infrastructure projects and are required to

be paid b all building projects located within their service area, regardless of whether or

not on-site sstems can be utilized to meet individual suppl and treatment needs.

Some municipalities have instituted innovative fee structures, such as the Cit of Portlands

Bureau of Environmental Services in Oregon, which allows for emergenc-onl connections

31 Eisenberg, David, Sonja Persram. Code, Regulator and Sstemic Barriers Affecting Living BuildingProjects.

32 US EPA. Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices.Washington, DC: US EPA, 2007.

33 US EPA. Funding Decentralized Wastewater Sstems Using the Clean Water State Revolving Fund.Washington, DC: US EPA, June 1999.


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to their wastewater treatment facilities but charges large use fees in the event that the

utilit connection is actuall needed.

Removing regulator barriers to decentralized sstems can help spur market innovations

and new products available to designers and homeowners pursuing net zero water

strategies, thus bringing down upfront costs and reducing life ccle cost paback periods.

Foryears,nancialincentivesforenergyefciencymeasuresandon-siterenewables

sstems have been accelerating market adoption of lower energ products and strategies.

The energ sector provides a good eample of how similar approaches can be used to

accelerate advancements in on-site water sstems.

CULTURAL BARRIERSInadditiontoregulatoryandnancialbarriers,publicperceptionsaboutthesafetyofwater

reuseandon-sitewastewatermanagementpresentsignicantobstaclesfornetzero

water projects. Such fears are rooted in our historical management of water and waste

and the resulting public health issues that have surfaced. Previous generations suffered

greatl from tphoid fever, cholera and dsenter until laws and regulations were passed to

support water-carriage removal of waste from urban areas.34 Toda, education is needed to

assure the public of the safet of modern decentralized water sstems and inform them of

theirenvironmental,socialandeconomicbenets.

Thanks to a histor of disease outbreaks, coupled with marketing efforts b earl

ushtoiletmanufacturers,ushingitawayiswidelyviewedasmorecivilizedand

advanced than an other solution for dealing with our water and waste. On-site sstems

are reminiscent of stepping backwards in time and technolog to a less developedage. Education and awareness building among regulators, designers, engineers and

building occupants is necessar to full highlight the environmental risks associated

with wasteful practices. Water that has been treated for drinking purposes, requires

large inputs of energ to be conveed to buildings, contaminated with human ecrement,

conveed awa again and treated with energ-intensive processes that release polluted

water back into the environment does not represent our best technological advancements.

Addressing cultural barriers around decentralized water sstems requires a shift in the

fundamental was in which we view water and human waste. Instead of the current out of

site, out of mind thinking, we need to take ownership not onl of how we use water inside

our buildings and for irrigation, but how we operate, maintain and replace on-site sstems

over time. In doing so, we will treat water as the precious resource that it is.

34 Burrian, Steven J., Stephan Ni, Robert E. Pitt, and S. Rock Durrans. Urban Wastewater Managementin the United States: Past, Present, and Future. Journal of Urban Technolog. 7.3 (2000): 33-62


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references

Burrian, Steven J., Stephan Ni, Robert E. Pitt, and S. Rock Durrans. Urban Wastewater

Management in the United States: Past, Present, and Future. Journal of Urban Technolog.

7.3 (2000): 33-62.

California Energ Commission, Californias Water Energ Relationship: Final Staff

Report, (2005): 1-180.

Copeland, C. Hurricane-Damaged Drinking Water and Wastewater Facilities: Impacts,

Needs, and Response, Congressional Research Service, Librar of Congress, 2005: 1-6.

Chanan, A., J. Kandasam, S. Vigneswaran, and D. Sharma. A Gradualist Approach toAddress Australias Urban Water Challenge. Desalination. 249.3 (2009): 1012-16.

Disinfection B-ProductsTrihalomethanes. Wilkes Universit Center for Environmental

Qualit Environmental Engineering and Earth Sciences. Wilkes Universit, n.d. Web. 7 Sep

2010. http://www.water-research.net/trihalomethanes.htm.

