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L.E.P. Associates Lee Traynham Erin Gardner Pascal Mues. Stanford Green Dorm Project: Exterior Water System. June 7, 2005. Project Overview Green Roof Rainwater Harvesting System Irrigation System Research and Education. L.E.P. Associates Green Dorm Exterior Water System June 7, 2005.
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L.E.P. Associates Lee Traynham Erin Gardner Pascal Mues Stanford Green Dorm Project: Exterior Water System June 7, 2005
Project Overview • Green Roof • Rainwater Harvesting System • Irrigation System • Research and Education L.E.P. Associates Green Dorm Exterior Water System June 7, 2005
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Project Overview • Goals • 50% reduction in wastewater flow • stormwater vs household wastewater • zero net use of lake water for irrigation • potential for expansion • flexibility for future modification • greywater irrigation system • Research and Education
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Major Systems • Green Roof • reduction of stormwater • Rainwater Harvesting • reduced/zero net irrigation water use • expansion potential (potable) • Irrigation System • reduced net irrigation water use • All: Monitoring • research and education
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Design Emphasis • Adaptability • enable later fundamental changes to system • Sustainability • conserve water, water quality, and resources • Research Potential • plan for sub-unit monitoring and data collection
Project Overview • Green Roof • Rainwater Harvesting System • Irrigation System • Research and Education L.E.P. Associates Green Dorm Exterior Water System June 7, 2005
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 The Green Roof Benefits • Runoff Reduction • Runoff Quality • Insulation • Energy Savings • Noise Reduction • Heat Island Effect • Beautification
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Preliminary Design Two main types: • Extensive (continuous or modules) • Intensive (continuous) Extensive Total roof area is approx. 4,500 ft2 • About half (2,500 ft2) green roof area • Extensive Modules • Intensive Continous Intensive Continous Modules
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Extensive Section • Modules for testing purposes- changeable substrate/vegetation • One module per two student rooms for testing • 2 rooms/module * 9 modules * 110 ft2/ room = 2000 ft2 • Intensive section = 800 ft2 7 rooms
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Intensive Section • Structural Concerns • Imposes an additional weight of between 290 and 970 kg/m2 (59-199 lb/ft2). • Typical intensive roof requires irrigation.
Roof Membrane • Underlayment • Permanent in modules and standard green roof. L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Researching the Green Roof • Substrate • Vegetation • Easily variable with modules • Semi-permanent with standard green roof design
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Substrate • Lava and Pumice • Lightweight • Can be difficult to obtain • Light Expanded Clay Granules (LECA) • Lightweight • Large pore space • Absorb water • Crushed clay brick or tiles • Stable, uniform • Possibly raise pH of substrate Source: Dunnertt, Nigel, Noel Kingsbury, Planting Green Roofs and Living Walls
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Vegetation Options • Mixing types of vegetation • Native plant species • Established plant species • Mixing with different substrates
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 California Native Plants Artemisia Californica “Trailing Sagebrush” • 0-0.5 m • 31-76 cm of rainfall Castilleja foliolosa “Woolly Indian Paintbrush” • 0.1-1 m • 30-80 cm of rainfall Brodiaea Pulchella “Wild Hyachinth” • 0.1-0.4 m • 41-93 cm of rainfall Ceanothus gloriosus “Moutain Lilac” • 0.1-1 m • 50-140 cm of rainfall Source: Las Pilitas Nursery, www.laspilitas.com, www.mynativeplants.com
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Standard Vegetation Semi-extensive (10-20 cm) Extensive (0-10 cm) Ixia (Iridacea) • 20 cm • High drought tolerance • Frost-free climates Jovibarba (Crassulaceae) • 20 cm • High drought tolerance • Clump-forming perennial Koeleria (Poaceae) • 20 cm • High drought tolerance • Poor free-draining soils Acinos (Lamiaceae) • 15 cm • High drought tolerance • Creeping perennial Aloe (Aloeacea) • 30-60 cm • High drought tolerance • Frost-free climates Source: Dunnertt, Nigel, Noel Kingsbury, Planting Green Roofs and Living Walls.
Extensive Plan View Intensive Plan View Elevation L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Preliminary Design Two main components: • Extensive (modules) • Intensive (continuous)
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Estimating Runoff • Storage Capacity depends on: • Season • Substrate depth • Layers of roof used in construction • Physical properties of growing media • Slope of roof • Vegetation used • Rainfall intensity • How much will the green roof reduce runoff?
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Method • Mass Balance: • Difference between precipitation (inflow) and evaporation (outflow) plus storage capacity of green roof to get runoff. • All data from California Irrigation Management Information System • Off ice of Water Use Efficiency, California Department of Water Resources • wwwcimis.water.ca.gov/cimis/welcome.jsp • Used data from San Jose Station (July 1987 to August 2002)
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Method (continued) • Daily Precipitation Volume = Precipitation x Area • Daily Evaporation Volume = Crop Coefficient x Potential Evapotranspiration x Area • Runoff = Daily Precipitation Volume - Daily Evaporation Volume
Species Low KC High KC Sedum Acre 0.25 0.25 Pistachio 0.04 1.12 Olive 0.58 0.80 L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 The Crop Coefficient (KC) Source: “A Guide to Estimating Irrigation Water Needs of Landscape Plantings in California,” University of California Cooperative Extension, California Department of Water Resources, 14.
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Low Precipitation • Water year 1988 (Oct. 1, 1988 to Sept. 30, 1989)
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 High Precipitation • Water year 1997 (Oct. 1, 1997 to Sept. 30, 1998)
Water Outlet L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Green Roof Element Design Continuous Modules Gutter
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Other Benefits… • Reduces noise pollution. • Reduces the urban heat island effect. • Beautification of area.
