Federation of Cdn. Municipalities Guide to Green Infrastructure for Cdn Municipalities

7/31/2019 Federation of Cdn. Municipalities Guide to Green Infrastructure for Cdn Municipalities

1/47

GreenMunicipalities

A Guide to GreenInfrastructure for

Canadian

Municipalities


2/47

Prepared for: Prepared by:

Federationof CanadianMunicipalities

Green M unicipali tiesA Guide to Green Infrastructure

for Canadian Municipalities

May 2001


3/47

CONTENTS

1. A City Transformed ................................................................ 1Historical Perspectives and Important Trends ............................... 1A Vision for What Lies Ahead ........................................................ 3

2. Features of Green Infrastructure............................................ 4

3. Benefits of Green Infrastructure ............................................. 15Social Benefits ............................................................................... 15Economic Benefits ......................................................................... 15Environmental Benefits.................................................................. 17

4. Best Practices For Green Infrastructure ................................ 18Stormwater Systems ..................................................................... 18

Liquid Waste .................................................................................. 22Potable Water Systems ................................................................. 25Energy Systems ............................................................................ 27Solid Waste Systems..................................................................... 30Transportation and Communication Systems................................ 32

5. Common Obstacles to Greening Your Infrastructure ............. 36Formulae Thinking ......................................................................... 36Fragmentation of Ecologies ........................................................... 36Sunk Investments .......................................................................... 36

Inflexible Policies ........................................................................... 36Bundled Fees ................................................................................ 36Rate-basing ................................................................................... 36Larger Utilities Supporting Status Quo .......................................... 37Lack of Comprehensive Cost/Benefit Models................................ 37

6. Tools For Making It Happen ................................................... 38Total Cost Assessment .................................................................. 38The Integrated Design Process ..................................................... 38Public-Private Partnerships ........................................................... 39Micro-utilities.................................................................................. 39

Urban Ecology Planning ................................................................ 39Risk Management.......................................................................... 40Policies That Reward Performance ............................................... 40An Environmental Management Framework ................................. 41Watershed Management ............................................................... 42Green Building and Development Guidelines................................ 42Increased Use of Energy and Material Flow Models ..................... 43Rules of Thumb for Selecting Optimum Scale and Location ......... 43

The Sheltair Group Resource Consultants Inc. A Guide to Green Infrastructure for Canadian Municipalities

i


4/47


1

model for what our cities will look like in yearsto come.

HISTORICAL PERSPECTIVESAND IMPORTANT TRENDS

Infrastructure is a term for describingmechanisms that transform raw resources intothe essential services required for ourhouseholds and businesses. No city canoperate without infrastructure, and thus systemdesigns date back to cities of antiquity. Insome cases, the systems havent seen muchchange since that time. In fact, cities in Europeare still using elements of water supplysystems that are over 2000 years old. Manyancient systems were well-designed, providingbeautiful civic structures and clever integration

of resource flows. The pools of the Siloam,described in the Bible, were actuallyJerusalems cesspools, where farmers wouldgather to collect the highly valued sludge foruse on their market gardens. Many Romansettlements in northern Europe were piped withdistrict heating systems that used warm gasesfrom the large kitchens to heat floors

throughout clusters of buildings.

The large, centralized water, waste, sewage

and energy grids, that are so familiar in citiestoday, were first engineered in the 19th century,with water and sewer infrastructure beginningin the 1840s, and electricity grids in the 1870s.At that time, water and sewer systems, alongwith electricity, were massive and nobleundertakings. Social activists and human-itarians focused on these types of housingservices as the best way to improve familyhealth, comfort and standards of living. In fact,the social movements of the early 20th century- including womens liberation - were largely

focused on transforming the built environment,indoors and outdoors. (A similar process isnow underway in many developing countries.)Little thought was given to environmental limitsor to possibilities for integrating systems.Instead, single purpose agencies andbusinesses were created, often with monopolystatus, and with a mandate to increase supply.

A

CityT

ransfo

rmed

1. A City TransformedA world-wide effort to improve urbansustainability over the past decade has producedsystems and buildings that are increasinglydiverse and complex, with greater functionalintegration at all scales, from the building and

site, to the neighbourhood and to the city.

The pattern is becoming clear. Infrastructuresystems are evolving into ecological forms thatare more effective at looping scarce resources,and at cascading energy flows through multipleend uses. Greater emphasis is placed uponachieving thermodynamic efficiency for thesystems as a whole, and upon creating systemsthat are inherently more adaptable and resilient.The net result is an integrated infrastructuresystem with a reduced ecological footprint over

its life cycle, and with significant benefits for thecommunity economy and quality of life. This isreferred to as Green infrastructure.

Like the term green building, the concept ofGreen infrastructure has evolved over time.Initially the focus was on using elements of thenatural environment to replace or supplementthe built forms with which we are more familiar.Moderating the scale of the infrastructure wasseen to be equally important. More recently we

have been looking to incorporate appropriatetechnologies and green materials that match thequality of the resources and system design tothe user needs. From this perspective, naturaland low-tech products and systems are appliedbefore complex or resource-intensive solutions.On-site and renewable resources are usedwherever possible, and then supplemented bylarger scale infrastructure as necessary. Green

infrastructure is actually hybrid infrastructure

that is more resource efficient, adaptable andsustainable.

As a consequence of Green infrastructure, theprocess of system design and assessment isbecoming more challenging and interdisciplinary.This Guide is one attempt to meet this challenge.It is intended to help each of us better understandand apply the concepts underlying the newGreen infrastructure, and develop a new mental


5/47


2

In the mid 20th

century, the same process wasrepeated for transportation and communitysystems.

These traditional 19th

and 20th

centuryinfrastructure systems are becoming increasinglycostly to operate on a per person basis. A

number of trends contribute to these rising costs:

on-site demand for resources per dwelling is

declining, as our homes and offices becomemore efficient;

average occupancy per dwelling is also

decreasing;

the cost of securing a unit of resource is

increasing; and

land for facilities and distribution systems is

ever more scarce and costly to acquire.

The cumulative effect of such trends is that agrowing proportion of resources is being used inunproductive generation and distribution

operations. At the same time, we are witnessingchanges to technology and the economy that arecreating radically new opportunities for Greeninfrastructure. For example:

Urban density is increasing (or is planned

to increase);

New micro utility servicing equipment

is on the market, including small-scalesystems for water treatment, water recycling,cogeneration and heat transfer;

Innovative storage systems are improving

potential for renewable energy and on-siteinfrastructure. In some cases, the grid is alsobeing used as a storage substitute. As flowsof electricity, heat and water become bi-directional, on-site systems can easily sharesurplus resources and top-up local capacity.

Artificial intelligence (AI) can now be used

to reduce the need for expensive fail-safesystems, and to reduce maintenance costsfor small-scale systems. AI can also facilitatethe management of innovative storage andhybrid systems.

Deregulation of utilities is helping to

transform single-minded monopolies intoflexible and market driven businessesfocused on a broad range of customer needs

- in some cases offering a servicepackage of gas, electricity, water, cable,insurance, telephone, appliances andsewage from a single supplier.

Delivery of infrastructure is nowchanging from traditional generalcontracting to a more performance-based

system, where a consortia of firmsundertake to design, build, own, operateand transfer systems in accordance withbroad, objective-based requirements.

All these innovations are opening the door toa far more flexible, diverse and integratedapproach to providing urban services. It isimportant not to underestimate the extent ofchange now underway. Green infrastructureis likely to change the city as much as theintroduction of automobiles, electricity orconcrete. In fact, we may be talking aboutthe first major change in urban form andfunction since cities were invented.

Long time constants will serve to soften theimpacts of such change for example,existing buildings may last 40 or 60 years, andhighways and pipes can last even longer.However, the scale of change in our cities isanalogous to what has already occurred withcomputers, where a large, centralized,

expensive and single purpose main frameinfrastructure has been almost completelyreplaced by a network of on-site systems.

