Water quality in Lough Derg and the Shannon river is improving, contrary to the national trend, says a consultant's report.
Thanks to a three-year programme costing £2.3 million, which got 85 per cent EU subsidy, the number of unpolluted rivers in the Lough Derg-Lough Ree catchment has risen by almost 10 per cent in five years.
The report, compiled by Kirk McClure Morton of Belfast in association with Brady Shipman Martin and presented to the Mid-West Regional Authority, reports that while 55 per cent of the rivers were classed as unpolluted in 1995, 64.5 per cent are now clean.
The project co-ordinator, Dr Alan Barr, said: "There is a Uturn in the Shannon while the rest of the country is going downhill. We are winning the first battle, but there is a major war to be won yet."
The consulting engineers set up 360 stations to take weekly samples, and now Lough Derg and Lough Ree have a fully integrated water-quality monitoring and management programme for the first time. The consultants are to continue the campaign in a new four-year programme.
The main problems identified were phosphorus, mostly from farm slurry and fertilisers, and detergents from domestic and industrial effluents. The worst blackspot was the Nenagh-Cloughjordan area, where farming was the main culprit.
The report says actions taken so far have resulted in a reduction of more than 100 tonnes of phosphorus in the waters of the catchment area. The phasing out of phosphorus in detergents in the next two years and a £60 million investment so far in treatment plants in the catchment will accelerate improvements.
Dr Barr said if the rate of decline in water quality experienced since 1970 had continued "in 20 to 30 years Ireland would have lost all its pristine rivers and lakes".