"More needs to be done urgently"
Environment minister Rebecca Pow admitted that the results fell well short of the standards the government is expected to meet, saying that "more needs to be done urgently".
She added: "These results show we have a long way to go, with a new way of testing for chemicals more accurately reflecting what is in our water environment.
"While it's not comfortable reading, this will allow us to plan more effectively to tackle the scourge of pollution."
The chair of the Environment Agency, Emma Howard Boyd, said: "Water quality has plateaued since 2016, which isn't good enough."
She noted improvements over the past couple of decades, but said even the UK's own targets - which the environment minister said the government was "absolutely committed to" - were still well out of reach.
"The 25 Year Environment Plan aims for at least three quarters of our waters to be close to their natural state, but today just 14% of our rivers are.
"To get where we want to be everyone needs to improve how they use water now and that means water companies, farmers and the public."