In the emerging green communities, elementsof urban infrastructure systems are alreadymoving much closer to or inside thebuildings themselves, even in large urbancentres. Increasingly, we see a blurring of thetraditional boundaries that separate one typeof building from another, and buildings fromtheir civil infrastructure. Large distribution

grids and remote treatment and generationfacilities are giving way to a network ofdistributed or on-site infrastructure systems,with shared elements, finely integrated into thefabric of the built environment.

More diverse land use and building typescomplement the on-site infrastructuresystems, by evening out the demand for

A

CityT

ransfo

rmed


6/47


7/47


4

Feat

uresofG

reenInfrastructure

1. Distributed

Centralized plants and facilities are replacedwith a variety of smaller scale systems,distributed throughout the service area. Thedistribution patterns take advantage of wherethe renewable resources are located. New

infrastructure is also piggybacked onto localcapital projects like hospitals, schools, parks,and roads.

2. Features of GreenInfrastructure

Ten features that help to define Greeninfrastructure are described and illustratedbelow. In combination, these features appearto produce infrastructure systems that areinherently more sustainable.

For example, a distributed energy systemmight collect thermal energy from manysources: methane at landfills or sewagetreatment facilities, heat pumps connected topipes in the ground or water bodies, solarwater heaters on roofs, and industrialprocesses all connected through a district

heating system. Electricity might be generatedat many points on the grid, using windmills nextto lakes or on hills, and turbine generators inthe local rivers, water pipes or ocean channels.Growing communities may also want todistribute electrical generating capacity withineach new cluster of buildings along theprinciple transportation corridors providingon-site electricity for lighting, appliances andthe public transit system, while using the wasteheat from electrical generators to heat thenew buildings and domestic hot water.


8/47


5

2. Clustered

The distributed network is composed of nodes,structured in a hierarchy, from inter-urban, tointra-urban to intra-building. The nodes in thisstructure offer opportunities for adjusting andoptimizing the location, load base, and the scale

Feat

uresofG

reenIn frastructure

of elements within each infrastructure system.The nodes also provide convenient locationsfor integration of infrastructure. Spacesbetween nodes may be sized to match thescale of the servicing technology, therenewable resource base, food requirements,water treatment and supply needs.


9/47


6

Feat

uresofG

reenInfrastructure

3. Interconnected

A multi-service connectivityis provided between thecluster centre and points ofdemand and supply, and tostorage and treatmentfacilities. Ideally this multi-service connectivity iscapable of embracing all theflows - including resources,people and information.One approach may bemulti-purpose corridors;another might be utilidorswith standardizedconnections. It is theseconnections that are used

to create loops, or in otherwords the trading,balancing, reusing andrecycling of resources.Ultimately, a series of miniloops and bigger loops willlead to a circularmetabolism for the city andits hinterland. Like a livingecology, the essentialnutrients are cycled throughthe system, driven by the

renewable energy sources.


10/47


7

4. Integrated

Integration of infrastructure meansusing the existing components of theurban environment - roads, buildings,greenways, and so on - to serve aselements of the infrastructure system.An integrated system does not standdistinct from the surrounding built ornatural environment, and instead isfunctionally integrated at all scales.Integration begins at the building (ormicro) scale, and then moves outwardsas necessary. At the building scale,integration may mean that walls, roofs,entranceways and other elements ofthe building serve to capture energy,water and wind, treat and separate

wastes, and contribute to accessibilityand transportation. These internalcollection and separation systemsallow the building to produce rawmaterials like clean, reclaimed water,photovoltaic electricity, used paper,CO

2, and so on. At the neighbourhood

scale, systems are integrated with landuses and with other resource flows.Properly planned, this type ofintegration creates a true urbanecology.

Feat

uresofG

reenIn frastructure


11/47


8

5. Service Orientation

A service orientation means that theobjective is no longer to connectbuildings and distribute resources, butrather to provide a service. Instead ofproviding, say, natural gas, the focusis on providing comfort, cooking andcleaning services. In some cases thismay be best accomplished bydelivering natural gas; in other casesthe best solution may be improvedhome design, or a solar water heater.Thus rather than simply sizinginfrastructure systems for the worst-case demand scenario, andexpandability, Green infrastructureinvestments seek to optimize supply

and demand management to providethe best service. Sometimes aninvestment in demand sidemanagement can serve to reduce thesize of loops and permit more efficient

Feat

uresofG

reenInfrastructure

resource exchange. Or,

demand side managementmay help to avoid costlyexpansions of off-siteinfrastructure, and to limit theloads to only what can beaccommodated by theneighbourhood scalesystems. Making infra-structure more sustainablemeans reducing the energyand resource intensity of theservice, while enhancingvalue. This concept issometimes referred to aseco-efficiency.


12/47


9

FeaturesofG

reenInfrastructure

Green infrastructure can also respond to the historical patterns for both built and naturalenvironments. What kinds of local plants and animals work well together? and is it possible touse a similar combination of species and shapes for creating green spaces and cityscapes? orWhy did the traditional architecture use large roof overhangs, and how might such architecturalfeatures also become functional elements of on-site infrastructure?

6. Responsive

One of the advantages of on-site local, smaller scalesystems is their ability torespond to the localopportunities and constraints.On the input side, a system canbe designed to accommodatethe specific waste resourcesavailable from industry (e.g.sawmill waste, hot water) orfrom the local environment(tidal power, lake cooling,micro-hydro, wetlands). Onthe output side, a local systemcan be designed to preserve orenhance the local carrying

capacity of the airsheds,watersheds, soils, and landbase, and the integrity of thelocal ecosystems.


13/47


10

7. Renewable, Low-impact

Similar to Greenbuildings, Greeninfrastructure isintended to maximizeuse of existing on-site resources and,where possible, toincorporate livingmachines designedto mimic naturalecosystems. One ofthe best examples ofrenewable, low-impact technology isan ecologically-e n g i n e e r e d

wastewater systemthat treats run-off andsewage with micro-organisms andvegetation. Othercommon examplesare systems thatobtain usable energyfrom sunshine,micro-hydro, wind,and geothermalsources.

In theory, there issufficient local naturalresource wealth ofthis type to provideadequate levels ofservice for housing,without anya d d i t i o n a li n f r a s t r u c t u r e .However, from an

e c o n o m i cperspective the bestsolutions are hybridsystems thatsupplement theselocal, renewableresources withimports fromelsewhere.

Feat

uresofG

reenInfrastructure


14/47


11

8. Appropriate (or Well-Matched)

The choice of technologies and materialused for constructing infrastructure shouldbe appropriate for the users requirements,and for the social context. Choices shouldalso contribute to greening the entireeconomy. Most importantly, this meansmatching high quality resources with themost demanding end uses. For example,high quality water is used for drinking andfood production, lower quality water ismatched to washing and flushing, and thelowest quality water is used for irrigationand water features. Energy is treatedsimilarly (see next page).

Feat

uresofG

reenIn frastructure


15/47


12

High quality energy, like electricity, isused for lighting, computers, motorsand transportation; natural gas is usedfor cogeneration, industrial processesand steam; waste heat is used forwater heating and, lastly, spaceheating. Of course, it is also importantto cascade the energy resources,using the waste resource from oneend use as the input for a lower qualityend use.

Another aspect of appropriate design is theselection of materials used for constructinginfrastructure elements. The same principlesapply: match the quality of the material to the

users end needs, and ensure that thematerials are designed and installed in waysthat facilitate later reuse or recycling. Finally,the system design itself needs to beappropriate; for example, by matching thelevel of complexity with the management andmaintenance abilities of the local operators.As systems become more localized, the needsmay increase for modularization, standard-ization, and computerization.

FeaturesofG

reenInf

rastructure


16/47


13

9. Multi-Purpose

Each element in a newinfrastructure system canbe designed to contributeto a multitude ofpurposes and thusprovide a range ofadditional services to thecommunity. This processemulates the elements ina living ecosystem (bio-mimicry) where a stableand efficient system iscreated by using singlecomponents for multiplefunctions. In the case ofneighbourhood scale

infrastructure, a goodexample might be polishingponds for wastewater.Properly designed, thesemight become part of amultipurpose on-site pondsystem that is aestheticallylandscaped, and thatfunctions as aquaculture,groundwater recharge,irrigation water storage,prefiltered stormwaterdetention, wildlife habitat andemergency fireflowreservoirs. Even a waterstorage tower can bedesigned to serve multiplepurposes: e.g. a viewingtower, a gathering place, a

support for solar and windpower, a means ofadvertising theneighbourhood values, and ameans of contributing to thebeauty and diversity of urbanareas.

