Perceptions of Rainwater & Greywater

As climatic, demographic and land use changes continue to occur, the UK, which has one of the highest average water consumption figures in North West Europe, faces a number of challenges in relation to the management of it’s water resources1,2. Two adaptive strategies that can help deal with these challenges include greywater recycling and rainwater harvesting. This literature review aims to uncover whether people’s perceptions of rainwater harvesting and greywater recycling in a domestic setting are acting as a barrier to the widespread uptake of these water technologies in the UK.

Overall Findings

The research reviewed is from a global context and apart from one study3, is focused within a domestic setting. Key research themes included: surveying both existing3,4,5,6,13,14,15,16 and non-users7,9,11,12,13,14,15,16, researching the factors and attributes that determine people’s level of acceptance3,4,10,13,14,16, comparing the perceptions of people with mandate and retrofitted domestic rainwater tanks5,13 and acceptable uses of rainwater and greywater3,5,9,10,11,12,13,15,16

This review summarises the key findings from this research, with the overall finding being that generally the perceptions of both these technologies is positive if used for non-potable uses and so long as health isn’t compromised1,3,4,5,6,7,8,9,10,11,12,13,14,15,16. The two key factors that influence this finding were found to be health1,4,7,8 and level of personal contact5,9,10,11 and these are discussed in more detail below. There also appears to be a lack of knowledge regarding system function and design1,4, the options available5,6, and associated environmental and health risks6.

Key Perception: Non-potable uses more acceptable

A key finding was that rainwater and greywater being used for non-drinking (non-potable) uses; watering the garden, washing the car and toilet flushing for example, is generally viewed as more acceptable than being used as drinking water (potable use)3,9,10,11,12,13. Toilet flushing was found to be the most accepted non-potable use based on the literature3,5,9,10,11,12,16, perhaps due to less personal contact and therefore a lower perceived health risk14.

Key Perception: Health

One suggested reason for the limited uptake of greywater recycling systems, which can also be applied to rainwater harvesting, is the perceived health risk associated with greywater use and that this perceived risk acts as a barrier to people having greywater recycling systems installed1,4,7,8. For example, Domènech & Saurí4 found that if the perceived health risk was great, the acceptance level was low and vice versa.

These perceived health risks are in relation to fears of ingesting rain or greywater accidentally as well as cross-contamination with the plumbing system, with the perceived risk being heightened if children live in the household7. Other concerns include the safety and the contents of the recycled greywater being used, for example if sourced from a washing machine the belief that cleaning agents may reduce the water quality7,8.

Key Perception: Level of Personal Contact

An important factor in determining which activities the public view as acceptable uses of greywater and rainwater is the level of personal contact with the water in question. Seidl et al.9 discuss the idea of a “ladder of acceptance”, in other words a scale in relation to rainwater reuse that can also be applied to greywater reuse.

This is based on the recurrent finding across the literature: that a lower level of acceptance is given to uses that require a high level of personal contact with the rain or greywater (drinking and washing for example) and this acceptance is increased as the level of personal contact decreases3,5,9,10,11,15,16Therefore, uses at the top of the ‘ladder’ are the most accepted due to limited human contact and uses at the bottom of the ‘ladder’ are the least accepted as a result of human contact being high.

Conclusions

As discussed previously, the overall finding was that generally people have positive perceptions of both rainwater harvesting and greywater recycling if used for non-drinking (non-potable) uses, particularly toilet flushing3,5,9,10,11,12,16, and if health isn’t compromised1,3,4,5,6,7,8,9,10,11,12,13,14,15,16. Health1,4,7,8 and level of personal contact5,9,10,11 were found to be the two most influential factors in relation to this finding.

If rain and greywater reuse was used to help supply drinking (potable) water in the future, then more research is required into what actions the public believe need to be undertaken in order for them to accept this alternative drinking water supply, for example stricter regulations. 

