- 3 Way Segregation of Household Waste following 2 Bin 1 Bag System
- Completely Natural, Do-It-Yourself, Low Cost Community Composting Solution using Steel Wire Mesh Bins
Watch this short film to see how the Garden Estate community has taken responsibility for the waste it generates.
Since February 2016, an efficient system of in-house waste management in Garden Estate has ensured cost savings financially along with many environmental benefits. This detailed case study discusses the following aspects:
Waste Segregation System in Garden Estate
- 3-way segregation of household waste plus e-waste management
- Reduction in plastic pollution due to most homes not using dustbin liners
- Challenges faced during the awareness campaign and learnings thereof
Community Level Composting System in Garden Estate
- Waste audit and learnings from the composting pilot
- Process of natural composting using steel wire mesh bins & SOPs followed
- Leaf composting process
- Dimensions and loading capacity of the composting bins
- One time set-up cost & monthly maintenance cost for this Do-It-Yourself system
Impacts of Garden Estate’s Waste Management Initiative
- 80% reduction in the waste going to the landfill
- Nourishment of the soil by the rich compost created from the food and garden waste that the community was throwing away earlier
- Direct financial saving of Rs 50,000 every year that the community was spending earlier on buying compost from the market
- Better recovery of recyclables
- Responsible recycling of toxic electronic waste
- Reduction in plastic pollution
Garden Estate Waste Champion’s Advise to other Communities
Replication of this Low-Cost, Natural Community Composting Solution
- Advantages of this solution
- Do-It-Yourself vs Vendor-based Model
- Number of bins, shape of bins and space requirement in 3 different scenarios based on the Garden Estate Do-It-Yourself Model (kitchen waste of 100 homes, 200 homes & 370 homes) and 2 different scenarios based on a similar Vendor-based Natural Community Composting Model (kitchen waste of 500 & 1000 homes)
DETAILS ABOUT THE GARDEN ESTATE COMMUNITY
- Number of households: 373
- Flats or independent houses: Both
- Location and address: M G Road, Opposite Guru Drona Charya metro station, Gurgaon – 122002
- Contact name and email id of waste champion in the community: Mr. Keshav Jaini, firstname.lastname@example.org
HOW DID THE IDEA GROW?
Keshav Jaini, Waste Champion from Garden Estate says, “Our community had already implemented many eco-friendly initiatives over the years such as constructing rain water harvesting pits, sewage treatment plant, storm water drain recharge and rejuvenation of barren areas by planting native trees. What was disturbing us immensely was seeing the garbage mess all around the city. By sending out plastic bags full of mixed waste every day from the 373 homes in our community, we realised that we were being part of the problem. Instead of blaming the government, we realised that we should do our bit by taking responsibility for managing the waste generated in our own complex.
The President of our Resident Welfare Association (RWA) was very supportive and gave the go ahead for a waste segregation and composting pilot. The brief from the RWA was very clear. They wanted a waste management system which was economical in its set up cost & monthly maintenance cost and which would be simple to operate, cost effective and sustainable in the long run where our community would not be burdened with rising monthly payments to composting vendors or rising electricity costs or expensive annual maintenance contracts. This brief ruled out any semi-mechanised and mechanised composting systems as such solutions are all expensive in their capex and opex. As part of our research on sustainable low-cost community composting solutions, we came across a Do-It-Yourself (DIY) model implemented by Rainbow Drive residential complex in Bangalore (https://savitahiremath.com/category/community-composting). On one of my trips down South, I visited this condominium to understand the system better. The belief that ‘our waste is our responsibility’ guided the Rainbow Drive Waste Champion, Mr. K.P. Singh and his team of eco-residents to implement the 2 bin 1 bag system of 3 way waste segregation in their community of 250 plus homes and compost their segregated kitchen waste. The compost is being used to grow a variety of fruits and vegetables in their complex. After seeing the set up at Rainbow Drive, I felt confident of replicating this DIY, low cost, completely natural solution of bin composting in my own complex. The idea was to follow a completely natural process of composting and let nature do the work without much interference on our part so as to keep our cost and the carbon footprint minimal.
At a meeting called for discussing this idea, the positive response of the residents was overwhelming. People agreed to contribute 1000 rupees per household to set up a community level composting system. Around 20 folks – young and old volunteered to get the waste management initiative off the ground. Finally, the RWA decided to fund this initiative eliminating the need to take any financial contribution from the residents.”
