Global fresh water resources are under increasing pressure from rapidly growing demands and changing climatic conditions. Wastewater reclamation is becoming an important alternative for sustainable water resources management and building climate change resiliency in many regions around the world. Public acceptance and trust of consumers in the quality of reclaimed water is considered by many to be the most important factor determining the outcomes of water reclamation projects. Knowledge of the urban water cycle and water reuse perceptions of student, faculty and staff at Western University were investigated. Results showed that members of the university community are more likely to accept reclaimed wastewater for applications that do not involve drinking or close personal contact. Knowledge of the urban water cycle and water resources in Canada is modest among the university community with a moderate (G = 0.303, p < 0.05) positive relationship between ‘water knowledge’ and ‘close contact acceptability’. The majority of the university community (75.8%) thinks that reclaiming water to provide an alternate source of water in southwestern Ontario is a good idea, but there are still concerns about the presence of chemicals such as pharmaceuticals from reclaimed water and the long-term effects on human health from exposure to these contaminants.
- public perceptions on water reuse
- wastewater reclamation
- water resources management
Achieving sustainable water resources management around the globe is a complex task, with unique challenges to every specific region. These challenges include physical water scarcity, economic water scarcity, water quality degradation, and socio-political circumstances among others. Fresh water only constitutes 3% of the total amount of water on the planet and out of this 3%, 99% is locked up in icebergs, glaciers, and underground (Brooymans 2011). Global water resources are already under increasing pressure from rapidly growing demands for agriculture, production of energy, industrial uses, and human consumption. In addition, global climate change is expected to exacerbate current and future stresses on water resources from population growth and land use, and increase the frequency and severity of droughts and floods (UNESCO 2012).
Reducing water consumption through water conservation strategies and technological advances and searching for new water sources are the main forms of reducing the pressure that results from physical water scarcity. New water sources may include the recovery of rain and stormwater runoff, desalination of seawater or brackish groundwater, on-site gray water reuse, and the reclamation of municipal wastewater effluents (NRC 2012). Wastewater reclamation is becoming an increasingly important alternative for achieving sustainable water resources management in many regions of the world. It is the process of treating wastewater to high quality standards to make it suitable for reuse. Depending on the level of treatment, reclaimed wastewater may be utilized for potable or non-potable applications.
The main factors driving water reclamation projects around the world have been identified to include lack of water availability, high levels of local water demand, the need for reliable sources of water, the protection of aquatic environments and stringent restrictions on effluent disposal (Exall et al. 2006; Jimenez & Asano 2008). The highest levels of wastewater reclamation take place in regions suffering from water scarcity, such as in the Middle East, Australia, the Mediterranean and the south western USA (Exall et al. 2006). Agriculture is by far the most important reuse option in terms of volume, basically because it accounts for 70% of total water withdrawals for all sectors/human uses (UNESCO 2012).
Urban wastewater reclamation can be classified into non-potable, indirect potable, and direct potable reclamation. Non-potable uses include irrigation, nature restoration (environmental flows), household toilet flushing, and industrial process water (Rygaard et al. 2011). Indirect potable reclamation is the process of supplementing natural water bodies utilized as drinking water supplies by the addition of treated wastewater (Asano et al. 2007). Direct potable reclamation is the introduction of reclaimed water directly into the potable water supply distribution system. In addition, some authors make a distinction between intended and unintended, indirect potable reuse (Asano et al. 2007; Wintgens et al. 2008; Rygaard et al. 2011). Unintended (de facto) indirect potable reuse occurs along major river catchments around the world, where the drinking water supplies are influenced by wastewater discharges by upstream users, while intended indirect potable reuse includes applications such as aquifer and surface water reservoir recharge.
