An Environmental Protection Agency conference in Galway has heard warnings about the serious levels of pollution in Irish lakes and rivers.
The EPA says millions of euro will have to be spent on improving badly polluted water sources between now and 2015 to meet strict EU directives.
The latest survey by EPA inspection teams on lakes and rivers across the country has found that 931 are either moderately or badly contaminated.
EPA Programme Manager Gerard O'Leary said much of this comes from agricultural effluent or badly maintained municipal waste water treatment plants.
Ireland is already facing a possible EU fine of €2.7m for its failure to deal with almost 500,000 polluting septic tanks.
Environment Minister Phil Hogan is expected to tell the 300 delegates the Government is fast-tracking new legislation to tackle the pollution problem with strong inspection and enforcement powers.
However, the Rural Dwellers Association has reacted angrily to proposals to implement an inspection, monitoring and registration system for septic tanks.
Acting Secretary Jim Connolly said that fees associated with registration and inspection of septic tanks would be an additional tax on rural dwellers.
Mr Connolly said that there was no scientific base to blame pollution on rural septic tanks.
He said that the association would be opposing any plans to introduce the measures without a full scientific study.
