Ireland has failed to put in place adequate programmes to reduce and prevent water pollution, the European Union's highest court has found.
In the latest in a series of negative rulings on Irish environmental policy, the European Court of Justice said discharges from agricultural and marine installations had not been properly monitored or controlled.
However, the court found against a claim by the European Commission that such failures had directly led to increased pollution of Irish waters.
Minister for the Environment Dick Roche said the situation had greatly improved as regards regulation since the investigation took place.
"Such outstanding technical issues which arise from the judgment are being dealt with," he said.
The ruling arises out of complaints made in 1990 over Ireland's failure to implement an EU directive on water pollution.
Criticising the stringency of provisions under the Local Government (Water Pollution) Act, 1977, the court said: "The effectiveness of the system rests in large measure on the notices issued by local authorities.
"Those notices are, however, issued in a discretionary manner by each local authority in each specific situation, with no relation to any parameter as to water quality, which is lacking in that statute.
"This absence of uniform statutory criteria does not guarantee a homogenous, comprehensive and consistent application of the directive."
The report questioned the reliability of certain monitoring systems, and cited an absence of authorisation systems for the aerial spraying of fertiliser, and discharges from marine and agricultural installations.
In addition, Ireland had failed "to make certain local authority discharges, such as drainage discharges and storm water overflows, subject to authorisation".
However, the court conceded the issue had been addressed subsequent to its deliberations in the Urban Waste Water Treatment Regulations, 2001.
The commission had claimed that Ireland's delay in transposing the directive had allowed "a statutory tolerance for degradation of water quality".
However, the court said the commission had "failed to demonstrate adequately" that there had been an increase in pollution.
Welcoming this finding, the Minister said: "Irish water quality is actually high. In comparison to many European countries it is very high."
The court ordered Ireland to pay the costs of the action, and left it open to the commission to suggest an appropriate fine.
In a separate ruling last April, the court found Ireland guilty of "general and persistent" flouting of EU rules on waste disposal by ignoring illegal dumping throughout the State.
Mr Roche said he hoped the two rulings would be the last "for some significant time".
He admitted the relationship between his department and the commission had been "not great" in the past.
But, he said, in the last few months he had put together a departmental task force to follow EU complaints, and he was confident this was working.
