Building an Ethical and Efficient Recycling Supply Chain in India

by Diana Drake

Knowledge@Wharton High School is often curious about the business talent right at our doorstep – namely undergraduate students who are exploring and pioneering in all areas of entrepreneurship and leadership. When we heard about rePurpose, a digital recyclable waste marketplace created by undergrads Peter Wang Hjemdahl, Svanika Balasubramanian and Aditya Siroya, we invited Svanika into the studio to tell us more about this unique social impact startup. Mumbai, India, is a city where 21 million residents generate 9,000 tons of garbage every day. How to divert much of it from landfills, while also boosting the annual income of marginalized waste pickers known as kabadiwalas? RePurpose has an app for that.

An edited version of the transcript appears below.

Knowledge@Wharton High School: Chances are, you haven’t heard of the kabadiwalas of India. These unsung environmental heroes collect waste from individual households, sort and process the scrap, and sell the materials to larger recyclers for very small amounts of money. This is where rePurpose enters the picture. This non-profit social venture, launched by a team of Wharton undergrads, wants to create an ethical and efficient recycling supply chain. By doing so, rePurpose will double the income of kabadiwalas and divert waste from landfills toward recycling. Svanika Balasubramanian, who cofounded rePurpose, is here to tell us more about the startup that this year won a class of 2018 President’s Engagement Prize.

Hi, Svanika. Thank you for joining us today.

Svanika Balasubramanian: A pleasure to be here. Thank you so much for having me.

KWHS: Our pleasure. So, I think a great place to start is for us to better understand the rePurpose business model. Can you tell us a little bit about your organization?

Balasubramanian: When we think about rePurpose, we think about it as being a marketplace for waste (garbage). So, if you want to buy anything [other than waste] — you know exactly where to get it from. And there’s this kind of efficiency associated with it. But when you want to buy waste and you want to recycle it, there really isn’t any one place you can go. And this lack of efficiency was what we wanted to correct.

RePurpose, at a very high level overview, is a marketplace that connects the different players. And so, I can go a little bit into who these different players are. On a high level, there are three players. First are the waste generators — like you and me. We get a bottle of Coke and we drink it. Now we have this plastic bottle and we don’t know what to do with it. So the first link is just us, the people who produce this waste. And then the second link — especially in developing countries where you see most of it — are people who come in and they collect these bottles, paper, plastic — whatever it may be. We call them kabadiwalas. They bring it back to their stores, and they’re the ones who sort it into the different subcategories of waste. So if you take a plastic bottle, the screw top is a thicker kind of plastic and so it recycles differently to the remaining part of the bottle. And again, the paper — the wrapper paper, that, again, recycles differently. So they differentiate it. They break it apart into little pieces and then they sell it to the third part. The third stakeholders in this marketplace are the recyclers. They’re the ones with the machines that can actually take in these different products and crunch them, make [the waste] into little pellets. And then they go on and actually recycle it.

If you look at places like India, the Philippines, Brazil, you see this common problem that there really isn’t any kind of good connection between these three links. And so, there’s no way for people like you and I to efficiently reach these kabadiwalas in the middle. And what happens today is the kabadiwala wakes up and goes, “I need to sort waste today. So I’m just going to go knock on every household that I see. And I’m going to knock on their door and be like, ‘Hey, do you have any paper? Do you have any plastic? Do you have any metal that I can buy off of you?’” Whatever this kabadiwala is able to salvage, he brings it back and this is pretty much the only way that recyclable waste gets into this chain, because everything else that this kabadiwala is not able to salvage ends up in a landfill. Places like India don’t necessarily have recycling bins in all places. And there isn’t that kind of a system put into place.

Then on the other side, this kabadiwala, once he finishes sorting it, has no clue who the recycler is that he actually has to sell to. So, suppose I’m the recycler and I have machines that I bought that can actually recycle plastic. And there’s plastic type A, type B and type C. I wake up in the morning and I say, “My type A machine is at capacity. My type B machine I don’t have enough waste. So I’m just going to send my truck to roam the cities of India.” [Let’s say] I’m in Mumbai. So, I’m going to have a truck roam through Mumbai and just see if I can find any kabadiwala who will sell me plastic. And so, if he finds it, good for him. If not, then you know, the type B plastic machine is not operating at capacity.

