The complaint concerns a combined heat-and-power plant for energy recovery from municipal waste in Sofia, Bulgaria. The raised allegations concern non-compliance of the project with EU environmental legal standards and waste management targets, oversized capacity of the combined heat and power plant, privatisation of Toplofikacia and service concession for heating and electricity generation, negative impact of the project on air quality, and specifically particulate matter and access to project-related information (e.g. the cost-benefit analysis). The complaint consisted of five allegations, namely the: · Project compliance with EU municipal waste recycling targets. · Project’s capacity. · Privatisation of Toplofikacia and service concession for heating and electricity generation. · Project’s impact on air quality with the focus on particulate matter (PM). · Access to project-related documents.