Donn, Jeff, PHARMAWATER-RESEARCH: Research shows pharmaceuticals in water

could impact human cells, Associated Press, n.d. Web. 7 Sep 2010. http://hosted.ap.org/

specials/interactives/pharmawater_site/da1_03.html

Drinking Water Chlorination. Health Living. Health Canada, 14 Dec 2006. Web. 7 Sep

2010. http://www.hc-sc.gc.ca.

Eisenberg, David, Sonja Persram. Code, Regulator and Sstemic Barriers Affecting Living

Building Projects, Seattle: Cascadia Green Building Council, 2009. (2010): 1-90.

Etnier, Carl, Richard Pinkham, Ron Crites, D. Scott Johnstone, Mar Clark, Am Macrellis,

Overcoming Barriers to Evaluation and Use of Decentralized Wastewater Technologies and

Management. London: IWA Publishing, 2007.

Federal Interagenc Stream Restoration Working Group (FISRWG) Stream CorridorRestoration; Principles, Processes and Practices. Washington, D.C.: FISRWG, 1998.

Health Canada. Drinking Water Chlorination. Website. www.hc-sc.gc.ca/hl-vs/ih-vsv/

environ/chlor-eng.php.


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IEEESpectrumPodcastsDecentralizedWaterTreatmentismoreefcient,exibleand

resilient.. Web. 7 Sep 2010. http://spectrum.ieee.org/podcast/green-tech/conservation/decentralized-water-treatment-is-more-efcient-exible-and-resilient.

KingCounty.CombinedSewerOverow(CSO).PublicHealth-Seattle&KingCounty.

King Count, 03 Feb 2010. Web. 8 Sep 2010. http://www.kingcount.gov/healthservices/

health/ehs/toic/cso.asp.

Nelson, Valerie. New Approaches in Decentralized Water Infrastructure. Decentralized

Water Infrastructure. (2008): 1-79.

PacicInstitute,WaterFactSheetLooksatThreats,Trends,Solutions.,2008.Web.7Sep

2010 http://www.pacinst.org/reports/water_fact_sheet.

PacicStatesMarineFisheriesCommissionandtheOregonFisheriesCongress,When

Salmon Are Dammed., 04 Apr 1997. Web. 7 Sep 2010. http://www.psmfc.org/habitat/

salmondam.html.

Paladino and Compan, Inc. Onsite Wastewater Treatment Sstems: A Technical Review.

Seattle: Seattle Public Utilities, 2008.

Slaughter, S. Improving the Sustainabilit of Water Treatment Sstems: Opportunities for

Innovation. Solutions. 1.3 (2010): 42-49. http://www.thesolutionsjournal.com/node/652.

Urban Land Institute, Infrastructure 2010: Investment Imperative. Urban Land Institute,

(2010): 1-90.

US EPA. About Water & Wastewater Pricing. Sustainable Infrastructure. US EPA, 08 Apr

2010. Web. 8 Sep 2010. http://water.epa.gov/infrastructure/sustain/about.cfm.

US EPA, Decentralized Wastewater Treatment Sstems: A Program Strateg. Cincinnati:

U.S. EPA Publications Clearinghouse, 2005.

US EPA. Funding Decentralized Wastewater Sstems Using the Clean Water State RevolvingFund. Washington, DC: US EPA, June 1999.

US EPA. Reducing Stormwater Costs through Low Impact Development (LID) Strategies and

Practices. Washington, DC: US EPA, 2007.


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30

34

36

37

41

SECTIONS

Integrated Water Management

FitandEfciency

Communit Involvement

Risk Management

Beaut and Inspiration


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best mAnAgementPrActices

This document provides guidance for teams pursuing net zero water projects and offers

insight to regulator bodies seeking to better understand and evaluate the net zero projects

that come across their permitting desks. Central to the success of these sstems is an

integratedapproachtotheirdesignandcarefulconsiderationofeachsystemstand

efciency,wheretisdenedastheadaptationofthesystemtoconditionsonordesiredat

thesite,andefciencyisdenedasthesystemsabilitytodelivermaximumperformance

atminimumcost.Thisperformanceisgaugednotonlybynancialreturnoninvestment,

butalsobylifecyclecostsandbenets.

integrAted wAter mAnAgement

In The Logic of Failure: Recognizing and Avoiding Error in Complex Situations, Dietrich Dornereplains, . . . in comple situations we cannot do onl one thing. Similarl, we cannot

pursue onl one goal. If we tr to we ma unintentionall create new problems.