Considerations Taking into account other rooftop technologies Solar Panels Night Sky Water Cooling L.E.P. Associates Green Dorm Exterior Water System June 7, 2005
Monitoring Performance Runoff Measure gutter flows Storage tank level changes with rain events/season Monitor street storm drain flows L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 L.E.P. Associates Green Dorm Exterior Water System June 7, 2005
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Monitoring: Stormwater Control • Extensive Green Roof (modules) • Individual outlets (discrete sampling) • Gutter flows (flowrate data) • Intensive Green Roof • Bulk and local monitoring • Flowrates (comparison with extensive) • Storage Tank level • Street Drains • Locating sensor for green dorm total outflow
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Monitoring: Insulation Effect • Temperature sensors • Indoor ambient temperature • Outdoor ambient temperature • Rooftop temperature • Indoor ambient temperature of comparable row houses • Sensor Placement • Edge effects • Module sizing
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Monitoring: Stormwater Quality • Extensive Green Roof (modules) • Individual outlets (discrete sampling) • Selective plumbing to downspouts (reuse) • Intensive Green Roof • Bulk sampling • In-roof sensors • City standards • Monitoring as a regulatory advantage
Project Overview • Green Roof • Rainwater Harvesting System • Irrigation System • Research and Education L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 L.E.P. Associates Green Dorm Exterior Water System June 7, 2005
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Rainwater Harvesting Benefits • No-Cost Supply • Reduces Unnecessary Use of Potable Supply • High Quality • Decrease in Stormwater Runoff Volume
Recommended Not Recommended Metal Asphalt Slate Asbestos Clay Chemically Treated Wood Tile Some Painted Roofs L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Rainwater HarvestingRoof Area Safety Depends on Material
Roof Material Type Drainage Coefficient Pitched Roof Tiles 0.75 – 0.9 Flat Roof Smooth Tiles 0.5 Flat Roof with Gravel Layer 0.4 – 0.5 L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Rainwater HarvestingRoof Area
Rainwater HarvestingTransport L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Transport Channels • Gutters • Downspouts Contaminant Removal • Leaf Screens • Roof Washers
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Rainwater HarvestingDistribution Typical System Components • Filter • Smoothing Inlet • Submersible Pump • Suction Filter • Pressure/Switch Flow Controller • Solenoid Valve • Float Switch • Type ‘A’ Air Gap 11. Overflow Trap
Rainwater HarvestingStorage Tanks L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Expected Rainwater Runoff Roof Area x Drainage Coefficient x Filter Efficiency x x Annual Runoff 2,250ft2 x 0.75 x 0.85 x 368mm = 209m2 x 0.75 x 0.85 x 0.368m = 49.03m3 ≈ 50,000 Liters
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Rainwater HarvestingStorage Tanks Plastic Storage (Polyethylene and Fiberglass) • Wide Variety of Shapes, Sizes, & Colors • Above and Below Ground Designs • Least Expensive • Light-weight • Degradable – Require Coating
Potable Filtration + Disinfection Ultraviolet Light Ozone Chlorine L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Rainwater HarvestingTreatment Nonpotable Only Filtration • Sediment Filter • In-Line Filters • Activated Carbon Filter • Reverse Osmosis
Rainwater HarvestingMinimizing Stormwater Runoff L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Bypass Chamber Inflow Outflow Treatment Chamber Figure from Rinker Materials, http://www.rinkermaterials.com/stormceptor
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Rainwater HarvestingMinimizing Stormwater Runoff • Underground Oil–Sediment Separator Tank (OSS) • Separates Oil, Grease, and Sediment from Stormwater Runoff • Prevents Resuspension and/or Scouring of Previously Collected Pollutants • Potential 80% Total Suspended Solids (TSS) and 90% Oil and Grease Removal Rates
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 IrrigationAlternative Sources In addition to municipal supplies: Gray Water Rainwater
Irrigation Distribution Systems L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Drip Irrigation (a.k.a. Trickle, Micro-) • Applies Water Slowly and Directly to Roots • 80% Efficiency – Highest • Use 30-50% Less Water than Sprinklers • Necessary for Gray Water (Safety) • Recommended for Use On: • Trees • Shrubs • Flowers
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 IrrigationDistribution Drip Irrigation Components • Polyvinylchloride (PVC) Mainlines • Polyethylene (PE) Distribution Lines • Emitters • (0.5, 1, 2 gallons/min) • 12 – 24 Inches Apart • Filter: 150 – 200 mesh screen • Gray Water and Green Roof Pretreatment • Pressure Regulator: 20psi
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 IrrigationSupported Area
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Monitoring: Quality for Use • Rainfall data • Available water • Collected quantity • Irrigation requirements • Flow rate and area irrigated • Distribution system compatibility • Treatment to Potable standards • Optimization of treatment system • Regulatory standards
Project Overview • Green Roof • Rainwater Harvesting System • Irrigation System • Research and Education L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 L.E.P. Associates Green Dorm Exterior Water System June 7, 2005
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Research and Education • Scientific research • Data generation (monitoring) • Design variation • Engineering research • System testing (monitoring) • Component variation • Educational activities • Accessibility of information
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Supporting Research • Provision for general data collection • Built-in monitoring infrastructure • Discrete sampling arrangements • Provision for experimentation and testing • Rapid adjustment • Systems support • Rooftop power taps, data bus • Catwalks
L.E.P. Associates Green Dorm Exterior Water System June 7, 2005 Supporting Education • Visible Elements • Green Roof • Rainwater collection tank • Greywater-irrigated landscaping (orchard) • Accessibility • Rooftop catwalks (physical access) • Zero-outside-water garden (intellectual access) • Educating Regulators • Monitoring / Permiting interactions