Karen DuBose

1
Water Reuse in Corvallis A model of public
acceptance

• Karen DuBose
• March 11, 2009

2
The Situation

• Corvallis wastewater treatment plant will exceed
  its TMDL water quality requirements as the city
  grows

• Wastewater recycling is an excellent solution
• No need to discharge into the river
• Advances the citys sustainability ethic

3
Goals of this study

• Discover what factors influence the public
  acceptance of water reuse in Corvallis
• Make recommendations to the city about how to
  pursue a wastewater recycling project

4
Factors that have been found to influence public
opinion

• Age
• Gender
• Education
• Income
• Occupation
• Length of residence
• Degree of contact
• Prior knowledge of water reuse

• Awareness of water problems
• Presence of children
• Trust in local public utility
• Health effects
• Environmental effects
• Cost of project
• Public opinion of reuse

5
Methods

• December 2008 survey of registered voters, 46
  response rate
• 19 questions, six were demographic
• Multiple linear regression

6
A model of public acceptance in Corvallis

• Acceptance ß0 ß1(Informed) ß2(Knowledge)
• ß3(Aware)
  ß4(Sustainability) ß5(Trust)
• ß6(Gender) ß7(Age)
  ß8(Children present)
• ß9(Education)

• Dummy variables knowledge, aware, gender, age,
  children present

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Measuring knowledge
8
Measuring sustainability ethic
9
Acceptance of recycled water uses
10
Percentage of respondents choosing "very
favorable" or "favorable" for various recycled
water uses.
11
Grouping uses of recycled water

• Factor analysis looks for patterns in responses
• 3 groups of recycled water uses
• High contact (irrigate schools, public parks,
  edible crops)
• Low contact (irrigate business parks, golf
  courses, non-edible crops, use in industrial
  processes)
• Other uses (building cooling, toilet flushing,
  fire hydrants, car washes)
• Factor scores were used in 3 regressions, one for
  each group

12
Regression coefficients for factors of water
reuse acceptance
P-values for the coefficients are in parenthesis.
Red values are significant at 95 denote
significance at 90.
13
Policy implications

• City should pursue water reuse there is high
  acceptance of most uses
• Low contact uses are most accepted
• Make sure a program adheres to the principles of
  sustainability
• Educate public about wastewater treatment, water
  reuse, technologies, and reason for water reuse
• If high contact uses are chosen, make a special
  effort to include women

14
Study limitations

• Results should be considered hypothetical
• Studies show that factors influencing acceptance
  change when specific plans are presented
• Little information about water reuse was
  presented due to space
• Many respondents stated they wanted more
  information

15
Questions?
Support provided by Institute for Water and
Watersheds
Master of Public Policy Program