In dealing with comple sstems, it is important to take an integrated or sstems thinking

approach.Systemsthinkingreferstodeningasystemsboundariestoadequately

encompasssignicantcausalrelationshipsandunderstandtheinterconnectionsamong

resources and activities within that sstem. Advantages of decentralized options are often

onl apparent when taking a more integrated approach. For eample, on-site reuse of

grewater can provide a partiall drought-resistant source of landscape irrigation. 35

An integrated or sstematic approach to water sstem design gears all water-related

activities to one another, thereb recognizing the interconnected nature of water and

35 Etnier, Carl, Richard Pinkham, Ron Crites, D. Scott Johnstone, Mar Clark, Am Macrellis, OvercomingBarriers to Evaluation and Use of Decentralized Wastewater Technologies and Management. London: IWAPublishing, 2007.


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Best Management Practices Page 31

wastewater sstems and allowing a concurrent evaluation of a whole sstems potential

costsandbenets.Augmentingexistingresourcesthroughrainwaterharvest,managing

demandviaxtureefcienciesandotherconservationstrategies,re-useofwaterprior

to its release back into a larger sstem and on-site management of stormwater and other

landscapeconcernsallneedtobeaddressedintandem,asthereisbutanelineof

distinction between them.

36

An integrated approach is necessar when attempting to create net zero water projects

with closed-loop sstems where all of the water used on a project is being captured,

treated, used/reused and released on-site. In this report, rainwater harvest and

wastewater treatment and reuse are organized into separate chapters, and stormwater and

other landscape concerns are minimall addressed. This is simpl a wa to organize the

information and is not intended to impl that the related design processes are separate or

unrelated endeavors. To the contrar, an integrated approach is the single most important

process to be understood when considering the best practices for designing a water sstem

as part of a larger integrated design or process for an entire project.

ESTABLISHING WATER BALANCEA water balance is a numerical account of how much water enters and leaves a site. A

water balance sheet should contain detailed information about the amount of water used b

each process. The water balance is a crucial instrument to understand and manage water

owsthroughouttheplant,toidentifyequipmentwithwater-savingopportunitiesandto

detect leaks.37 For a net zero water project, the amount of water entering and leaving a site

shouldideallyreectthenaturalhydrologyofthesite.

Bruggen and Braecken offer a step-b-step method to optimize the water balance, in

three steps:

1. Investigate the current water balance in detail.

2. Combine water consuming processes and reuse water where possible for other

purposes requiring a lower water qualit.

3. Regenerate partial waste streams and re-introduce them into the process ccle.

Figure B-1 provides an overview of the multiple pathwas design teams ma choose to takein establishing a water balance.

36 Buehrer, Mark. 2020 ENGINEERING. Bellingham, Washington. 1996.

37 Van der Bruggen, B., and Braeken L. The Challenge of Zero Discharge: from Water Balance toRegeneration. Desalination. 188.1-3, 2006.


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treatment+reuse

USESOURCE

COMPOSTINGFIXTURES

EXTERIORUSE

TREATMENT+REUSE

2

1

GROUND WATER

RAINWATER

ONSITE RECLAIMEDWATER

OFFSITE RECLAIMEDWATER

MUNICIPAL WATER

SURFACE WATER /STORM WATER

WATER

WATER

BATH/SHOWER

DRINKING FOUNTAIN

LAVATORY SINK

LAUNDRY

KITCHEN SINK

DISHWASHER

FIRE SUPRESSION

PROCESS WATER/HVAC

HIGH EFFICIENCY TOILET (HET)

TOILET WITH URINE SEPARATION

HIGH EFFICIENCY URINAL

WATERLESS URINAL

MICROFLUSH

COMPOSTING TOILET

EXTERIOR WATER USE/IRRIGATION

HET

PREFERRED

POSSIBLE

QUALITy OF WATER

POTABLE:

