MILLIONS of litres of water gush through our sewerage system each week, but where does it all go? Star reporter Rachael Clegg takes a tour of Sheffield’s main sewage works, which is undergoing a £78 million transformation.
DAVID Harthorne stands next to a gigantic pit into which thousands of gallons of brown, mucky water flows.
“This is the breakfast run,” says David. “Everyone’s had their breakfast and they’re all going to the toilet at the same time.
“Whenever there’s a big football match on, we know when it’s the break because there’s a huge surge in the water coming in.”
David’s in-depth knowledge of Sheffield’s toilet habits is excusable, he is a project manager at Sheffield’s main sewage works, Blackburn Meadows, near Meadowhall.
And, in spite of being a sewage works, it is awe-inspiring.
David stands at the lip of ‘the mushroom,’ a huge chasm into which all the waste flows.
The mushroom’s diameter spans 19.6 feet and takes in 3,000 litres of water a day. It is thanks to this enormous pit that the city’s sanitation system functions as it does.
This sewerage infrastructure, which has been improved since the floods of 2007, can accommodate six times the amount of a normal day’s waste. At that point, the sewage water is then treated and then pumped into the River Don.
Behind the ‘mushroom’ is a watchtower in which colossal pumps deliver water from the ground to the treatment works.
But while impressive already, Blackburn Meadows is soon to undergo a huge makeover.
Yorkshire Water is about to pour £78 million into improving the Blackburn Meadows facility, which will mean the sewage works will not only be able to treat more water, but will also treat that water more effectively.
This, David says, also means that ammonia levels in water discharged into the river will also be reduced.
“A reduced amount of ammonia in the river will mean that fish such as trout, grayling and salmon can be supported,” he says.
“As well as this, improved water quality means the Don, once dubbed one of the most polluted rivers in Europe, can support other wildlife such as otters, water voles, invertebrates, plants and flowers.”
In this sense, the Don will return to its pre-industrial former glory. Believe it or not, before the Industrial Revolution, the Don had a thriving salmon population. But the advent of mass industrialisation made the river an unsuitable habitat.
But this improvement to the Don is dependent upon a new water treatment system - one that requires a state-of-the-art bio-energy plant.
In this new plant, dirty ‘sludge’ water will be treated with a type of good bacteria that attacks the bad bacteria.
David says: “It’s actually called the ‘Sheffield Process’ - it’s an aeration system that dates back to the 1900s.”
This bio-aeration was the brainchild of a man called John Haworth, who conducted experiments in sewage treatment throughout the First World War. The system was properly installed at Blackburn Meadows in 1956 and has become standard practice is sewage treatment across the country ever since.
“But we have refined it,” says David. “It means that we can use the remains as fertiliser for agriculture. It will be green waste.
“An additional benefit is the process generates a gas that can be consumed in a gas engine to generate electricity.”
The importance of Blackburn Meadows is revealed by statistics - the average person flushes the toilet about five times a day and each flush uses about 3.6 gallons of water.
David says: “With 555,500 people - that’s 99,000,000 gallons of water a day going through Sheffield’s sewage system.”