The United Kingdom's first ever bus powered on food waste and human waste launched this week, which engineers believe could provide a sustainable way of fuelling public transport - cutting emissions in polluted towns and cities.

The 40-seat Bio-Bus, which runs on gas generated through the treatment of sewage and food waste that's unfit for human consumption, helps to improve urban air quality as it produces fewer emissions than traditional diesel engines, according to the company.

Running on waste products that are both renewable and sustainable, the bus can travel up to 300km (186 miles) on a full tank of gas generated at Bristol sewage treatment works – a plant run by GENeco, a subsidiary of Wessex Water.

This week GENeco became the first company in the U.K. to start injecting gas generated from food waste and sewage into the national gas grid network and at the same time installed a gas refuelling plant for the bus.

GENeco general manager Mohammed Saddiq said: “Through treating sewage and food thats unfit for human consumption we're able to produce enough biomethane to provide a significant supply of gas to the national gas network that's capable of powering almost 8,500 homes as well as fuelling the Bio-Bus.

“Gas powered vehicles have an important role to play in improving air quality in U.K. cities, but the Bio-Bus goes further than that and is actually powered by people living in the local area, including quite possibly those on the bus itself.

The first passengers to get on board for the Nov. 20 launch of the Bio-Bus were visitors to the U.K. who were commuting from Bristol Airport to the historic city of Bath.

Bath Bus Co., which is operating the service, will be using the Bio-Bus for its rapidly growing A4 service from Bath to Bristol Airport via South Bristol, which serves up to 10,000 passengers monthly.

Bristol sewage treatment works treats around 75 million cubic metres of sewage waste and 35,000 tonnes of food waste, collected from households, supermarkets and food manufacturers, every year.

Through a process, known as anaerobic digestion, 17 million cubic metres of biomethane is generated a year at the Bristol plant – the equivalent of meeting the power needs of 8,300 homes. A newly built state-of-the-art gas plant injects the gas into the grid.

The Bio-Bus has received backing from a number of businesses including the manufacturer of the bus, Scania, as well as companies including Roadgas, CNG Services Ltd, Dampney’s Agri Environmental, Trant, Grontmij and AIR Decker.