Water suitable fordrinking

NON-POTABLE:co-mingled water fromushtoiletsandurinals

NON-POTABLE:water from bathroomsinks shower, bathtub,laundr

NON-POTABLE:water from kitchen sinksand dishwashers

NON-POTABLE:urine onl,nutrient rich water

NON-POTABLE:waterfromushtoiletswith urine separation

FIGURE B-1. DESIGNPATHWAyS TO NETZERO WATER


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REUSETREATMENT OUTFLOW

MEMBRANE

BIOREACTOR

CONSTRUCTED WETLANDS/

LIVING MACHINE

POTABLE

NON-POTABLE

INSIDE IRRIGATION

OUTSIDE SUBSURFACE

FOOD CROP IRRIGATION

OUTSIDE SUBSURFACE

LANDSCAPE IRRIGATION

DRAINFIELD

quality A

quality B

AQUIFER RECHARGE

AGRICULTURE

FERTILIZER

COMPOSTING UNIT

RECEIVING

WATER BODY

LIQUID

COMPOST

BIOFILER

OTHER

OFF-SITE TREATMENT


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Imag

e:Perkins+Will


fit And efficiency

Designers face the challenge of choosing the right water sstem, at the right place, at the

rightmomentandtherightscale.Awatersystemhastoconsiderallimpactedowsand

account for environmental, social and economic risks associated with the sstem, both

on and offsite. Flows include rainwater, stormwater, groundwater, drinking water andwastewater.Inaowsperspective,owsshouldtinachain-managementapproach,

from cradle to grave or, even better, from cradle to cradle.38 It is critical to make the

upstream,on-siteanddownstreamowsttogetherinahealthyclosedloop.

CLIMATERegional climate is a major consideration when choosing and sizing a projects water

system.Forexample,inthePacicNorthwest,therearesomeareasthatreceiveas

much as 140 inches of precipitation per ear. However, those same areas receive nearl

noprecipitationfromJulythroughSeptember.AcrosstheUnitedStates,therearevedifferent major climate zones and sizable variabilit within those zones.39

38 United Nations Environment Programme, Ever Drop Counts: Environmentall Sound Technologies forUrbanandDomesticWaterUseEfciency.Delft:UNEP,2008.

39 US Energ Information Administration. U.S. Climate Zones for 2003 CBECS. Independent Statisticsand Analsis. US Energ Information Administration, n.d. Web. 8 Sep 2010

The Center for Urban Waters in Tacoma, WA, harvests rainwater in t wo 36,000-gallon above ground cisterns.


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Further, the warming of the climate due to human and non-human causes is alread

impactingweatherpatternswithineachzone,andisexpectedtosignicantlyand

progressivel alter precipitation patterns across the United States in the coming decades.

An ecess or lack of water with the change of precipitation patterns ma present the

greatest hazard we face in building durable buildings and communities.

It is also important to consider the microclimatic conditions on the project site itself. The

macroclimate, or long-term weather conditions for a region, is derived from accumulated

da-to-da observations often made at weather stations far awa from the towns and

citieswheremostbuildingsareconstructed.Signicantclimaticvariationscanoccurover

distancesofonlyafewmiles,makingitimportanttounderstandthespecicconditions

present and likel to evolve on the site when making design decisions. Some of the main

factorsinuencingthemicroclimateofasiteare:urbanheatisland,topography,terrain

surface (natural or manmade), vegetation and obstructions.40

Finall, it is important to consider that climate not onl impacts the availabilit ofprecipitation or groundwater for use. The amount of water required b humans and other

actors within a given climate varies enormousl depending on environmental and climatic

conditions such as temperature and humidit.

FIT-FOR-USEThe vast majorit of the water used in the U.S. is drawn from freshwater supplies of

surfaceandgroundwaterthentreatedtopotablestandardsasdenedbytheSafeDrinking

Water Act. A large multifamil or commercial building can use more than 120,000 gallons

of potable water in a single da.41

Once used, the water is tpicall released as wastewater.Accesstothistreatedwaterhasgreatlybenetedpublichealth,butitalsohasresultedin

a sstem that utilizes potable water for virtuall ever end use, even when lesser qualit

waterissufcient.Inadditiontoconservationmethods,usingandre-usingalternative

sourcesofwaterwillbenecessaryformoreefcientuseofwaterresources.42

Treatment of water is a collective term for methods of improving the water qualit b

phsical, chemical and/or biological means. The level of water treatment should be

determined b the intended use or destination of the water. It is wasteful and not necessar

tousepotablewaterforactivitiessuchasushingtoiletsorirrigatingplants.Untreatedor

minimallytreatedrainwatercanbeusedforactivitiesincludingtoiletushing,irrigation,

40 Sharples, Stephen, and Hocine Bougdah. Environment, Technolog and Sustainabilit. New york:Talor & Francis Group, 2010.

