Donald Carpenter, Ph.D. HSW Engineering, Inc

For more information and to register visit: www.greenroofs.org

Donald Carpenter, Ph.D.HSW Engineering, Inc.

& Lawrence Tech University will be presenting“The Lawrence Technological University Green Roof Performance Evaluation Project”

at the Hillsborough County Green Roof Symposium on Wednesday, June 18, 2008a one-day workshop co-sponsored by

Green Roofs for Healthy Cities, Hillsborough County, and SWFWMDThe workshop will be held at the University of South Florida, Tampa, in the Marshall Center

This symposium is being held in Florida for the first time! Don and HSW are proud to be part of it!

HSW Engineering, Inc.Don Carpenter, Ph.D.

[email protected]

URL: www.hsweng.com

http://www.greenroofs.org/

mailto:[email protected]

Southfield

Rouge River Watershed

Lawrence Technological UniversityLawrence Technological UniversityTheory and PracticeTheory and Practice

Southfield

Southfield

Campus MapCampus Map

• Southfield, Michigan • Founded in 1932• 120-acre campus• 4,300 students• Colleges of :

• Architecture and • Design, • Arts and Sciences,• Engineering, and• Management

Southfield

Rouge River Watershed

Lawrence Technological University

City of Southfield

Main CampusMain CampusB

G

E

B

B

DB

F

C

AB

Implemented Projects

Proposed Projects

A: Green roof

B: Bioretention

C: Bioswale

D: Porous Pavers

E: StormwaterTreatment Wetland

F: Naturalized Detention

G: Riparian Buffer

H: Cistern

H

Green RoofGreen RoofDefinitionDefinition

A green roof consists of vegetation and A green roof consists of vegetation and soil, planted over a waterproofing soil, planted over a waterproofing membrane. They can be either membrane. They can be either extensive or intensive.extensive or intensive.

LTU ProjectLTU Project10,000 sq ft extensive green roof 10,000 sq ft extensive green roof designed by designed by HydrotechHydrotech..Research project to determine the long Research project to determine the long term effectiveness with regards to term effectiveness with regards to water quality and quantity (USEPA and water quality and quantity (USEPA and LTU COE).LTU COE).

Maintenance = Medium (2 years) / LowMaintenance = Medium (2 years) / Low

Effectiveness = HighEffectiveness = High

Green RoofGreen Roof

Extensive Green RoofHydrotech 6125 – Garden Roof AssemblySaturated Weight = 15.1 lbs/ft2

LTU GREEN ROOFLTU GREEN ROOF

Green Roof in Lawrence Technological University is constructGreen Roof in Lawrence Technological University is constructed on the roof of ed on the roof of A. Alfred Taubman Student Services Center.A. Alfred Taubman Student Services Center.

Green Roof Research in LTUGreen Roof Research in LTU

Research GoalsResearch Goals

The goals of this research project are as follows:The goals of this research project are as follows:

Determine the overall percent of precipitation retained and detaDetermine the overall percent of precipitation retained and detained by ined by

the green roof (water quantity).the green roof (water quantity).

Determine the a nutrient loading attenuation capabilities of theDetermine the a nutrient loading attenuation capabilities of the green roof green roof

(water quality).(water quality).

Determine the reduction in ambient temperature associated with tDetermine the reduction in ambient temperature associated with the he

green roof (air quality).green roof (air quality).

Determine the reduction in storm water temperature associated wiDetermine the reduction in storm water temperature associated with the th the

green roof.green roof.

Establish longEstablish long--term monitoring station capable of determining the term monitoring station capable of determining the

temporal performance of the green roof.temporal performance of the green roof.

Green Roof CrossGreen Roof Cross--Section at LTUSection at LTU

Components of Green Roof at LTUComponents of Green Roof at LTU

Conventional stoneballastNine varieties of sedum

Embeddeddrip irrigation

1. 1. Teledyne Isco Avalanche Transportable Teledyne Isco Avalanche Transportable

Refrigerated SamplerRefrigerated Sampler::

It is furnished with a refrigerated sampler.It is furnished with a refrigerated sampler.

