Every drop matters!
By Maitri Shah
Every year, the worldwide freshwater demand increases by 1% due to population growth, urbanization, industrialization, and economic development. [1] According to the world bank, the population residing in urban areas in India was 34% in 2017[2] and it will increase to 40.76% in 2030 as surveyed by the UN.[3] With urban growth, freshwater demand will also increase. The minimum water supply of 135 litres per capita per day (LPCD), as a service benchmark should be provided for domestic purposes in urban local bodies as mentioned in Indian standard(IS) Code 1172:1993. However, only 69.25 LPCD freshwater supply is given according to the Central Public Health and Environmental Engineering Organisation (CPHEEO) currently. This indicates vast gap between the demand and supply of water in urban areas of India.[4] At the other end, the average annual per capita water availability in the year 2011 was assessed as 1545 cubic meters which may further reduce to 1486 cubic meters and 1367 cubic meters in the years 2021 and 2031 respectively due to population growth, according to Union Minister of State for Jal Shakti & Social Justice and Empowerment.[5]This freshwater scarcity will drive people to consume contaminated or unhygienic water for various purposes which will expose them to health risks. This situation could lead to economic and social crisis for household hence country. This depleting water availability from natural resources and increasing water demand thrust us to regulate the use of freshwater and also to think about reusing or recycling of wastewater. This essay talks about the reuse or treatment of wastewater in various water cycles at a household level to reduce freshwaterconsumption.
Approximately 50–70% of the water used in urban households is turned into greywater and not even 5% of it is recycled.[6] The greywater refers to wastewater generated at the source without any faecal contamination. Bathroom, sink, Washbasin, washing machine, dishwasher, etc. are the sources of greywater. With that concern, various low maintenance and economic solutions are made available for treating greywater that can be reused for flushing and gardening. For example, an average Indian urban household, taking the standard 135 litres of freshwater per person per day. A family of four generates approximately 324 litres of greywater daily (considering 60% of greywater is generated). If it is recycled for gardening, flushing, car washing, freshwater consumption can be reduced by 50%. Additionally, the cost of disposal, channellings, treatment, etc. can be saved at a large scale if the greywater is utilized at the household level.
Water conservation lessons from Home:
Another wastewater management strategy is to reuse utilized water before it turns into greywater or reduce the contamination and pollution load into it. This can reduce or even eliminate the need and therefore cost of the wastewater treatment system. Choice of cleansing products & quantity used also reduce the contamination in the greywater.
For example, we, a family of two, live in a rented independent house in Bangalore city. We have been practicing following water cycles since 1.5 years and are able to reduce the freshwater consumption by 50%.
· We usually wash our clothes once or twice a week. Every wash generates approximately 80–120 litres of greywater. Since we can’t invest in any treatment system, we use bio/non-toxic detergent. After every wash, we collect the water in buckets and use it for gardening and washing verandah (Refer diagram 1). Reuse of Water is more affordable compared to going for a treatment plant.
· Water remaining after washing vegetables can be used for the same or to cook vegetables (vapour cooked).
· We reuse the waste water after rinsing milk/buttermilk utensils as well as washing Rice/lentils. By doing this, we are not only reusing wastewater but also saving on the plant fertilizer as it contains nutrients that control the pest & also boost the plant growth respectively. (Refer Diagram 2)
Our own small garden of 7m² needs about 140–175 litres of water per week except Monsoon. Wastewater fromwashing our clothes and groceries itself exceeds that requirement. This is when we’ve not even tapped into the potential of treating/reusing washbasin, bathroom & kitchen wastewater (we would be water positive, if we did!). This way, we are able to reduce 9360–10400 litres of fresh water requirement per year without spending anything on the wastewater treatment system and in addition to that, get plant nutrients. As there is a saying,
‘You are the only one who can make our world a better place to inhabit;
so, don’t be afraid to take a stand.’(Ankita Singhal)
Even the smallest of adjustments like, installing aerator taps, two bowl sinks (from which one can be used for washing vegetables and another for utensils), using bio enzyme/non-toxic products/natural homemade cleaners, etc. can make the system efficient and also cost-effective. As shown in diagram 3, if the wastewatertreatment system along with the features mentioned above is integrated in house, then treated water can be used for various purposes.