As you can see, it’s a very haphazard system and there isn’t much consolidation. There isn’t much horizontal or vertical integration. That’s where rePurpose comes in. We say we’re just going to connect all of these different moving parts together. And so, again, just to re-cap — three links. You have the waste generators — people like us — houses, housing complexes, universities. Then you have the kabadiwalas in the middle. And then you have the recyclers on one end.

Instead of kabadiwalas going from door to door, we say, “Why don’t you connect with us and we’ll put you in touch with bulk waste generators, like, big housing complexes, like universities.” Universities produce so much more garbage than a household would. And it’s so much more efficient for us to connect individual kabadiwalas and pool them and take them to a housing complex because it’s just way higher volume. And in that sense, we’re able to double their volume. And then, on the other side of things, we are able to connect these recyclers with the kabadiwalas. The recyclers wake up and they send us a text message saying, “Today I need 3 tons of type B plastic. What can you do for me?” And we say, “Okay, we have a pool of 150 kabadiwalas we’re working with and we know what kind of plastic they have. We know what kind of waste they have. So, we’re going to send our truck to get 200 KGs from this guy, 300 from here, and we’re going to pool that across and give it to the recyclers.” It’s making the whole system more streamlined. And in doing so, we’re increasing margins. We’re increasing volumes. And together, these kabadiwalas are doubling their income on an annual basis. So, by year one, we’re thinking about a full $100,000 income increase for these kabadiwalas. And about 52,000 tons of waste that will be diverting away from landfills and into the recycling supply chain.

KWHS: It’s really a social enterprise in both ways.

Balasubramanian: Yes. Environmental and [increasing income for] the kabadiwalas.

KWHS: How did you arrive at this idea? And my guess is that you probably did quite a bit of market research with the kabadiwalas, as well. Is that true?

Balasubramanian: Yes, we did. We spent a long time in India. We actually identified the environmental problem first. My co-founders and I were at one of India’s — one of Asia’s — largest landfills. It’s called Deonar East. And this is an enormous landfill. It’s almost like a city of waste. If you walk through it, it’s just buildings of waste rising on both sides. And you’re walking through it and you’re like, “Is this going to fall on me at any time?” It’s just tons and tons of garbage, dogs roaming about. And at one point we realized that we thought we were walking at ground level, but we were actually walking on 15 feet of waste. They just covered it with a layer of soil. But we were not at sea level. We were on 15 feet of waste. And there was like a 30-feet-of-waste continuum on either side. And we thought, “This is not sustainable.” You have a growing city right next door, and as the population increases, their consumption is going to increase as is their waste generation. And so we needed to come up with a better solution that doesn’t direct all the waste into these landfills.

We were thinking, “What are we going to do about this? What can be done?” And right at the gate of this landfill we saw a kabadiwala. At that point, we hadn’t actually met many kabadiwalas. So we said, “Okay, he looks like he’s dealing with some kind of garbage. There’s trash in his shop. Let’s go talk to him.” And what he said to us — that first kabadiwala — really shook us, because he said, “I barely have enough waste on a daily basis to make any kind of meaningful income. I can’t send my children to school. I don’t have enough for health-care concerns. Dealing with waste, you get a lot of respiratory conditions. And I don’t have any money to treat that. And I’m making less than seven dollars a day.” He just had all of these complaints because he was not well connected. And he didn’t have enough supply of waste. And we thought, “There’s this fundamental mismatch between people like him who are impoverished, who need waste. They want to recycle waste and are not able to access it. And he’s just feet away from this landfill that has tons and tons of recyclable waste that now cannot be retrieved because it’s inside the dumps.” And we said, “Okay, this is where we come in.” And there’s this way of redirecting this waste so that it solves both of these problems.

KWHS: You’re a senior graduating in a few weeks. Have you always considered yourself an entrepreneur? Have you been developing this idea all throughout your time here at Wharton? What’s your journey been like?

Balasubramanian: My journey? It’s very interesting because I was born in India, but I grew up in the Middle East. I grew up in Oman. All my life, I’ve been raised in this mindset that there’s a lot of change to be created in the world. My grandparents were very involved in the Indian independence movement. They ran refugee camps in India. My parents were involved in migrant rights issues in Oman. And so, I always knew that when I grew up, I’d be doing something to create social good. I came to Wharton — I chose to come to Penn — because I think for-profit social enterprises are the best way to create change in today’s society. They’re the most efficient ways of creating change. That’s what my business education was informing me towards.

