Greywater is water from the bathroom and kitchen sinks, bathing area and washing machines. While greywater may look ‘dirty’, it is a safe source of water (after natural purification) for watering your home garden. Letting it mix with the sewage water from your toilets and go into the drain is a criminal waste of water when India is in the midst of a huge water crisis.
WHY IS REUSING GREY WATER IMPORTANT?
According to the Centre for Science and Environment (CSE), more than 70% of water supplied per household per day in India is consumed in the kitchen, in the bathing area and for washing clothes. Treating this grey water, reusing the purified grey water for watering your home garden and then channelising it into the ground will result in:
Huge saving of water and reduction in your water bill.
Keeping the grey water out of the sewer system, thereby not allowing it to pollute the local water bodies.
Improving the ground water table in your neighbourhood.
This film and blog explains how grey water from your home can be treated and purified naturally in a simple and cost effective way and be directed into the ground to recharge the ground water table where you live. With 70% of India’s water aquifers having dried up and India facing a huge water crisis, every urban and rural family having an independent house can contribute towards improving our nation’s rapidly depleting ground water levels by implementing grey water management in this natural way.
STEPS FOR PURIFYING GREY WATER AND DIRECTING IT INTO THE GROUND
Re-route Grey Water from the House to the Garden Area
The first step is to re-route the pipes from your bathroom (carrying the water from the washbasins and the bathing area), area where the clothes are washed and the kitchen sink in your house to your garden area such that they do not mix with the pipe carrying the sewage water from the toilet flushes. This would require some plumbing work but is easily doable in an individual house either at the stage where the house is being constructed or even later. Mrs Savargaonkar did some plumbing work in her house much after it was built in such a way that the 3 pipes carrying water from her rooftop garden, washing machine area and kitchen sink drain at 3 different places in the garden patch outside her house.
Make Pits to Treat and Purify Grey Water in a Natural Way
Mrs Savargaonkar got 3 pits dug in her garden for treating the grey water coming out of the 3 pipes. Size of each pit is 1 metre by 1 metre by 1 metre. Each pit has been given a 4 to 6 inch slope at the bottom in the direction of the natural flow of water on the road next to the garden. At the bottom of each pit, gravel has been put for about 6 inches. Above that sand has been put for 12 inches. Whatever place was left at the top, dry leaves were put. Dry leaves act as natural carbon material which is a very important part of the grey water purification process.
“When I started doing the grey water filtering process, I realised that with water going into the pits, the dry leaves would get compacted. I simply put more dry leaves on the top of the pits. In addition to dry leaves, you can also use wood husk, dry tree branches, tree barks, crop husk, plant residues (any of these or in combination) as carbon material in the grey water purification pits,” says Poornima Savargaonkar.
Put Naturally Water Purifying Plants around the Grey Water Pits
After 3 months, Mrs Savargaonkar planted naturally water purifying plants such as Kaina, Banana, Syngonium, Umbrella Palm and Spider Lily around the 3 grey water pits in her garden.
“I do not use non-chemical based natural detergents for washing utensils and clothes in my home but use commercially available soaps and detergents. This soapy grey water is filtered through the layers of carbon rich dry leaves, sand and gravel in the pits before it reaches the ground.These water purifying plants do the job of soaking the leftover chemicals in the grey water. This ensures that the water going down into the ground is pure, chemical free water. Banana plant has been specifically put next to the water outlet pipe from the kitchen which has only the non-soapy water that drains out after washing vegetables, grains and pulses. This nutrient rich water helps in getting good quality bananas for consumption by my family members,” says Mrs Savargaonkar.
Use Natural Insecticide to keep Mosquitoes & Bugs Away from the Grey Water Pits
Twice a year and specifically once before or after the monsoon rains, Mrs Savargaonkar puts a handful of Rakh (powder obtained from burning of wood) or Choona (lime used in construction of houses) in the grey water pits as this acts as a very effective natural insecticide to keep mosquitoes and bugs away.
