ALLOTMENT holders have been told that ground water may have been contaminated from diesel during building work at Oxford University’s controversial Castle Mill development.

A warning has been issued by Oxford City Council as an investigation gets under way to find out whether wells used by allotment holders may have been polluted by a diesel leak on the site.

But there is anger this week that it has taken more than three months for an alert about the potential health risks to people.

Cripley Meadows Allotment holders were only told on July 11 that an “unknown quantity of diesel” had spilt from a tank on the site on Roger Dudman Way in April.

The allotments are close to the site where the university has built accommodation blocks on the edge of Port Meadow, which campaigners say have ruined historic views.

Allotment holder Gina Cowen said: “I am surprised that it has taken three months before we found out about it.

“It feels like there is something wrong.”

Allotment holder Nigel Earl was horrified to find black oil when he filled a bucket from a well on Sunday.

He said: “There are accidents that happen but this is simply not on. I knew nothing about this.”

The university said it had only recently learnt of the leak during contamination tests on the site.

Spokesman Matt Pickles said: “While carrying out planned tests, one reading was found to be higher than normal.

“When the contractor was asked what might have caused this, it was found there had been a diesel spill.

“Immediate steps were taken by the university to notify the Environment Agency and the city council.

“The allotment association has also been informed and we have provided fresh water taps for allotment holders to use while the water is tested.

“We will monitor the ground water and carry out additional remediation as necessary to ensure that the site is ready for residential use and the allotment site is safeguarded.”

The city council’s head of environmental development, John Copley, told users of the allotments not to drink water from the irrigation wells.

He also urges them to take extra vigilance with hand and vegetable washing.

Mr Copley said: “Elevated levels of total petroleum hydrocarbons within the diesel range were detected in a ground water sample 20m from the spill.

“Environmental consultants working on behalf of Oxford University are currently excavating soils that have been contaminated.

“Water samples were taken from four irrigation wells on the allotment site on July 10 and are being analysed.

“Once the results are known, we can advise what risk, if any, exists and what action should be taken.”