Feat

uresofG

reenIn frastructure


17/47


14

FeaturesofG

reenInf

rastructure

10. Adaptable

Adaptability refers to the capacity of systems to accommodate substantial change. Over thecourse of a systems lifetime, change is inevitable, both in the social, economic and physicalsurroundings, and in the needs and expectations of consumers. All other things being equal, asystem that is more adaptable will be utilised more efficiently, and stay in service longer, becauseit can respond to changes at a lower cost. A longer and more efficient service life should, in turn,translate intoi m p r o v e de n v i r o n m e n t a lperformance over thelifecycle.

The concept ofadaptability can bebroken down into anumber of simplestrategies that are

familiar to mostdesigners: flexibility,convertibility, andexpandability. Inpractice, thesestrategies can beachieved throughchanges in design, and through the use of alternative materials and technologies. A districtheating system, for example, can use a single, convertible boiler to quickly switch the wholeneighbourhood from one source of heating energy to another. Thus the community can effortlesslyadapt to changes in energy availability, cost, environmental impact or whatever. Infrastructure

that is smaller scale,

and distributed, maybe inherently moreadaptable, because itis less vulnerable toe n v i r o n m e n t a lchanges or socialtransformations. Itmay also be moreadaptable than a one-time investment inlarge systems,

because anincremental pace ofgrowth cana c c o m m o d a t ediverse andi n n o v a t i v etechnologies andpolicies.


18/47


15

3. Benefits of GreenInfrastructure

Green infrastructure contributes to urbansustainability because it generates significantbenefits in all three spheres of concern:social, economic and environmental. The fullrange of such benefits is presented in thischapter. These benefits represent theessential arguments for adopting andpromoting the features of Greeninfrastructure.

Interestingly, the same list of benefits can becited as an argument for any type of Greeninfrastructure system - from energy to solidwaste to transportation. More detailed

examples of features and benefits for eachtype of infrastructure will be described in thenext Chapter.

SOCIAL BENEFITS

Resilience

A cluster structure, with diverse technologies,can be much more resilient when confrontedwith ice storms, earthquakes, tsunamis, fire,terrorism, civil unrest and other calamities.

Loads can be shared if one system isdestroyed, and resources can be substitutedat the scale most appropriate.

Aesthetics & a Sense of Place

On-site infrastructure offers new opportunitiesfor beautification of public spaces andcreating a sense of place. The vegetationand watercourses associated with openstormwater systems, for example, can helpmake a neighbourhood both distinct andbeautiful. A number of communities in

Europe have used leading architects todesign the local wastewater treatmentgreenhouses and the community heat andpower plants. These facilities becomelandmarks and statements for the community.Moreover, integrated, on-site systems offercities a more human scale environment.

Amenities

If capital projects are carefully designed formultiple uses, the community benefits from newamenities and recreational opportunities.

Flexibility

Sometimes it can be a problem to locate newgrowth in specific locations because of the needto pump sewage or extend pipelines. On-siteinfrastructure can thus allow cities to moreeffectively use their land base.

Conflict Avoidance andResolution

It is becoming increasingly difficult to exportwastes from cities, and to locate largeinfrastructure elements, including facilities andright-of-ways. Incorporating infrastructure intothe more organic process of neighbourhood andbuilding development is likely to be moreamenable to community control and acceptance.

A Greater Choice of Lifestyles

A diversity of infrastructure systems creates thepossibility for greater choice in lifestyle. Theneighbourhoods can make trade-offs betweenconvenience and cost. For example, smallresidential communities, in the Netherlands, oftenchoose very different approaches to dealing with

automobile access, with some neigbourhoodsrestricting parking spaces, others sharing cars,and others offering transit passes and cycles aspart of property ownership.

ECONOMIC BENEFITS

Lower Costs

Green infrastructure often results in lowerlifecycle costs when compared to traditional

larger-scale, non-integrated systems. Forexample, demand side management (the serviceorientation) can reduce the need for publicexpenditure. Converting waste products intoresources creates a new revenue stream forconsumers. Small-scale facilities typically needmuch simpler fail-safe systems, which greatlylowers capital costs.

BenefitsofG

reenIn frastructu

re


19/47


16

Delayed Capital Outlays

Green infrastructure is more incremental, sincesome (or all) of the elements are located inbuildings or at the neighbourhood level. Thiscreates opportunities for more gradual phasingof investments, and thus helps to delay majorcapital expenditures. The incremental approachalso makes it easier to match capacity withdemand, and thus avoid the cost of over-sizingsystems.

User-pay

To the extent that infrastructure elements andfunctions can be integrated into buildings orurban development projects, the municipalityand utility can off-load a portion of the capitalcosts to the users. This is consistent with a User-pay principle, and encourages more efficiency

and conservation within the marketplace.

Longer-term Investments byStakeholders

As building owners and developers becomestakeholders in the creation of utility services,they are likely to see the wisdom of investing indemand side management and lifecycle costing.For example, if a developer can partner with amicro-utility, and create dwelling units withexceptionally low operating costs, the units arecertain to be more marketable. This can reducerisks for the developer and investors. The micro-utility may also allow the developer toparticipate in the long-term revenue streamrelated to provision of services like water, waste,energy, and communications. For example, asingle monthly management fee for owners maycover the costs (and provide profits) for providinga whole range of infrastructure services. Theincentives are thus created for private sectorinvestments in high performance housing, sincelower operating costs will increase profits both

from sales and the on-going management ofmicro-utilities.

Local Job Creation

Green infrastructure creates more employmentwithin the community. Less money is spent onconstructing and operating facilities in remotelocations. Less money is spent on importingproducts like electricity, gas and water. Instead,

a portion of the investments is made locally,and helps to circulate money within the localeconomy, and to create jobs closer to wherepeople live. The looping of waste materialsback into raw materials can also contribute tonew local industries and long-termemployment. Once raw materials are

reclaimed, additional processes can beintegrated within the building and/orneighbourhood to process the raw materialsinto products. And if the Green infrastructureis a more efficient system, it should leave moredollars in the hands of local residents - dollarsthat can be spent on protecting the localenvironment and enhancing thecompetitiveness of the community.

Local Procurement

Infrastructure elements that are integrated at

the local scale frequently involve localprocurement, which boosts business in thecommunity.

Security

Large systems dependent upon a singleresource flow are dangerous for the economy.For example, consider the recent flight ofbusinesses from California after the electricitybrownouts caused by natural gas scarcitiesand poorly regulated marketplaces. The

natural and adaptable features of Greeninfrastructure provide businesses with a lowerrisk of such business disruption. This alsoapplies to virus attacks, natural disasters, andother crises.

Quality of Service

Many types of Green infrastructure provide ahigher quality of service and providecommunities with a competitive edge. Districtheating, for example, can be more reliable andmore professionally managed and maintained

than would ever be possible for a single-building system; the users also save floorspace and reduce numbers of maintenancepersonnel. If transportation infrastructureincludes work at home options, and a goodmatch between housing and jobs, then Greeninfrastructure should significantly reduce thetransportation and overhead costs forbusinesses and employees.

BenefitsofG

reenInfrastructu

re


20/47


17

ENVIRONMENTAL BENEFITS

Efficiency

More efficient use of resources is achievedthrough reductions in the size of the distributionsystem, reductions in overall capacity, and bettermatching of resource quality to the users needs.

