Water and Waste Management Systems for

Stanford University’s Green Dorm

Client: Dr. Sandy Robertson, Stanford Green Dorm

Final Design Presentation

LCC Design, Inc.

Christine GeorgeCharlotte Helvestine

Leah Yelverton

Friday, June 8, 2007

I.I. Project Goals and Organization Project Goals and Organization

II.II. Final Design Schematic Final Design Schematic

III.III. Water Balance Water Balance

IV.IV. Regulations Regulations

V.V. Greywater System Greywater System

VI.VI. Blackwater System Blackwater System

VII.VII. Green Roof and Rainwater Green Roof and Rainwater HarvestingHarvesting

VIII. Conclusions: Living LaboratoryVIII. Conclusions: Living Laboratory

OrganizationOrganization

I. Project Goals and I. Project Goals and OrganizationOrganization

Design GoalsDesign Goals

• ProvideProvide plans for a water and waste management system that plans for a water and waste management system that meets the public demand meets the public demand

• MinimizeMinimize (1) the environmental impacts of the building, and (1) the environmental impacts of the building, and (2) the net usage of water by outlining methods for water (2) the net usage of water by outlining methods for water treatment and reusetreatment and reuse

• MaximizeMaximize (1) the opportunities for research and education, and (1) the opportunities for research and education, and (2) user health, safety, and satisfaction(2) user health, safety, and satisfaction

• Greywater Reuse SystemGreywater Reuse System

• Blackwater SystemBlackwater System

• Green Roof and Rainwater HarvestingGreen Roof and Rainwater Harvesting

Proposed TechnologiesProposed Technologies

Proposed ApproachProposed Approach

Initial Water Balance

Greywater Reuse System

Blackwater System

Green Roof and Rainwater Harvesting

(Entire LCC Design team)

(Christine George) (Leah Yelverton) (Charlotte Helvestine)

For each system, each individual will: 1. Determine regulations/restrictions, 2. Explore design options, 3. Assess environmental impacts of “green” approach vs. traditional technologies, 4. Explore operation/maintenance requirements of system

Final Adjusted Water Balance

(Entire LCC Design team)

Comparison to initial design goals

II. Final Design SchematicII. Final Design Schematic

III. Water BalanceIII. Water Balance

  JBM Water Balance LCC Water Balance

AlteredCategories

Appliance Usage Personal Usage Appliance Usage Personal Usage

Toilets 1.5 gal/flush 5.05 flushes/day 0.03 - 0.13 gal/flush1,2 6.5 flushes/day3

Laundry 40 gal/load 2.6 loads/week 25 gal/load4 1.1 loads/week3

Inhabitants 55 47

Base Data:Base Data: American Water Works Association Residential End Use SurveyAmerican Water Works Association Residential End Use Survey

JBM Stanford-Specific Adjustments:JBM Stanford-Specific Adjustments:- modified Toilet Flow to reflect 1.5 gpf toilets- modified Toilet Flow to reflect 1.5 gpf toilets- combined Bath and Shower use- combined Bath and Shower use- separated Kitchen Faucet from Bathroom Faucet- separated Kitchen Faucet from Bathroom Faucet

LCC Adjustments:LCC Adjustments:- Stanford Water Use Survey: toilet flushes and laundry loads- Stanford Water Use Survey: toilet flushes and laundry loads- Laundry and Toilet technologies- Laundry and Toilet technologies

LCC Design ModificationsLCC Design Modifications

1SeaLand Microflush Toilet2Wost Man Ecology EB Dual-Flush Urine-Diverting Toilet3CEE 179C Stanford Water Use Survey4 New York City Council. Water Conservation Plan Facts. 2002. Available Online: <http://www.nyccouncil.info/pdf_files/reports/waterfacts.pdf> Accessed 3 June 2007.

