Graywater Use by Urban Households: a sustainability issue

1. Graywater Use byUrban Households:a sustainability issue OLGAOregon Legal Graywater Association DAVID ZAHLER GEO 300 Environmental Conservation

2. The Scene – OLGA – Conservation – Conclusion Outline • The Scene • OLGA • Mission • Vision • Conservation • Water Use • Potential benefits • Other Conservation Measures • Graywater Rules • Conclusions http://www.oasisdesign.net

3. The Scene–OLGA – Conservation – Conclusion The Scene • 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 purposes

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

5. The Scene– OLGA – Conservation – Conclusion The Scene • Water Use by Customer Class OLGA Source: Mark Taratoot, Corvallis Public Works

6. The Scene– OLGA – Conservation – Conclusion The Scene • Projection of Water Demand by Population Source: Economic and Engineering Services, inc

7. The Scene– OLGA – Conservation – Conclusion The Scene • Projection: Anticipated rate of water withdrawal from the Willamette River Source: Economic and Engineering Services, inc

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

9. The Scene– OLGA – Conservation – Conclusion The Scene • Corvallis 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 eating • “Graywater” can be used as/considered a resource, not a waste item

10. The Scene – OLGA – Conservation – Conclusion OLGA • 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; • Energy used for water transport and purification is reduced; • City saves money on water coming and going;

11. The Scene – OLGA – Conservation – Conclusion OLGA One gallon of graywater used by urban households is one gallon of potable water reserved for its highest and best use—human consumption.

12. The Scene – OLGA – Conservation – Conclusion OLGA • 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.

13. The Scene –OLGA – Conservation – Conclusion Conservation • Household Water Use for an Average Home:

14. The Scene –OLGA – Conservation – Conclusion Conservation • Household Water Use for an Average Home: Blackwater Sources (?)

15. The Scene –OLGA – Conservation – Conclusion Conservation • Household Water Use for an Average Home: (some faucets) “Easy” Graywater Sources

16. The Scene –OLGA – Conservation – Conclusion Conservation • 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!

17. The Scene –OLGA – Conservation – Conclusion Conservation • Other 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.

18. The Scene –OLGA – Conservation – Conclusion Conservation • Graywater Rules: • Defines how a system should be constructed

19. The Scene –OLGA – Conservation – Conclusion Conservation • Graywater Rules: • Defines how a system should be constructed • Defines where a system can be constructed

20. The Scene –OLGA – Conservation – Conclusion Conservation • Graywater Rules: • Defines how a system should be constructed • Defines where a system can be constructed • Defines when a system can be used

21. The Scene –OLGA – Conservation – Conclusion Conservation • 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

22. The Scene –OLGA – Conservation – Conclusion Conservation • 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

23. The Scene –OLGA – Conservation – Conclusion Conclusion • Graywater Rules: • Such rules can make graywater use for irrigation purposes safe and part of the water conservation “toolkit” for urban households

24. The Scene –OLGA – Conservation – Conclusion Conclusion The State of Oregon, through DEQ rules, can proactively change the culture of domestic water consumption through safe, legal graywater use.