1. Graywater Use by Urban Households: a sustainability issue DAVID ZAHLER GEO 300 Environmental Conservation OLGA Oregon Legal Graywater Association

2. OutlineOutline The SceneThe Scene OLGAOLGA –Mission –Vision ConservationConservation –Water Use –Potential benefits –Other Conservation Measures –Graywater Rules ConclusionsConclusions http://www.oasisdesign.net

3. Graywater:Graywater: –Water from laundry, bathtub, shower and (some) sinks; –Water that has been used and is no longer drinkable; –BUT, graywater has NEVER come in contact with human waste OLGA wants to use this graywater for irrigation purposesOLGA wants to use this graywater for irrigation purposes The Scene

4. 2003 Corvallis Pop: 50,0002003 Corvallis Pop: 50,000 In 20-40 years: 60-80,000In 20-40 years: 60-80,000 Water sources:Water sources: –Rock Creek –Willamette River –Groundwater: 5 wells http://sarasota.extension.ufl.edu/

5. Water Use by Customer ClassWater Use by Customer Class Source: Mark Taratoot, Corvallis Public Works The Scene OLGA

6. Projection of Water Demand by PopulationProjection of Water Demand by Population Source: Economic and Engineering Services, inc The Scene

7. Projection: Anticipated rate of water withdrawal from the Willamette RiverProjection: Anticipated rate of water withdrawal from the Willamette River Source: Economic and Engineering Services, inc The Scene

8. Projections based on current Urban Growth BoundaryProjections based on current Urban Growth Boundary Changes in use patterns of any or all customer classes would change future water demandChanges in use patterns of any or all customer classes would change future water demand Other unforeseen changes may reduce future water demandOther unforeseen changes may reduce future water demand –City of Corvallis is exploring the possibility of recycling treated wastewater The Scene

9. Corvallis can produce enough drinkable water to support population projectionsCorvallis can produce enough drinkable water to support population projections But… single family dwellings are a major consumer of this water, and a significant volume is used for reasons other than drinking or eatingBut… single family dwellings are a major consumer of this water, and a significant volume is used for reasons other than drinking or eating “Graywater” can be used as/considered a resource, not a waste item“Graywater” can be used as/considered a resource, not a waste item The Scene

10. Organizational Vision Statement:Organizational Vision Statement: –…dedicated to the creation of sustainable Oregon Communities with respect to water use. –Water use as an important indicator for sustainability: A gallon used twice is a gallon that stays unprocessed in our waterways;A gallon used twice is a gallon that stays unprocessed in our waterways; Energy used for water transport and purification is reduced; Energy used for water transport and purification is reduced; City saves money on water coming and going;City saves money on water coming and going; OLGAOLGA

11. One gallon of graywater used by urban households is one gallon of potable water reserved for its highest and best use—human consumption. OLGAOLGA

12. Organizational Mission Statement:Organizational Mission Statement: … assist the State of Oregon to develop, test (through household demonstration sites), and adopting graywater use regulations that facilitate reduced water consumption in urban households through safe, effective, graywater use. OLGAOLGA

13. Household Water Use for an Average Home:Household Water Use for an Average Home: ConservationConservation

14. ConservationConservation Blackwater Sources (?)

15. Household Water Use for an Average Home:Household Water Use for an Average Home: ConservationConservation “Easy” Graywater Sources (some faucets)

16. Graywater Savings:Graywater Savings: –Use 9 gallons/person/day from showers –Use 5 gallons/person/day from faucets –Use 10 GPD from clothes washer… –…to water your garden perennials, you conserve about 25 GPD for “highest and best use” … 60 gallons per day in an average household! ConservationConservation

17. Other Conservation Measures: SAVINGSOther Conservation Measures: SAVINGS –Install high efficiency toilet: 10 GPCD –Install efficient showerhead: 3 GPCD –Install efficient clothes washer: 5 GPCD –Fix leaks! 5 GPCD TOTAL Savings:23 GPCD The irony: Increased efficiency leads to less available graywater for irrigation purposes.The irony: Increased efficiency leads to less available graywater for irrigation purposes. ConservationConservation

18. Graywater Rules:Graywater Rules: –Defines how a system should be constructed ConservationConservation

19. Graywater Rules:Graywater Rules: –Defines how a system should be constructed –Defines where a system can be constructed ConservationConservation

20. Graywater Rules:Graywater Rules: –Defines how a system should be constructed –Defines where a system can be constructed –Defines when a system can be used ConservationConservation

21. Graywater Rules:Graywater Rules: –Defines how a system should be constructed –Defines where a system can be constructed –Defines when a system can be used –Defines how graywater is applied ConservationConservation

22. Graywater Rules:Graywater Rules: –Defines how a system should be constructed –Defines where a system can be constructed –Defines when a system can be used –Defines how graywater is applied –Defines graywater and what nasty things shouldn’t be in it ConservationConservation

23. Graywater Rules:Graywater Rules: –Such rules can make graywater use for irrigation purposes safe and part of the water conservation “toolkit” for urban households ConclusionConclusion

24. The State of Oregon, through DEQ rules, can proactively change the culture of domestic water consumption through safe, legal graywater use. ConclusionConclusion