Digging into Bangalore’s Waste – Waste Characterization Study 2014

“So, what is the solution to handling Bangalore’s waste?”

The question is asked as if the answer is a simple one liner! And simply because a question is asked, comes the pressure of giving an answer. So we say things like “Segregation at source will solve all our problems” or “We can compost most of our waste and farmers are waiting to grow crops with our compost!”.

The lesser said the better about the success of segregation at source, despite efforts of the last 10 years. And as for compost, not much has been studied about the presence of heavy metals in municipal compost which might make it unsuitable for food crops. And even with the little that is currently composted, there are few or no takers for the compost. And what about the rest of Bangalore’s waste that cannot be composted? How much is that? What should happen to it? With majority of the current recyling industry being completely unchecked and unregulated, we will be fooling ourselves if we think that all our plastics are being safely handled. And then, there is that which can neither be recycled, nor composted, such as diapers, sanitary napkins, laminated packaging material, etc. Does it just vanish into thin air: Poof!? Unfortunately, even with the best of our magical abilities, it cannot be wished away.

Solutions to problems as complex as Waste Management cannot be arrived at through emotions alone. Thorough analysis and being open to various options is needed to design an appropriate waste management system. At this point in time, we do not have enough data to even analyse the current status of waste management in the city. This write-up will speak about a significant step we took in this direction – the recent Waste Characterization study that we undertook, what we discovered about the type of waste that is generated in Bangalore’s residential areas, the potential of the waste, and a look at directions we need to explore to arrive at appropriate solutions.

Need for the study

The last study as per the BBMP was done in 2007-08, the report of which is put up in the BBMP website. Even if we excuse the poor presentation of data, there are many glaring errors in this study, making the results suspecious and unscientific. Vishwas Vidyaranya, Associate Manager with Infosys’ Green Initiative team has analysed this report to find that:

“The categories of waste mentioned in that report ( might not be accurate as the waste types mentioned in physical composition table of the report are debatable. Example: It doesn’t clearly explain if the vegetable waste and organic waste which constitutes 53% of the total waste accounts for all the food waste (including non-veg waste). The individual waste fractions mentioned in the table doesn’t add to 100%, which might be a computational error and certain categories such as styofoam or thermacol are not included. While biomedical, batteries and electronic waste are considered, household hazardous waste is not included. Hence there is no defined boundary for waste types and it might be inappropriate to design waste management systems based on such data sets.”

Waste Characterization studies must be done periodically, at least once in 4 years, to get the status update of the changes in the waste stream, in terms of categories of waste as well as quantities. Waste Characterization studies are the necessary first steps to design or periodically review Waste Management systems. This prompted us to undertake the study to obtain first hand data about what exactly Bangalore’s residential waste is composed of, and what could be done with it.

The method we followed

Phase I of our study consisted of studying samples of residential waste of about 1 ton, from 3 wards in Bangalore. Usually, WC studies involve random sampling from landfills. However, this does not give a complete picture of the waste generated, as some of the items such as high value plastics are collected by the informal sector of waste pickers before disposal at the landfill, and hence

Bhaskar following the collection auto, to ensure we get the right sample

Bhaskar following the collection auto, to ensure we get the right sample

would not appear in the samples. In order to give a complete picture of every possible category of waste that is generated in the residential zones, we decided to collect samples directly from homes. In order for the sample to be the right representation of waste from residential locations, these steps were followed:

  1. The collection started with an empty garbage auto in the location under consideration

  1. 6-12 streets (roughly 150 homes) were then covered and unsorted waste was collected from each house to ensure around 100kgs was obtained

  1. The waste thus collected was completely emptied in the sorting station, making sure that no item (especially PETE bottles, milk packets, etc.) were removed from the samples by Pourakarmikas (garbage collectors)

  1. The initial weight of the entire sample was noted, before sorting began

We collected a total of 9 samples from HSR layout (ward 174), Gottigere (ward 194) and Konanakunte (ward 195). On different days, we studied samples from different income groups, to get a comparative idea of the variations in waste generated.