I’m a senior, and I’m in the Joseph Wharton scholars program. As part of the Joseph Wharton scholars program, we have to write a senior honors thesis. I was in this thesis class and one of my co-founders, Peter, also happened to be in that class. That’s how we met each other. He was working with the Indian waste management industry. And so, we met and we got talking. We got very excited about it and we said, “Okay, let’s look more into it.” Peter had been working on some variation of this for a year before. He started working on it through the Hult Prize that Penn also hosts. But he’d just been going through different models. Once I got on board, we also [brought on] a third member, Aditya Siroya, who’s a junior. Then, the three of us made multiple visits to India. Through the course of last semester, we were there in January. We were there for an entire month doing market research, putting together a proposal. That all just snowballed together. I think rePurpose fits very, very well with my interests, because I always wanted to have a social enterprise. So, it all came together.

KWHS: What’s the future for rePurpose? Now that you’re graduating?

Balasubramanian: It’s been very exciting because we’re extremely honored and so grateful to have won the President’s Engagement Prize for 2018. And as part of that prize, we get a $100,000 grant that goes directly towards the project. [We also get] $50,000 as individual stipends. We’ve been really fortunate to get a few other grants from other sources at Wharton, Wharton’s social impact initiative and other Penn organizations. And so, we’re going to take that funding that we have and [build on] the idea. Now it’s just implementation — putting it together and making this vision we have in our heads into reality. So we’re moving. The three of us are moving officially to Mumbai where we’re going to start operations end of July-beginning of August. And we’re going to just kick it into high gear and see how it goes.

KWHS: That sounds great. I wish you luck.

Balasubramanian: Thank you so much.

KWHS: So, what would you say is your greatest takeaway, thus far, from this process of developing your idea and becoming an entrepreneur? What would you say has really stuck with you and something that you feel is maybe life changing in the way you perceive things?

Balasubramanian: That’s very interesting. There are so many takeaways. And I think being an entrepreneur is amazing because you get to wear so many different hats every day. You go into work and today, you’re fundraising. Tomorrow, you’re brainstorming about different prototypes. The next day, you’re trying to come up with partnerships, you’re thinking about marketing initiatives. Every day is like a new discovery and you’re finding new talents that you didn’t know you had.

But I think maybe the biggest takeaway is that a lot of times people think that just having the passion and this ambition — this fire inside you to help people — is never enough. You think, “Before I can go ahead, get my feet wet, I need to have the perfect idea. I need to have the perfect solution at day one, or it’s not going to work.” Through this journey, my co-founders and I [have learned] that you’re never going to have the perfect solution at day one. And the real thing is to just keep pushing. You’re going to fail a few times. And it’s okay because you’re learning from it. I know it sounds clichéd and you hear this when you’re not doing it. You never internalize it. But it’s true. As long as you really, really believe in what you’re doing, you just keep persevering and things will work out. You need to have that faith that things are going to work out, because what you’re doing is meaningful and it’s going to help people.

KWHS: Svanika, thank you so much for joining us.

Balasubramanian: Thank you.

Related Links

Conversation Starters

How is rePurpose giving structure to an informal marketplace?

Why are the kabadiwalas so critical to the rePurpose business model? How did rePurpose’s market research put them in touch with kabadiwalas and inform their path forward?

Svanika Balasubramanian says, “Through this journey, my co-founders and I [have learned] that you’re never going to have the perfect solution at day one.” What does she mean by this? Why is this such an important realization?

14 comments on “Building an Ethical and Efficient Recycling Supply Chain in India

  1. Discussing the ways in which people innovate common business practices is very important. RePurpose is doing so by creating a marketplace where the players are connected. This will insure that more people will recycle and that all the players involved will consider this next time. Recyclers,consumers and people in developing countries who collect such items include the players. With any new idea comes skepticism and fear of future failures. Many kabadiwalas are skeptical of this model because there are health risks associated with collecting trash and many kabadiwalas earn up to $7 a day. The market research that they did allowed them to see first hand how much damage there was in India. They traveled to a huge garbage landfill and experienced the problems that come from having trash gather up. However, coming up with all the answers in one day. This is what she means. Coming up with business solutions is difficult and must be done over time. This is an important realization because businesses take time to develop and is very time consuming. Patience is a virtue and therefore must be respected in order to be successful in business.