41 yeang, Ken. Ecodesign: A Manual for Ecological Design. London: Brook House, 2008.

42 Kloss, Christopher, Managing Wet Weather with Green Infrastructure: Rainwater Harvesting Policies:US EPA, 2008.


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showeringandlaundry.Greywaterfromxtureslikelavatorybasinsorwashingmachines

can be reused directl in the building, often without treatment or with onl primar

treatment.

FIT-FOR-SCALE

Thewatersystemalsomusttwiththescaleofuse.Differenttechnologiesandstrategieslend themselves to different scales of use. This report addresses three basic scales in an

urban contet: the single famil home, multifamil residential or commercial buildings,

and a neighborhood or campus. There is great diversit even within each of these individual

typologies,emphasizingtheneedforsite-specicdesign.

As suggested in the Living Building Challenge, the appropriate scale for a water sstem

ma etend it beond the boundaries of the project site.

Depending on the technolog, the optimal scale can var when considering

environmentalimpact,rstcostandoperatingcosts.43

The scale of the sstem can impact the scope and boundaries of a risk assessment for

the project. Sstems that go beond a project boundar also naturall epand the role of

communit involvement during the planning phase.

community involvement

Water sstem proponents should decide on the appropriate level of communit

participation to include in the planning stages of the project. The primar audiencefor engagement would logicall include communit members that are the intended

beneciariesofthesystem,alongwiththosethathavethegreatestexposuretoresidual

risk associated with the sstem or whom might be otherwise impacted.

Multiple models eist for varing levels of communit involvement in planning local

projects and infrastructure. These levels range in intensit from consultation to

involvement to engagement. Consultation implies onl providing information to

a communit and requesting feedback. Involvement implies the need for the water

sstem to be responsive to the communits needs, and that the project leaders should

decide on the structures and decision-making processes in which to involve communit

members. Engagement, the most intensive form of communit participation, builds a full

collaborative relationship with a communit for both governance and sstem planning. A

43 McLennan, Jason, Eden Brukman. Living Building Challenge 2.0: A Visionar Path to a RestorativeFuture. Seattle: International Living Building Institute, 2009.


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project team will decide on the appropriate level of communit participation based on the

scale of the project.

In addition to seeking communit input, the project team should communicate earl and

oftenwithstateandlocalgovernmentofcialsandregulators.Theprojectteamshould

discusstheproposalandplanswiththerelevantofcialsandregulatorsasearlyaspossibleintheprojecttoensurethatallissuesareidentiedandaddressedpriortothe

design and permitting stages.

risk mAnAgement

The design of a net zero water sstem is intended to help address and mitigate the large-

scale impacts associated with energ-intensive centralized sstems. Of course, net zero

water sstems also epose users and communities to potential risks. These risks should

be viewed in a broader sustainabilit contet than that often used b the regulator

communit.

Man in the building regulator communit continue to view green and sustainabilit

goals as either tring to maneuver their wa around minimum code requirements or as

optional goals that etend beond their regulator scope of concern or responsibilit.

Meanwhile, the green building movement and . . . the Living Building Challenge

encompassesasignicantlymorecomprehensiveunderstandingofrisk.Inherentin

theirapproachesistheaimoftakingresponsibilityforbalancingthefullriskprolesof

built projects including all the current regulator concerns while simultaneouslseeking to address large, but currentl unregulated risks to present and future

generations and to essential ecological integrit.44

Net zero water projects must address social, environmental and economic risks that are

endemictoallwatersystemsandsomethatarespecictodistributedsystems.Arisk

management framework is the most effective wa to assure the appropriate qualit of

water for the proposed end use. Decisions concerning the scope and boundaries of the risk

assessmentmaybebasedonoperational,technical,nancial,legal,social,environmental

or other criteria. Criteria ma also be affected b the perceptions of stakeholders and b

regulator requirements. It is important to establish appropriate criteria at the outset that

correspond to the tpe of risks and the wa in which risk levels are epressed.