WASTE SEGREGATION SYSTEM IN GARDEN ESTATE
3-Way Segregation of Household Waste plus E-Waste Management
Garden Estate has used the popular 2 bin, 1 bag system for 3-way segregation of household waste (www.2bin1bag.in). In January 2016, the RWA bought two-colour coded bins (red and green bins) and the white bag for the recyclables for each of the 373 homes from a local supplier at a total cost of Rs 80,000. The bins have lids on them so there are no issues of smell or insects or flies when they are kept inside the homes or outside the homes for collection of waste.
How the 2 Bin and 1 Bag Segregation System Works?
Green bin is used for kitchen waste – All the food waste from the kitchen (vegetable and fruit peels, egg shells, meat bones, tea leaves, coffee grounds, left-over cooked food items like rice, roti, bread, biscuits, vegetables) is put into the green bin. This food waste is used as a resource to make high quality compost.
Red bin is used for reject waste – All the rejects such as household sweepings; chocolate and toffee wrappers; chips packets; sanitary waste in the form of baby and adult diapers and women’s menstrual pads; bio-medical waste in the form of bandages, soiled cotton; dog fur, bird droppings etc. go into the red bin. This waste which forms about 10% of the total waste generated is what is sent to the landfill.
White reusable bag is used for recyclable waste – Everything that can be recycled such as paper and cardboard (newspapers, magazines, paper bills, pizza boxes, cardboard boxes, egg boxes etc), metal (aluminium cans, foil, cheese tins etc), plastic (shampoo and liquid soap bottles, oil containers, milk pouches, all plastic jars and packets, take away food containers etc) and glass bottles go into the white reusable bag.
It is very important to wash and dry the recyclable items that contain liquid or solid food such as plastic milk pouches, cooking oil containers, cheese tins, take away food containers and then store in the recyclables bag so they do not smell or attract bugs. This also increases the recycling value of these waste items.
Electronic waste – E waste items in the form of old batteries, bulbs, wires, mobile phones, chargers, laptops, televisions, microwaves, geysers, air conditioners etc which contain toxic materials such as mercury, lead that are very harmful for human health and the health of the environment; are stored separately. This e-waste is given to an authorised government approved e-waste recycler who comes into the complex once every 2 months.
Elimination of Plastic Liners in the Dustbins
Jyoti Punj, a lady resident of Garden Estate says, “With the awareness created amongst the residents regarding waste dumping and the toxic impacts of plastic bags on our land, water and air; most homes in Garden Estate have stopped using plastic bin liners. It barely takes a minute to rinse the bins, dry them in the sun and reuse them.”
If all the homes had continued using plastic bin liners, that would be 373 homes using 2 bin liners for their 2 bins per day. That would have resulted in a lot of plastic pollution. By consciously refusing to use plastic bin liners, the Garden Estate community prevents more than 2,00,000 plastic bin liners going into the landfill every year.
Awareness Campaign for Waste Segregation
Awareness campaign with residents was carried out over a period of 6 months using segregation posters put up in strategic places in the complex, word of mouth and showing films and presentations on 3-way segregation. Posters, presentations and films were downloaded from the website www.2bin1bag.in. A few home visits were also done primarily to the homes of the very elderly residents by a core group of resident volunteers.
Training sessions with the household helpers were done to train the helpers in how to keep the waste separately in the homes, to wash and dry the recyclables before storing them and not to use any plastic bin liners in the dustbins.
Workshops were also conducted with the Garden Estate housekeeping staff and the waste workers to train them in the process of 3-way collection of segregated waste from all the households.
No outside agency’s help was taken to run this awareness campaign. The resident eco-volunteers carried out the awareness campaign.
Challenges Faced in Implementation of Waste Segregation
Keshav Jaini, Waste Champion from Garden Estate says, “The main challenge was in getting the residents to change their attitude towards their own waste i.e. my waste is not my problem but that of the waste worker or the RWA or the municipality. I have already paid the society charges for maintenance so why should I get involved in segregating my own waste.”
Not all the residents came on board initially. Keshav Jaini and the team of eco-volunteers went ahead with the implementation process once they had 60% of the residents on board. They were confident that the rest would follow eventually.
