Water conservation and reuse strategies
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Water conservation and reuse strategies

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USGBC San Diego kicks off its 2010 LUNCH + LEED® series with a discussion of water conservation strategies, features and benefits of rainwater harvesting, advantages of using regionally appropriate ...

USGBC San Diego kicks off its 2010 LUNCH + LEED® series with a discussion of water conservation strategies, features and benefits of rainwater harvesting, advantages of using regionally appropriate plantings to maximize water usage, and other efficiency-related subjects. This course provides a one (1) hour GBCI CE credit for credentialed LEED® Accredited Professionals.

Our presenter, Dr. Haselbeck, is a co-owner of San Diego-based Building Green Futures, Inc; a company that specializes in the design and installation of green (living) roofs and rainwater harvesting systems. She is a green roof accredited professional, a Certified GreenPoint Rater and a LEED® for Homes Rater In-Training. Dr. Haselbeck also lectures part-time in Biology at the University of San Diego.

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Water conservation and reuse strategies Water conservation and reuse strategies Presentation Transcript

  • Water Conservation & Reuse Strategies for Southern California Rosalind Haselbeck , PhD, LEED AP Building Green Futures Inc. LUNCH + LEED July 15, 2010
  • Learning Objectives 1. Apply the historical context to our current water crises, both globally and here in San Diego. 2. Identify strategies to reduce indoor water use. 3. Discuss the basic features of a rainwater harvesting system including benefits, components, and estimating supply and demand. 4. Develop an outside water usage and conservation strategy. 5. Identify resources to support water conservation and rainwater/graywater systems.
  • www.zmescience.com/.../2009/08/water_b.jpg View slide
  • Historical Context • How We Use Water • The Water Cycle and Urbanization • Water Usage in San Diego View slide
  • Water Footprint Item Gallons to produce Glass of Milk 52 Cup of Coffee 37 1 Apple 19 Cotton T shirt 530 Hamburger 635 Meat-based diet 1320/day Vegetarian diet 687/day Source: United Nations Development Report, 2006
  • Water Usage Location Water use GPC/day San Diego 164 US average 152 Japan 99 Germany 51 Nigeria 10 Uganda 4 Water scarcity <13 Source: SDWA Annual Report 2009
  • How We Use Water • “Reducing potable water demand by 10% could save approximately 300 billion kilowatthours of energy each year” (Michael Nicklas, Rainwater, High Performance Buildings, Summer 2008). • Use of potable water – Single vs. multi-use – Need for potable water indoor applications – According to the EPA, 80% of indoor use doesn’t require potable (Municipal Handbook Rainwater Harvesting Policies, 12/08)
  • Water Run-off: developed vs. natural Source: http://www.coastal.ca.gov/nps/watercyclefacts.pdf
  • Source: http://www.epa.gov/volunteer/stream/vms21.html
  • History of Water Usage in San Diego Old Mission Dam; completed 1815 San Vicente reservoir; 1947 Source: San Diego County Water Authority (http://www.sdcwa.org/about/who-history.phtml)
  • “Water conservation is the cheapest new source of water” --SDWA, ‘07 Source: SDWA Annual Report 2009
  • Indoor Water Usage • Water usage and fixture choices • Water reuse for indoor applications • LEED credits for Water Efficiency • Standards for indoor rainwater usage
  • Source: American Waterworks Association Research Foundation (AWWARF) Residential End Uses of Water, Denver, CO; 1999
  • Annual Indoor Water Usage Very High Efficiencyf vs. Standard** Fixture Average # Typical Gallons Gallons Very hi Gallons Gallons per uses per fixture per per year efficiency per year day per (gal or person family of fixture person family of 4 person* min)** per day 4 (gal or per day min)f Toilet 4 1.6 gpf 6.4 9,344 1.1 gpf 5.2 7,592 Lavatory 5 2.2 gpm 5.5 8,030 1.5 gpm 3.75 5,475 faucet 0.5 min 0.5 min Shower 1 2.5 gpm 15.75 22,995 1.75 gpm 12.6 18,396 6.3 min 6.3 min Clothes 7 per wk 55 gal* 20,020 (25 gal) 9,125 washer Family* Total 60,389 42,413 * Source: http://www.csgnetwork.com/waterusagecalc.html ** Source: EPAct 1992; http://www.epa.gov/watersense/docs/matrix508.pdf f Source: LEED-H Reference Guide WE 3.2; 2008