Municipal wastewater reclamation in Canada has been generally conducted on a small scale or experimental basis, mainly for golf course, urban landscape, and agricultural irrigation. Industrial wastewater recycling is a more common practice, where approximately 40% of the total water usage is recycled (Exall et al. 2006). National guidelines for wastewater reuse are limited to the use of domestic reclaimed water for use in toilet and urinal flushing (HC 2010). In addition, some guidelines and/or regulations for wastewater reclamation have been developed at the provincial level by British Columbia, Alberta, Saskatchewan, Manitoba, and Prince Edward Island (CMHC 2005). The lack of interest and legislated support for water reclamation in Canada may be driven by the general belief that Canada is a water-rich country and its inhabitants do not need to worry about water shortages. However, although Canada has 20% of the world's total fresh water resources, only 7% is renewable. Furthermore, 60% of this renewable water supply flows north to the Arctic Circle, making it unavailable for the majority of Canadians that resides along its border with the USA (Environment Canada 2013). Fresh water in Canada is not an unlimited resource and is already under pressure in some areas of the country due to population growth, changing climatic conditions, and excessive extraction by agriculture and industry.
Public acceptance and trust of consumers in the quality of reclaimed water is considered by many to be the most important factor determining the outcomes of water reclamation projects. A major psychological barrier to using reclaimed wastewater is its association with raw sewage, which creates discomfort in the majority of people. For this reason, wastewater reclamation advocates prefer to use the term ‘re-purified water’ instead (Po et al. 2003). A study by the Water Reuse Foundation in which 2,695 people were surveyed in five US cities, some of which are experiencing fresh water shortages, showed that reclaimed wastewater is less likely to be rejected if it has been certified as safe by scientists, has been highly processed, and/or has been in contact with natural systems such as aquifers and rivers for some time (Haddad et al. 2009). In addition, several studies (Table 1) conducted during the last decade have shown a higher degree of public acceptance of reclaimed water applications that do not involve close personal contact (such as industrial uses, lawn irrigation, firefighting, car washing, and agricultural uses). The use of reclaimed water for applications involving drinking or close personal contact, where there is risk of human ingestion, is less acceptable. Only one study in water reuse perceptions has been previously undertaken in Canada, which was commissioned by the Lake Simcoe Region Conservation in Ontario.
The goal of the present research is to study the perceptions of students, faculty, and staff at Western University, London, Ontario, Canada, about the reuse of treated wastewater for potable and non-potable applications. This survey is part of a broader research project investigating the potential for wastewater reclamation and purification in a high water demand region, such as southwestern Ontario.
Western University (formerly The University of Western Ontario), located in London, Ontario, has a community of over 30,000 people: 21,801 undergrad students, 4,770 graduate students, 2,461 full-time staff, and 1,408 faculty members (UWO 2013). The City of London is located in southwestern Ontario and has a population of 366,151 (2011 census). Potable water in the City of London is primarily extracted from two sources: Lake Huron and Lake Erie (see Figure 1). In addition, a network of seven groundwater wells from an unconfined overburden sand aquifer and a confined overburden sand and gravel aquifer are maintained as back up for emergency situations (UTRCA 2011; City of London 2014b). Wastewater is treated by six wastewater treatment plants operated by the city and discharged into the Thames River (City of London 2014a). The Thames River, which extends for 273 km, flows into Lake St. Clair. It is important to note that Lake St. Clair is part of the Lake Erie basin. Therefore, unintended (de facto) indirect potable reuse is already part of the daily lives of the inhabitants of southwestern Ontario.
An online survey was created to investigate the perceptions of students, staff, and faculty at Western University regarding wastewater reclamation. The survey was composed of 14 questions divided into three sections and included a schematic explanation of a generic wastewater reclamation process. The first section included demographics of the participants, the second section focused on general knowledge regarding water consumption and treatment, and the third section focused on the perception on wastewater reclamation (see Table 2). After the survey was approved by the University's Research Ethics Board for Non-Medical Research Involving Human Subjects, an invitation to participate in the online survey was launched and sent by e-mail to students, faculty, and staff on the main campus. The survey was hosted on a third-party website (www.surveygizmo.com), which permitted the participants to complete the survey online in a confidential manner. The raw data were subsequently retrieved at the completion of the survey (after 3 months) for analysis. A total of 432 participants completed the online survey from 15 September to 15 December 2013. Fifty-two (52) responses were not considered in the analysis because of incomplete answers to some of the questions. The remaining 380 responses allowed for an analysis with a confidence level of 95% and a margin of error of 5%. Statistical analysis was performed using the IBM Statistical Package for the Social Sciences, released 2013, version 22.