  2. rePurpose is creating a way for people to communicate through the process of trying to reduce the amount of waste there is in large and developing countries such as India. The goal is to streamline the communication aspect of this venture. Kabadiwalas are Critical as they are the main workers in the process, those who collect the waste. It put them in touch by creating a platform through which they are able to sell their materials and try to make the process as simple as possible. When she says that she is saying that you can and should have a plan in place, but you should always be able to adapt if the plan changes, or something needs to be fixed. This is important as everyone who is aiming at becoming an entrepreneur has to learn how to act in this manor.

  3. rePurpose gives structure to India’s internal waste marketplace not by consolidating it, but by empowering its kabadiwalas to work more efficiently and for recyclers to get their demand heard. Similar to a job board, where employers post jobs to be filled, rePurpose helps the kabadiwalas ensure a steady stream of waste.
    Without employees to pick up and sort it, the waste that rePurpose collects from universities is useless. In their market research, Mrs. Balasubramanian correctly identified the importance of kabadiwalas not only for her company, but also for its social entrepreneurship ends. They would likely have never identified a problem without doing broader market research in the Indian waste management system. According to their website, one of their co-founders studied the kabadiwala system in depth before proposing rePurpose.
    No good invention ever comes without a few prior failures, and rePurpose is no exception. Anyone who wants to be an entrepreneur must make changes to their business method to improve. She understands the importance of having a plan and also the need to change this plan if necessary.

  4. RePurpose is a new concept of business, by identifying an opportunity. Being an entrepreneur is about finding these opportunities and developing a way to make a profit out of them and help society. Furthermore, by focusing on connecting businesses and members of society, help to develop a more united community.

  5. RePurpose is creating a way for people to communicate through the process of trying to reduce the amount of waste there is in large and developing countries such as India. She is very critical to this model because if not followed businesses and the market can become full with wasteful trash that no one needs and curupts markets just like in India. Without employees to pick up and sort it, the waste that RePurpose collects from universities is useless. In their market research, Mrs. Balasubramanian correctly identified the importance of kabadiwalas not only for her company, but also for its social entrepreneurship ends. This is an important realization because no good invention ever comes without a few prior failures, and rePurpose is no exception. Anyone who wants to be an entrepreneur must make changes to their business method to improve.

  6. 1. RePurpose is giving structure to an informal marketplace by connecting all three types of people that are involved in recycling.

    2. The kabadiwalas are critical to the rePurpose business model because they play a key role in recyclable waste being spread around. rePurpose’s market research put them in touch with kabadiwalas by seeing a lot of them. The kabadiwalas said that they depend on recyclable waste for money.

    3. She means that you should never give up, even if you can’t find a solution straight away. This is an important realization because if you want to achieve your goal, you can’t just let go of it.

  7. RePurpose is creating a way for people to communicate through the process of trying to reduce the amount of waste there is in large and developing countries such as India.
    Without employees to pick up and sort it, the waste that rePurpose collects from universities is useless. In their market research, Mrs. Balasubramanian correctly identified the importance of kabadiwalas not only for her company, but also for its social entrepreneurship ends. They would likely have never identified a problem without doing broader market research in the Indian waste management system. According to their website, one of their co-founders studied the kabadiwala system in depth before proposing rePurpose.
    No good invention ever comes without a few prior failures, and rePurpose is no exception. Anyone who wants to be an entrepreneur must make changes to their business method to improve. She understands the importance of having a plan and also the need to change this plan if necessary.

  8. 1. rePurpose is acting as an intermediary communicator so that the kabadiwalas can become more connected to the recyclers. Before kabadiwalas would just bring in their waste as they found it; but with rePurpose the kabadiwalas can understand how much of a certain material to bring, adding to its efficiency.

    2. The kabadiwalas are the key component to the entire waste recycling process in India. They collect the waste from consumers are sell to recyclers, making them a middle intermediary. The way rePurpose can help India is by creating a path for communication between the kabadiwalas and recyclers. rePurpose’s market reserch helped them identify what part of the population to target and what method would best suit this particular segment of the population in their path forward.