  • WE Credits for LEED-Homes: Maximum 15 points possible WE (min 3 pts) Credit Points WE 1: Water Reuse 1.1 Rainwater 4 points outdoor + 5 points max Harvesting System indoor (>50% roof) And/or 1.2 Graywater 1 point OR 3 pts max if use 1.3 Municipal instead of Recycled Water 1.1-1.2 WE 2: Irrigation 2.1 Hi-efficiency 3 points max 4 points max 2.2 3rd party 1 point max OR 2.3 Reduce 4 points max irrigation demand WE 3: Indoor Water 3.1 Hi-efficiency 3 points if all fixtures Usage fixtures/fittings 6 points max 3.2 Very hi-efficiency 6 points max Source: USGBC LEED for Homes Rating System, 2008
  • WE Credits for LEED-NC: Maximum 10 points possible WE (min 3 pts) Credit Points WE 1: Water Efficient 1.1 Use 50% reduction: 2 points Landscaping rainwater, graywater, or 4 points max recycled municipal OR 1.2 NO potable water 4 points or NO irrigation WE 2: Innovative Reduce potable water for 2 points Wastewater sewage conveyance or 2 points max treat to tertiary (50%) WE 3: Water use 3.1 Use 30% Reduction 2 points reduction (all indoor (20% is prerequisite v 3.0) fixtures; not irrigation) 4 points max 3.2 Use 35% reduction adds 1 point 3.3 Use 40% reduction adds 1 point Source: USGBC LEED for New Construction Rating System, 2009
  • Example Commercial Building Indoor Rainwater Application (WE 2 Option 1; LEED-NC v 3.0) http://www.sloanvalve.com Source: Building Green Futures (www.buildinggreenfutures.com)
  • CA Dual Plumbing Code 2010 • Air gap required (recycled and potable) • Water disinfected to tertiary recycled standard (CA Dept Public Health; filtration/chlorine) • Allowed structures specified by 13553 Water Code (no single-family residential) Source: California Plumbing Code Chapter 16A-Part II, 2010
  • Non-potable Indoor Use of Rainwater* • Gutters & tank inlet with debris screen • First flush/roof washer (first 10 gallons) • Return elbow or calming inlet • UV-resistant for above-ground • Air gap or back-flow assembly (municipal vs. rainwater) • Label pipes and fixtures • Disinfection is not required * Code Guide for Rainwater Harvesting; City of Portland for one and two family dwellings, 2001
  • Rainwater Harvesting Overview • Benefits of rainwater harvesting • System components • Water-harvesting earthworks • Estimating supply & demand to size tanks
  • Benefits of Rainwater Harvesting COMMUNITY • Storm water management (reduces run off to storm drains) • Reduces summer peak water demands (conserves water) INDIVIDUAL • Superior water for irrigation (soft, non-alkaline) • Lower water bills (1st tier) • Possible rebates/incentives (AB 1834)
  • Components of Rainwater Harvesting for Irrigation Roof catchment area Gutters & downspout Storage Tank To drip system/hose Overflow Pump Source: Building Green Futures (www.buildinggreenfutures.com)
  • Above-ground Tanks Source: RainHarvest Systems Source: Tankworks Australia Source: BH Tanks Inc. Source: Bushman Tanks USA
  • Below-ground Tanks Source: Graf Rainwater Tanks Source: Rainwater Collection Solutions Source: Xerxes Fiberglass Tanks Source: Atlantis Water Management
  • Using Earthworks Source: Building Green Futures (www.buildinggreenfutures.com)
  • Landscape Features that Manage Stormwater Source: EncinitasStormwaterManual, 2009 Source: SD County LID manual, 2007 Photograph: City of Encinitas, Roadside GrassCrete parking
  • Sustainable Water Management Source: Building Green Futures (www.buildinggreenfutures.com)
  • Sizing a Rainwater Tank based on Supply & Demand
  • Basic formula to calculate monthly or annual collection volume in gallons: SUPPLY (gallons) = Catchment Area (ft2) X Rainfall (ft) X Runoff Coefficient X 7.48 gallons/ft3 Note: Runoff coefficient = 0.9 for a typical roof Example scenario: a 2,000ft2 building: 2000ft2 x 0.83ft/yr x 90% x 7.48 gal/ft3 = 11,175 gallons per year!! Basic formula to calculate monthly or annual irrigation demand in gallons: DEMAND (gallons) = (ETo X Plant Factor) X Area (ft2) X 7.48 gallons/ft3
  • Estimating Supply & Demand Source: Building Green Futures (www.buildinggreenfutures.com)