Used for permanent site or portable, Used for permanent site or portable,

sequential, and composite sampling sequential, and composite sampling

applications. applications.

It is capable of collecting samples from a It is capable of collecting samples from a

variety of liquid sources. variety of liquid sources.

Suited to collect priority pollutant or Suited to collect priority pollutant or

general purpose samples in multiple bottles general purpose samples in multiple bottles

or a single bottle. or a single bottle.

Sampling Equipments used at LTUSampling Equipments used at LTU


2. 2. ISCO 730 Bubbler flow moduleISCO 730 Bubbler flow module

Measures the pressure needed to force airMeasures the pressure needed to force air

bubbles out of the line, the water level is bubbles out of the line, the water level is

accurately determined. accurately determined.

The 6700 Series or Avalanche Sampler then The 6700 Series or Avalanche Sampler then

converts the level into flow rate.converts the level into flow rate.

A 6" PalmerA 6" Palmer--bowlusbowlus flume is used with pipe flume is used with pipe

stubs on both ends, sampler tube, bubble tube, stubs on both ends, sampler tube, bubble tube,

to cover gasket with wing nuts.to cover gasket with wing nuts.


3. 3. Isco 674 Rain GaugeIsco 674 Rain Gauge::

Connects directly to AvalancheConnects directly to Avalanche™™ SamplersSamplers

The Isco 674 Rain Gauge uses a tipping The Isco 674 Rain Gauge uses a tipping

bucket design for rainfall measurement. bucket design for rainfall measurement.

88--inch diameter orifice and factoryinch diameter orifice and factory--

calibrated to tip at either 0.01 inch or 0.1 calibrated to tip at either 0.01 inch or 0.1

mm of rainfall.mm of rainfall.

Flowlink 5 software is used for Data Flowlink 5 software is used for Data Retrieval & Analysis. Retrieval & Analysis.

The Beginning Stages of Green Roof Construction At The Beginning Stages of Green Roof Construction At LTULTU

09/06/2008 17

Types:

Intensive green roofs:

•may include larger plants•require deeper substrate layers (usually > 10cm)•require ‘intense’maintenance, and •accessible to the general public.

Extensive roofs:

•are limited normally to drought tolerant succulents such as Sedum•can be sustained in a shallow substrate layer (< 10 cm)•require minimal maintenance, and •generally not accessible.

09/06/2008 18

Extensive Green Roof Intensive Green Roof

09/06/2008

Extensive green roofs are mostly applied since :

•designed with minimal thick medium.•plants able to survive, regenerate and maintain in harsh weather condition over long periods of time.•do not normally require irrigation.•need minimal maintenance and are the least expensive category of green roofing.•need less structural support.

19

09/06/2008 20

reviewed documents are from several locations, they show that:

•the hydrologic response is diverse due to variation in the physical properties of the media and the layered structure of the systems. •performance is strongly dependent on climatic condition.

Contd:

09/06/2008 21

Green roof systems must be close analogues to the proposed application and that the climatic conditions must be similar to those under which the data was collected. It is therefore essential to study its performance in the region of application.

Purpose of study:

09/06/2008 22

Objectives of Study:

•Comprehensive review and analysis of available data on green roof application in North America

•Evaluate the performance of the green roof at Lawrence Tech University with respect to stormwater quantity and quality

contd.

09/06/2008 23

•Develop and calibrate a simple model of the green roof

•Conduct model simulation to its performance at LTU with respect to stormwater quantity and compare with experimental observations

09/06/2008 24

Experimental Set up:

An area of 3496 square feet from the entire green roof is monitored.it’s performance is compared with two other roofs,

•existing rock ballast roof and, •a conventional roof, acting as the control station.

09/06/2008 25

Monitoring Equipments:

ISCO Avalanche SamplersISCO 730 Bubbler FlowmeterISCO 674 rain gauge4" Palmer-Bowlus FlumesTemperature sensors

09/06/2008 26

Proposed Research Plan:

Review and analyze up to date research of application of extensive green roof in NA with focus on:

•Characteristics of green roof•Stormwater quantity•Stormwater quality•Locations

Contd.