Keshav says, “We had to be very patient. Every time people called with problems and issues, we would ask them to help out so they could help us figure out the solutions. Another challenge we faced was to keep the volunteers motivated. Initially, 20 people had volunteered to help out with the segregation drive but then people lost their enthusiasm. In the end, we were left with only a handful of volunteers. But now when I look back I feel that all we need are a few passionate, committed residents to get this off the ground.”
Learnings from the Pilot and Awareness Campaign for Segregation
In the words of Garden Estate Waste Champion Keshav Jaini:
- It is not a one-time process. The awareness programme has to be continuous and ongoing as residents keep moving and household helpers and housekeeping staff also keep changing. Providing a standard note on 3-way segregation of waste for new residents moving in to the complex is helpful.
- Doing a pilot project with 20 homes in 2 towers helped us to understand the kind of issues and problems coming up with segregation, the process of collection of segregated waste and how to resolve these issues. For example, Garden Estate complex has independent houses as well as apartments. Each building has 5 floors. There is no separate service lift so when we did the pilot study in two towers, we figured that it is best if the waste picker carries one bin for the food waste and 2 bags (one for the rejects and the other for the recyclables) using the stairs to each of the 5 floors in the buildings to collect the segregated waste from each home.
- Refusing to pick waste from homes unless it is properly segregated.
- Single minded push by one resident with support from a small core group, the RWA President, horticulture and housekeeping staff.
What did not work?
The suggestion of Challans / Fines for not giving out segregated waste did not go down well with the residents. This line of thought was not pursued as it was leading to resentment amongst the residents.
Collection Process of Segregated Waste from Homes
The waste collected in 3 ways from each household by the waste pickers is brought down and emptied into a big drum kept for the kitchen waste and 2 different bags kept for the recyclables and the reject waste in the waste picker’s cart. None of the waste picker’s collection bins are lined with plastic bags. This cart is taken to the site allocated for waste management in the complex. At the waste management site, the kitchen waste is taken to the composting area and the recyclables are sorted separately.
Sale of Recyclables by Waste Workers
All the recyclables are sorted and taken by the waste workers free of cost to sell to the recyclers in the market. Waste Champion Keshav Jaini from Garden Estate says, “The RWA or Garden Estate residents do not profit from the sale of these recyclables. We are very happy for the waste workers to have this additional source of income.”
COMMUNITY LEVEL COMPOSTING IN GARDEN ESTATE
Full scale composting operation for the entire community started in February 2016. But before that, a waste audit and a pilot for segregation and composting was done.
Waste Audit and Composting Pilot
Household waste – Waste audit was carried out internally by the resident eco-team volunteers and the housekeeping staff when the segregation and composting pilot was done from October to December 2015 to assess the quantity of kitchen waste, recyclable waste, reject waste and plastic waste generated from 20 homes in two towers. The kitchen waste generated from 20 homes was then extrapolated to estimate the kitchen waste that would be generated by all the 373 homes in the complex. This helped in deciding how many total composting bins would be required.
Horticulture waste – Garden Estate complex is spread over 23 acres of land and has lots of trees, plants, bushes and flowers. Bulk of the dry leaves are collected in the shedding season from March to May every year. Smaller quantities are collected from time to time during the rest of the year. The dry leaves are stored in gunny sacks kept in the composting area. The horticulture waste generated is approximately 20-30 trailer loads by volume annually.
- 50 – 60% of the horticulture waste is used in the composting process along with the kitchen waste.
- Leaf composting is done using the remaining dry leaves to make nutrient rich leaf mulch.
- Branches from the trees are given to nearby villagers for their use free of cost.
Do-It-Yourself, Low Cost, Natural Community Composting Solution Adopted
After studying many natural and semi-mechanised composting options and carrying out a pilot project, Garden Estate adopted the Do-It-Yourself, Steel Wire Mesh Bin System of Aerobic, Natural Composting. This in-house, low cost and completely natural system of community level composting is being used in Bangalore and other Indian cities as well. It is based on a simple to operate process with no use of machines, electricity or water making the carbon footprint of this composting solution extremely minimal. Occasionally, only a small shredder is used to manage the large volume of dry leaves in the shedding season and to speed up the composting process as dry leaves take longer to compost. This composting solution is based on the housekeeping staff managing the essential components of aerobic composting i.e. C:N ratio (Carbon:Nitrogen), Moisture and Air properly. The system requires proper monitoring by the housekeeping supervisor on a daily basis and the eco-team members on a weekly basis to ensure that the Standard Operating Procedures (SOPs) are being adhered to so there are no issues of smell, compacting etc and the compost generated is of high quality.