RESULTS AND DISCUSSION
Out the 432 respondents, 221 (51.2%) were female and 208 (48.1%) were male, which is comparatively close to the number of females and males of the Western University community. Students accounted for 63.8% of the respondents, while faculty and staff accounted for 17.4 and 18.7%, respectively. Furthermore, among the student respondents, 47% were undergraduate students and 53% were graduate students. Therefore, the survey responses show an under-sampling of undergraduate students and an over-sampling of graduate students, faculty, and staff. This is consistent with the results of a similar survey undertaken at Ohio State University Campus (Vedachalam & Mancl 2010) where graduate and older students were more likely to respond. Therefore, post-stratification weights were applied to the survey results to make the responses more representative of the university population in terms of occupation. Table 3 shows the proportion of respondents and the university community demographics in terms of occupation, and the post-stratification weights applied to the data.
Tests of independence between ‘occupation’ (Undergraduate, Graduate, Staff, and Faculty) and the rest of the survey questions were performed using the chi square test. Whenever there were cells with an expected count less than 5, Fisher's exact test was used. If the null hypothesis was rejected (p < 0.05), the strength of association was measured by Cramer's V coefficient. The tests' independence showed that answers to the majority of the questions were not significantly dependent (p > 0.05) on the occupation of the respondent. Only responses to questions 8a and 8b were significantly dependent on the respondent's occupation (p < 0.05). Nevertheless, the strength of association was weak in both cases. Table 4 shows the results of test of independence for questions 8(a) and 8(b).
The first question of the second section (Q3) was regarding knowledge of average domestic water usage by Canadians. Average daily residential water usage in Canada is currently 251 liters per capita (Statistics Canada 2013). Therefore, Canadians consume approximately TWO times the average daily global domestic water use (SASI Group & Newman 2006). If all uses are included, Canadians consume approximately three times the world average. Twenty-four percent (24%) of the university community answered correctly that average daily domestic water usage by Canadians is approximately twice the global average. Only 9% of the university community believes domestic water usage by Canadians is about the same as the world average. The remaining 67% of the university community believes Canadians use more than twice (three or four times) the average daily global domestic water. The second question of this section (Q4), regarding fresh water availability was answered correctly by 92% of the university community. The third question of this section (Q5) was concerned with knowledge about the source of domestic potable water consumption. Fifty percent (50%) of the university community answered correctly that their drinking water comes from the Great Lakes. Approximately 10.3% responded that their drinking water comes from a groundwater well, which is only correct if they reside outside of London in a region that depends on groundwater. About 5.5% of the university community responded that their drinking water source is the Thames River, which is definitely incorrect, and 3.5% responded that their drinking water comes from a source not stated in the survey. An astonishing 30.7% of the university community did not know where their drinking water came from. The fourth question of section 2 (Q6) was answered correctly by 80.3% of the university community. Some 9.2% responded that wastewater is treated by a septic tank, which is only correct if they reside in a rural area, and 10.5% of the university community did not know who took care of domestic wastewater. The fifth question of section 2 (Q7) was concerned with knowledge about the discharge of treated municipal wastewater. Exactly 26.9% of the respondents answered correctly that treated wastewater effluent is discharged into the Thames River, and 23.4, 5.2, and 6.7% of the respondents believed treated wastewater is released to the Great Lakes, underground or other location not mentioned in the survey, respectively. Nearly 40% (39.7%, precisely) of respondents did not know where treated wastewater was released to. The sixth question of section 2 (Q8) was regarding familiarity with terms broadly used in the water resources management field. Questions 8(a) and 8(b) were significantly dependent on the occupation of the respondent. Responses to question 8a, which asked about familiarity with the ‘potable water’ term, shows that 93% of the faculty, 85% of graduate students, 72% of the staff, and 69% of undergraduate students know what it means. Similarly, question 8(b), which asked about familiarity with the term ‘non-potable water’, shows that 93% of the faculty, 86% of graduate students, 67% of the staff, and 68% of undergraduate students know what it means. Responses to questions 8(c)–8(h) were significantly independent of the occupation of the respondent. The percentage of the university community that knows what the following terms mean are: stormwater (78.5%), gray water (39%), blackwater (22.7%), wastewater (80.5%), recycled water (68.1%), and reclaimed water (30.4%). Figures 2⇓⇓⇓⇓⇓⇓–9 show a summary of the responses to section 2 of the survey.