Wastewater treatment system at a level of neighbourhood like for cluster of homes or gated community can also be potent alternative to recycle wastewater from household. Some of the gated communities in metro cities are using cost effective and ecological models and reusing the wastewater for flushing and gardening purpose. For example, 375 household gated layout, Rainbow drive in Bengaluru demonstrates the responsible decentralized wastewater management model. After treating the wastewater, it is being used for flushing and landscaping. The community obtains around one lakh litres treated water per day from which 50,000litres are used by residents, 25,000litres go to ground and remaining 25,000 are sold to neighbouring farmers.[7] This indicates, well-managed wastewater not only reduce freshwater requirement but also become economic asset.
Wastewater management in India:
According to the Central pollution control board’s report in 2015, India has the capacity to treat approximately 37% of its wastewater. Moreover, many of the treatment plants are not in working condition.[8] Most of the cities in India have centralized wastewater treatment plants with underground sewage pipe connections. However, it is expensive to build, which has high energy consumption, high operating cost and also requiresskilled workers. Small towns and villages in India cannot afford to build one. Hence, we should look forward to having decentralized wastewater treatment stations. Nowadays, many organizations in cities are working towards developing a system that is economical and more effective. Few metro cities also have successfully running decentralized sewage treatment plants.
A policy backing of a concrete framework can direct people and ensure implementation of efficient wastewater treatment at the source. Even if one decides not to use treated water, still it is also important that primary treatment is given to wastewater before releasing it into any water body/open area. Measures taken at the source level can protect the natural water bodies from water pollution and also reduce the impact on the environment.
Small steps taken at household or community level could bridge the gap between supply & demand of fresh water and help to prevent water crises. Thus Decentralized treatment system is one of the potent solution to address the issues of water scarcity and pollution at world level. It’s like,
‘Everyone can do simple things to make difference and every little bit really does count.’
(Stella Mccarthey)
References:
- Coates, David, and Richard Connor. “The United Nations World Water Development Report 2018: Nature-Based Solutions for Water.” UNESCO. International Institute for Applied Systems Analysis (IIASA). p.10. The United Nations Educational, Scientific and Cultural Organization. 2018.
unesdoc.unesco.org/ark:/48223/pf0000261424/PDF/261424eng.pdf.multi - Wikipedia contributors. “Urbanisation in India.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 21 May. 2021. Web. 15 Jul. 2021.
wikipedia.org/wiki/Urbanisation_in_India#cite_note-2 - Wikipedia contributors. “Urbanisation in India.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 21 May. 2021. Web. 15 Jul. 2021. wikipedia.org/wiki/Urbanisation_in_India#cite_note-2
- Dkhar, Nathaniel B, and Qazi Syed Wamiq Ali. “India’s rampant urban water issues and challenges.” The Energy and Resource Institute (TERI). Dec. 28, 2018. www.teriin.org/article/indias-rampant-urban-water-issues-and-challenges
- Kataria, Rattan Lal. “Per Capita Availability of Water.” Union Minister of State for Jal Shakti & Social Justice and Empowerment. PIB Delhi. March. 02,2020. pib.gov.in/PressReleasePage.aspx?PRID=1604871
- Adlakha, Nidhi. “Every drop counts: why grey water recycling is a must.” The Hindu. March. 02,2020.
https://www.thehindu.com/life-and-style/homes-and-gardens/grey-water-recycling-is-a-must-for-a-water-starved-country-like-india/article31117504.ece - Venkat, Apurva. “Rainbow Drive Layout to replenish groundwater.” Bangalore Mirror. June. 09,2015.
https://bangaloremirror.indiatimes.com/bangalore/civic/rainbow-drive-layout-groundwater-sarjapur/articleshow/47591884.cms - Sugham, Rudresh Kumar, et al. “Rethinking wastewater management in India.” The Third Pole. May. 15,2017
https://www.thethirdpole.net/en/pollution/waterwaste-management-in-india/