JBM LCC Water Balance

SourceCategory Item

Flow(gpcd)

Flow(gpcd)

Flow(gal/day)

EndCategory

potable Dishwashers 1.0 1.0 50 black

potable Other Domestic 1.6 1.6 80 n/a

potable, grey Leaks 2.7 2.7 130 n/a

potable Faucet - Kitchen 6.7 6.7 310 black

potable Faucet - Bathroom 4.2 4.2 200 grey

potable Shower 12.8 12.8 600 grey

grey Clothes Washers 15 3.9 180 grey

grey Toilets - Low-Flow 1.5 gpf 7.6 9.8 460 black

grey Toilets - Urine-Diverting ------- 1.7 80 black

grey Toilets - Composting ------- 0.8 40 black

Total 52 34 - 43 1600 - 2000

LCC Final Water BalanceLCC Final Water Balance

Total greywater available for reuse (shower, bathroom faucet, clothes washer) (gal/day) 1000Total greywater demand (toilet flushing and clothes washers) (gal/day) 200 - 650Leftover water for irrigation (gal/day) 350 - 750Sewage discharge (toilet, kitchen faucet, dishwasher) (gal/day) 400 - 800Total rainwater available variable

IV. RegulationsIV. Regulations

Greywater RegulationsGreywater Regulations

• Requires Tertiary Treatment LevelRequires Tertiary Treatment Level– Toilet FlushingToilet Flushing– Laundry ReuseLaundry Reuse

• Subsurface IrrigationsSubsurface Irrigations– Filtration size 115 microns Filtration size 115 microns – A minimum of 6 inches of soil cover over the dispersal A minimum of 6 inches of soil cover over the dispersal

systemsystem– Closed loop distribution lines, periodic flushingClosed loop distribution lines, periodic flushing– All distribution lines should be the color purple to identify All distribution lines should be the color purple to identify

it as a non-potable waterit as a non-potable water– Issued operation permitIssued operation permit

V. Greywater SystemV. Greywater System

Greywater Design OverviewGreywater Design Overview

• Benefits of Greywater SystemBenefits of Greywater System

– Reduce Water Potable UsageReduce Water Potable Usage

– Reduce Ecological FootprintReduce Ecological Footprint

• Proposed DesignsProposed Designs

– Subsurface IrrigationSubsurface Irrigation

– Toilet Flushing/Laundry ReuseToilet Flushing/Laundry Reuse

Rainwater Storage

Showers

Bathroom Faucet

Clothes Washer

Subsurface Irrigation

Gravity Tank

Coarse Filtration

•Backwashsand filter

TERTIARY

BiologicalTreatment

MembraneFiltration

Disinfection

Grey Storage

Bathroom Faucet

Clothes Washer

Automatic Greywater Filtration System Automatic Greywater Filtration System for Subsurface Irrigationfor Subsurface Irrigation

• Irrigation Treatment Irrigation Treatment DesignDesign– Gravity tank and a Gravity tank and a

backwashing sand filter backwashing sand filter

– Filter size 115 micronsFilter size 115 microns

• AdvantagesAdvantages– Removal of heavy and Removal of heavy and

floating particlesfloating particles11

– Pathogen reductionPathogen reduction11

1. O.R. Al-Jayyousi, Greywater reuse: towards sustainable water management, Desalination 156(2003) 181-192

Subsurface IrrigationSubsurface Irrigation

• Equaris Total Household Water Equaris Total Household Water Recycling and Wastewater Recycling and Wastewater Treatment SystemTreatment System

– Biological treatment, membrane Biological treatment, membrane filters and UV disinfectionfilters and UV disinfection11

– Provides tertiary level water Provides tertiary level water treatmenttreatment22

– Capacity: 1500 gpd, 3 systemsCapacity: 1500 gpd, 3 systems22

– Cost: 75,000 dollars plus Cost: 75,000 dollars plus installation costinstallation cost33

– Footprint: 120 cubic feetFootprint: 120 cubic feet11

1 Equaris Corporation. Water Recycling System. <http://www.equaris.com/default.asp?Page=Disinfection>

2 Elston, Clint. Today’s Fuel Cell and Cell Phone of Water and Wastewater Treatment. <http://www.equaris.com/ppt/05-0605AWRAPaperwithCaptions.pdf>

3 Equaris Corporation. Price List. <http://www.equaris.com/default.asp?Page=PriceList>

Equaris Total Household Water Equaris Total Household Water Recycling and Wastewater Recycling and Wastewater

TreatmentTreatment11

Equaris SystemEquaris System

• Z-MOD S Z-MOD S

– Packaged Treatment SystemPackaged Treatment System11

• ZeeWeed MBR ZeeWeed MBR

• UV disinfection UV disinfection

– Capacity: 2900 gpdCapacity: 2900 gpd11

– Provides tertiary level water Provides tertiary level water treatmenttreatment

– Footprint: 845 square feetFootprint: 845 square feet11

Z-MOD S: Below Ground Packaged Plant2

1 Zenon Membrane Solutions. GE Water and Process Technologies. The Earth Rangers Centre. <http://www.zenon.com/PDF/Case%20Studies/Products/Packaged%20Plants/Z-MOD/Z-MOD%20S/ZMOD%20S%20Earth%20Rangers% 20Case%20Study.pdf>