Learnings from the Composting Pilot
Along with the waste segregation pilot, a composting pilot was done from October to December 2015. Kitchen waste from two towers i.e. about 20 households was collected and put in one steel wire mesh bin layered with dry leaves everyday over a period of a few weeks.
Garden Estate Waste Champion Keshav Jaini says – “The pilot helped us to figure out what can go wrong when we try to compost the waste of so many homes together and what are the solutions we need to look at. Many specific issues were studied and resolved such as the waste pile compacting and turning anaerobic, smell issues, time taken in the bins for the first stage of the composting process, how to aerate the waste pile in a labour efficient manner etc. For example, we realised that the height of the composting bin should not increase more than 3 feet as it helps to minimise the need to physically turn the pile for aeration. Also, we realised that by putting 2-3 pipes (with holes) in the composting bins at a slanting angle helps to aerate the waste pile well and reduces the need for the housekeeping staff to manually turn the waste pile for aeration. So essentially, the pilot study helped us to figure out how to solve issues at low cost, using less labour and other resources.”
Process of Natural Composting using Steel Wire Mesh Bins
Two housekeeping boys have been trained to carry out the composting operation. On a daily basis, it takes them about 2 hours to do all the jobs at the composting site. When the segregated kitchen waste from the homes is brought to the composting site, the housekeeping boys first carry out a secondary process of segregation to ensure that any plastic or metal or glass put by mistake by the residents or the household helpers in the kitchen waste is removed. Items like coconut shells are removed as they take too long to compost. Meat bones are put in. After the secondary process of segregation is done, the housekeeping boys cut down the bigger and harder pieces of food waste like water melon peel, other fruit and vegetable peels using a knife.
Aerobic composting requires carbon, nitrogen, air and moisture. The nitrogen content is obtained from the food waste, primarily the fruit and vegetable peels. Food waste should be mostly fruit and vegetable peels and about 15 – 20% can be cooked food for this natural composting process to work efficiently. Dry leaves, saw dust and cocopeat are used to get the carbon content. Saw dust is mixed in the chopped food waste.
This mixture of food waste and saw dust is then put into the steel wire mesh composting bin and covered properly with dry leaves. This ensures that no flies or bugs are attracted to the bins and there are no issues of smell. Once the composting bin is full, the food waste and the horticulture waste is left in the bins for 5 weeks to compost naturally. 2 pipes have been put in each of the composting bins to allow for air to go in easily and aerate the pile. The waste is also turned once or twice every week using a rake to provide for better air circulation. Every bin has been given a jute cloth lining to cover the sides so that the waste does not fall out of the bin. It also helps to control the extreme temperatures, moisture levels and pests from entering inside.
To absorb the leachate that drains out during the composting process, sand or cocopeat is placed on top of the cement structures built under the bins. After 5 weeks, the compost which is about 70% done at this stage is taken out of the composting bin and taken to an open area where it is left to cure for another 5 weeks. In case any waste item like meat bones are not decomposed fully, they are just put back into the composting bin with the fresh waste. Total time taken for compost to be made using this natural aerobic system of bin composting is 10 weeks. About 5-6 kgs of the 70% done compost or the ready compost is put as an accelerator at the base of the composting bins to increase microbial activity at the time of restarting the process of loading the bins each time. Additionally, about 1 kg of the compost can also be put 2-3 times during the loading cycle.
Standard Operating Procedures (SOPs)
Regular training of housekeeping staff is done to ensure that they:
- Carry out a proper secondary segregation process to take out any plastic, foil, glass pieces put into the kitchen waste by mistake.
- Cover the food waste with leaves properly so there are no flies and smell issues.
- Understand that the dry leaves (source of carbon content) should be about 3 times in volume (or same quantity in weight) as compared to the kitchen waste (source of nitrogen content) to get a good Carbon:Nitrogen ratio.
