Swimmers enjoying Dublin Bay over the bank holiday weekend did so in waters which were cleaner than they had been for decades, according to Dublin Corporation.
The improvement in the water quality is a result of the recent commissioning of the first phase of the corporation's £200 million Dublin Bay Project, Mr Michael Phillips, the city engineer, says in a report.
The Dublin Bay Project is the largest waste water treatment plant currently under construction in Europe and phase one involved upgrading the Rings end treatment plant. It will be followed by a submarine pipeline to be laid across the bay this summer to a new pumping station at Sutton. This, in turn, will allow untreated sewage which is currently pumped into the sea at Howth to be pumped instead to the Ringsend plant.
Some piling work will be carried out at night as well as during the day this summer because of the need to complete the piling before wintering birds return in the autumn.
New fine screens will remove plastic, rags, grit, fats, oils and grease from waste water before it is treated and traditional weak spots in terms of hygiene, such as Dollymount Strand, are expected to qualify for blue flag status once the new system is in operation.
Dublin Corporation stopped dumping sludge from treatment plants into the bay some years ago. It is now thermally dried at high temperature at Ringsend in a process which removes pathogens and produces a high-quality, pasteurised organic fertiliser and soil additive. This is suitable for spreading on agricultural land and is marketed under the name Biofert. It is absorbed easily into soil, removing the need for large quantities of artificial fertiliser.
Some 12,000 tonnes of Biofert are produced annually at Ringsend and it is spread on farms, although spreading has been temporarily suspended due to the foot-and-mouth crisis.
The Dublin Bay project is expected to be completed by summer 2002 and, according to Mr Matt Twomey, assistant city manager, it will bring noticeably cleaner water "for the half-million people who walk, fish, swim and sail here every year".
The report is one of a series of progress updates and newsletters on the Dublin Bay Project which have been issued by Dublin Corporation.
