More than 80 percent of rivers in England have been polluted by phosphates, according to a study published Tuesday that's likely to focus more criticism on British water companies for their wastewater discharges.
The first annual report from the water quality monitoring network Angling Trust said there was an "urgent need for action" over waterway pollution.
It said that "of the 163 rivers where regular samples were recorded, 83 percent failed to meet the phosphate standard for good ecological status in at least one sample".
Phosphates in rivers mostly come from discharges from wastewater treatment plants and from its use on agricultural land. Excessive phosphates can deplete oxygen levels in waterways by encouraging explosive growth of algae and other aquatic plants.
"We need to see much more enforcement and an update of existing laws to tackle the scourge of river pollution and hold polluters to account," said Jamie Cook, Angling Trust CEO.
Much of the report was carried out by volunteers taking water samples across the country, with 240 fishing clubs monitoring water quality.
UK water companies have been criticised for a number of years for wastewater discharges into rivers and the sea due to a lack of investment in sewage networks, many of which date from the 19th century.
Improvements would cost billions but the firms have accumulated more than £60 billion ($75 billion) in debt since they were privatised in 1989 under prime minister Margaret Thatcher.