I personally found no smell or saw any stagnation or any mosquitoes or bugs around Poornima Savargaonkar’s grey water pits and can personally vouch for how happy the plants in her garden looked! If every family who has an independent house in India (in every village, every town and every big city) implements grey water management like Mrs. Savargaonkar, we as citizens can make a huge difference in improving the depleting ground water levels of our country and avoiding day zero scenarios when our taps will run dry.
For any comments, feedback or clarifications on this blog, please write to the author Neelam Ahluwalia at this email id: email@example.com
For any further clarifications on grey water treatment talked about in this blog, reach out to firstname.lastname@example.org
Links to Other Water Blogs & Films on this Website
India is one of the most water stressed countries in the world. Niti Aayog (a prominent Government of India think tank) report of 2018 states that 21 major cities in India (Delhi, Bengaluru, Chennai, Hyderabad and others) are racing towards reaching zero groundwater levels affecting access of water for more than 100 million urban Indians. The reportalso states that by 2030, India’s water demand is projected to be twice the available supply, implying severe water scarcity for millions of people. If we want to prevent the water crisis that Cape Town in South Africa witnessed, a decentralised collective approach to water management is the key.
Watch this film to see 15+ practical solutions that different residential communities in Gurgaon city in the water starved National Capital Region have implemented to conserve water. These water saving measures can be adopted by any residential condominium, township, office complex or institution anywhere in India.
HIGHLIGHTS OF THE BLOG
How to be Water Rich:
Respecting water by following the 4 Rs of water conservation is the only way forward if we do not want to experience day zero conditions when our taps will run dry. This blog details some water smart solutions that residential communities / office complexes / institutions can adopt under each of the below heads:
Case Study showing how a community reduced its water use by 20%
Recycle Grey Water & Sewage Water
Recharge Ground Water (a short video where a water expert talks about how to design community level ground water recharge structures efficiently and a detailed write up on implementation of Swales, a permaculture based ground water recharge technique)
SAVING WATER BY REDUCING CONSUMPTION
Water Meters – “What cannot be measured, cannot be improved.” It is critical to install water meters to determine the amount of water being used on a daily, monthly and yearly basis.
Waterless Urinals – As shown in the Water Rich Communities film, Richmond Park residential complex in Gurgaon has been using waterless urinals in their high usage public areas – club house and common area toilets for the past few years.
See these links below and explore using waterless urinals for the men’s common area toilets in your residential community and office complex.
Sprinklers and Shower Handles –Horticulture uses a lot of water. Using sprinklers and shower handles attached to pipes to water green spaces reduces water use by 50%.
Mulching –Putting dry leaves in plant beds and around trees significantly reduces amount of water used for horticulture as dry leaves act as a natural barrier preventing the soil from losing moisture as a result of exposure to the wind and the sun.
Planting Native Species – Planting has to be thought through very well keeping in mind the ecology of the region. In a semi arid or arid landscape, if you plant species which are water thirsty i.e those belonging to a moisture rich climate ecology, then these plants will require more waterwhich is criminal in these water stressed times. For example, in Gurgaon city, it is not water wise to plant Bengali Kadam which is a tree species from the moisture rich Bengal area and thus will require more water. This short film presents the views of Vijay Dhasmana, an ecologist and rewilder who talks about why planting native species of the right ecology is critical from the water availability point of view and how native plantation helps to create more biodiversity rich habitats in urban areas.
SAVING WATER BY REDUCING WASTAGE
Water Audit – This is an essential tool which helps to determine where all the water is being used in the complex, points of water wastage etc. Conducting periodic water audits and addressing the following questions helps in reducing wastage of water:
What is the kind of water wastage happening in our residential / office complex?
Are there any leaking taps, pipes and toilet cisterns?
Do our water tanks overflow at any time?
What mechanisms can we put in place to prevent different kinds of water wastage?