2 Zenon Membrane Solutions. GE Water and Process Technologies. Z-MOD S Below Ground Packaged Plant Specifications. <http://www.zenon.com/products/packaged_systems/Z-MOD/Z-MOD_type_s_below_ground.shtml>

Z-MOD SZ-MOD S

• Aqua Reviva Aqua Reviva – Packaged treatment Packaged treatment

option option 11

• Steel control boxSteel control box

• Biological treatment in Biological treatment in treatment cell treatment cell

– Cost: 90,000-135,000 Cost: 90,000-135,000 dollarsdollars22

– Capacity: 1665 Capacity: 1665 gallons/day, 9 systemsgallons/day, 9 systems33

– Footprint:142 squareFootprint:142 square44

Treatment System and Control Box 4

1 Aqua Reviva. Product Specifications. <http://www.aquareviva.com.au/product_info.asp>

2 Aqua Reviva. Prices. <http://www.aquareviva.com.au/prices.asp>

3 Aqua Reviva. How It Works. <http://www.aquareviva.com.au/how_it_works.asp>

4 Aqua Reviva. Photos and Diagrams. <http://www.aquareviva.com.au/photos.asp>

Aqua RevivaAqua Reviva

Criteria Equaris8,9 Z-MOD S2 Aqua Reviva5

Water Quality      

BOD5 ---- < 2 mg/L10 < 10 mg/L

TSS ---- < 0.2 mg/L9 < 10 mg/L

NH3 ---- < 0.2 mg/L9 -----

P ---- <0.015 MG/L9 -----

Total Coliform <1 MPN/100 ml ----- -----

Fecal Coliform <1 MPN/100 ml ----- <10 Faecal Coliforms /100ml

DisinfectionIncluded Yes, UV Disinfection

Yes, UVDisinfection9

Yes, modal contact time of 30 minutes (but US standards require at least 90 minutes)

Foot Print      

Capacity (gal/day)

500 gal/day per system8,1500 gal/day (3 systems) 2,900 gallons10

185 gal/day per system, 1670 gal/day 9 systems

Volume (cubic ft)

40 ft3 per system, 120 ft3 for 3 systems 845 square feet9

16 ft3 per system, 142 ft3 for 9 systems (treatment system

and control box)

Cost ($)$75,000 plus the cost of

installation ---- $90,000-$135,000

Design ComparisonDesign Comparison

Design Comparison ReferencesDesign Comparison References

11 Equaris Corporation. www.equaris.com Equaris Corporation. www.equaris.com

22 GE Water Process Technologies. Southern California SeaWater Desalination GE Water Process Technologies. Southern California SeaWater Desalination Project. www.zenonenv.comProject. www.zenonenv.com

33 Residence time for MBR taken from L. Defrance, Contribution of various constituents of activated sludge to Residence time for MBR taken from L. Defrance, Contribution of various constituents of activated sludge to membrane bioreactor fouling, Bioresource Technology Volume 73(2) June 2000 105-112membrane bioreactor fouling, Bioresource Technology Volume 73(2) June 2000 105-112

44 Taken from JBM Associates, Stanford University’s Green Dorm Water System Management Taken from JBM Associates, Stanford University’s Green Dorm Water System Management Project, section 3.4.3 (June 2005)Project, section 3.4.3 (June 2005)

55 Aqua Reviva. www.aquareviva.com.au Aqua Reviva. www.aquareviva.com.au

66 GE Water Process & Technologies. Zenon Membrane Solutions. GE Water Process & Technologies. Zenon Membrane Solutions. http://www.zenonenv.com/newsroom/articles/2006/10/earth_rangers.shtmlhttp://www.zenonenv.com/newsroom/articles/2006/10/earth_rangers.shtml

77 Taken from JBM Associates, Stanford University’s Green Dorm Water System Management Project, section 3.4.3 Taken from JBM Associates, Stanford University’s Green Dorm Water System Management Project, section 3.4.3 3.4.3 Comparison of Two Systems (June 2005)3.4.3 Comparison of Two Systems (June 2005)