Innovation and Upgrading

A distributed system using small scale, cluster-structure technologies, is a system that is wellsuited for trying out new technologies, and forintegrating technological advances in a rapid,incremental style. Consequently, all marginalinvestments in new infrastructure can beaccomplished using the latest (and now rapidlyimproving) green technologies. The net effectof such ongoing improvement is to upgrade the

average lifetime efficiency of the entire system.Restoration

Because Green infrastructure is responsive tolocal conditions, it can respect local carryingcapacity and adapt to the environmentallysensitive areas. For example, if a community islocated close to wetlands that are at risk, thenthe new housing developments can employbiofiltration technologies, daylight the streamsand re-create natural systems that protect thesensitive area from run-off. Such land use and

wastewater management techniques canactually contribute to restoring and enhancingthe wetland by regulating and augmenting waterflows.

Synergy

By converting wastes into raw resources withinthe city, Green infrastructure creates newopportunities for commercial and industrialactivity close to where people work and live.These short loops contribute to the emergenceof municipal and industrial ecologies. Land usecan be explicitly organized around maximizingthe potential synergy from converting wastes intoprofitable resources and commodities. Forexample, water flows through a city can becascaded from energy generation to residential,industrial and finally agricultural sectors, oncethe municipality co-ordinates the land use andindustrial strategy for this purpose.

BenefitsofG

reenIn frastructu

re

Biodiversity and Productivity

By responding to environmental constraints,and incorporating living elements andecological systems as elements ofinfrastructure, the biodiversity and productivityof the local area is increased andstrengthened.


21/47


18

4. Best Practices forGreen Infrastructure

STORMWATER SYSTEMS

A Green Perspective

Historically it made sense to pipe stormwateraway from urban areas, and dump it straight intothe receiving waters. Pipes were neededregardless (for sewage) and these sunk costsmade alternative stormwater systems appearcostly. This situation has now changed. Pipedstormwater needs to be treated in order toprotect the quality of receiving waters, and thistreatment adds significantly to operating costs.Moreover, the capacity requirements of thetreatment plant and pipes need to be much larger

to cope with the peak storm flows - or the resultis overflows and pollution. As cities age, thestormwater pipes are becoming costly anddifficult to maintain and replace. Finally, thequantity of stormwater flow is increasing asurban areas become dense, mixed-usecommunities with a higher percentage ofimpervious area.

For all these reasons the traditional curb, gutterand storm drain systems are contributing to

higher cost sewage treatment systems, systemfailures, and increasing run-off intowatercourses. The increased run-off watercauses deterioration in water quality, bankerosion, increased flooding, low summer baseflows and degradation of fish habitat and riparianecosystems.

The best way to avoid these negative impactsis to eliminate most of the stormwater pipes, andinstead slow down and store the run-off, thenrelease it slowly, in order to more closely mimic

natural conditions. Essentially, the builtenvironment of a city has to function like a forestin the rain. Three approaches can be adopted,in the following order:

1. increase tree and vegetative cover to increasecapture of rain above ground, and to increaseevaporation,

BestP

racticesforGreenInfrastruc

ture

3. store stormwater in shaded detentionstorage areas for later release.

Storage of stormwater is the last optionbecause it can lead to disruptions in streamflows and concentrations of polluted sludgeovertime.

Regardless of which approaches are used, thebest strategy is always to start at the source -the impervious building and site. Rainfallcapture on private building parcels should bemaximized, and then supplemented andbalanced as necessary by means of improved

street design, and storage ponds or wetlandsdownstream.

The natural open features of a Greenstormwater system are significantly less costlythan the conventional curbs, gutters and pipes,with a 30% average savings in capital costs.Maintenance costs may be slightly higher,although it is sometimes possible to allocatethese costs to the budget for parks andrecreation, since an open system providesmore diverse and attractive landscaping, withimproved microclimate, habitat and foodproduction.

2. absorb rainfall back into the ground whereit is filtered and returned slowly to thereceiving waters, by interflow in the soils,and


22/47


19

Integration of StormWaterSystems at the Scale of Buildingand Site

Green roofsand directing roof run-off: Inhigh-density urban areas, much of the building

site will be dedicated to roof areas. Thereforepart of on-site stormwater infrastructure includes:

Vegetative cover to capture and slowly releaserainwater. A typical green roof can hold 25mmof rainfall, the equivalent of a one- or two- daysmall storm event. A portion of this rainfall isretained by the roof and used by the plants orre-released into the air. The remainder isdrained more slowly from the roof, thusmitigating the negative impacts of run-off.

Directing roof run-off to cisterns allows it to becollected and stored. Depending upon thenatural environmental conditions at the site, thisstored water could either be released slowly tothe stream, or re-used as non-potable water in

BestP


ture

the building for toilet flushing and laundrypurposes. There is also a role for gardenirrigation.

Directing roof run-off to landscaped areas,drywells and infiltration basins allows water toseep into the ground. The landscaped areas

should use berms, curbs and depressions todirect and retain flows and allow time forinfiltration. Drywells, or French drains, areparticularly valuable for small sites, since theycan supplement limited infiltration areas.

Manufactured sediment traps are availablethat intercept run-off from drainage areas, andslowly release it while trapping sediments.

Best practices for site development can bedescribed in guidelines, and used to ensure

that land clearing, excavation and construc-tion activities are not allowed to generate run-off, erosion and silting problems in surface wa-ters.


23/47


20

BestP


ture

Integration of StormwaterSystems at the NeighbourhoodScale

Grass swales and vegetated strips areshallow depressions with vegetative cover

designed to accept run-off. They can be usedto transport run-off on the surface to detentionareas or catch basins. They also allow forpercolation, nutrient uptake and the reductionof the transportation of suspended solids.Swales along roadways can very effectivelyintercept and store run-off water, especially ifthe swale is constructed using deep soils, withhigh organic content (25%).

Dry detention ponds temporarily detain run-off for up to 24 hours, using a fixed outlet toregulate outflow at a specified rate. This allowssolids and pollutants to settle out.

Constructed wetlands: Wetlandsconstructed specifically for the purpose oftreating run-off and wastewater are known asconstructed wetlands. These permanentpools temporarily impound run-off, then settleand retain suspended solids and associated

pollutants.

Matching area and type of pond surfacesto their use: Use impervious pavement(concrete & asphalt) only where regular car,bus or truck traffic is expected. Use porousasphalt, paver blocks or large aggregateconcrete for parking and highly used bicycleand pedestrian areas. Use lattice blocks foroverflow parking, and crushed stone or brickfor pedestrian paths.


24/47


21

B

tP

ti

f

G

I

f

t

t

Integration of StormwaterSystems with other forms ofInfrastructure

Elements of Green stormwater infrastructure canbe integrated into systems for transportation,food production, sewage treatment, and organic

solid waste management. For example:

Use of deep landscape soils throughout thecity not only increases infiltration on-site, butalso increases plant growth, andsubstantially reduces irrigation requirements.These soils can also be used on rooftops,where they act as a temperature buffer, orin community gardens and private gardenswhere they are ideal for vegetables.

The organic matter additive to the above

soils can come from composting operations

Infiltration systems can be integrated withwalking/cycling routes and public squares,by using pervious paving materials andplantings.

Surface run-off and treatment systems cansometimes be combined with bio-remediation and constructed wetlands forsewage treatment, for enhanced waterflows and wetland performance.

that divert organic waste from the solidwaste stream, or from composted sewagesludge. On-site composting by occupantscan also provide an on-going supply of top-dress.

Storage of roof rainwater in cisterns notonly reduces stormwater impacts, but also

provides water for limited irrigation (dripsystems), flush toilets or laundry purposes- with corresponding reductions in potablewater supply from municipal systems.


25/47


22

Amble Greene, District of Surrey, BC:Amble Greene, District of Surrey, BC:Amble Greene, District of Surrey, BC:Amble Greene, District of Surrey, BC:Amble Greene, District of Surrey, BC:Case Study of On-site StormwaterCase Study of On-site StormwaterCase Study of On-site StormwaterCase Study of On-site StormwaterCase Study of On-site StormwaterManagementManagementManagementManagementManagement

To address these stormwater-related issues, somemunicipalities in British Columbias Fraser Valley began

using innovative stormwater infiltration systems. Designedin 1979, Ambleside Greene was the largest of thesedevelopments. The infiltration system in Amble Greene (adevelopment within the larger Ambleside site) is made upof a combination of grass swales and French drains. One

small section ofAmble Greene is connected to a traditional storm drainsystem; most of the site is not. The infiltration system isdesigned to allow continuous and ubiquitous infiltration ofstormwater. For enhanced infiltration, the project design callsfor a simple street section without a conventional curbedroad system. The installed system was substantially lessexpensive than the conventional alternative at that time. In

current dollars, the system costs translate into approximately$150 per linear meter of the stormwater system; with a totalstormwater system cost for the 153 units of $140,100.