09/06/2008 27

Analyze and compare data for the three roofs at LTU for stormwater quantity.

Analyze and compare data for the three roofs for stormwater quality with respect to:•Temperature•Selected PAHs•Heavy metals such as Copper and Zinc

09/06/2008

Greenroof’s action on stormwater:

•interception•absorption•evapo-transpiration•runoff

28

09/06/2008 29

Result on Stormwater management:

Quantity:

Retention ranged from 30 to 90 %.Detention varied from several minutes to several hours.

09/06/2008 30

Quality:

•not much study done.•no study at all for PAHs.•very few on heavy metals.•some are on nutrients.

09/06/2008 31

Common PAHs in roof runoff:

•Fluoranthene•Pyrene•Benzo[b] Fluoranthene•Benzo[k] Fluoranthene•Benzo[a] pyrene•Naphthalene •Benzo[a]anthracene

Source: Preliminary examination of the nature of urban roof runoff in New Zealand, August 2001.

09/06/2008 32

Model Development:

•Based on the rainfall and runoff data, a simple model defining the Retention Capacity of this particular LTU green roof is developed.

•The calculation is done over a period of time consisting a number of rainfall events and different moisture condition of the media.

Are much lighter in weight with soil depths ranging from 3" to 7Are much lighter in weight with soil depths ranging from 3" to 7". ".

They are typically planted with very hardy species such as sedumThey are typically planted with very hardy species such as sedums, tolerate s, tolerate extreme temperature and moisture conditions.extreme temperature and moisture conditions.

http://www.commons.bcit/images.com` http://www.igra.world.com/

http://www.igra.world.com/

Extensive Green RoofsExtensive Green Roofs

Comparing the Two RoofsComparing the Two RoofsCharacteristics Intensive Green Roof Extensive Green Roof

Soil Requires minimum of one foot of soil depth

Requires only 1 to 5 inches of soil depth

Vegetation Accommodates large trees, shrubs, and well-maintained gardens

Capable of including many kinds of vegetative ground cover and grasses

Load Adds 80-150 pounds per square foot of load

Adds only 12-50 pounds per square foot

Access Regular access accommodated & encouraged

Usually not designed for public accessibility

Maintenance Significant maintenance required

Annual maintenance walks are performed

Drainage Includes complex drainage systems

Simple drainage system

Storm Water ManagementStorm Water ManagementThe green roofs studied function as excellent Best Management PrThe green roofs studied function as excellent Best Management Practices (BMPs) for water retentionactices (BMPs) for water retention

and peak flow reduction. and peak flow reduction.

Green rooftops reduce runoff problems by a variety of means, incGreen rooftops reduce runoff problems by a variety of means, including:luding:

a) The storage of water in the substrate a) The storage of water in the substrate

b) Absorbing water in the root zoneb) Absorbing water in the root zone

c) Capturing and holding precipitation in the plant c) Capturing and holding precipitation in the plant foilagefoilage

http://www.asla.org/land/050205/greenroofcentral.html#

Reduction of Urban Heat IslandReduction of Urban Heat Island

'Urban Heat Island Effect' 'Urban Heat Island Effect' -- difference in temperature between a city and the difference in temperature between a city and the

countryside. countryside.

A green roof will have a noticeable impact on the heat gain and A green roof will have a noticeable impact on the heat gain and loss of a building, as loss of a building, as

well as the humidity, air quality and reflected heat in the surrwell as the humidity, air quality and reflected heat in the surrounding neighborhood.ounding neighborhood.

On a summer day, the temperature of a gravel roof can increase bOn a summer day, the temperature of a gravel roof can increase by as much as 25 y as much as 25 °°C C

(77 (77 °°F), to between 60F), to between 60--80 80 °°C (140 C (140 -- 176 176 °°F).F).