Installing Water Aerators in all the Taps – This simple solution helps to reduce water use by more than 60% per tap. Sunil Pachar, Sustainability Consultant who supplies water aerators to individuals, residential communities, corporates and institutions says that aerators must be chosen on the basis of the purpose for which the tap is used. Mr. Pachar can be reached at email@example.com
20-25% of fresh water can be saved in homes / offices just by using aerators as per the below recommended specifications:
Bath showers: Spray type aerator with flow rate of 9-10 litres per minute.
Jet sprays: Spray type aerator with flow rate of 2-5 litres per minute.
Gardening: Spray type aerator with flow rate of 2-5 litres per minute.
Dish washing: Foam type aerator with flow rate of 5-10 litres per minute.
Wash basins: Spray type aerator with flow rate of 1-4 litres per minute.
Fixing Sensors in Overhead Water Tanks – Veena Padmanabhan, RWA member, Richmond Park complex in Gurgaon shares, “Earlier, there used to be a lot of water wastage in our condominium from overflowing water tanks on the roof tops. Now, after we have installed sensors, when the water tanks are getting full, the indication comes on a panel kept in our maintenance room. Even if the plumbers are busy, any staff member goes and shuts the valve which avoids any water from overflowing in the overhead tanks.”
Reducing Number of Common Area Taps and Switching to Push Taps – “Regulating water use is the key to reducing wastage of water. We figured that there were a lot of non-monitored taps in our condominium which could be opened by anyone (RWA staff members, drivers, part time helpers) at any point of time. We realised that quite often a lot of water would overflow because of some tap being left open by someone, somewhere by mistake. To address this problem of water wastage, we closed 3-4 of the common area taps. In the 2 existing common area taps, we have changed the system to ‘push taps’ to avoid water overflowing from buckets while people get busy chatting with each other,” shares Veena Padmanabhan, RWA member, Richmond Park complex in Gurgaon.
Prompt Fixing of Leaks – Leaking pipes, taps, toilet flushes are a big source of water wastage. System should be put into place to fix these immediately.
Mandating Designated Time for Car Cleaning – Instead of drivers and car cleaners having access to water taps all day long to clean cars, fixing car cleaning time for 2-3 hours in the morning helps to regulate water use.
Re-routing Water Dripping from Air Conditioners –Water dripping from the air conditioners in buildings is a big source of water wastage. This water can be easily rerouted to the water recharge pits using pipes.
Case Study: Water Management at Ireo Grand Arch Condo, Gurgaon
Water Use Reduced by 20% by following 2 Rs of Water Conservation
Raman Chawla, RWA President, Ireo Grand Arch, Gurgaon shares, “The builder handed over our residential complex to us without there being any piped water supply from HUDA – Haryana Urban Development Authority. The Grand Arch, located off Golf Course Extension Road in Gurgaon houses around 700 families and we have been dependent on getting water from tankers every day. HUDA water lines were connected to our condominium in June 2019 but they just meet about 10-40 percent of our total water needs as supply is very erratic. As a result, our dependence on water tankers remains high. At current consumption levels, residents pay a sum of INR 0.52 per sq ft for water use which works out to about INR 1200 per month for an average size 3 bedroom apartment.”
A Water Conservation Committee comprising of residents and RWA members was set up to study all possible aspects to reduce the huge water expenses being incurred by the residents. A detailed audit was carried out by the RWA and it was decided to monitor consumption patterns and plug-in wastages. Grand Arch has been helped by a Sustainability Consultant – Sunil Pachar, who helps RWAs, Corporates and Institutions to carry out water audits, suggests measures for water conservation and helps with the implementation of the same. Mr. Pachar can be reached at firstname.lastname@example.org
Following water conservation measures based on reducing water wastage and consumption were implemented by Grand Arch RWA:
Water aerators have been installed in all the sinks in the bathrooms and kitchens in all the flats using RWA funds. According to Sunil Pachar, Sustainability Consultant who supplied the water aerators to Grand Arch, “Every RWA should adopt this extremely effective water saving approach. This simple step of installing water aerators has helped to bring down overall water use per household by 20-25% in Grand Arch. Buying in bulk reduces the price of the aerators significantly. The RWA ended up paying INR 80-85 per water aerator for a leading German brand called NeoPerl. Neoperl (www.neoperl.net) is the market leader with about 70% of the market share. The other players are too small and do not offer the diversity of water aerators that Neoperl provides. Moreover, the quality of Neoperl aerators is far superior as compared to other brands,”
The water audit pointed out that leakages in the basement were major contributors to water being wasted in the complex. Steps were taken to plug in all the leakage points.