Moreover, such systems dont simply managethe wastewater, but instead transform theresource into reclaimed water, soils, nutrients,CO

2and biodiversity. By incorporating natural

systems at a local scale, it becomes possible tore-integrate these resource flows into the urbanecology contributing to local industrialprocesses, while minimizing distribution costsand land use.

Integration at Building and Site

Flow reduction at source: Green wastewaterinfrastructure begins with measures to reducethe flow of wastewater leaving the building.Stormwater is directed into open drainage

systems. Water use indoors is minimizedthrough use of water-conserving fixtures.

On-site composting: At one extreme it ispossible to cope with all the sewage at thebuilding site, using waterless compostingtoilets. An aerobic composting system iscontinually ventilated and reduces the volumeof waste by 90%. The end product is a humus-like soil amendment product that is rich innitrogen and other useful elements.

Returning nutrient-rich humus to the earthrestores depleted soil conditions. Fluid wasteis treated in small reed patches next to building.Substantial amounts of water are savedrelative to conventional flush toilets.

LIQUID WASTE

A Green Perspective

A number of companies and communities inCanada have been adopting integrated,ecological approaches to wastewater treatmentand water reclamation.

The growing acceptability of using naturalsystems for treatment has set the stage forbroader application. Green wastewaterinfrastructure can offer superior service byremoving not only pathogens, but also VOCs,hydrocarbons, nutrients, herbicides andpesticides.

BestP


ture


26/47


23

BestP

racticesforGreenI

nfrastruc

ture

On-site primary treatment: It is sometimes anadvantage to a install primary sewage treatmentsystem only at the building scale. For example,multi-unit residential buildings in urban areas canbe equipped with watertight, concrete septictanks next to their foundation. These tanks thenbecome the primary treatment stage for all

wastewater. The advantage of locating theprimary treatment system next to the building isthat it becomes possible to provide very low cost,flexible and advanced secondary treatment atthe neighbourhood scale. Basically, asubmersible pump is used to decant the fluid ineach septic tank, and then economicallytransport the fluid through small-diameter PVCpipes over short or long distances to aneighbourhood scale digester.

Integration at NeighbourhoodScale

Constructed wetlands: Wetlands constructedspecifically for the purpose of treating run-off andwastewater are known as constructedwetlands. These permanent pools temporarilyimpound run-off, and settle and retainsuspended solids and associated pollutants.Two approaches are possible: surface flowwetlands that are suitable for buildings or largeclusters, and subsurface flow wetlands suitable

for smaller volumes (using 1/4 the land area but

at 4 times the cost). When properly designedand operated, surface flow wetland systemsare similar to tertiary treatment - theyeffectively reduce biochemical oxygendemand, suspended solids, nitrogen, metals,trace organics and pathogens in wastewaterto levels that meet environmental standards.

Advanced secondary treatment usingaggregate or membrane filtration: Thesesystems can be dedicated to serve large multi-unit residential buildings, or clusters, or evensmall towns. Essentially a piped systemtransfers effluent from septic tanks to a centrallocation. A recirculation pump repeatedlysprays the effluent over a subterranean gravelor membrane filter, which drains back to thetank. After 2 or 3 days of periodic spraying,the aerobic digestion is complete, and the

effluent is colourless and odourless (althoughstill high in nitrogen). This treated effluent issuitable for use in augmenting and flushingponds and rivers, and for use in irrigation, innon-potable water systems, and in industrialprocesses. The filter bed can occupy a smallarea between the cluster of buildings, where itcan serve as a multi-purpose outdoorcourtyard for passive recreation activities.

Solar aquatic sewage treatment systems:

Solar aquatics is an ecologically-engineeredsewage treatment technology that replicatesthe natural purifying processes of fresh waterstreams, meadows and wetlands. In a solaraquatic system, the wastewater flows througha series of clear-sided tanks located in

greenhouses, and then throughengineered streams andconstructed marshes wherecontaminants are metabolized orbound up. Bacteria, algae,plants and aquatic animals are

all part of the treatment system.Solar Aquatics technology canbe used to treat sewage flowsfrom 20,000-500,000 gallons perday. The treatment has beenapplied to sewage, septage,boat waste and ice creamprocessing waste.


27/47


24

Reclaimed water: Tertiary treated sewage canbe classified and sold as reclaimed water whentaken through a number of additional andprudent steps (UV disinfection, carbon andmembrane filtration). Alternatively the reclaimedwater can be used for irrigation of golf courses,

parks and grounds, or for toilet flushing,construction uses such as aggregate washing,concrete manufacture, and wetland and streamaugmentation. Permaculture landscaping canhelp to convert water reclamation facilities intoproductive and diverse gardening systems,converting the nutrients into useful biomass andbiodiversity.BestP


ture

Methane capture: The decomposition ofmunicipal organic wastes and sewage mayproduce methane, which can be piped tobuildings or to a cogeneration plant forelectrical generation and heat. Some sewagetreatment plants are powered and heated bymethane from this source.

Integration of Liquid WasteSystems with Other Forms ofInfrastructure

Heat from sewage: In a decentralized waterreclamation system, energy can be extracted

from discharged water by means of efficientwater-to-water heat pumps. The captured heatcan then be used to heat water for spaceconditioning of greenhouses and other buildings.

Bioponics: An integration of aquaculture andhydroponics is defined as a bioponicssystem. Usually housed in a greenhouse,these systems can be integrated withgreenhouse based water reclamation systems.

Humus: Sludge is collected from sewagetreatment plants and used as an organicadditive to support the stormwater filtrationsystems and other types of urban landscaping,agriculture production and land restoration.


28/47


25

BestP

racticesf

orGreenInfrastruc

tureErrington, BC: Case Study of a MunicipalErrington, BC: Case Study of a MunicipalErrington, BC: Case Study of a MunicipalErrington, BC: Case Study of a MunicipalErrington, BC: Case Study of a Municipal

Solar Aquatic Wastewater TreatmentSolar Aquatic Wastewater TreatmentSolar Aquatic Wastewater TreatmentSolar Aquatic Wastewater TreatmentSolar Aquatic Wastewater TreatmentFacilityFacilityFacilityFacilityFacility

Errington is a remote mobile home communitythat suffered from a failure in their sewagetreatment system when excessive infiltrationoverloaded the disposal fields. Their solutionwas to replace the fields with an above-groundgreenhouse. The new Solar Aquatic Systemwas designed to utilize the existing networkof septic tanks and pump stations. The homeswere fitted with low flush toilet devices, low

POTABLE WATER SYSTEMS

A Green Perspective:

Green infrastructure for potable water beginswith matching the quality of water to the enduse, and then cascading the wastewater flowsthrough a series of lower quality uses. Highquality potable water is best used only for top-grade drinking water, and by the food and

beverage industries. Other functions, such astoilet flushing, landscape irrigation, clotheswashing, and so on, can be fulfilled using non-potable water such as greywater.

After matching quality with needs, designersand planners should optimize investmentsbetween increased water supply on one hand,and more water-efficient technologies on theother. Investments may be low flow fixtures,water efficient appliances, and droughtresistant gardening. High returns are possiblefrom investments.

Load management is a third strategy, and mayinclude on-site storage of water in cisterns, aswell as behavioural modification throughmetering, rate structures, water bans and soon.

flow showerheads, and sink aerators.Stormwater flows by gravity into a septic tankfrom where it is pumped into a blending tank.From there it is processed through a seriesof solar tanks located in a 210 m2greenhouse.

The tanks contain pond plants, such as waterhyacinths. The greenhouse also supportsintegrated bioponics - producing compostfertilizers, garden bedding plants, fish andsnails, and hydroponic herbs and flowers.