88 Equaris Corporation. Water Recycling System. http://www.equaris.com/default.asp? Equaris Corporation. Water Recycling System. http://www.equaris.com/default.asp?Page=DisinfectionPage=Disinfection

99 Zenon Membrane Solutions. GE Water and Process Technologies. The Earth Rangers Centre. Zenon Membrane Solutions. GE Water and Process Technologies. The Earth Rangers Centre. <http://www.zenon.com/PDF/Case%20Studies/Products/Packaged%20Plants/Z-MOD/Z-MOD%20S/ZMOD<http://www.zenon.com/PDF/Case%20Studies/Products/Packaged%20Plants/Z-MOD/Z-MOD%20S/ZMOD%20S%20Earth%20Rangers% 20Case%20Study.pdf>%20S%20Earth%20Rangers% 20Case%20Study.pdf>

1010 GE Water & Process Technologies. Zenon Membrane Solutions World Headquarters and Assembly Plant. GE Water & Process Technologies. Zenon Membrane Solutions World Headquarters and Assembly Plant. http://www.zenon.com/pdf/case%20studies/products/packaged%20plants/z-mod/z-mod%20s/z-mod%20shttp://www.zenon.com/pdf/case%20studies/products/packaged%20plants/z-mod/z-mod%20s/z-mod%20s%20zenon%20hq%20case%20study.pdf%20zenon%20hq%20case%20study.pdf

VI. Blackwater SystemVI. Blackwater System

What is Blackwater?What is Blackwater?

Blackwater = an untapped Blackwater = an untapped resourceresource

Nutrients Energy

Nutrient content of human Nutrient content of human wastewaste

Nutrient (g/ppd) Urine Feces Total

Nitrogen 11 1.6 12

Phosphorus 1 0.5 1.5

Potassium 2.2 0.8 2.9

BOD5 7.5 11 18.5

COD 15 33 48

TS 65 44 109

Nutrients produced by one person in one day.

Swedish EPA. 1995b. “What does household wastewater contain? Report 4425, Swedish Environmental Protection Agency, Stockholm, Sweden.Ligman, K., Hutzler, N. and Boyle, W. “Household Wastewater Characterization.” Journal of the Environmental Engineering Division. Feb 1974.Jonsson, H., Stenstrom, T-A., Svensson, J., and Sundin, A. “Source separated urine – nutrient and heavy metal content, water saving and faecal contamination. Wat Sci and Tech. 35(9) pp. 145-152.Del Porto, D. and Seinfeld, C. The Composting Toilet System Book. Center for Ecological Pollution Prevention. Massachusetts, USA. 2000.Henze, M. “Waste design for households with respect to water, organics and nutrients. Wat Sci and Tech. 35(9) pp. 113-120

Energy potential of human Energy potential of human wastewaste

C6 H12 O6 3 CH4 3 CO2+

0.35 liters CH4 / g CODBased on correspondence with Sara Marks and Sandy Robertson.

Technologies ConsideredTechnologies ConsideredUrine-diverting Toilet

Composting Toilet

Anaerobic Digester and MBR

Scenario 1: “Business as Scenario 1: “Business as usual”usual”

Source StandardToilet

Sewer

  End location (g/ppd)

Nutrient SewerUrine Storage

Compost

N 12    

P 1.5    

K 2.9    

BOD5 18.5    

COD 48    

TS 109    

Inflow volume = 37 L / ppdDischarge vol. = 38 L / ppdCH4 potential = 17 L / ppd

Scenario 2: Urine-diverting Scenario 2: Urine-diverting toiletstoilets

Source Urine-divertingToilet

Urine to Storage

Feces to Sewer

  End location (g/ppd)

Nutrient Sewer Urine StorageCompost

N 1.6 11 (92%)  

P 0.5 1 (67%)  

K 0.8 2.2 (76%)  

BOD5 11 7.5 (40%)  

COD 33 15 (31%)  

TS 44 65 (60%)  

Inflow volume = 6.4 L / ppdDischarge volume = 6 L / ppd

CH4 potential = 12 L / ppd Urine storage vol. = 2 L / ppd

Scenario 3: Composting Scenario 3: Composting toiletstoilets

SourceMicro-flush

Toilet ComposterCompost to Garden

Leachate to Sewer

  End location (g/ppd)

Nutrient Sewer*Urine Storage Compost

N 0.09   12 (100%)

P 0.06   1.4 (93%)

K -   -

BOD5 -   -

COD 0.5   47 (98%)

TS 0.1  109 (100%)

Inflow volume = 3 L / ppdDischarge volume = 4 L / ppdCH4 potential = 0.2 L / ppd

*Based on leachate nutrient estimates from one study. Lee, T., K. Crawford, and T. Hill. “Analysis of Monitoring Results of the Separation and Graywater Treatment System at Chester Woods Park, Olmsted County, Minn.” Olmsted County Water Resources Center. Rochester, MN.