44 Eisenberg, David, Sonja Persram. Code, Regulator and Sstemic Barriers Affecting Living BuildingProjects, Seattle: Cascadia Green Building Council, 2009.


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Theriskassessmentprocessshouldbeginwithdeningtheextentofthewatersystem

andorganizingitintoalogicalframeworkthathelpsensurethatsignicantrisksarenot

overlooked.Theprojectteamshouldconstructaowdiagramshowingallofthestepsin

the sstem from source to end use that includes:

All steps of the process, both within and outside the control of the project team

Source(s) of water

Proposed sstem components

Proposed end uses

Residuals produced from the sstem

Unintended or unauthorized end uses

Discharges or releases to the environment

Receiving environment and/or routes of eposure

An additional considerations needed to maintain the qualit and/or safet of the water

Theowdiagramshouldbesignedoffforauthenticityandstatusbytheteamleader.45

Oncethecontextofthesystemisestablishedwithaowdiagram,simpleriskassessment

matrices are available for prioritizing hazards and identifing the tolerable level of risk

eposure. Risks to be considered can be grouped under three basic categories: social risk,

environmentalriskandnancialrisk.

SOCIAL RISKThe provision of safe water and sanitation has been more effective than an other public

service in promoting public health. Distributed water sstems should be designed and

operated without jeopardizing public health gains achieved historicall via the adoption

of centralized deliver and treatment. Of greatest concern with the use of decentralized

sstems is the associated health risk, especiall the risk of eposure to microbial

pathogens and chemicals-of-concern potentiall present in rainwater and reccled water.

Table B-1 lists potential hazards that ma be present in water before, during or after

treatment. In addition to those presented in the table, trace constituents including caffeine,

estrogen and other hormones have also been detected in the United States.

Health risks can be mitigated with appropriate preventive measures that place barriers

between the rainwater/reccled water and members of the communit. Eamples of

preventive measures include water source protection46, water treatment, protection and

45 Adapted from New South Wales, Department of Water and Energ. Interim NSW Guidelines forManagement of Private Reccled Water Schemes. 2008.

46 Source protection ma include protecting rainwater from animal and human waste and controlling thequalit of water discharged into grewater sstems.


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TABLE B-1: LIST OF POTENTIAL HAZARDS IN RECyCLED WATER

Adapted from the Australian Guidelines for Water Recycling, 2006.

POTENTIALHAZARD

DESCRIPTION

Biological

Algae Simple chlorophll-bearing plants, mainl aquatic & microscopic in size. Under suitable conditions, some

tpes of algae ma grow in untreated or partiall-treated wastewaters, producing algal toins such asmicrocctins, nodularins, clindropermopsin & saitoins.

Bacteria Unicellular micro-organisms tpicall smaller than 5 microns. Bacteria common to blackwater includepathogens such as Camplobacter, Salmonella, Clostridium, & Legionella.

Helminth An invertebrate that is parasitic to humans & other animals. Helminths include tapeworms, roundworms&ukes.

Protozoa A phlum of single-celled animals tpicall ranging in size from around 1 to 300 nanometers.

Viruses Molecules of nucleic acid ranging in size from 20 to 300 nanometers that can enter cells & replicate inthem. Some common viruses found in untreated blackwater include norovirus & enterovirus.

Phsical

Hpoia Ogen depletion brought about b the bacterial breakdown of organic matter in the water.

pH An epression of the intensit of the basic or acid condition of a liquid.

Screenings The solid waste collected in the inlet screens to a treatment process including solids disposed of towastewater.

Suspended solids Suspendedsolidsmeasuresthepresenceofnesuspendedmattersuchasclay,silt,colloidalparticles,plankton & other microscopic organisms.

Chemical

Ammonia Ammonia dissolves rapidl in water & is a food source for some microorganisms, & can support nuisancegrowth of bacteria & algae. Ammonia can be a pollution indicator as it can formed as an intermediateproduct in the breakdown of nitrogen-containing organic compounds, or of urea from human or animalecrement.