The system was built for $200,000 and serves46 homes. The annual operating/maintenance cost is $10,000.


29/47


26

Ottawa, ON: Case Study of Water Capture On-site, Mountain Equipment Co-opOttawa, ON: Case Study of Water Capture On-site, Mountain Equipment Co-opOttawa, ON: Case Study of Water Capture On-site, Mountain Equipment Co-opOttawa, ON: Case Study of Water Capture On-site, Mountain Equipment Co-opOttawa, ON: Case Study of Water Capture On-site, Mountain Equipment Co-op

Integration of Building and SiteCisterns can be used at the building site to storewater captured from roofs, and to provideoccupants with a source of water for toiletflushing, irrigation and - with filtration - drinkingand washing.

Grey water systems within buildings help tocascade water flows from bathtubs, showers,bathroom washbasins, and water from clotheswashing machines, laundry tubs into toilet

flushing and garden irrigation.

Two-pipe systems provide buildings with themeans for using reclaimed water. The reclaimedwater may be generated at the neighbourhoodscale from wastewater, and looped back intobuildings in a separate piping system for all non-potable uses. An increasing number of citiesare adopting two-pipe systems for all new com-mercial buildings (e.g. in San Diego and HongKong).

Integration at the NeighbourhoodScale

Water reclamation: Reclaimed water iswastewater that has been treated to meet orexceed drinking water standards before beingreintroduced into the raw water supply.

Integration with Other Typesof Infrastructure

Cooling: Potable water can be used as acoolant to provide supplementary airconditioning for buildings.

Heating: Potable water can also be used asa source of heat, if heat pumps are submersedin the wells, reservoirs or storage tanks.

Electricity: Water reservoirs with flow control

dams can be equipped with micro-hydrogenerators for on-site electricity. Windmills canalso be integrated with the water system toassist with pumping water from the ground andoverland. The windmills provide electricitygeneration during times when pumping is notrequired. Water infrastructure at the regionallevel may require substantial amounts ofpumping power and can represent the largestsingle energy account in a region.

BestP


ture The Mountain Equipment Co-op building in

Ottawa has a pre-cast, concrete rain storagecistern that stands adjacent to the building. Ithas a storage capacity of 65,000 litres. Its

dimensions are 2.4 m (8 ft) in diameter and 6.0m (20 ft) high. The storage device receivesstormwater from the buildings rooftop. Therainfall-capture potential for a 635 M2 roof inOttawa is approximately 550,000 litres per year.Water from the cistern is used to irrigatelandscaped areas in summer months. Anoverflow mechanism diverts stormwater tomunicipal pipes when the cistern has reachedits storage capacity.


30/47


27

BestP


ture

ENERGY SYSTEMS

A Green Perspective

Green energy infrastructure refers primarily tosystems that rely on low-impact renewableresources. These resources can vary dependingupon the location, and include wind, sunshine,geothermal, run-of-river hydro, tidal and wavepower, wood waste, landfill gas and biogas,agricultural, forestry and animal wastes, and lakeand ocean cooling. Generally, the use of suchrenewable resources can greatly benefit fromthe existing energy grids. The grid absorbs peakdemands, and acts as a storage system whenrenewable sources are surplus.

Green energy infrastructure should be anintegrated and planned system that connects all

activities within the city. Municipalities innorthern Europe have demonstrated theadvantages of integrating energy into urbanplans, rather than focusing on energyconservation and efficiency in isolation. Aplanned system helps to ensure a mix of energysupply, and a more effective matching of energyquality to end-use. Buildings and industriesbecome both suppliers and consumers of heatand power. Energy flows are engineered tocascade from the highest quality to lowest qualityuses. Distribution losses and transformation

losses are minimized by means of on-sitegeneration. The urban form and buildingplacements are carefully designed to optimizeuse of on-site forces like sunshine, breezes,hydro and heat generating activities. And finally,energy resources are extracted fromwastewater, solid waste, and all other resourceflows within the city.

As the energy marketplace is deregulated andbecomes diverse, all cites will face new choices

about their energy partners, their mix of energysources, and how their energy commodities areconverted, stored and transferred. Such choicescan radically alter the energy efficiency of theentire city. For example, the City of Torontoconverts raw energy resources like coal anduranium into usable energy at an estimatedefficiency of 50%, while the City of Helsinki,which uses waste heat from energy generation

1The Potential for District Energy in Metro Toronto, Metro

Toronto Works Dept., CANMET NRCan, Ontario Hydro, 1995

Building and Site

Solar space heating: Many surfaces onbuildings can serve to harness solar energy.Passive solar heating already representsabout 15% of the energy supply to houses.With appropriate planning and design, this canbe economically increased to 20 to 25%.Innovative capture and storage systems caninclude seasonal shading devices, solarorientation, thermal storage using building

materials, and double envelope construction.

Solar hot water heating at the building levelhas the potential for supplying over 50% oftotal needs.

Solar-powered parking lot lighting can re-place conventional systems, with on-sitebatteries used to store PV energy for night-time lighting.

Heat pumps and free cooling systems canbe incorporated into larger buildings or clustersof buildings. These systems are especiallyeconomical when used to extract heat orcooling from nearby water bodies.

to heat 91% of the housing, achieves anefficiency of 68%.1 In future, the involvementof cities in energy systems planning willbecome an important strategy for enhancingthe competitiveness and resiliency of the localeconomy, and for achieving social goals foraffordable housing and a cleaner airshed.


31/47


28

Shoal Point is a residential multi-familydevelopment in Victoria, BC. It is a thirteen-storey complex that provides two floors ofcommercial use below 156 waterfront

condominiums. One of the many innovativeenergy-efficient features is the use of groundsource heat to warm and cool the building. Ageothermal heat pump in the building will drawocean water from the nearby Inner Harbour. Itwill extract and transfer the heat to a circulatingliquid that runs through a closed-loop internalsystem, throughout the building. Suites thathave an individual heat pump will extract andcirculate the heat into their suite. During hotweather, the procedure is reversed - the pumps

draw heat from indoors, dissipating it into theocean water as well as providing cool air forsuites. The system is designed to be an open-loop system, returning the ocean water back to

Shoal Point, Victoria, BC: Case Study of Renewable Energy Supply On-site,Shoal Point, Victoria, BC: Case Study of Renewable Energy Supply On-site,Shoal Point, Victoria, BC: Case Study of Renewable Energy Supply On-site,Shoal Point, Victoria, BC: Case Study of Renewable Energy Supply On-site,Shoal Point, Victoria, BC: Case Study of Renewable Energy Supply On-site,

Photovoltaic panels on roofs and awnings arebeing used in many residential areas to generateelectricity, much of which is fed back into thegrid. The grid allows this energy source to be

utilized continuously: for example, office roofssupplement power to households onweekends, residential roofs supplement power

to the offices weekdays.

BestP


ture

the Inner Harbour after circulation. The

technology has a coefficient of performanceof 3.0 to 6.0, versus conventional electric orfossil fuel burning technologies that are 0.6 to0.8.


32/47


29

Integration at theNeighbourhood Scale

Co-generation at local scale can involve micro-generators sized to match the base heating loadfor the development. In this way all the waste

heat from electricity generation can be usedlocally, greatly increasing the overall efficiency.Supplemental electricity and heating needs canthen be met by grid sharing, or by a combinationof other on-site technologies.

District heating can involve using a singleboiler complex to supply heat for space andwater heating throughout the neighbourhood.Loops of small-diameter, well-insulated hotwater pipes efficiently transfer the heat tobuildings as far away as seven kilometres. The

boiler complex can be located in a largercommercial centre (hospital, mall) or industrythat requires a large, well-managed systemregardless. The energy resource mix andemission controls for the entire neighbourhoodcan be adjusted at a single location. Eachbuilding benefits from reductions in floor spacerequirements, higher quality service, and theother benefits of Green infrastructure.

Renewable resources are collected from theregional inventory, and distributed to the buildingclusters as part of the energy supply system.Local sources may include:

methane from landfill and composters;

micro-hydro;

wind turbines.