Section 3 of the survey, which was concerned with perceptions about wastewater reclamation, comprised six questions (Q9–Q14). Five of these questions were categorical and one was open ended. To the first question of this section (Q9), which asked the participants whether or not they thought undertaking water reclamation projects as an alternate source of water in southwestern Ontario was a good idea, 75.8% of respondents considered it a good idea; 21.6% was unsure about it and 2.5% thought it was not a good idea. Question 10, asked about the acceptability of specific uses for reclaimed wastewater. Responses show that the closer the reclaimed wastewater is to human contact or ingestion, the lower is its acceptability. Table 5 summarizes the responses to question 10.
Responses to question 11, which was concerned with trustworthy sources of information about the safety of reclaimed wastewater, show that the university community considers university professors and the regional health unit to have the highest level of trustworthiness among the given options. The internet and the media were considered the less trustworthy sources of information. Table 6 summarizes the responses to question 11.
Question 12, which considers changes in the level of acceptability of reclaimed wastewater under different scenarios, shows that acceptability considerably increases if the reclaimed water only includes stormwater and/or gray water. If ‘high increase’ and ‘slight increase’ are combined, the increment of acceptability of the proposed scenarios would rank as (highest to lowest): (1) the reclaimed water only includes stormwater; (2) the reclaimed water only includes stormwater and gray water; (3) the reclaimed water is used for aquifer recharge before use; (4) the reclaimed water is mixed with natural lake water before use; and (5) the reclaimed water is mixed with natural river water before use. Table 7 summarizes the responses to question 12.
Question 13 asked the participants if they agree or disagree with a group of statements regarding wastewater reclamation. The statement with the highest level of agreement (90.8%) by the university community was ‘if the benefits to the environment are extensive, they would support water reclamation initiatives as long as it is safe for humans'. The statement with the lowest level of agreement (25.5%) by the university community was ‘Natural water from lakes, rivers and aquifers are of higher quality than reclaimed water from the treatment plant’. Table 8 summarizes the responses to question 13. Figures 10⇓⇓⇓–14 show a graphical summary of questions 9–13.
Question 14 was an open-ended question that gave the respondents the opportunity to comment on water reclamation. A total of 92 respondents submitted their comments regarding water reclamation initiatives. The following are a few of the respondents' comments randomly selected (simple random sample):
Respondent #18: I support use of water reclamation, but am absolutely puzzled that there is not an irrigation water system. I am baffled that we use potable water to water a lawn.
Respondent #22: As long as water is treated for human consumption, I don't care where it comes from. So-called ‘natural water’ is not used without treatment (to remove run-off, sediments, fish feces, dead insects, or whatever) so I don't care about re-used/reclaimed water either. Unlike many of my contemporaries, I am not squeamish about these things and don't feel the need to live in an antiseptic, plastic bubble.
Respondent #40: Water reclamation is a great idea. Most people don't understand a lot of times it's cleaner than the stuff coming out of their taps. It's a psychological thing – we need a fairly significant paradigm shift before it will become publicly acceptable.
Respondent #60: I noted that reclaimed water wasn't acceptable for golf course or landscape irrigation because I think these are unnecessary. I don't think *any* water should be used for these.
Respondent #91: Initiatives taken on campus regarding use of reclaimed water are a positive step forward. Continued education regarding the benefits and environmental savings of such programs need to be in the forefront of campus media (i.e., through the Facilities Management portion of the primary website).