Comparison of ScenariosComparison of Scenarios

  Scenario 1 Scenario 2 Scenario 3

% N capture 0 92 100*

% P capture 0 67 93*

Inflow vol (L) 37 6 3

Discharge vol (L) 38 6 4

CH4 potential (L) 17 12 0.2

*These numbers have a high degree of error and do not include nutrient losses.

The 4The 4thth Scenario? Scenario?

optimizing choice of urine-diverting optimizing choice of urine-diverting and composting toiletsand composting toilets

• Value of urine and compostValue of urine and compost

• Value of natural gasValue of natural gas

• Research opportunitiesResearch opportunities

Picture SourcesPicture Sources

• Kitchen sink = Kitchen sink = http://www.inmagine.com/house-proud-photos/digitalvision-http://www.inmagine.com/house-proud-photos/digitalvision-dv812dv812

• Toilet = Toilet = http://www.ci.austin.tx.us/watercon/images/ASChampionSkyline.jhttp://www.ci.austin.tx.us/watercon/images/ASChampionSkyline.jpgpg

• Sewage = Sewage = http://www.oceannet.org/medag/images/sewage_pipe.jpghttp://www.oceannet.org/medag/images/sewage_pipe.jpg

• Tree = Tree = http://www.ci.austin.tx.us/watercon/images/ASChampionSkyline.jhttp://www.ci.austin.tx.us/watercon/images/ASChampionSkyline.jpgpg

• Gas = http://picturethis.pnl.gov/PictureT.nsf/All/4VXNUE?Gas = http://picturethis.pnl.gov/PictureT.nsf/All/4VXNUE?opendocumentopendocument

• Bacteria = Bacteria = http://www.sdnhm.org/exhibits/epidemic/naturalhistory.htmlhttp://www.sdnhm.org/exhibits/epidemic/naturalhistory.html

• Anaerobic digester = Anaerobic digester = http://pasture.ecn.purdue.edu/~jiqin/PhotoDigester/Digester1.jpghttp://pasture.ecn.purdue.edu/~jiqin/PhotoDigester/Digester1.jpg

VII. Green Roof and VII. Green Roof and Rainwater HarvestingRainwater Harvesting

• Goals of the Stanford Green Roof and Goals of the Stanford Green Roof and Rainwater Harvesting SystemRainwater Harvesting System– Reduced Stormwater RunoffReduced Stormwater Runoff– Rainwater Capture and ReuseRainwater Capture and Reuse– Thermal BenefitsThermal Benefits– Research OpportunitiesResearch Opportunities

Bass, Brad and Bas Baskaran. Evaluating Rooftop and Vertical Gardens as an Adaptation Strategy for Urban Areas. National Research Council Canada and Institute for Research in Construction. 2003.

Amy Christine. A North Carolina Field Study to Evaluate Green Roof Runoff Quantity, Runoff Quality, and Plant Growth. North Carolina State University, 2004.

Cross-section of Green Roof Extensive Green Roof in North Carolina

• BenefitsBenefits11

– Lower discharge volumes to sewerLower discharge volumes to sewer– Lower risk of combined-sewer overflow Lower risk of combined-sewer overflow

(CSO) (CSO)

• Expected Stormwater RetentionExpected Stormwater Retention– Compare to observed stormwater retentionCompare to observed stormwater retention

•Range of 55-70% annual retentionRange of 55-70% annual retention2-42-4

– Mass-Balance modelingMass-Balance modeling•Evapotranspiration + Runoff = PrecipitationEvapotranspiration + Runoff = Precipitation•Crop CoefficientsCrop Coefficients55: ET: ETcc = ET = EToo*K*Kcc

– 0.6 for intensive (warm-season turf), 0.25 for 0.6 for intensive (warm-season turf), 0.25 for extensive (sedum groundcover)extensive (sedum groundcover)66