    3. Svanika is trying to convey that coming up with successful business ventures is a working process, the final product will not appear instantly. Instead, many steps must be taken to achieve the end goal, even if some are failures. This is important for all entrepreneurs to understand as it explains why failures happen and how they are part of the learning process. Also it allows entrepreneurs to understand that they should take progress in their business step-by-step instead of all-in all at once to reduce risk.

  9. The purpose of Repurpose is to connect all the people involved in recycling in India so that they can help conserve the environment and help people make as much money as possible in the business. It’s more efficient for the communication between the three parts of the recycling system in India. Kabadiwalas are critical for the Repurpose business model because they are the part that gives the recyclers the recycled trash. They’re the ones that separate the recyclable trash into different categories. The recyclers on the streets in India tell the people in Repurpose that they need a certain type of waste for their machine. The people in Repurpose get into communication with the Kabadiwalas to give their waste to the recyclers. It’s an efficient method for interchanging waste and for communication. When Svankia says that you’re never going to have a perfect solution at day one she means that creating a structure and system is a long process. It takes many tries to make a system work. There are going to be a lot of mistakes along the way, but that doesn’t mean to get discouraged. These systems take a while to get organized and become efficient as possible. She just means that you have to work through the process even if you get frustrated along the way. It’s an important realization because not everything is going to be perfect that first time you do it. It takes a lot of time and effort to perfect something. It’s not always going to be an easy process.

  10. rePurpose is a great tool to make recycling easier in India. It makes the communication very efficient for the 3 recycling systems in India. Kabadiwalas are the key people in the system. Kabadiwalas help recycle trash into different recycling categories. rePurpose makes this task as efficient as possible and makes the whole job more organized. The system still has a long way to go, but it is already making a significant progress.

  11. rePurpose is a tool that is really effective to make recycling in India easier. IT makes communication very useful for the 3 recycling systems. Kabadiwalas are the key to people that are using the systems, they help recycle and trash into other recycling places. rePurpose is also great for people to have a job. This system has a long way, but once it is working it will change India forever.

  12. I completely resonate with the idea of pushing boundaries on a continual basis rather than having an all inclusive idea at the onset. The world today stands out from the past in its sheer dynamism. Even if we believe that we have the perfect recipe, the world will compel us to improvise. Hence, it is important to make optimisations along the way rather than having a rigid and inflexible chain of thought. This concept has ubiquitous manifestation- from the biggest players in the market to the smallest companies. For example, even Amazon and Walmart are expanding into a arena which they traditionally and originally did not encompass, offline and online respectively. The consumer itself tells us how to change in the form of their purchase behaviour.

    On a different front, the story of rePurpose also makes us ideate about the importance and relevance of ‘middlemen’. While there is a widespread trend of people advocating for the elimination of middlemen, it is important for us to comprehend and recognise the fact that in some cases the overhead gained by removing the middlemen is more than outweighed by the benefits and contributions he brings into the supply chain.

    A couple of articles to expound upon that-

    rePurpose recognises the role of the kabadiwalas in the recycling model of India and other developing nations and seeks to empower and capacitate them rather than trying to remove them altogether from the process like other enterprise are (like )doing. The reason why this is right is because the supply chain of a recycling model in order to be impactful needs an expansive outreach and the best way to achieve that in underdeveloped countries without much hassle and inefficiency is through kabadiwalas.

    In light of this article, let me share a personal experience. I live in India and am pretty familiar with the concept of kabadiwalas. In fact , there is one kabadiwala that comes to my housing complex regularly. One day I was having a conversation with him and it was indeed disheartening to know of the perception they have come to be associated with. He was telling me how people lambaste him and other kabadiwalas as “ low people who pick up and move around with ‘garbage’ and ‘xxx’.”
    Any effective recycling initiative must counter this notion. We must realise that the kabadiwalas are not ‘low people’ but rather , as I like to see it , agents of social change who are humble enough to collect waste and make a positive contribution towards a sustainable living. We must create awareness about this among people and try to extirpate the meaningless bias in the minds of people with respect to kabadiwalas!

    I would also like to take this opportunity to wish luck to rePurpose as they embark upon their journey later this month!

    Please feel free to let me know your thoughts on these notions.

    • I 100% agree with you. How would you propose this change? I too believe that kabadiwalas are vital to the waste management of India’s mega cities, but in a country where culture and tradition are paramount, how would this change happen?

      I think that if the upcoming generation in India was raised with a “no caste system” environment, and governments created companies/corporations to manage waste management in India, then kabadiwalas would be seen as civil servants like garbage men in the US.