- Follow SOPs in terms of maintaining proper system of aeration, moisture levels, mixing saw dust (source of carbon content) in the chopped food waste, adding old compost to kick start the microbial activity at the time of loading fresh waste into the composting bins etc.
Dimensions of the Steel Wire Mesh Composting Bins
Garden Estate Waste Champion Keshav Jaini says, “We bought 4 rolls of steel wire mesh (1-inch square) and then our internal staff fabricated 12 circular steel wire mesh bins of 4 feet diameter and 3 feet height to manage 225 kg of kitchen waste daily coming from 373 homes in Garden Estate. We kept the height of the composting bins at 3 feet to minimise the need to physically turn the pile for aeration.”
Loading Capacity of the Composting Bins
Each bin of size 4 feet diameter and 3 feet height takes about 110 kgs of kitchen waste daily and the same quantity in weight of the dry leaves i.e. about 110 kgs of dry leaves daily up to seven days. In Garden Estate as the total kitchen waste is about 225 kg daily, 2 bins are loaded simultaneously in the first cycle for a week till they are full. After five weeks when the compost is about 70% done, it is taken out of these bins for the curing process. Then the loading process of the fresh waste is restarted in these 2 bins.
Capital Cost i.e. one-time set up cost = Rs 1,85,000
- Cost of composting bins – 12 steel wire mesh composting bins were made in-house in January 2016 at a total cost of Rs 50,000. This cost includes the cost of rolls of steel wire mesh bought to make the bins, cost of the jute cloth bought to line the bins and the labour cost to put all the bins together.
- Cost of making the tin composting shed and brick flooring – Rs 1,35,000
Garden Estate Waste Champion Keshav Jaini says, “We got a shed made for our composting unit as the composting process needs protection from direct sun, rain, cold and wind. From the construction work happening inside Garden Estate at that point, we requested residents to give bricks, marble slabs etc for the flooring. This way we kept the set up cost minimal.”
Maintenance Cost i.e. monthly cost for running the composting operations = Rs 7,000
- Labour cost for carrying out the secondary segregation process and loading of the composting bins comes to about Rs 5,000 per month (paid to the housekeeping boys involved in the composting operation over and above their monthly salary. As the society housekeeping boys are involved in running the composting operation, part of the labour cost is already covered in their regular housekeeping payments).
- Consumables (saw dust and cocopeat) – About Rs 2,000 per month
Leaf Composting Process in Garden Estate
Garden estate has a huge green cover and a lot of garden waste is generated. The dry leaves that are not used in the waste composting process with the food waste are used to make nutrient rich leaf mulch. Leaf mulch helps to protect and aerate the soil and save water by retaining moisture in the soil.
Garden Estate has used steel wire mesh bins of about 3 to 4 feet in diameter and 4 to 5 feet in height for leaf composting. The bins have been placed in a shaded, flat and clean area near the nursery. The earth at the bottom is watered before adding the leaves and flowers waste. A handful of accelerator in the form of cow dung slurry (made by mixing dry cow dung with water) or some compost or sour butter milk is sprinkled on top occasionally to increase the microbial activity and speed up the decomposition process. Water is sprinkled on the pile to keep it moist. This process is repeated every day or as and when extra leaves are available. It can take 6 – 8 months for the decomposition process depending on factors such as size and type of leaves, weather (too hot or too cold), moisture levels etc. The bottom most layer in the bin starts decomposing first. An opening has been provided at the bottom to take out the ready leaf mulch. Leaf composting in steel wire mesh bins makes it a continuous composting process as leaf and flower waste is added from the top and leaf mulch is taken out from the bottom. When leaf mulch is taken out, any leaves that are not fully decomposed are put back on top with the fresh leaf waste.
GARDEN ESTATE WASTE MANAGEMENT INITIATIVE – IMPACTS
Better Recovery of Recyclables
Garden Estate has had a family of waste pickers working with them for many years. They are very happy with the community for implementing segregation as the sale of clean recyclables helps to fetch them more money. It has also given the waste workers more dignity of labour. Waste Worker Inda Dun says, “Earlier when we were collecting mixed, unsegregated waste from the homes, it took my family hours to sift through the garbage to recover the recyclables. A lot of precious time was wasted and many recyclable items would get spoiled as a result of the wet kitchen waste and the dirty sanitary waste all mixed up in the same bag.”