Long term storage facilities can be providedat the neighbourhood scale. For example, alarge underground reservoir can be heated fromsolar water heaters mounted on a cluster ofbuildings. In this way, the heat from summer

sunshine is stored for use throughout the winterand contributes from 50 % to 70 % of the overallheating demand in the cluster. The storagevolume can be incrementally increased to matchthe growth of housing, using earth ducts withhigh mass.

Heat transfer between hot & cold spacescan reduce the total energy requirement.Large buildings may need cooling year roundand the heat can be concentrated and pipedto smaller buildings that need heating.Ventilation of larger parking garages is anothersource of heat for nearby buildings.

Integration of EnergyInfrastructure with Other Typesof Infrastructure

Incineration of solid wastes is sometimes asource of energy supply, if no economic op-tions exist for the recycling of some plasticsand organics.

Methane is a renewable energy source derived

from liquid waste digesters and landfills.

Heat pumps can draw useful heat from sew-age flows and water reservoirs.

Photovoltaic arrays can be mounted alongthe south-facing walls of highway barriers, andother accessible, low-impact locations.

Mini-turbine generators can be mounted inwater supply and stormwater systems, and atoutlets of large water reservoirs.

BestP


ture


33/47


30

SOLID WASTE SYSTEMS

A Green Perspective

Green infrastructure systems for solid wastemanagement are actually systems for managingmaterial resources, and eliminate wastealtogether. A Green material managementsystem requires coordination among all theplayers involved in the supply chain, in order toensure that materials are designed, packaged,transported, and assembled in a manner thatminimizes material use and that facilitates re-use and recycling. The use of toxic products isminimized throughout the construction process,as are superfluous materials for decorativefinishing.

To facilitate green procurement policies,

manufacturers may choose to become serviceproviders. In this role they are contracted toprovide a service instead of a product. Thusany materials and goods remain the property ofthe manufacturers and are directly repossessedat the end of their useful life.

Elimination of waste means that urban landdevelopment must be consciously planned topreserve existing vegetation, compost materials,or landscape debris. Roads and sites shouldbe layed out in ways that help to equalize the

cut and fill, thereby reduce haulage and disposal.

Organic materials from homes and restaurantsmust be kept within the neighbourhood (insteadof being trucked large distances to landfills) andused to enrich the landscape and to enhancethe performance of other infrastructure systems.The nodes for collecting, separating, storing andre-using waste materials need to be carefullyintegrated into the neighbourhood land use soas to ensure accessibility and social

acceptability.

Integration of Building and Site

Compost production: Biosolids, biomass andoffsite community based organic materials canbe composted onsite with combinations of in-vessel composters and vermiculture

BestP


ture

Integration at NeighbourhoodScale

Re-use it and recycling depots: A key nodefor Green material management is thewalkable re-use it and recycling depot. Suchfacilities can be integrated with schools, localindustrial centres or parks. Depending uponlocation, scale and local economy, they canhandle a wide variety of items from bottlereturns to used building parts. They can also

function as a place to meet your neighbour anda source of local employment.

Composting:

In-vessel composters are large containersthat process organic wastes over a two-weekperiod. A hopper at one end is used to load

Separation and storage facilities: Wastemanagement at homes, offices and shops canbe greatly improved if design guidelines

stipulate adequate space for separation andstorage, at convenient locations on-site.

Construction waste management plans: Alarge percentage of the waste stream iscomprised of land clearing, construction anddemolition materials. The only effectivesolution to managing this system is for eachurban development project to adopt aconstruction waste management plan, asdefined in current publications by CMHC andothers.

composters. Heat and CO2

generated fromsuch activity can be added to greenhouses forincreased productivity.


34/47


31

BestPr

acticesforGreenIn

frastructure

Halifax, NS: Case Study of Waste Diversion and CompostingHalifax, NS: Case Study of Waste Diversion and CompostingHalifax, NS: Case Study of Waste Diversion and CompostingHalifax, NS: Case Study of Waste Diversion and CompostingHalifax, NS: Case Study of Waste Diversion and Composting

the vessel. An auger automatically mixes andturns the waste materials. A fan is used toensure adequate supplies of oxygen. Additionalmaterials may be added to the vessel to ensurethat the mix of organics is suitable for efficientcomposting. The end product emerging fromthe opposite end of the vessel is humus that can

be used in manufacturing soils, and in restoringdamaged landscapes.

Vermiculture systems use worms to rapidlydigest and sanitize organic wastes, includingkitchen waste and shredded cardboard. The endresult is more worms, and a high quality organicfertilizer.

Enzyme-based composting systems areproprietary machines that process organicwastes over several days using enzymes thataccelerate the decomposition process.

Windrows of organic waste typically requirea few acres of land. Raw organic materials

such as yard trimmings are laid out in rowsand turned periodical ly. After they aredegraded by microbial activity, the end productis relatively stable, reduced in quantity, andfree of offensive odours. The humus-likematerial can be recycled as a soil amendmentand fertilizer substitute.

What started as organized opposition to a failed landfill and aproposed incinerator resulted in one of the most innovativesolid waste management systems in North America. The HRMhas a population base of 350,000, with annual wastegeneration of 260,000 metric tons. In the early 1990s, afteryears of usage, the wetland area landfill servicing the region,was discovered to have had caused severe environmentaldamage that affected nearby residents. Ultimately, the HRMcompensated the community, approximately $5 million, andbought out the adjacent homes. The situation prompted areview process to determine a new waste managementstrategy for the region.

The end result of this process was the Halifax Regional Municipalitys (HRM) advanced municipal solid waste

(MSW) management system. This system has significantly reduced the amount of waste that goes to landfill,and as a result, contributed to a decrease of approximately 0.5 megatonnes of carbon dioxide equivalent (MtCO2E) GHG emissions per year, or about 1.4 tonnes per resident compared to 1995, from the municipalityslandfill site. The system has also helped achieve a 61.5% reduction in the amount of waste per person sent tolandfill between 1989 and fiscal year 1999/2000.

The new system was implemented without a property tax increase. Capital costs, which totalled $70.1 million,were financed through a mixture of public and private capital, along with design/build/operate contracts betweenthe private sector and the municipality. While operating costs for the new systems have been more expensivethan the old system, $32.5 million per year compared to $23.4 million in 1996, both public and governmentalbodies are satisfied with the new system, and consider the additional costs incurred justifiable. It should alsobe noted that a significant portion of the operating costs (approximately 33%) is recovered through tipping fees,and that 125 jobs were created through public private partnerships.

The HRM solid waste management system includes an innovative combination of new policies and facilities: Residents are asked to separate waste into recyclables, compostables, and hazardous materials; Collection zones are rationalized into eight (from 25 before amalgamation); A combined mixed waste processing facility, a 13-bed composting system and landfill; Two privately-owned composting facilities handling 61,000 metric tonnes per year; An expanded materials recovery facility.

The landfill handles stabilized materials only and is virtually methane-free, has no odour problem, and no on-site leachate collection system.


35/47


32

Aerobic digesters use thermophilic (heatresponsive) microbes to process organic wasteover a 72-hour period with zero harmfulenvironmental discharge. The digested waste isconverted into organic fertilizer products with highmarket value in both liquid and dry-pellet form.

Transfer and sorting stations: Neighbourhoodscan accommodate small transfer and sortingstations that can be used to further separate thewaste stream and compact the material beforeshipping to users of the resource. Local stationsincrease opportunities for workers to live nearby.It may also be possible for other small-scaleindustry to locate close to the station, and benefitfrom reduced transportation requirements.

Integration of Solid WasteInfrastructure with Other Types

of Infrastructure

Stormwater: Organic wastematerials can becomposted and incorporated as an absorptivesoil additive in an open stormwater managementsystem.

Energy: Local, renewable energy source caninclude the methane generated from compostingsolid wastes, and from incineration.

Water supply: Organic waste materials can alsobe top dressed on landscaped areas, and usedto minimize irrigation water supply requirements.

