Sewage 'safe' as farm fertiliser

ONE OF the biggest drawbacks to using human sewage as farm manure has been overcome, according to the water company that is pioneering a new method of turning human waste into fertiliser, writes Steve Connor.

Wessex Water finished a six- week trial of a fertiliser made from dried sewage sludge last week, and pronounced that the problem of toxic heavy metals such as zinc, cadmium and lead is not as great as feared. Gareth Jones, director of science and quality at Wessex Water, said the fertiliser, which looks like grey coffee granules, is a safe alternative to artificial fertilisers.

'There is no pollution, it is odour-free and is rich in phosphates and nitrogen. The levels of heavy metals contained in the granules are lower than those found in many other fertilisers such as fish meal and dried blood,' he said.

Previous research had indicated that sewage sludge, which is derived from domestic and industrial waste, is rich in heavy metals which can persist in the soil for centuries. But Wessex Water said heavy metal in its fertiliser was well within legal limits.

The Wessex Water granules are produced by drying out fermented sludge in a tumbling drum that is infused with hot air. The sludge is heated to about 90C, which kills most harmful bacteria, viruses and human parasites in the waste. Methane from the fermenting sludge is used as heating fuel. Keith Fitzgerald, environmental regulation manager at Wessex Water, said the resulting fertiliser was worth about pounds 22 a ton to farmers, although initially it was being offered free.

Field trials conducted by the government Agricultural Development and Advisory Service at a farm near Chippenham, Wiltshire have shown the granules can perform as well as artificial fertilisers, Mr Fitzgerald said. However, nitrogen will have to be added if farmers intend to use the granules alone for longer periods, he said.

All the water companies are looking at methods of dealing with sewage sludge because of a ban on dumping at sea that comes into effect in 1998. Wessex said it could end sea dumping by the end of this year. Many other companies, however, intend to incinerate the sludge on land.

Suggested Topics
Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Life and Style
A still from a scene cut from The Interview showing North Korean leader Kim Jong-un's death.
tech
Voices
'That's the legal bit done. Now on to the ceremony!'
voicesThe fight for marriage equality isn't over yet, says Siobhan Fenton
Life and Style
Approaching sale shopping in a smart way means that you’ll get the most out of your money
life + styleSales shopping tips and tricks from the experts
Arts and Entertainment
Bianca Miller and Katie Bulmer-Cooke are scrutinised by Lord Sugar's aide Nick Hewer on The Apprentice final
tvBut Bianca Miller has taken on board his comments over pricing
News
in picturesWounded and mangy husky puppy rescued from dump
News
newsAstonishing moment a kangaroo takes down a drone
Life and Style
Duchess of Cambridge standswith officials outside of the former wartime spy centre in Bletchley Park
tech
News
people
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Ashdown Group: IT Support Technician - 12 Month Fixed Term - Shrewsbury

£17000 - £20000 per annum: Ashdown Group: IT Helpdesk Support Technician - 12 ...

The Jenrick Group: Maintenance Planner

£28000 - £32000 per annum + pension + holidays: The Jenrick Group: Maintenance...

The Jenrick Group: World Wide PLC Service Engineer

£30000 - £38000 per annum + pesion + holidays: The Jenrick Group: World Wide S...

The Jenrick Group: Project Manager

£35000 per annum + Pension+Bupa: The Jenrick Group: We are recruiting for an e...

Day In a Page

Surrounded by high-rise flats is a little house filled with Lebanon’s history - clocks, rifles, frogmen’s uniforms and colonial helmets

Clocks, rifles, swords, frogmen’s uniforms

Surrounded by high-rise flats is a little house filled with Lebanon’s history
Return to Gaza: Four months on, the wounds left by Israel's bombardment have not yet healed

Four months after the bombardment, Gaza’s wounds are yet to heal

Kim Sengupta is reunited with a man whose plight mirrors the suffering of the Palestinian people
Gastric surgery: Is it really the answer to the UK's obesity epidemic?

Is gastric surgery really the answer to the UK's obesity epidemic?

Critics argue that it’s crazy to operate on healthy people just to stop them eating
Homeless Veterans appeal: Christmas charity auction Part 2 - now LIVE

Homeless Veterans appeal: Christmas charity auction

Bid on original art, or trips of a lifetime to Africa or the 'Corrie' set, and help Homeless Veterans
Pantomime rings the changes to welcome autistic theatre-goers

Autism-friendly theatre

Pantomime leads the pack in quest to welcome all
The week Hollywood got scared and had to grow up a bit

The week Hollywood got scared and had to grow up a bit

Sony suffered a chorus of disapproval after it withdrew 'The Interview', but it's not too late for it to take a stand, says Joan Smith
From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?

Panto dames: before and after

From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?
Thirties murder mystery novel is surprise runaway Christmas hit

Thirties murder mystery novel is surprise runaway Christmas hit

Booksellers say readers are turning away from dark modern thrillers and back to the golden age of crime writing
Anne-Marie Huby: 'Charities deserve the best,' says founder of JustGiving

Anne-Marie Huby: 'Charities deserve the best'

Ten million of us have used the JustGiving website to donate to good causes. Its co-founder says that being dynamic is as important as being kind
The botanist who hunts for giant trees at Kew Gardens

The man who hunts giants

A Kew Gardens botanist has found 25 new large tree species - and he's sure there are more out there
The 12 ways of Christmas: Spare a thought for those who will be working to keep others safe during the festive season

The 12 ways of Christmas

We speak to a dozen people who will be working to keep others safe, happy and healthy over the holidays
Birdwatching men have a lot in common with their feathered friends, new study shows

The male exhibits strange behaviour

A new study shows that birdwatching men have a lot in common with their feathered friends...
Diaries of Evelyn Waugh, Virginia Woolf and Noël Coward reveal how they coped with the December blues

Famous diaries: Christmas week in history

Noël Coward parties into the night, Alan Clark bemoans the cost of servants, Evelyn Waugh ponders his drinking…
From noble to narky, the fall of the open letter

From noble to narky, the fall of the open letter

The great tradition of St Paul and Zola reached its nadir with a hungry worker's rant to Russell Brand, says DJ Taylor
A Christmas ghost story by Alison Moore: A prodigal daughter has a breakthrough

A Christmas ghost story by Alison Moore

The story was published earlier this month in 'Poor Souls' Light: Seven Curious Tales'