Reduction in Quantity of Single Use Plastic sent to the Landfill
Since the implementation of waste segregation in Garden Estate, majority of the households (about 75%) have stopped lining their dustbins with plastic bin liners. By consciously refusing to use plastic bin liners, the community is preventing plastic pollution that would have been caused by more than 2,00,000 bin liners going into the landfill every year.
Responsible Management of the Community’s Waste
Waste Champion Keshav Jaini says, “Segregation of waste at each home level, community level composting and recycling of dry waste and e-waste ensures that we are able to responsibly manage almost 80% of the total waste generated by our community. About 60% of our total waste is kitchen waste which is converted to high quality compost. 20-25% of the waste from all the homes is paper, cardboard, plastic, metal, glass and electronic waste which is recycled. Only the remaining 15-20% that cannot be composted or recycled such as sanitary waste, household sweepings etc. goes to the landfill now.”
Minimal Carbon Footprint
Since the community composting model is in-house so no transportation cost is incurred in carrying the waste anywhere. Moreover, it is a completely natural system with no machines so there are no electricity costs or any extra resources used.
Creating Wealth from Waste
Before the implementation of the segregation drive, Garden Estate was throwing away almost 225 kg of kitchen waste every single day. After the community has started segregating, Garden Estate saves almost 82000 kg of kitchen waste from going to the landfill every year. Instead wealth in the form of nutrient rich compost is created out of this waste. Annually, Garden Estate produces about 9 tonnes of compost. Most of this is used within the complex in the parks and green areas. Residents are sold the compost for use in their gardens. Some compost is gifted to NGOs.
Win-Win Situation for the Community and the Planet
Keshav Jaini says, “We are using all our horticulture waste effectively in making compost and leaf mulch so we are preventing the pollution that could have been caused with these leaves going out of the complex and getting burnt somewhere, polluting the air we all breathe. There is also a direct financial saving of Rs 50,000 every year to the community which we were spending earlier on buying compost for our green areas from the market. The compost that we are producing is very high quality. We are now using twice the amount as it is freely available and we have been able to green many areas that were lying barren in our complex. Our plants and trees are very happy as this compost is very high in nutrients. So, the in-house waste management is a win-win for everyone – the residents, the waste workers, the RWA, the soil, the plants, the trees…”
ADVISE TO OTHER COMMUNITIES
In the words of Garden Estate Waste Champion Keshav Jaini:
- Make a very strong core group of eco-conscious, dedicated and committed resident volunteers to help out in the awareness and implementation process.
- Look at the waste management system for its long-term sustainability. Keep it simple. The process should be system driven, not person driven.
- Do a pilot for segregation as well as composting as each community will have different sets of issues. The pilot helps to identify the problems and figure out solutions which then helps in the smooth scale up of operations.
- Set up detailed SOPs and checklists. Have efficient reporting systems in place.
- Do regular workshops (twice a year) for training of household, housekeeping and horticulture staff as people keep leaving and new staff joining.
- Recognise good work. Honour the housekeeping, horticulture staff and the waste workers for their efforts to make them feel appreciated for their hard work to keep them motivated.
- Use the eco-consciousness built in the community with the implementation of waste segregation and composting to take up other environment friendly initiatives such as building sewage treatment plants, implementing the saying no to single use plastic campaign, native tree planting, creating organic community vegetable gardens, building rain water harvesting structures in the community for recharging ground water levels, installing solar heating and lighting and other energy efficient measures, celebrating festivals in an eco-friendly manner etc.
REPLICATION OF THIS LOW-COST, NATURAL COMMUNITY COMPOSTING SOLUTION
This low-cost natural system of composting using steel wire mesh bins can easily be adopted by any residential community or an organisation like a school or an institution with enough open space for composting. For this natural composting process to work efficiently, food waste should be 80% fruit and vegetable peels and about 20% can be cooked left over food items. As the process is simple to operate, the in-house housekeeping staff of the RWA or the organisation can be trained to run the show without any problems. Care has to be taken that regular monitoring is done to ensure that standard operating procedures are adhered to.
