Sewage is flowing into the River Foyle from a faulty pipe in the heart of Derry's city centre.
The problem in the Foyle Street area was recently uncovered by Northern Ireland Water during a major investigation into the state of Derry's sewerage system.
Funding has now been secured to fix the problem and prevent any more sewage seeping into the Foyle.
Water chiefs believe there is a 'very good chance' the work will also remove the pungent sewage smell which is a common problem in the Foyle Street area (above).
Details of the broken Foyle Street pipe emerged this week during a presentation by NI Water officials to Derry City Council.
Speaking at a meeting on Tuesday of the council's Regional Services committee, Nigel McKee, Senior Project Manager with NI Water, said his organisation planned to spend around £7m upgrading Derry's sewerage system in 2014 and 2015.
In relation to the Foyle Street problem, Mr McKee said it emerged during the recent investigation that sewage was being discharged directly into the Foyle from the faulty pipe.
He told the meeting that the necessary funding had now been secured to fix the problem.
SDLP councillor Gerard Diver highlighted that there was often a 'significant smell' in the Foyle Street area.
He asked McKee if the planned reapir of the Foyle Street sewage pipe would have an impact on this smell.
Mr McKee said there was a 'very good chance' the work would resolve the smell problem.
The senior NI Water official also revealed plans to relocate an emergency discharge pipe from beside the offices of Derry City Council at Strand Road.
Mr McKee said any discharge from the pipe was visible from the popular riverside pathway which runs alongside the council offices.
He said a decision had been taken to move the discharge pipe to somewhere 'away from public view'.
He said this work would cost anything from £50,000 up to £250,000.
Mr McKee said work was also necessary on one of sewage pipes which runs across the lower deck of the Craigavon Bridge.
He said the work would necessitate the closure of the lower deck fo several days.
Mr McKee said talks were continuing about the best time to carry out this work but added that the current suggestion was that it would be carried out at weekends.
DUP Alderman Gary Middleton said he would be concerned at the impact on local businesses if the lower deck of the bridge was closed at weekends.
He suggested the possibility of the work being carried out during evening times when shops were closed.
In relation to other NI Water projects in Derry, Mr McKee said work on a £1m sewage pumping station at Buncrana Road would begin in January 2015.
He said £1.6m in total was also being spent on improvement works in the Strathfoyle area.
He said repair work was also planned on sewage and drainage pipes at a number of busy local streets, including Fountain Hill, Spencer Road, Shipquay Street and Great James Street.
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