The ‘Yuck Factor’
Negative perceptions among apartment residents limits uptake of treated wastewater.
Sahana Balasubramanian and Sneha Singh
‘It might hinder the well-being of people at home’. This was a concern that came up often during our conversations with apartment residents on whether they were averse to using treated wastewater for non-potable purposes, i.e. apart from drinking and cooking. People are wary about the water even after it has been processed by decentralised sewage treatment plants.
With Indian cities becoming increasingly water-stressed and polluted, there is an urgent need to explore alternatives to freshwater for uses that require non-potable water quality. Wastewater treatment and reuse is one such solution but how can the negative perception around it be overcome?
Read | Why wastewater holds the key to building climate-resilient cities
Under CSEI’s Green Cities Initiative, we have been studying why treated wastewater was going unused in Bengaluru despite the mandate that apartments with more than 20 units have to install decentralised STPs and adhere to the Zero Liquid Discharge (ZLD) policy. There are now over 2,000 decentralised STPs in the city and yet there was limited success with respect to the reuse mandate in the residential context.
Based on our interviews and secondary research, we put together a research brief that sums up six key insights that explain this wastage. One of them, the focus of this blog post, is the negative cultural perception among a central stakeholder — apartment residents.
Grey to Green
The Karnataka Pollution Control Board’s mandate recommends that treated wastewater is used for gardening and toilet flushing. But smaller apartments are unable to 100% reuse their STP treated water even after using it for these two activities. This is why it’s important to explore ways to expand the usage of STP treated water for purposes other than gardening and toilet flushing.
Read | Is the STP in your Apartment Always Out of Order?
Bengaluru’s decentralised STPs offer residents a huge opportunity to substitute freshwater for activities that require water of non-potable quality such as mopping floors, cleaning surfaces and vehicles. But this can’t be done effectively unless residents’ negative perception about treated wastewater is first addressed
Apart from reuse within the apartment complex itself, treated wastewater can also be collected and transported for construction and industrial activities as well as for greening public spaces. This is why CSEI has joined hands with the Karnataka Pollution Control Board (KSPCB) in piloting the Grey to Green Campaign, through which we aim to divert excess treated wastewater from apartments for greening public parks and medians in Bengaluru’s Yelahanka Zone.
We conducted interviews with 20 residents welfare associations (RWAs) as well as builders and architects in Bengaluru to understand current practices, people’s misgivings and how to allay them. Here’s what we found:
- A majority of the residents were using treated wastewater only for landscaping.
- Only 10 out of the 20 RWAs we spoke to were using it for toilet flushing. They were able to do so because these apartments had dual plumbing systems installed (which handle greywater (water from shower drains, kitchen sinks, laundry) and blackwater (water from toilets) separately).
“We have dual plumbing systems installed but we are hesitant to use treated wastewater for vessel washing, floor mopping as it might hinder the well being of the members at home”
- Five out of 20 RWAs trusted the output water quality through visual markers like whether the water is clear and colourless, and free from particles and odour.
- There is a lack of trust in water quality reports. Residents feel that the numbers recorded on paper are inaccurate compared to the colour of the water. These reports are possibly altered to avoid penalties imposed by KSPCB for malfunctioning STPs.
- Residents said they have experienced odour issues and discolouration of toilets because of flushing with treated STP water.
“Trust decreases when the output water colour changes, more turbid appearances”
The need for well-maintained, good systems
A well maintained and operated STP produces colourless, odourless and particle-free STP-treated water. This is the standard residents expect when they visually inspect treated wastewater from their own STP. If the treated water is not clear, emits odor or has particles suspended in it, then they lose trust over the treated water, which in turn feeds a negative perception about wastewater reuse in general..
Moreover, most apartments in Bengaluru treat blackwater and greywater together. We visited an apartment with dual plumbing systems in Sarjapur to understand if separately treating blackwater and greywater could improve the acceptance of using treated wastewater. We found that even here, treated greywater was only being reused for landscaping and toilet flushing, while the treated blackwater was being released into the stormwater drains.
We also found plastic bottle caps, shampoo sachets and other bits of waste in the shower drains, a clear indication that greywater is not valued as a resource by apartment residents.
Wastewater in construction
Through the course of our study, residents were very particular about not directly coming into contact with treated wastewater in any form; they feared it would affect their health. But they were willing to use treated wastewater for non-potable purposes. One resident even expressed his willingness towards using treated wastewater for groundwater recharge as long as there are standards prescribed by the government and they are followed (currently, such guidelines don’t exist).
Read | Impact of COVID-19 on Wastewater Reuse
We spoke to builders and architects in the city to understand how they navigated this negative perception and the Bangalore Water Supply and Sewerage Board’s (BWSSB) rules that mandate the use of centralised STP treated water in construction. We found that acceptance rate was low among them. Builders are cautious about publicising the use of treated wastewater in construction as they say it could affect their business.
“Clients feel that wastewater is impure, and are uncomfortable constructing areas of their homes like puja (prayer) rooms with it,” one of the builders told us.
Key levers for change in negative perception
It is critical to change this negative perception among apartment residents in order to ensure wastewater reuse is carried out more efficiently. Here are some possible ways we identified:
- Building awareness on wastewater reuse through case studies
Demonstrating that treated wastewater is safe for reuse through case studies (both domestic and international contexts) would help build awareness and educate the end users.
- Creating data to show freshwater savings through WW reuse
Freshwater is a dwindling resource especially in rapidly-urbanising cities like Bengaluru. This tangible benefit of wastewater reuse can play a role in helping shift perceptions. Countries such as Singapore and Israel have successfully demonstrated savings in the cost of buying freshwater and also saved freshwater
- Building trust on WW reuse
In order to build trust among residents, the STP needs to be well operated and maintained. As mentioned above, a well functioning STP produces colourless water free from any odour and particles. People are less likely to want to use it if this standard is not consistently maintained. Additionally, installing water monitoring devices, which enable residents to monitor STP treated water in real time could also address concerns about water quality.
Edited by Kaavya Kumar
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