Karen DuBose March 11, 2009

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 city’s sustainability ethic

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

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

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

A model of public acceptance in Corvallis Acceptance = β 0 + β 1 (Informed) + β 2 (Knowledge) + β 3 (Aware) + β 4 (Sustainability) + β 5 (Trust) + β 6 (Gender) + β 7 (Age) + β 8 (Children present) + β 9 (Education) Dummy variables: knowledge, aware, gender, age, children present

Q-4 For the following terms, please indicate if you know what the term means, have heard of the term but don’t know its meaning, or have not heard of the term at all. Have not heard of the term at all Have heard of the term but don’t know its meaning Know what the term means a. Potable water 123 b. Wastewater 123 c. Greywater 123 d. Sewage 123 e. Recycled water 123 f. Effluent 123 Measuring knowledge

Measuring sustainability ethic Q-6How important are each of the following when choosing an approach to meeting the new water quality regulations in the Willamette River? If you have no opinion of one, please leave it blank. Not Important at All Limited Importance Somewhat Important ImportantVery Important a. Prevent pollution b. Protect human health c. Be a long term solution d. Be energy efficient e. Be financially sound f. Protect fish and wildlife g. Have low greenhouse gas emissions 12345

Acceptance of recycled water uses Q-7How much do you favor the use of recycled wastewater for each of the following? If you don’t know or have no opinion of a use, please leave it blank. Highly Unfavorable UnfavorableNeutralFavorableHighly Favorable a. Irrigate golf courses b. Irrigate landscaping in business parks c. Irrigate public parks d. Irrigate school grounds e. Irrigate non-edible agricultural crops (grass) f. Irrigate agricultural crops for human consumption g. Use in industrial processes h. Use to cool buildings i. Flush toilets in public buildings j. Supply fire hydrants in the city k. Supply car wash businesses 12345

Percentage of respondents choosing "very favorable" or "favorable" for various recycled water uses.

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

Regression coefficients for factors of water reuse acceptance Independent VariableHigh ContactLow ContactOther Uses Informed (0.794) (0.184) (0.157) Knowledge of wastewater (0.909) (0.009) (0.120) Aware of problem (1=yes) (0.000) (0.862) (0.694) Sustainability index (0.051) (0.101) (0.003) Trust to serve public interest (0.109) 0.125* (0.067) (0.237) Gender (1=male) (0.004) (0.029) (0.474) Age (0.324) (0.306) (0.355) Education (0.627) (0.485) (0.028) Children present (1=no) (0.663) (0.104) 0.172* (0.088) P-values for the coefficients are in parenthesis. Red values are significant at 95%; * denote significance at 90%.

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

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

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