As the quantity of waste to be handled goes up, the number of trained people to handle the composting operation will also need to be increased. For example, where the quantity of waste being handled is more, having a Supervisor to oversee the work of the staff handling the composting operations will be useful to ensure that SOP s are strictly followed.
Shape and Dimensions of the Composting and Curing Bins
The shape of the bins can be round, square or rectangular. Care has to be taken that height or width of the bins is not increased too much, otherwise it becomes difficult to aerate and manage the waste pile. Then issues such as the waste compacting, the waste pile becoming anaerobic and smelling can occur.
Rectangular bins will take less space but cost of making rectangular bins is higher as compared to circular bins. Also, rectangular bins cannot be made in-house. They will need to be made by an outside fabricator.
Advantages of this Do-It-Yourself, Natural Composting Solution
- Highly modular and adaptable system – Depending on a community’s or organisation’s total space availability and requirement, the system can be designed and implemented.
- Flexible – As the bins are not fixed to the ground, they can be easily moved to another location if required. Also depending on quantity of waste generated and space available for composting, shape of the composting and curing bins can be circular, square or rectangular. This composting solution offers flexibility in the curing process as well. Garden Estate complex has a lot of space so the 70% done compost is left in an open area to cure naturally. Where space is limited, this curing process can take place in specially designed steel wire mesh curing bins so as to optimise the space available.
- Neat and clean system – As the kitchen waste is well covered with dry leaves, there are no flies and insects. The jute / green net lining on the sides of the bin ensures no spilling of the waste and helps to insulate the composting process from heat and cold.
- Very low-cost community composting model – As no machines are used or any outside vendor is used for carrying out the natural composting operation, there is no electricity cost or expensive annual maintenance contracts for any machines or any monthly payments made to vendors. Both one-time set up cost and monthly running cost for this do-it-yourself solution are minimal which makes this a very economical model for a community or organisation which has open space for composting.
- Provides for good aeration – 2 inch diameter pipes with holes in them that are put in the bins help with the aeration. One or two 2 pipes should be put in each composting bin.
- Facilitates a continuous process of composting – Every 5 weeks, the 70% done compost is taken out from the composting bins and the loading process is re-started.
- Allows for easy maintenance of standard operating procedures – This system is very easy for any housekeeping staff to understand. Important factors for aerobic composting such as Carbon:Nitrogen Ratio, Aeration, Moisture and Temperature can be easily managed in bin composting.
Natural Community Composting Solution using Steel Wire Mesh Bins – Do-It-Yourself vs Vendor-Based Model
Learning from the experience of Garden Estate Community’s Do-It-Yourself (DIY) Waste Management System, Malibu Town residents in Gurgaon have set up their own Low Cost, DIY, Natural Composting Model using funds collected from the community. We will share their fascinating story in one of the subsequent blogs on this website.
Balancing Bits, a social enterprise based out of Gurgaon working in the area of providing waste management solutions to residential communities and organisations in Gurgaon, Delhi and other cities is also following this low cost, natural system of bin composting (http://balancingbits.com).
Communities or organisations who want to use this low cost, natural system of bin composting but do not have the human resources for setting up and implementing the system on their own, can get vendors like Balancing Bits to set up and run the natural composting operations for them. Please bear in mind that the set up and monthly maintenance cost in hiring the services of a vendor will go up as compared to the ‘Do It Yourself’ extremely low-cost model like the Garden Estate one as payments will need to be made on a monthly basis to the vendor for providing labour and expertise to run the composting operation.
Capital Cost to Set Up the Composting Bins
Each bin can cost anything between Rs 3000 to Rs 12,000 depending on the size, shape, do it yourself or outside vendor used. Shed cost and cost of flooring is extra.
Number of Bins and Space Requirement for this Natural Composting Solution
Space required for composting operations will depend on factors such as:
- design of the composting bins,
- whether the curing process is being done in the bins or in the open,
- availability of space for composting in the complex
Number of bins used will depend on several factors such as:
- area available for composting,
- size and shape of the bins,
- layout of the space available,
- amount of kitchen and horticulture waste that needs to go in daily,
- turn-around time
Number of Circular Composting Bins required based on Garden Estate Do-It-Yourself Model
Following are some calculations done by Waste Champion Keshav Jaini if the dimensions of the composting bins are kept the same as the ones used in the Garden Estate composting set up i.e. circular steel wire mesh bins of 4 feet diameter and 3 feet height.