Covered with grass, the temperature of that roof would not rise Covered with grass, the temperature of that roof would not rise above 25 above 25 °°C (77 C (77 °°F), F),

thus resulting in energy cost savings. thus resulting in energy cost savings.

Rooms under a green roof are at least 3 Rooms under a green roof are at least 3 -- 4 4 °°C (5.4 C (5.4 -- 7.27.2°°F) cooler than the air outside, F) cooler than the air outside,

when outdoor temperatures range between 25when outdoor temperatures range between 25--30 30 °°C (77 C (77 -- 86 86 °°F).F).

LTU GREEN ROOFLTU GREEN ROOF

Green Roof in Lawrence Technological University is constructed oGreen Roof in Lawrence Technological University is constructed on the roof of A. Alfred n the roof of A. Alfred Taubman Student Services Center.Taubman Student Services Center.

Green Roof CrossGreen Roof Cross--Section at LTUSection at LTU

The Beginning Stages of Green Roof Construction At The Beginning Stages of Green Roof Construction At LTULTU

REFERENCESREFERENCES

‘‘Sweet SedumSweet Sedum”” Profiles of five green roofs, from Profiles of five green roofs, from MetropolisMetropolis magazine magazine

A timeline of notable green roofsA timeline of notable green roofs from from MetropolisMetropolis magazine magazine

A map of U.S. green roofs and facts about the technologyA map of U.S. green roofs and facts about the technology from from MetropolisMetropolismagazine magazine

May your roof be greenMay your roof be green Article on green roofs in Egypt Article on green roofs in Egypt

The Creekside Centre in Deptford (Greenwich) The Creekside Centre in Deptford (Greenwich) -- London, UK has a green London, UK has a green roof roof

The Urban Ecology Centre The Urban Ecology Centre -- Montreal, Canada, has installed a model green Montreal, Canada, has installed a model green roof and offers public workshops and visits roof and offers public workshops and visits

Why Green Roof Standards? FLL Guideline? Why Green Roof Standards? FLL Guideline?

The German Landscape Research, Development & Construction SocietThe German Landscape Research, Development & Construction Societyyhttp://www.ifenergy.com/50226711/the_history_of_green_roof_technhttp://www.ifenergy.com/50226711/the_history_of_green_roof_technology.ology.phpphp

http://http://www.epa.gov/heatisland/strategies/greenroofs.htmlwww.epa.gov/heatisland/strategies/greenroofs.html Michigan State Michigan State University Green Roof Research University Green Roof Research

http://http://www.earthpledge.www.earthpledge.orgorg//

Garden RoofGarden Roof ®®

HistoryHistory European technology and European technology and experience is over 35 years oldexperience is over 35 years oldTens of millions of square feet Tens of millions of square feet installed in Europe and around installed in Europe and around the world.the world.

Leaders in Garden Roof Technology…


Ecological BenefitsEcological BenefitsProcessing of airborne toxinsProcessing of airborne toxinsCarbon Sink Carbon Sink …… (re(re--oxygenates the air) oxygenates the air) Wildlife corridors. Wildlife corridors. Reduces Urban Heat Reduces Urban Heat Island effectsIsland effects

keeps urban areas coolerkeeps urban areas coolerreduces power demandsreduces power demandsreduces smogreduces smog

Washington D.C.


Technical BenefitsTechnical BenefitsReduces temperature extremes on roofReduces temperature extremes on roofPrevents mechanical damage to roof membranePrevents mechanical damage to roof membraneReduction of noise transmission into buildingReduction of noise transmission into buildingIncreased energyIncreased energyefficiencyefficiencyStorm waterStorm watermanagementmanagement ..


100%100% 100%100% 100%100%5%5%

95%95% 80%80%

20%20% 50%-90%50%50%--90%90%

50%-10%50%-10%

Storm water runoffStorm water runoff

Sloping roof Flat Roof Garden Roof Garden Roof ®®U U U

CisternCisternSeparateSeparatesystemsystem

PondRainwater retention

Draining ditch

Clarification plant

CombinedCombinedsystemsystem

ToiletToiletToilet


Owner BenefitsOwner BenefitsAdditional usable tenant spaceAdditional usable tenant spaceIncreases property value Increases property value Creates therapeutic, peaceful Creates therapeutic, peaceful environments.environments.Financial incentives from Financial incentives from government . government .


