Almost 200 people went behind the scenes to discover how the rubbish they throw away is used to power and heat Sheffield buildings.
In total 180 residents attended the free tour of the Veolia energy recovery facility at Bernard Road, which turns black bin waste into energy and hot water used by dozens of buildings across the city.
They visited the control room to see how rubbish is mixed and lifted into the incineration unit to be burned before taking part in a quiz and sitting in bin lorries.
Manager Antony Smith said: “The open day has been an astounding success and we have been blown away by just how popular the day has been.
“It is great for us to be able to show residents what happens to the waste they put in their black bin after it has been collected and the environmental benefits of managing non recyclable waste in this way.
“Residents were truly astonished by what they saw and we look forward to opening our doors again next year.”
Dan Kelly attended this year with his niece, Milly.
He said: “It was really interesting.
“It is amazing to think that the hot water in public buildings we regularly use, such as Ponds Forge and the City Hall is created from our black bin waste.
“Milly had a fabulous time and even had a go at using the crane to pick up the waste.
“She was proud to have picked up three tonnes of waste in one go.”
Veolia, which runs the facility for Sheffield Council, organises the open day every year to show residents how their waste is dealt with to reduce the amount that is sent to landfill.
Coun Jack Scott, Sheffield Council’s cabinet member for enviroment, said: “It is great that so many people came to see for themselves how the non-recyclable waste they throw in the black bin is used to heat homes and buildings in the city.
“Not only does this mean Sheffield has one of the lowest waste to landfill rates in Europe but it also saves 13,000 tonnes of C02 from being released into the atmosphere each year.”
For more information about the Energy Recovery Facility, open days or waste and recycling services, call 0114 273 4567 or visit www.veolia.co.uk/sheffield.