  • Outdoor Water Usage • Drought-tolerant and native plant choices (and soil/mulch) • Brief introduction to gray water for irrigation • Rainwater Harvesting Design Strategies (for San Diego County) • Example projects
  • Graywater Code for California • Ch 16A “Nonpotable Water Reuse Systems” added to 2007 California plumbing code August 4, 2009 • 1603A.1.1 Clothes Washer System and/or Single Fixture System: May be installed without a permit if in compliance • May not result in ponding or run-off • Design directs to irrigation and contained on site • If released above-ground requires >/= 2” mulch
  • Graywater System to Mulch Basins www.yourhome.gov.au/technical/fs74.html
  • Characteristics of Drought-tolerant Plants Source: Building Green Futures (www.buildinggreenfutures.com)
  • Resources for Drought-Tolerant and Native Plants • Sunset Western Garden Book by Editors of Sunset Books and K. N. Brenzel; watering designation 1 or 2 • San Diego County Native Plants by James Lightner (2006, San Diego Flora) • http://www.water.ca.gov/wateruseefficiency/docs/wuc ols00.pdf Water Use Classification of Landscape Species (University of California Cooperative Extension) • http://www.bewaterwise.com/knowledge01.html California Friendly Garden resource (from MWD) • http://www.thegarden.org/ Water conservation Garden at Cuyamaca College; bookshop & classes
  • Project 1: An Above- ground System with a 550 gallon tank Source: Building Green Futures (www.buildinggreenfutures.com)
  • Project 2: An Above- ground System with (2) 2,000 gallon tanks and French drains to landscape Source: Building Green Futures (www.buildinggreenfutures.com)
  • Project 3: a Rainwater Pillow Source: Building Green Futures (www.buildinggreenfutures.com)
  • Source: Building Green Futures (www.buildinggreenfutures.com)
  • Project 4: A Modular Underground Storage System Source: Building Green Futures (www.buildinggreenfutures.com)
  • Source: Building Green Futures (www.buildinggreenfutures.com)
  • WE Credits for LEED-Homes: Maximum 15 points possible WE (min 3 pts) Credit Points Project item WE 1: Water Reuse 1.1 Rainwater 3 points outdoor 2 x 1700 gallon 5 points max Harvesting System 1 point indoor cisterns for irrigation And/or only = 3 1.2 Graywater 1 point Clothes washer = 1 OR 3 pts max if use 1.3 Municipal instead of Recycled Water 1.1-1.2 WE 2: Irrigation 2.1 Hi-efficiency 3 points max 4 points max 2.2 3rd party 1 point max OR 2.3 Reduce 4 points max irrigation demand WE 3: Indoor Water 3.1 Hi-efficiency 3 points if all fixtures All fixtures meet Usage fixtures/fittings standards = 3 6 points max 3.2 Very hi-efficiency (6 points max) TOTAL = 7 System size = Harvest area/Total Roof Area Storage capacity = 0.62 gal/ft3 x Harvest area Therefore 2,000 ft2 roof area min capacity = 620 gallons; max = 12,000 gallons
  • Project 5: Rainwater Harvesting at NC Schools: indoor and outdoor usage Diagrams and Photo Courtesy of Innovative Design (Raleigh, NC)
  • Resources • http://www.sandiego.gov/water/conservation Rainwater harvesting information; residential water surveys (free) • http://www.bewaterwise.com ; Rebates and incentives (So Cal Metropolitan Water District) • http://socalwatersmart.com/index.php; Rebates/incentives • http://www.harvesth2o.com/ ; Online rainwater harvesting community • http://www.arcsa.org/Rainwater-10-09.pdf; Rainwater Catchment Standards ARCSA and ASPE
  • Resources; continued • http://www.epa.gov/npdes/pubs/gi_municha ndbook_harvesting.pdf; EPA Rainwater Harvesting Guidelines • http://www.whollyh2o.org; California’s Integrated Water Reuse Management Center • http://www.h2ouse.org; California’s Urban Water Conservation Council • http://www.oasisdesign.net/greywater/law/ca lifornia/; California Graywater Policy Center • Rainwater Harvesting for Drylands vol 1-3 by Brad Lancaster, Rainsource Press (2005-2011)
  • IF we combine low water use fixtures with water reuse indoors and outdoors we can: • Reduce wastewater and stormwater runoff • Reduce use of potable water • Increase water reuse • Restore natural hydrologic cycle • Preserve freshwater for future generations
  • “." Contact: Rosalind Haselbeck, PhD, LEED AP (619) 300-7114 rosalind@buildinggreenfutures.com