Conventional Green Roofvs.Garden RoofAssemblies

Garden Roof Assembly®

Conventional Green Roof


Ordinary Soil Ordinary Soil -- high in clay contenthigh in clay content

Very heavy Very heavy -- especially when wetespecially when wetProne to compaction Prone to compaction --especially at shallower depthsespecially at shallower depths

loss of oxygen/nutrientsloss of oxygen/nutrientssoil acidificationsoil acidification

poor drainagepoor drainagefungus growth & root rot.fungus growth & root rot.


Garden RoofGarden Roof®®ComponentsComponents

PlantsPlants

Lightweight soilLightweight soil

System Filter SFSystem Filter SF

Floradrain Floradrain -- water drainage,water drainage,retention & aeration layerretention & aeration layer

Moisture retention layerMoisture retention layer

Root barrier & protection courseRoot barrier & protection course

Monolithic Membrane 6125Monolithic Membrane 6125--FRFR


Garden Roof Garden Roof ®®

-- InsulatedInsulated

PlantsPlants

Lightweight soilLightweight soil

System Filter SFSystem Filter SF

Floradrain Floradrain -- water drainage,water drainage,retention & aeration layerretention & aeration layer

Moisture retention layerMoisture retention layer

STYROFOAM* with air layerSTYROFOAM* with air layer

Root barrier & protection courseRoot barrier & protection course

Monolithic Membrane 6125Monolithic Membrane 6125--FRFR


Floradrain 25, 40 & 60 Floradrain 25, 40 & 60 -- Drainage/Water Retention/Ventilation LayerDrainage/Water Retention/Ventilation LayerReproduce basic elements of natural groundReproduce basic elements of natural groundDrainage of excess waterDrainage of excess water

prevent fungus growth, root rotprevent fungus growth, root rotRetention of water for plant useRetention of water for plant useAir circulationAir circulation

provide necessary oxygen provide necessary oxygen to root zone.to root zone.

FD 40

FD 60


Garden Roof Soil CharacteristicsGarden Roof Soil CharacteristicsMust be able to retain Must be able to retain moisture/nutrients and drain freelymoisture/nutrients and drain freelyph level must be correctph level must be correctLighter than ordinary soilLighter than ordinary soil

Types Types --Humus (organic)Humus (organic)Expanded Shale, Slate Expanded Shale, Slate or Clay (mineral)or Clay (mineral)


PlantsPlantsResistant to direct radiationResistant to direct radiationDrought resistantDrought resistantFrost resistantFrost resistantWind resistantWind resistantRegenerative.Regenerative.


Planting Growth


EXTENSIVE EXTENSIVE Garden RoofGarden RoofLightweightLightweightLow maintenanceLow maintenanceNo irrigation (typically)No irrigation (typically)Limited varietyLimited varietyof plantsof plantsNonNon--recreational recreational Simple design.Simple design.


Ordinary Soil (6”)

Pea Gravel (6”)

Weight (lb/sq.ft.)Dry

36 60

53 60

89 120

Wet

Grass Lawn (Conventional Green Roof)


Intensive Soil (6”)

Drainage/Retention


30 45

4 4.7

34 49.7

Wet

Grass Lawn (Garden Roof Assembly)


Extensive Soil (3”)

Drainage/Retention


17 22.5

0.4 1.2

17.4 23.7

Wet

Extensive - Garden Roof Assembly (min. thickness)


INTENSIVEINTENSIVE Garden RoofGarden RoofGreater soil depthGreater soil depthRequires careRequires careMust be irrigatedMust be irrigatedRecreational useRecreational useWide varietyWide varietyof plants,of plants,shrubs, andshrubs, andsmall trees.small trees.