4 circular bins can manage kitchen waste of 100 homes
100 families will approximately generate 50 – 60 kg of kitchen waste daily. Each circular bin of size 4 feet diameter and 3 feet height will take 50-60 kg of kitchen waste plus 50-60 kg of horticulture waste in weight daily and will take about 14 days to fill. The turn around time is 5 weeks for each bin. In 5 weeks, the compost which is 70% done will be taken out from the composting bin and left to cure in an open area for another 5 weeks. This is how the cycle works.
6 circular bins can manage kitchen waste of 200 homes
200 families will generate approximately 100 – 110 kg of kitchen waste daily. Each circular bin of size 4 feet diameter and 3 feet height takes 100-110 kg of kitchen waste plus 100-110 kg of horticulture waste (in weight) daily and will take 7 days to fill. The turn-around time will be 5 weeks. In 5 weeks, the compost which is 70% done will be taken out from the composting bin and left to cure in an open area for another 5 weeks. This is how the cycle works.
12 circular bins can manage kitchen waste of 370 homes
Garden Estate has 370 homes and about 225 kg of kitchen waste is generated daily. Each circular bin of size 4 feet diameter and 3 feet height takes 100-110 kg of kitchen waste plus 100-110 kg of horticulture waste (in weight) daily and takes 7 days to fill. In Garden Estate, 2 bins are loaded in the first cycle. The turn-around time is 5 weeks. After 5 weeks when the compost is about 70 percent done is taken out of these bins for the curing process, the loading process of the fresh waste is restarted in these 2 bins.
Space required for composting based on Garden Estate model
In Garden Estate where curing of the 70% done compost happens in the open, to compost kitchen waste of 225 kgs daily along with the same quantity in weight of dry leaves, 1500 square feet of total space is used. The composting area in Garden Estate where the 12 bins are kept is about 1000 square feet which includes storage space and the area where secondary segregation takes place. Garden Estate has a lot of open space but if space was limited, the entire composting operation could easily be carried out in two-thirds of this space (about 650 square feet).
In Garden Estate, the open area where curing of the 70% done compost takes place is 500 square feet. Since direct sunlight and rain are not good for the composting process, the curing area is protected from direct sun light by the natural shade of trees. A plastic sheet is kept over the compost that is being cured during the monsoon months and other times when it rains heavily.
- If the 70% done compost is cured using bins, the space required for curing reduces.
- As the quantity of waste increases, size of the bins will need to be changed to rectangular as they take less space and more waste as compared to circular bins.
Number of Rectangular Composting & Curing Bins and Space required based on Balancing Bits Vendor Based Model
16 rectangular composting bins & 5 curing bins can manage kitchen waste of 500 homes
“According to Rahul Khera of the social enterprise Balancing Bits (http://balancingbits.com), “For 300 kg of kitchen waste (from 500 homes) plus same quantity of horticulture waste in weight daily, approximately 16 composting bins and 5 curing bins will be required to complete 30 days of composting cycle plus about 10 days of curing. Rectangular bins of size 4 feet x 4 feet x 3 feet or 5 feet x 3 feet x 3 feet will occupy minimum 750 – 800 square feet of space. This is based on our experience of composting kitchen waste of 500 homes plus horticulture waste at Uniworld Garden 1 complex in Gurgaon.”
Rahul Khera at the community composting site in Uniworld Garden 1, Gurgaon that his firm Balancing Bits is operating
32 rectangular composting bins & 10 curing bins can manage kitchen waste of 1000 homes
According to Rahul Khera, “For 500 – 600 kg of kitchen waste (from 1000 homes), plus same quantity of horticulture waste in weight daily, approximately 32 composting bins and 10 curing bins will be required to complete 30 days of composting cycle plus about 10 days of curing. Rectangular bins of size 4 feet x 4 feet x 3 feet or 5 feet x 3 feet x 3 feet will occupy minimum 1500 square feet of space.”
For queries and guidance on implementation of the 3-way segregation process and the Do-It-Yourself, natural community composting solution detailed in this case study, please contact: Mr. Keshav Jaini, Garden Estate, Gurgaon.
For any comments, feedback or clarifications on this case study, please write to the author – Neelam Ahluwalia at the email id mentioned.
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