TRANSPORTATION AND

COMMUNICATION SYSTEMS

A Green Perspective

Green transportation infrastructure begins byredefining transportation as a service. Theobject is accessibility, not moving people.Hence, the Green infrastructure fortransportation may actually consist of land useplanning that locates jobs close to or insidehouses, and that ensures clusters of serviceslike shops, schools and parks are within

walkable distances from most residences. Thecluster structure is thus a key design element.Connections between clusters, at varyingscales, should provide resource-efficienttransport, including the provision of a safe,dependable and convenient transit system,high quality amenities for non-vehiculartransport (bicycles and walking) and theprovision of amenities for non-fuel poweredvehicles. Connections are also important,since communications technologies cansometimes provide access with less movement

of people, vehicles and materials.

Electricity generated from renewableresources is especially well suited for light railsystems and trolleys. Longer distancesbetween major nodes are best suited for masstransit. European cities have demonstratedthat it is possible to lure people out of theirsingle occupancy vehicles when dense mixed-use neighbourhoods are combined withextremely clean, convenient and affordable

transit. Ultimately, we are looking for a systemthat discourages use of private vehicles insidecities, and that converts the large road surfacesand fuel expenses into amenities that improvethe quality and scope of living within the cluster.

Solid waste management depots in theneighbourhood can also be used to reducerequirements for roads and to support lifestylesthat include neighbourhood shopping andwalking.

BestPr

acticesforGreenIn

frastructure


36/47


33

BestP

racticesforGreenI

nfrastruc

ture

Live-work spaces: Building designs caninclude swing spaces that can be easilyconverted into home offices with soundproofwalls, direct access to exterior, and suitablewiring, cable connections and lighting.

Comfortable and convenient access to

transit: Design details can make a bigdifference to the level of accessibility andcomfort provided to transit users. A clear lineof sight to transit stops is ideal, with paths thatavoid crossing traffic, and with weatherprotected shelters over doorways, transit stopsand high traffic pathways.

Charging facitilies for electric vehicles(EV):Access to charging stations may show marketpenetration of electric vehicles. The solution

is for each building to promote at least one EVparking stall for every 20 on-site stalls.

Integration of Building and Site

Complementary building occupancies:Locating several complementary occupancieswithin a project housing, services, retail,commercial and/or light industry ofteneliminates the need for many automobile trips,as occupants use lower-impact transportationmodes such as biking, walking and transit.Parking spaces in mixed-use buildings anddevelopments can often be shared betweenoccupancies with differing schedules, reducingthe area of impervious parking pavement,stormwater peak flows and pollution.

Pedestrian and bicycle amenities: The needfor automobiles is also reduced by makingstreets safer and more attractive to pedestrians,

by providing bicycle facilities at destinations andby creating safe, continuous bicycle paths.Building design can encourage these options byproviding secure bicycle parking, showers andchanging facilities. Building designs can improvethe comfort and safety of pedestrians withappropriately scaled and detailed facades andviews of the street for building occupants. Ifpedestrians are also provided with a choice ofsun or shade, they are more likely to use theseoutdoor spaces.


37/47


34

Integration at Block andNeighbourhood Scale

Network of pathways: The provision ofpedestrian and bicycle paths encourages walkingwithin the neighbourhood as an alternative todriving to other locations to satisfy basic needs.

Paths should connect residential areas toamenities as well as to neighbouringcommunities. A fine-grained network will includelocal connections within blocks that in turnconnect with a neighbourhood system as wellas the larger citywide network.

Integration of TransportationInfrastructure with Other Typesof Infrastructure

Transportation routes can serve as integrated

utilidors with pipes for heating, cooling, methane,hydrogen, communications and so on.

Transportation: Walk and cycle paths can alsofunction as filtration strips for stormwater.

Solid waste: Walkable communities can usecentral locations to provide residents with easyaccess to material recycling and re-use depots.

Stormwater: Urban run-off from paved surfacescan be reduced and treated on-site if the roadsurfaces are minimized and if the remaining non-vehicular pathways and open areas aredesigned to be permeable. Natural landscapingcan also be integrated into car parking areas,where it can help to treat run-off and replenishground water supplies.

Energy: Shading of parking areas and buildingsurfaces reduces the amount of solar radiationreaching them, which can in turn significantlylower energy demand for building cooling.

BestPr

acticesforGreenIn

frastructure


38/47


35

BestPr

acticesforGreenIn

frastructure

Portland, OR: Case Study of a Transit-oriented, Pedestrian-friendly Housing ProjectPortland, OR: Case Study of a Transit-oriented, Pedestrian-friendly Housing ProjectPortland, OR: Case Study of a Transit-oriented, Pedestrian-friendly Housing ProjectPortland, OR: Case Study of a Transit-oriented, Pedestrian-friendly Housing ProjectPortland, OR: Case Study of a Transit-oriented, Pedestrian-friendly Housing Project

The 3.7-acre infill mixed-use developmentincludes three housing projects and twocommercial/retail areas that collectively providea range of affordable rental housing prices and

sizes and the potential for convenient residentialservices. The development process was highlycollaborative, with the general contractor, majorsubcontractors, engineers and designers allinvolved in the design process from thebeginning. The development illustrated theimportance of establishing a dialogue with thevarious city agencies involved in theimplementation of projects.

Environmentally sound business practices were a major goal of the project. The developmentspecified materials with high recycled content for the insulation, sheet rock, carpet pads, and

finishing materials, participated in construction period recycling, applied low-VOC, non-toxicadhesives and paints for improved indoor air quality, installed energy star window (21% moreefficient than code requires), and utilized continuous ventilation systems. The landscaping ismaintained without the use of pesticides, and biodegradable cleaning products are used in thebuilding.

The developer chose the property to use existing publictransportation infrastructure and convenient, underusedlocation. The project is within walking distance of majorshopping and community centres, light rail buses,employment districts and recreational facilities. Situatedin a neighbourhood within Portlands central city, the

project is located nine blocks from light rail, within fiveblocks of four high-frequency bus lines, and surroundedby a growing network of bike lanes and routes. Lockingbike racks, lockers to store bike equipment, pumps, anda workstand for resident use are all provided on site.CarSharing Portland, Inc. located several vehicles at thecomplex, and with help from the City of Portland, head-in parking was added to narrow the street, slow trafficand create a pedestrian buffer.

Issues surrounding water conservation and stormwaterwere addressed with the installation of low-flow plumbingfixtures and close to 95% on-site stormwatermanagement (half of the site posses 100% on-sitemanagement, the other half experiences 80-90% on-site management). On-site stormwater retention andmitigating features include narrow driveways, severalbioswales, a 2,000 sq/ft extensive green roof, permeablesurfaces and a back-up dry well.


39/47


36

5. Common Obstacles toGreening yourInfrastructureUnderstanding the form and function of Greeninfrastructure is the first step. However,

integrated multi-functional infrastructure projectsare, by nature, a difficult sell. Many of thebenefits are indirect, the risks appear to besubstantial, and the number of stakeholders canbe overwhelming. The change managementstrategy must address many challengingobstacles.

FORMULAE THINKING

Engineers have been trained to use slice-and-

dice, component-based design methods that aresimple, clear and wrong because they optimizecomponents in isolation (thus pessimizing thesystems of which they are a part) and focus onsingle rather than multiple benefits.

FRAGMENTATION OFAUTHORITY

Historically, the development of each type ofinfrastructure occurred at different times, largely

in isolation. This has left us with agencies,industries, and monopolies organized aroundspecialized mandates and with compart-mentalized worldviews.

FRAGMENTATION OFECOLOGIES

It is especially hard to respond to local carryingcapacity and constraints if other decision-makerserode the benefits. For example, reducing

pollution in your valley or river can be pointlessif another jurisdiction, upstream, then choosesto pollute at much higher levels. For example,the British Columbia lower mainland has beenimproving air quality for the last 10 years, butthis is now threatened by a proposed power plantto be located just across the US border.

SUNK INVESTMENTS

The very substantial capital outlays that havebeen dedicated to existing infrastructure caneliminate the potential for cost savings fr

Documents

Federation of Cdn. Municipalities Guide to Green Infrastructure for Cdn Municipalities