Chloride Chloride comes from a variet of salts (including detergents) & is present as an ion (Cl-). Chloride isessentialforhumans&animals,contributingtotheosmoticactivityofbodyuids.However,itcanbetoxicto plants, especiall if applied directl to foliage or aquatic biota.

Disinfection b-products

Disinfection b-products are formed from the reactions bet ween disinfectants, particularl chlorine, &organic material. Chlorine reacts with naturall occurring organic components or ammonia to product b-products such as dicholoroacetic acid, trichloroacetic acid & THMs & chloramine b-products.

Metals Heav metals, such as cadmium, chromium, & mercur ma be present in raw wastewaters as a result ofindustrial discharges.

Pesticides Pesticides harmful to humans & a wide range of species ma enter water sstems b a variet of meansincluding stormwater runoff, personal use & illegal disposal.

Pharmaceuticals Pharmaceuticals & their active metabolites are ecreted b humans &/or disposed of direc tl into watersstems.

Total dissolvedsolidsTotal dissolved solids (TDS) include dissolved inorganic salts & small amounts of organic matter. Claparticles, colloidal iron & manganese oides & silica ma also contribute to TDS. Major salts in reccledwaters ma include sodium, magnesium, calcium, carbonate, bicarbonate, potassium, sulphate &chloride.

Total nitrogen An important nutrient found in high concentrations in reccled waters, or iginating from human &domestic wastes. In high concentrations can cause off-site problems of eutrophication of receiving bodies.

Total phosphorus Originating mainl from detergents but also from other domestic wastes, in high concentrations cancause eutrophication of receiving bodies.


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maintenance of distribution sstems and storages47, restrictions on the distribution and use

of reccled water48, and education of end users.

The most common and effective barrier used is treatment of the captured or reccled water

before use. The level of treatment and disinfection depends on the source of the reccled

water, the potential for fecal contamination and potential for eposure to communit

members, which is generall determined b its intended use and release back into the

environment (See Fit-for-use above).

Beond the more immediate health considerations, other social risks to address include

the sstems ease of operation and maintenance over its lifetime.

ENVIRONMENTAL RISKThere are a variet of environmental risks associated with an water sstem, including

distributed sstems. These include the lifeccle impacts of the sstems component parts,

theimpactsofthesystemonsiteanddownstreamowsandwaterquality,andtheenergyrequired for the construction and operation of the sstem, including an pumping and

treatment process.

The pipe and pumping requirements to conve wastewater from its point of generation to

itspointoftreatmenthassignicantenvironmentalimpacts.Lifecycleanalysisofthese

conveance sstems point toward greater environmental impacts as the length of pipe

and the number of pump stations required increases. Sstems where a series of pump

stations are used to conve wastewater across elevation changes consume large amounts

of energ. Conclusions can be drawn to the etremel important role of service area

topograph in assessing the feasibilit of smaller-scale distributed sstems.49

FINANCIAL RISKFinancial assessment of the long-term viabilit and sustainabilit of a water sstem is

important. According to the 2004 Valuing Decentralized Wastewater Technologies report

prepared b the Rock Mountain Institute for the U.S. EPA, decentralized and distributed

systemscanbemoreexibleinbalancingcapacitywithfuturegrowth.Insmaller-scale

sstems, capacit can be built house-b-house, or cluster-b-cluster, in a just in time

47 Eamples of protection and maintenance of distribution sstems and storages include buffer zones,minimizinglighttorestrictalgalgrowth,maintainingdrainage,andbackowpreventionandcross-connection control.

48 Preventive measures that restrict the distribution and use of reccled water include: signage andcolor coding of pipes; buffer zones; control of access; control of method, time and rate of application; usercontrolled diverter switches; hdraulic loading and interception drains; management plan; prohibition ofrecycledwaterinspecicareas.

49 Cascadia Green Building Council, Clean Water, Health Sound: A Life Ccle Analsis of WastewaterTreatment Strategies in the Puget Sound Area, in progress (2011)


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fashion. This means that the capital costs for building future capacit is spread out over

time, reducing the net present value of a decentralized approach and resulting in less debt

to the communit as compared to the borrowing requirements of a large up-front capital

investment. This is especiall true in the event that a communit sees less growth than

anticipated in their ini

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