Respondent #111: I think water reclamation is very important and we need to study how this can be done safely. Global climate change (warming) is happening very quickly and water may become scarce much sooner than people think.
Respondent #121: It is difficult to know who to trust since the general public are uninformed about these processes and how the decisions are made and based on what?
Respondent #137: I am concerned about lingering chemicals/pollutants in reclaimed water provided for drinking, cooking and bathing….
Respondent #139: I think that water renewability and abundance is an important topic that many North Americans do not often consider. Education of the general public on the situation of our extremely slowly renewing aquifers and the amount of usage our lakes and rivers are undergoing currently may improve support for water reclamation programs.
Respondent #175: From a financial perspective, the ROI must make it feasible (at least break even). Would probably be easier to sell to the public if they didn't know the details – just say it's tested, safe, and the same as natural water.
Respondent #177: Water is the most important resource on Earth, it should be treated as such. Using potable water to flush toilets is a waste of resources. Water from natural sources (lakes, rivers) should be protected from agricultural pollutants and screened very carefully before consumption. Water from aquifers should be protected since it would take a long time to renew. Water should be used wisely, having a golf course in places where water is scarce is not a wise use of it. Therefore I support the idea of water reclamation as a way to improve the efficiency of water use and to protect wet ecosystems.
Only 24% of the respondents correctly answered that the average daily domestic water usage by Canadians is approximately twice the global average. Therefore, it can be concluded that accurate knowledge of domestic water consumption among the university community is low. However, since only 9% of the respondents believe domestic water usage by Canadians is about the same as the world average, it can be deduced that the majority of the university community believes that water usage in Canada is excessive when compared to the rest of the world. This is especially true when other uses such as power generation and industry are taken into consideration. On the contrary, knowledge about fresh water availability in Canada is high, since 92% of the university community correctly answered this question. Although the majority of the university community (80.3%) knows that wastewater in London is treated by the municipal sewage treatment system, there is low to moderate knowledge of the urban water cycle in London, Ontario. Fifty percent (50%) of the university community knows where London's drinking water comes from and only 26.9% knows where wastewater is released to, after treatment.
University faculty are more familiar with the terms ‘potable water’ and ‘non-potable water’ than students and staff. Furthermore, graduate students are more familiar with these terms than undergraduate students and university staff. Familiarity with the remaining terms specified in question 8, which are not significantly dependent on the occupation of the respondents, was higher for the terms ‘wastewater’ (80.5%) ‘stormwater’ (78.5%), and ‘recycle water’ (68.1%).
Subsequently, the six questions of part 2 of the survey were recoded, computed and collapsed into a single ordinal variable named ‘water knowledge’ with three symmetric categories: low (1), moderate (2), and high (3) knowledge. It can be concluded that 60.4% of the university community has a medium level knowledge of water resources and urban water cycle in London, Ontario. Moreover, 13.8% and 25.8% of the university community has low and high water knowledge, respectively. Table 9 shows the percentage of respondents from the university community that falls in each category. Figure 15 shows a histogram of these results.
Results of question 10 of the survey were consistent with previous studies regarding perceptions and acceptance of wastewater reclamation. Acceptability of reclaimed wastewater for application not involving drinking or close personal contact was very high (>85%) in all the stated cases, regardless of water availability. Acceptability of applications involving drinking or close personal contact showed higher variability depending on the respondent's perceived risk. These include: drinking (42.1%), cooking (51.1%), public swimming pools (63.6%), bathing (67.2%), food crops irrigation (72.9%), vegetable irrigation (73.5%), aquifer recharge (81.8%), laundry (81.9%), and snow making (82.8%). However, when extreme drought conditions are considered, acceptability of applications involving drinking or close personal contact substantially increase. For instance, acceptability for drinking increases from 42.1 to 76.4% and for cooking from 51.1 to 79.8%.
