The Department of the Environment said the changes already applied to effluent discharges from combustion plants and will be extended over the next four years. Under the new scheme, firms will routinely monitor their own effluent for toxic chemicals.
The pollution inspectorate will carry out random spot checks to verify a company's samples.
The new measures are part of the Department of the Environment's policy of 'integrated pollution control', where many of the powers of the rivers authority to control and monitor water pollution are transferred to the inspectorate, which has a much smaller monitoring team.
Environmental groups criticised the move because the rivers authority has earned itself a track record in pursuing polluters. It took 282 incidents to court in 1990 and secured convictions in 272 of them. This compares with just nine companies prosecuted by the pollution inspectorate between 1987 and 1991.
Tim Birch, water pollution campaigner at Greenpeace, said: 'The performance of the pollution inspectorate is nothing short of appalling. Asking polluters to police themselves is ridiculous . . . We are now back to a situation where industry is both poacher and gamekeeper.'
A spokeswoman for the Department of the Environment said that the pollution inspectorate would still be the overseeing body for monitoring water discharges.Reuse content