All the gardeners in the complex have been trained to (a) use showers/sprinklers while watering the green spaces (b) stagger watering timing in summer to early morning/late evening to avoid wastage through evaporation.
All defective garden sprinklers have been repaired or replaced.
Members of the Water Conservation Committee have been sensitising the residents by sending e-mails/whatsapp messages, putting up posters on notice boards in different towers and the club house and by involving children who have been doing ‘Nukkad Nataks’ during cultural events and painting competitions on the critical importance of reducing wastage and consumption of water.
House-maids have been trained to save water since they participate in all the cleaning chores like washing utensils, clothes, mopping floors etc.
Measures were also taken to rectify the sewage treatment plant (STP) which was not working at the desired level of performance.
According to Raman Chawla, RWA President, Ireo Grand Arch, Gurgaon, “All these measures have translated to a tangible 20% i.e. 30 lakh litres of water saving within our condominium. There is however a definite scope of further improvement. Our RWA is currently in the process of exploring all available options to reduce water usage by installing smart metering systems which will help our residents to monitor and reduce water consumption at their home level. Another critical thing that we need to look into is ground water recharge.”
SAVING WATER BY REUSING AND RECYCLING
Can this water be given one more life?Can it be used one more time before it is finally drained out? These are powerful questions that help to flip our approach to the way we look at water management. All you need is some investment in piping or plumbing to reroute the water to reuse the same.
Reusing Swimming Pool Water for Horticulture – “We do not let any drop of water go waste in our complex. Even the swimming pool water is re-routed every year at the end of the season to the community garden using a pump. This water is used by the gardeners for watering the green spaces instead of just being drained. Our plants have survived the chlorinated water without any problem!”, shares Veena Padmanabhan, RWA member, Richmond Park complex in Gurgaon.
Using Recycled Grey Water and Treated Sewage Waterfor Horticultureare 2 extremely water smart solutions as the water saving on an everyday basis is huge as your community or office complex or institution is not using thousands of litres of fresh water for this purpose. As water availability in Indian cities goes down over the next few years, using treated grey water (waste water from baths, sinks, washing machines) and black water (sewage water from toilet flushes) is the only way, residential and office complexes would be able to maintain their green spaces. According to Sunil Pachar, Sustainability Consultant, “Water recycling is very cost effective as the cost of water recycling works out to around 4-5 paisa per litre as compared to the huge cost of withdrawing water from the ground which is depleting at alarming levels in most Indian cities.”
Grey water recycling is really easy to implement as it just requires a tank to be built below the building to collect the water coming from the bathroom wash basins, shower areas and washing machines. This tank needs to be cleaned once in 15 days. A simple pre chamber can be built using small pebbles, carbon blocks and alum which helps in avoiding any smell issues.
Surbhi Iyer, Eco Team Member from Silver Oaks shares, “Total cost of setting up 9 grey water recycling tanks with a capacity of 5000 litres per tank came to approximately INR 3,60,000 (INR 40,000 per tank x 9 tanks). We built 9 tanks over a period of 5 years so it was not a drain on the RWAs financial resources.”
Researchers from Bangalore have shown that recycling and reusing grey water for gardening, flushing, cleaning cars etc in a residential complexreduces almost 70% of the total fresh water requirement. The study was carried out at ‘T-Zed Homes’ residential complex which saved almost Rs 10 lakh per annum in fresh water bills and reduced its groundwater withdrawal.