1U.S. Environmental Protection Agency. National Pollutant Discharge Elimination System: Combined Sewer Overflows. < http://cfpub.epa.gov/npdes/home.cfm?program_id=5> 2Moran, Amy Christine. A North Carolina Field Study to Evaluate Green Roof Runoff Quantity, Runoff Quality, and Plant Growth. North Carolina State University, 2004. 3Hutchinson, Doug et al. Stormwater Monitoring Two Ecoroofs in Portland, Oregon, USA. City of Portland, Bureau of Environmental Services. 2003.4VanWoert, Nicholaus D. et al. Green Roof Stormwater Retention: Effects of Roof Surface, Slope, and Media Depth. Journal of Environmental Quality. 34, pg. 1036-1044. 2005.5California Irrigation Management Information System. ET Overview. 2005. < http://www.cimis.water.ca.gov/cimis/infoEtoOverview.jsp> 6California Department of Water Resources. A Guide to Estimating Irrigation Water Needs of Landscape Plantings in California. 2000. <http://www.owue.water.ca.gov/docs/wucols00.pdf>

Stormwater RetentionStormwater Retention

Stormwater RetentionStormwater Retention

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Estimated Runoff (gal/sf)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

% Retention

Intensive RoofExtensive RoofReference RoofIntensive RetentionExtensive Retention

Estimated runoff and retention from the different roofs.Estimated runoff and retention from the different roofs.

• BenefitsBenefits– Reduced demand of potable waterReduced demand of potable water– Reduced stormwater runoffReduced stormwater runoff

• Quality ConcernsQuality Concerns– Green Roof Runoff Green Roof Runoff

• Substrate acts as sink for heavy metalsSubstrate acts as sink for heavy metals11

• Compost can increase concentrations of N and P, Compost can increase concentrations of N and P, which can lead to algae blooms and contaminationwhich can lead to algae blooms and contamination1-31-3

– Reference Roof RunoffReference Roof Runoff• Dissolved chemicals from roof material, Dissolved chemicals from roof material,

atmospherically deposited microbes and chemicalsatmospherically deposited microbes and chemicals44

– Treatment: minimum gravitational settling and Treatment: minimum gravitational settling and mechanical filtrationmechanical filtration44

Rainwater Capture and ReuseRainwater Capture and Reuse

1Berndtsson, Justyna Czemiel et al. The Influence of Extensive Vegetated Roofs on Runoff Water Quality. Science of the Total Environment, Vol. 355 pg. 48-63. 2006. 2Hutchinson, Doug et al. Stormwater Monitoring Two Ecoroofs in Portland, Oregon, USA. City of Portland, Bureau of Environmental Services. 2003.3Meera, V. et al. Water Quality of Rooftop Rainwater Harvesting Systems: A Review. Journal of Water Supply: Research and Technology – AQUA. 55.4, pg. 257-268. 2006.4Texas Water Development Board and Center for Maximum Potential Building Systems. Texas Guide to Rainwater Harvesting, Second Edition. 1997.

Rainwater Capture and ReuseRainwater Capture and Reuse

Example green roof layout, based on Feasibility Study sketchExample green roof layout, based on Feasibility Study sketch11..

1EHDD Architecture and Stanford Department of Civil and Environmental Engineering. Green Dorm Feasibility Study. 2006. <http://www.stanford.edu/group/greendorm/greendorm/feasibility_study.html>

Rainwater Capture and ReuseRainwater Capture and Reuse

Intensive Roof1400 sf

5,000 gallons annually

Reference Roof7600 sf

52,500 gallons annually

Extensive Roof1500 sf

8,000 gallons annually

Rainwater Storage Tank15,000 gallons

Laboratory Analysis

Laboratory Analysis

Laboratory Analysis

Suggested Flows of Harvested RainwaterSuggested Flows of Harvested Rainwater

• 65,000 gallons available annually (20% losses through leaks, 65,000 gallons available annually (20% losses through leaks, filtration, treatmentfiltration, treatment11))

• 15,000-gallon tank to store dry season green roof irrigation demand15,000-gallon tank to store dry season green roof irrigation demand22

• 50,000 gallons available (Oct-April) for toilet flushing, washing 50,000 gallons available (Oct-April) for toilet flushing, washing machines, and additional irrigationmachines, and additional irrigation