  13. In 2016, a deadly fire raged for three months at Deonar East, Mumbai’s largest landfill. The toxic smoke spread for miles, causing health problems for young children and the elderly, and even forced some to move. Due to pressure from the public, the Brihanmumbai Municipal Corporation (BMC, the regulatory body that governs the city) closed down the Deonar East landfill. Immediately the Kabadiwalas, who’s livelihood depended on dangerous landfill, threatened to not cast their votes, and the BMC was forced to reopen the dangerous landfill. Kabadiwalas are only recycling as a way to earn money. Why can’t we try to decrease the harmful amount of landfill waste, and find a safer, better source of income for them? India needs to get mega cities to start decreasing waste creation from the beginning and thus undergo a green revolution to become cleaner.

    Svanika Balasubramanian’s rePurpose empowers the Kabadiwalas while boosting recycling by providing a platform, connecting buyer and seller. But they could impact society at a larger scale if they focused on the bigger problem: the harmful amount of waste created by India’s mega cities. According to Brihanmumbai Municipal Corporation (BMC, the regulatory body that governs Mumbai) the city creates more than 10,000 metric tons of waste a day. With Mumbai’s three landfills (Deonar, Mulund, and Kanjurmarg) already operating near capacity, and the BMC scheduling the shutdown of Mulund this October, the city will need to innovate if it wants to become cleaner and more efficient at handling its waste. Instead of sourcing for recyclers via the Kabadiwalas, rePurpose should work with the BMC to source “recycling at the source” machinery, and get the Kabadiwalas to be government employees, trained to maintain this machinery. This is possible because India has already done the exact same thing in the south.

    In the cities of Alapphuza, and Mysuru, city councils have embraced Prime Ministers Modi’s Swachh Bharat Abhiyan (Clean India Initiative) plan and have transformed recycling culture in their towns. In Alapphuza, subsidized biogas plants and pipe composts were installed near homes, and garbage collectors were trained to install, and maintain these small plants. In Mysuru, the system implemented in Mysuru is a product of the aggressive community awareness programs led by Dooda Thimmaiah Magegowda, a Mysuru politician. He established a system where the community (you and me) would segregate the waste and other worker employed by the Mysuru Municipal Corporation, would transport the segregated waste to processing plants throughout the city. Here the waste is sorted out more so some can be sold to scrap dealers. These dealers sell to recyclers, and the organic waste is sold to farmers to be used as fertilizer. By decentralizing waste management (making you and I segregate the waste before it goes out for processing) both Alapphuza and Mysuru are able to recycle more efficiently.

    Things are already starting to change in Mumbai. A case study conducted in 2016 included the activities of Virle Parle, a housing society in Mumbai. The residents constructed a system of managing their own waste by segregating dry and wet waste, and also using vermicomposting to convert wet waste (Kitchen waste, residual waste food, etc) into fertilizer via earthworms. The leftover waste gets sold to a local kabadiwalas (whose job is now easier and safer because the garbage he is collecting is already sorted.

    Decentralization: getting all the citizens to process at least some of their own waste would enable Mumbai to decrease the amount of waste that is simply dumped into landfills, and boost profits for kabadiwalas (by either being employed by the government to maintain new recycling infrastructure, or by being able to sell more waste because they are outsourcing the sorting of waste to the community). All that needs to happen is a joint awareness and education effort by local Mumbai NGO’s and the BMC, to help kickstart a recycling revolution.

    I loved this video because it made me question how such a sophisticated city like Mumbai could rely on this massive unrecognized underbelly economy. I understand it is partly due to the idea that “if it isn’t directly affecting me, it’s not my problem” but I feel that if these people (kabadiwalas, rag pickers, etc) were brought under regulated banner via a join effort from the community and the local government, Mumbai could become the blueprint for future megacities. After all, population is rising, and if we don’t solve the problem today, it will only grow tomorrow.

    -Ved Bhagat

    -Closing of Mulund Dumping ground:

    -Status of Mumbai’s dumping grounds:

    -Clean India Initiative:

    -Alappuzha Waste Management + info on Deonar fire in Mumbai:

    -Mysuru’s Waste Management:

    -Case Study (scroll to page 5):

Leave a Reply

Your email address will not be published. Required fields are marked *