The effects of the new waste law on the environmental impact and costs of waste management Puhas Oy is a waste management company, owned by five municipalities: Joensuu, Ilomantsi, Kontiolahti, Liperi, and Polvijärvi. On behalf of these municipalities, Puhas provides legally required waste management services. The catchment area of Puhas comprises approximately 112 000 inhabitants. The service network includes centrally tendered transport services for combustible waste and biowaste, local waste stations and the Kontiosuo waste center. The network is complemented by eco-points intended for household use, reception points for hazardous waste and decommissioned electrical equipment, as well as the waste management service advice. Case Puhas Oy Puhas Oy wanted to find out the global warming effects and costs of the waste management in its operating area with the household collection and processing obligations required by the waste law reform. The effects were also assessed with more restrictive obligations than the new waste law requires. As a result of the study, Puhas Oy received important information about the environmental and cost effects of the waste collection obligation required by the waste law reform, and the effects of tighter obligations. The results of the study contained the carbon footprints (in the unit of tons CO2 equivalents per year) and the costs (€ per year) of municipal collection and processing of recyclable waste. The degrees of recovery of recyclable waste in differents options were also assessed in the study. The study covered the built-up areas of the municipalities of Puhas Oy’s operating area. Global warming effects and costs were calculated for biowaste, small metal, glass, cardboard, and plastic. The modelling included the whole processing chain of waste types, starting from the collection bin up to material recycling of waste or energy recovery. The separate waste collection modelling was carried out by using the JEKO tool that Etteplan developed, and GaBi software was used for assessing the environmental effects. We have also carried out a separate waste collection study for Puhas Oy in the year 2019.