Chantal Kubwimana, a mother of two children, is all smiles. The single mother has just received news that she would be given an in-calf dairy cow by the firm she works for. Kubwimana has been working for a briquette-making co-operative, Environment Conservation Company (COCEN), for over four years now. She is one of the tens of workers who collect and sort domestic waste from which COCEN makes briquettes. "Since I joined this co-opertaive in 2008, my life and income have greatly improved,” she says. She adds that the cow she will get would further boost her income from milk sales and the nutrition for her children.Like Kubwimana, the tens of other workers at the co-operative have had a steady income stream since they started collecting domestic waste for the co-operative.Besides protecting the environment from getting choked on garbage, it has helped people save. "I have been saving Rwf100 every day since I started cooking using briquettes. Briquettes are good and do not produce carbon dioxides like charcoals. They are also environment-friendly energy,” Clemance Umuhoza, adds. The beginningThe project started with 150 people in 2002, who would collect domestic waste in Kimisagara and Nyakabanda sectors and earn Rwf18,000 per month, thanks to a European Union project. The waste was processed to make briquettes. When the project ended after one-and-half years, the beneficiaries formed an association to continue with the service. Justine Nyirabakiga, the COCEN board president, says sustaining the project was hard after their their funders pulled out.  "Because most of us relied on this job to sustain our families, we persisted,” she says.Later in 2008, the association was transformed into a co-operative with 45 members. "That’s when we started to get funding from non-government organisations,” narrates Nyirabakiga. In 2011, the COCEN co-operative was registered as a private company.How the co-operative worksCOCEN members collect domestic waste from households daily, and then separate organic and inorganic materials. After, the organic fractions are sun-dried, they are crushed by machine into powder. The powder is then made into briquettes, which are used as an alternative source of fuel firewood and charcoal. The briquettes are sold for Rwf100 per kilogramme, Nyirabakiga says.COCEN produces over 10,000 tonnes of briquettes per year, which they sell to prisons, schools and households.The inorganic waste, especially plastics, are taken to a dumping site at Nduba in Gasabo district.COCEN members’ benefitCOCEN employs 65 permanent workers, who earn between Rwf30,000 and Rwf230,000 per month. Eliazar Iyabuze, 65, used to earn Rwf15,000 per month as a gardener before he joined the co-operative. Today, he earns Rwf30, 000 per month."This job has changed my life. I am able to pay Mutual de santé (health insurance) for my family without a problem...when you have a job with a monthly salary, you are secure,” he says.Jean d’Amour Nsabimana says he has started building a house, thanks to his salary savings. Nyirabakiga, however, says residents who pay late for garbage collection affect the project’s operations. The domestic waste collection prices set by Rwanda Utilities Regulatory Agency are  Rwf1,900 for the poor, Rwf3,900 for middle-income earners and Rwf5,600 for the rich. Kubwimana says when her cow delivers, her family will have enough milk to drink, while some would be sold to neighbours. "I will also get manure for my gardens, which will increase crop production,” she says.