Grey water recycling is an eco-friendly, economical and effective way of providing water security to every residential and office complex in India. Countries such as Japan are using grey water recycling extensively to overcome their water deficit. Using small treatment plants and closed-loop water supply system at the building level, Japan reuses more than 53 million litres of water every single day.
“While using STP water, an important precaution that needs to be taken is to use the treated water within 24 hours. If it is stored for longer, issues of smell can come in. In such a situation, it is best to re-filter the water before using it for horticulture,” shares Keshav Jaini, Eco Team Member from Garden Estate.
SAVING WATER BY RECHARGING GROUND WATER
‘Will our children and future generations get water to drink’ is the thought that should motivate every community, office complex and institution to invest in constructing rain water recharge structures. Currently in India, we barely recharge 10% of the rain water. In urban areas, rain water recharge is negligible. With so much concretisation in our cities, there is hardly any place for the rain water to sink in and it leads to water logging in all our streets across urban India every monsoon. This needs to change. Groundwater recharge needs to be taken up on war footing in all our towns and cities if we do not want to face ground zero situation when our taps will run dry.
Ground Water Recharge Structures – From a community / office / institution perspective, what are the things to keep in mind while designing an efficient rain water recharge structure that will allow maximum percolation of rain water into the ground? This video presents the views of Sunil Pachar, a Sustainability Expert working in the area of providing water management solutions to RWAs, corporates and institutions. Mr. Pachar can be reached at email@example.com
Swales as shown in the Water Rich Communities film are trenches dug on gently sloping land / natural drains / storm water drains (nallahs) to capture rain water so that it is absorbed in the ground rather than let it flow out of the area which would then be lost in drainage.
The permaculture principles at work in swales are called the 3S: Slow it, Spread it and Sink it. The swale is blocked at every 10 feet or so using wooden logs or sand filled bags to further slow and collect the rain water thereby allowing only the overflow to go to the next trench. Soil holding, filtration plants can be planted in the swale to help more water to sink in. Organic brown material in the form of dry leaves and wooden branches from the horticulture waste can be added to make the soil more porous. The worms and microbes start acting on this carbon material. As it decomposes and becomes mulch in the ground, it helps to open the soil below, thereby making it easier for the water to seep into the ground.
Typically, the site where you want to dig the swale has to be assessed and studied for soil, slope, erosion, porosity and the flow, volume and speed of water. It is important to study the water coming in. If the water is too polluted, a natural filtration process using plants or filtration media (stones, pebbles) should be created. Please note that soil is a natural filter and will clean the water as it gets absorbed.
Keshav Jaini, Eco Team Member, Garden Estate, Gurgaon shares, “In our residential complex, we already had several rain water recharge structures made in 2002. We implemented the swales project to capture the rain water flowing out of our estate in the storm water drain. We have created individual trenches of 2ft X 2ft over a length of 150 feet. The total holding capacity of the entire swale is 600 cubic feet which can hold about 17000 litres of water. Initially, when it starts raining, the soil is dry and so the rain water seeps in very quickly. Once the soil absorbs the initial rush of water, the absorption rate becomes slower. In one normal 30 minutes rain, we collect and sink about 25000 litres of water in the complete swale. Time taken for the water to sink in ranges from 1 hour to 3 hours. If it rains again after 3 or 4 hours, the swale is again ready to absorb another 25000 litres. We calculated that in the month of August 2019, when we had 12 rounds of monsoon rains, our swale helped us recharge about 300,000 litres of water (25000 litres x 12 rains) into the ground. This is a very economical, ground water recharge solution. All we spent was INR 5000 as labour cost for digging the swale. The whole project is completely natural helping to regenerate mother earth in multiple ways.”
For queries and guidance on implementation of swales techniqueas a ground water recharge solution,please contact: Mr. Keshav Jaini, Garden Estate, Gurgaon at this email: firstname.lastname@example.org
For any comments, feedback or clarifications on this blog, please write to the author Neelam Ahluwalia at the email: email@example.com