1Texas Water Development Board and Center for Maximum Potential Building Systems. Texas Guide to Rainwater Harvesting, Second Edition. 1997. 2Rana Creek Living Architecture. Designing the California Academy of Sciences Living Roof: An Ecological Approach. 2005. <http://www1.eere.energy.gov/femp/energy_expo/2005/pdfs/t_s7a.pdf>

• BenefitsBenefits1-31-3

– Reduced Roof TemperatureReduced Roof Temperature• Reduces urban heat island effect and indoor Reduces urban heat island effect and indoor

temperaturetemperature

• Extends lifetime of roofExtends lifetime of roof

– Reduced Heat FluxReduced Heat Flux• Reduces space-conditioning energy demandReduces space-conditioning energy demand

• Estimated Heat FluxEstimated Heat Flux– Heat flow through insulationHeat flow through insulation44: q = : q = ΔΔT/RT/R

• qq is the heat transfer (Btu/hr-ft2), is the heat transfer (Btu/hr-ft2), ΔΔTT is the difference is the difference between the outdoor and indoor temperatures, and between the outdoor and indoor temperatures, and RR is the insulation value of the green roof (hr-ft2-ºF/Btu) is the insulation value of the green roof (hr-ft2-ºF/Btu)

• Assume indoor temp of 70F, average monthly Assume indoor temp of 70F, average monthly maximum outdoor temperaturesmaximum outdoor temperatures55, substrate , substrate insulation of R-3/inchinsulation of R-3/inch66

Thermal BenefitsThermal Benefits

1Bass, Brad et al. Evaluating Rooftop and Vertical Gardens as an Adaptation Strategy for Urban Areas. National Research Council Canada. 2003. 2United States Environmental Protection Agency. Vegetated Roof Cover: Philadelphia, Pennsylvania. EPA Office of Water, Low-Impact Development Center. October 2000. 3Sonne, Jeff. Evaluating Green Roof Energy Performance. ASHRAE Journal. February 2006.4Gil Masters. CEE 176A: Energy Efficient Buildings. Course Notes. 7 Jan 2007. 5California Irrigation Management Information System. Monthly: Station 132. http://wwwcimis.water.ca.gov/cimis/logon.do?forwardURL=/frontMonthlyReport&selTab=data6Peck, Steven and Monica Kuhn. Design Guidelines for Green Roofs. Sponsored by Canada Mortgage and Housing Corporation, Ontario Association of Architects.

• Compare to reference roof heat flux of 2.1-2.8 Btu/hr-ftCompare to reference roof heat flux of 2.1-2.8 Btu/hr-ft22 (1,2)(1,2)

Thermal BenefitsThermal Benefits

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

May Jun Jul Aug Sep Oct

Heat Flux q (Btu/hr-ft2)

68

70

72

74

76

78

80

82

84

86

88

Average Maximum Ambient Temperature (F)

8"

24"20"

16"

12"

4"

Estimated heat flux through the Stanford green roof for varyingEstimated heat flux through the Stanford green roof for varying substrate depths during warm months.substrate depths during warm months.

1Bass, Brad et al. Evaluating Rooftop and Vertical Gardens as an Adaptation Strategy for Urban Areas. National Research Council Canada. 2003. 2Sonne, Jeff. Evaluating Green Roof Energy Performance. ASHRAE Journal. February 2006.

VIII. Conclusions: Living VIII. Conclusions: Living LaboratoryLaboratory

• Promote and refine water recycling Promote and refine water recycling technologiestechnologies– GreywaterGreywater

• Monitor the quality of greywater as it changes over timeMonitor the quality of greywater as it changes over time• Experiment with different treatment technologies and their Experiment with different treatment technologies and their

effects on qualityeffects on quality

– BlackwaterBlackwater• Explore waste as a resource.Explore waste as a resource.• Experimental systems provide ample opportunity for Experimental systems provide ample opportunity for

research of blackwater treatment and reuse.research of blackwater treatment and reuse.

– Green Roof and Rainwater HarvestingGreen Roof and Rainwater Harvesting• Test different vegetation and substrate materials/depths Test different vegetation and substrate materials/depths

for their effects on stormwater retention, runoff quality, for their effects on stormwater retention, runoff quality, and thermal insulationand thermal insulation

• Experiment with blackwater-derived compostExperiment with blackwater-derived compost

• Publicize sustainable water management for Publicize sustainable water management for campuses and buildings worldwidecampuses and buildings worldwide

Living Laboratory: Research for the FutureLiving Laboratory: Research for the Future

Questions?Questions?