Subsequently, the applications involving drinking or close personal contact of question 10 were recoded, computed and collapsed into a single ordinal variable named ‘close contact acceptability’ with three symmetric categories: low (1), moderate (2), and high (3) acceptability. The results show that 68.6% of the university community has a high acceptability of wastewater reclamation for applications involving drinking or close personal contact. Furthermore, 23.2 and 8.1% of the university community has medium and low acceptability. Table 10 shows the percentage of respondents from the university community that falls in each category. Figure 16 shows a histogram of these results.
The strength and direction of the relationship between these two collapsed ordinal variables (knowledge and acceptability) was measured by the Goodman and Kruskal's Gamma method. Table 11 shows the cross tabulation results between the variables ‘water knowledge’ and ‘close contact acceptability’. The results from the Gamma test reject the null hypothesis (p < 0.05) and show that there is a moderate (0.303) positive relationship between ‘water knowledge’ and ‘close contact acceptability’ (see Table 12).
Responses to question 11 show that the university community has a high degree of trust in qualified university professors and the regional health unit when it comes to information on the safety of reclaimed water. Moderate level of trust was observed on the federal, provincial, and local government, as well as on private consultants and staff at the water treatment facility. Low degree of trust was observed regarding the media and the internet. High trust in the regional health unit may be due to its focus on public health issues. High trust in university professors may be due to the perception that research universities are more likely to consider issues and uncertainties, such as the effects of low-term exposure to low concentrations of PPCPs, its degradation by-products and metabolites, without political interference.
Responses to question 12 show that acceptability increases substantially when the source of reclaimed water is perceived as cleaner than municipal wastewater, such as stormwater and gray water. The highest increase of acceptability was observed for stormwater (41.5%), followed by a combination of stormwater and gray water (19.3%). In addition, acceptability of reclaimed wastewater increased when it is put back into natural systems before use. The highest increase of acceptability was observed when treated wastewater is allowed to percolate into an aquifer (27%), followed by lake augmentation (15.3%), and discharge into a river (11.4%).
Responses to question 13 show high agreement by the university community regarding two of the statements. First, 90.9% of the university community agree that they would support water reclamation initiatives if the benefits to the environment are extensive and it is safe for humans. If we compare this to question 9, in which only 75.8% of respondents considered water reclamation initiatives to be a good idea, we can infer that support increases if the safety to humans and benefits to the environment are clearly known. Second, 60% of the university agrees that there is much scientific/technological uncertainty regarding the removal of chemicals such as pharmaceuticals from reclaimed water and the long-term effects on human health from exposure to these contaminants are not known. This highlights the importance of this type of research at post-secondary institutions.
The university community at Western University, London, Ontario, Canada is more likely to accept reclaimed wastewater for applications that do not involve drinking or close personal contact. However, acceptability for applications involving drinking or close personal contact improves when benefits to the environment are extensive, it is safe for humans, the source of reclaimed water is perceived as cleaner than municipal wastewater, and the reclaimed wastewater is put back into natural systems with long retention times, such as aquifers. Western University professors and the regional health unit are considered the most trustworthy sources of information regarding the safety of reclaimed water by the university community. Knowledge of the urban water cycle and water resources in Canada is moderate among the university community and the Gamma measure of association shows that there is a moderate (0.303) positive relationship between ‘water knowledge’ and ‘close contact acceptability’. The majority of the university community (75.8%) thinks that reclaiming water to provide an alternate source of water in southwestern Ontario is a good idea, but there are still concerns regarding the presence of chemicals such as pharmaceuticals from reclaimed water and the long-term effects on human health from exposure to these contaminants. Wastewater reclamation is becoming an important alternative for sustainable water resources management not only in regions experiencing water scarcity, but also in places that do not have scarcity issues, such as southwestern Ontario, as a way to become resilient to changing climatic conditions and long-term sustainability of fresh water resources.
This research was supported by Training Program in Clean Technologies for Water Refining and Nutrient and Energy Recovery (TWENER) at the University of Western Ontario, funded by the Collaborative Research and Training Experience Program (CREATE) of the Natural Sciences and Engineering Research Council of Canada (NSERC).
- First received 28 October 2014.
- Accepted in revised form 22 January 2015.
- © IWA Publishing 2015