Intensive Roofscape (Conventional Green Intensive Roofscape (Conventional Green Roof)Roof)

Ordinary Soil (12”)

Pea Gravel (6”)


72 120

53 60

125 180

Wet


Intensive Soil (8”)

Drainage/Retention


45.6 70.4

5 7.4

50.6 77.8

Wet

Intensive Roofscape (Garden Roof Assembly)Intensive Roofscape (Garden Roof Assembly)


Vegetation FreeZones


Planning ConsiderationsPlanning ConsiderationsStructural capacitiesStructural capacities…… weight loads to considerweight loads to considerWind loadingWind loading…… UL and FM guidelines & approvalsUL and FM guidelines & approvalsFire ResistanceFire Resistance…… UL and FM guidelines & approvalsUL and FM guidelines & approvalsSlopeSlope…… dead level to 2dead level to 2”” in 12in 12”” possiblepossibleDetailingDetailing…… transitions to hardscape, perimeterstransitions to hardscape, perimetersAccess/Maintenance.Access/Maintenance.

DETAILS


ProjectsProjects


ProjectsProjects

CisternCistern

DefinitionDefinitionAn underground retention facility that An underground retention facility that holds storm water for reuse.holds storm water for reuse.

LTU ProjectLTU ProjectA 10,000 gallon cistern that captures A 10,000 gallon cistern that captures excess roof water from student services excess roof water from student services center for gray water reuse.center for gray water reuse.

Maintenance = Very LowMaintenance = Very Low

Effectiveness = HighEffectiveness = High

Normalized Hydrographs - June 10, 2008

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0 2 4 6 8 10

Time (hours)

Dis

char

ge (c

fs) p

er 1

000

sq ft

roof

0

0.005

0.01

0.015

0.02

0.025

0.03

Rai

nfal

l (ft) Black

StoneGreen15 min rainfall

Cumulative Depth - June 10, 2008

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0 2 4 6 8 10

Time (hours)

Cum

ulat

ive

Run

-off/

Rai

nfal

l (ft)

BlackStoneGreenRainfall

Normalized Hydrographs - May 30, 2008

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0 1 2 3 4 5 6

Time (hours)

Dis

char

ge (c

fs) p

er 1

000

sq ft

roof

0

0.005

0.01

0.015

0.02

0.025

0.03

Rai

nfal

l (ft) Blackroof

StoneroofGreenroofRainfall

Cumulative Run-off - May 30, 2008

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0 1 2 3 4 5 6

Time (hours)

Cum

ulat

ive

Run

-off/

Rai

nfal

l (ft)

BlackroofStoneroofGreenroofRainfall

Run-off Comparison

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Rainfall (in)

Run

-off

Dep

th (i

n)

BlackroofStoneroofGreenroofLinear Poly. (Stoneroof)Poly. (Greenroof)

Green Roof Run-off Coefficient

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Rainfall (in)

Run

-off

Coe

ffici

ent

PLANT LIST Student Services Center Green RoofLAWRENCE TECHNOLOGICAL UNIVERSITYSouthfield, Michigan

QTY. BOTANICAL NAME/COMMON NAME SIZE ROOT SPACING COMMENTS

3430 Dianthus plumarius 2 1/4" pot 9" O.C. peat pot preferred3430 Koeleria glauca 2 1/4" pot 9" O.C. peat pot preferred3430 Sedum album 2 1/4" pot 9" O.C. peat pot preferred3430 Sedum floriferum 2 1/4" pot 9" O.C. peat pot preferred3430 Sedum spurium 2 1/4" pot 9" O.C. peat pot preferred

PERENNIALS

Questions?Questions?

Thanks!Thanks!

[email protected]

http://www.ltu.edu/stormwater/index.asp

mailto:[email protected]

LID LID StormwaterStormwater Practices Practices on the Campus of on the Campus of

Lawrence Technological UniversityLawrence Technological University

Donald D CarpenterDonald D Carpenter

Laura Laura HallamHallam, LTU, LTUMark Mark HeiberHeiber, Harley Ellis , Harley Ellis DevereauxDevereaux

Documents

Donald Carpenter, Ph.D. HSW Engineering, Inc