Despite this review finding the perceptions of these alternative technologies generally positive1,3,4,5,6,7,8,9,10,11,12,13,14,15,16, the uptake level of rainwater harvesting and greywater recycling systems in parts of the world, including the UK, is still relatively low1,13.This suggests that there are perhaps other barriers to the uptake of these technologies, including cost 1,4,6,7,8,12 as well as a lack of knowledge1,4,5,6,10,13 and financial incentives16.  Although these other barriers are beyond the scope of this literature review, they do highlight the need for increased efforts into educating and consulting people about rainwater and greywater reuse as well as financial incentives1,2,3,4,6,10,13,14,15,16 - both of which were found to be reoccurring priorities within the literature during this review.

References 

1. College for Estate Management (CEM). (2013). Greywater for UK Housing. Reading: College for Estate Management in partnership with Hoare Lea.  

2. Adaptation Sub-Committee. (2012). Climate change–is the UK preparing for flooding and water scarcity. Committee on Climate Change, London.

3. Ilemobade, A. A., Olanrewaju, O. O., & Griffioen, M. L. (2013). ‘Greywater reuse for toilet flushing at a university academic and residential building’. Water SA, 39(3), 351-360.

4. Domènech, L., & Saurí, D. (2010). ‘Socio-technical transitions in water scarcity contexts: Public acceptance of greywater reuse technologies in the Metropolitan Area of Barcelona’. Resources, Conservation and Recycling, 55(1), 53-62.

5. Gardiner, A. (2010). ‘Do rainwater tanks herald a cultural change in household water use?’. Australasian Journal of Environmental Management, 17(2), 100-111.

6. Alternative Technologies Association (ATA). (2005). Smart Water Greywater Project Report. Melbourne: Alternative Technologies Association supported by the Smart Water Fund. 

7. Mustow, S., Grey, R., Smerdon, T., Pinney, C. & Waggett, R. (1997). Water Conservation: Implications of using Recycled Greywater and Stored Rainwater in the UK. Drinking Water Inspectorate, Department of the Environment.  

8. Allen, L., Christian-Smith, J., & Palaniappan, M. (2010). Overview of greywater reuse: the potential of greywater systems to aid sustainable water management. Pacific Institute: California. 

9. Seidl, M., De Gouvello, B., & De Oliveira Nascimento, N. (2010). ‘Perception of rainwater harvesting in public buildings: Comparison between two case studies in France and in Brazil’. NOVATECH 2010. 

10. Bulteau, G., Laffitte, J-D., Marchand, D. (2011). ‘Psychosocial analysis of public acceptance towards water reuse: Case study of rainwater harvesting and greywater recycling’. WATEREUSE, Barcelona 2011. 

11. Brown, R., & Davies, P. (2007). ‘Understanding community receptivity to water re-use: Ku-ring-gai Council case study’. Water Science & Technology, 55(4), 283-290.

12. Hyde, K., Smith, M. J., & Adeyeye, O. (2014). ‘Attributes of greywater reuse: well-controlled greywater treatment and user perception’. In: Memon, F.A. (Ed.) Proceedings of the Water Efficiency Conference 2015, 5-7 August 2015, Exeter, UK: WATEF Network/University of Brighton, pp. 20. 

13. Mankad, A., Fielding, K., & Tapsuwan, S. (2015). ‘Public perceptions, motivational drivers, and maintenance behaviour for urban rainwater tanks’. Rainwater Tank Systems for Urban Water Supply: Design, Yield, Energy, Health Risks, Economics and Social Perceptions, 181.

14. Ward, S., Butler, D., & Memon, F. (2008). ‘A pilot study into attitudes towards and perceptions of rainwater harvesting in the UK’. In 10th National Hydrology Symposium, 15-17 September 2008, Exeter, UK: British Hydrological Society.  

15. Hills, S., Birks, R., & McKenzie, B. (2002). ‘The Millennium Dome" Watercycle" experiment: to evaluate water efficiency and customer perception at a recycling scheme for 6 million visitors’. Water Science & Technology, 46(6), 233-240.

16. Ward, S., Barr, S., Memon, F., & Butler, D. (2013). Rainwater harvesting in the UK: exploring water-user perceptions. Urban Water Journal, 10(2), 112-126.