Duration: 9 days, between February 10 and March 28, 2014

Sample size: Each sample was around 100 kgs

Number of samples: 9

Total Quantity: 1027.45 kg

Locations: Wards: HSR Layout (174), Gottigere (194), Konanakunte (195)

Sample types: Residential – 4 samples from layouts having middle and high income groups, 1 from low-income households; Bulk waste generators – 3 samples from Apartments; Garbage on Ground – 1 sample from garbage truck containing garbage cleared from blackspots in a location with commercial establishments

The samples collected each day were weighed and then manually sorted into 16-20 categories, the details of which can be seen in the report Waste Characterization Bangalore 2014

Putting our hand into other’s garbage

We ensured that necessary protective gear for the sorters such as masks and gloves were put to use during sorting. There was some resistence from the sorters in Gottigere ward as they were not comfortable with the gloves. However, we insisted. Perhaps, this is one reason why the BBMP has not made too many efforts to provide gloves and masks to the Pourakarmikas – providing is easy, getting them to use it is another issue altogether!

On most days, Bhaskar and I joined in the sorting process. This was to get a hands-on experience of what it takes to manually sort

Gulabi Gang at work in Gottigere!

Gulabi Gang at work in Gottigere!

garbage and also because it simply did not seem right that we make others do something we ourselves would hesitate to do. So, we put our gloved hands into other’s garbage. There are no lines to be drawn here – everything is to be touched, removed and kept aside. That includes soiled diapers, used sanitary napkins and occassionally, used condoms. Once you handle these, the rotton food, smelly meat and watery curries will seem like heaven!

However, there was one day, when both Bhaskar and I simply could not get ourselves to touch the garbage, and felt awful that others had to do it. This was on day 8, when we got the sample from a blackspot which smelled absolutely terrible! Both of us were just recovering from a bout of nausea and diarrhoea (part of our hands-on experience with garbage!) and the sorters simply wouldn’t let us risk getting unwell again. I am always touched by just how much genuine care they have for us. It is during times like this that we realize that our Pourakarmikas are our Protectors – day after day, taking on our share of disease and discomfort, just so that we could be safe. How can any amount of money compensate that?

At the end of it, one of the sorters told us that if we intended to do more such samples (from blackspots), we should either drug them or get others (waste pickers) who are usually under the influence of alcohol or drugs to do this job! Honestly, what on earth are we thinking when we talk of formalizing and encouraging waste picking?! Just because it serves our purpose, we have completely blinded ourself to the inhuman conditions that waste pickers go through.

Like manual scavenging, waste picking too needs to be banned. And, smarter ways of garbage handling needs to replace manual handling, for the safety of our Pourakarmikas.

What does the study reveal?

During a casual conversation with a BBMP engineer during a workshop on waste management, he said that we generate around 30%-40% of food waste, and that it might be slightly more in locations with restaurants. He also said that we cannot think of Waste to Energy for Bangalore because our waste has a low calorific value. This is the language that is currently spoken. Nobody seems to have a clear idea of what is the composition of the waste and an even lesser idea of its calorific value. And with this approach of assumptions and half-baked information, we propose solutions in the air and blindly dismiss anything that involves a thermal process.

Despite taking samples from various income groups and even one from a blackspot, the data was quite consistent in terms of composition, especially of food waste. The data shows that the major chunk of what we generate includes around 60% of food waste, 10% yard waste, 9.5% plastics, 6% Sanitary waste, 5% Paper and the remaining 9.5% includes glass, tetra packs, fabric, thermocole, e-waste, laminates, metal, etc. The details can be viewed in the report.

The calorific content of any waste to be considered suitable for a thermal process should be above 7 MJ/kg. And Bangalore’s waste has a potential of 11.8 MJ/kg!! And this is inspite of including the food waste and yard waste. If we remove the food waste that can be treated through Aanerobic Digestion and exclude the items with resale value (PETE, HDPE, Carton, etc), the calorific value of the waste would go up to 18.41 MJ/kg, as shown in the analysis by Larry T. Buckle (refer to the report). This finding is a complete eye opener and suddenly throws open numerous possibilities in handling waste.

Realizing the potential of Bangalore’s waste

We had the opportunity to meet Larry sometime in January. Larry has over 20 years of experience in studying and implementing solutions for Solid Waste Management and was the Chief Technical Officer of Organic Energy Corporation, California. Currently, he is working as PE, International Engineering Services, Inc.,CA, USA.

The interesting thing about the way Larry looked at solutions was that we need a variety of suitable interventions, keeping in mind the composition of waste. So, it does not mean we have only one exclusive option, be it Waste-to-Energy or Recycling or Composting, but a combination of these. Inspite of his years of expereince in this field, not once did he recommend solutions that he was working on. Instead, he tried to understand what Bangalore’s situation is. Unless and until we have the exact data of what we generate and what our requirements are, no expert can help us with solutions. This is why the Waste Characterization study is the first step to even get a grasp of what we need to have in place to come up with solutions. Larry was kind enough to guide us throughout the study, and also analyse our report and write a critical review of the same (can be read in the report).

Larry’s analysis of our report explores three parallel methods of handling residential waste:

  1. The items with positive resale value such as PETE, HDPE, etc, could be straightaway seperated and sold to their existing markets

  2. Wet organics (food waste) can be put through a process of Anaerobic Digestion (biomethanization), with the resulting methane gas being converted to electricity. From Larry’s analysis, the food waste can be assumed to produce a continuous 8 MW of electricity!

  3. The remaining components which can neither be sold nor used in the AD process, could be put through a thermal process to generate electricity. He terms these Dry Organics and says that it can produce upto 15.9 MW of electricity!

This means, we have a total potential of generating around 24 MW of electricity from 1000 tonnes of waste!

24 MW-hours produced, means everyday there will be:

24 MW x 24 hours = 576 mega-watt-hours per day

and every year there will be:

576 MWh per day x 365 days per year = 210,240 MWh per year.

Vikshut Mundkur, who works on energy solutions, analysed some numbers and arrived at this – “Under ideal conditions and assuming that Bangalore generates 4,500 tonnes of waste per day, we have the potential of generating 850 Mega Units (MUs) of electricity annually. This amounts to a 6.2% contribution to the estimated total electricity consumption or a 20.7% contribution to the domestic electricity consumption in Bangalore last financial year. “

Note: This is under ideal conditions of tempretaure, pressure and moisture. With 140 days of rain and 60 days of cold in present Bangalore’s conditions, these vary and the percentages are individual functions of variables. 

The technologies and the solutions suggested by Larry are not exactly new to us. But we have not had successful examples and working models of these in India, reason being the piece-meal approach that was adopted and no due diligence being done in terms of feed stock, technical know-how, manpower requirements, etc. Many solutions were implemented in a rush, without taking care of the pre-requisite steps. The solutions that we propose should be part of the wholistic system and not stand-alone experiments.

What’s next?

This is only the first step towards obtaining relevant data for coming up with appropriate solutions.

In the next phase of the WC study, we will need to do a thorough physical and chemical analysis (as mentioned in Vishwas’s critical review in the report), and include other waste steams apart from

Municipal Solid Waste, such as Industrial, Hazardous, Construction & Demolition waste, Commercial waste and Sludge. Larry’s analysis gives us a good direction to explore and further understand solutions, be it Anaerobic Digestion, Thermal processes or even composting. In the coming months, our efforts would go towards completing the study and researching various options for solutions.


One thought on “Digging into Bangalore’s Waste – Waste Characterization Study 2014

  1. Dear Sir
    I am involved in a community project in my area (Kodihalli) where in I intend to visit individual homes in the apartments to encourage the idea of waste sorting before disposing. I would be grateful if you can let me have a list of all items that constitutes household waste but which has a positive resale value like PET, HDPE etc. Also I will appreciate if you can advise under which category does the milk packets come – having resale value or otherwise. I would like to meet your team and will be grateful if you could forward me contact particulars.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s