Testing for E.coli and intestinal enterococci bacteria across 400 sites during the 2021 bathing season, defined as May 15 to September 30, saw 70.7% of beaches and inland waters rated “excellent”.
A further 24% were rated “good” and 4.3% were awarded a score of “sufficient”.
The presence of E.coli and intestinal enterococci in water samples is often an indicator of sewage contamination.
The latest figures, published on Wednesday, compare to 98.3% in 2019 – the last full data set due to interruptions in monitoring caused by the pandemic.
When the Environment Agency first started monitoring water quality in the 1990s, some 28% of bathing areas met the highest standards in force at the time.
In 2015, the agency set a requirement for all water companies to install “event duration monitors” to storm overflows to monitor the frequency and duration of untreated sewage discharges.
Water quality has come under growing scrutiny over the past year, with headlines about the volume of sewage and chemicals discharged into waterways sparking public outcry.
Last summer, Southern Water was handed a record £90 million fine at Canterbury Crown Court for 6,791 unpermitted sewage discharges between 2010 and 2015.
In October 2021, the Government was forced to U-turn on its refusal to impose legal controls on water companies to prevent them dumping raw sewage into rivers and seas following a public backlash.
MPs were whipped to vote down an amendment to the Environment Bill, but the Department for Environment, Food and Rural Affairs (Defra) later said a duty to reduce sewage discharge “would be enshrined in law”.
The following month, it emerged water companies in England and Wales had issued 5,500 alerts of sewage being discharged into coastal waters in 2020 – up more than 87% on the previous year.
It rendered one in six days of the official bathing season unswimmable, according to research by environmental charity Surfers Against Sewage.
Commenting on the latest bathing water figures, Environment Agency chair Emma Howard Boyd said: “With billions spent on seaside visits every year, we know good water quality helps coastal towns prosper.”
She continued: “We cannot afford to be complacent. Public confidence in water quality has faltered in recent years with new evidence of pollution incidents getting much-needed attention as a result of some excellent campaigning.
“The polluter must pay. To restore trust, water companies, industry and farmers need to get the basics right or face legal action.”
Environment minister Rebecca Pow said: “Our Environment Act puts in place more protections against water pollution than ever before, we are investing in programmes to support farmers to tackle water quality issues, and we are clear that where water companies do not step up we will take robust action.”
But Surfers Against Sewage was sceptical that any progress had been made, pointing out that the number of sites rated excellent had fallen by a percentage point compared to 2019.
It was also critical of the fact that testing was not conducted outside the summer months, and that water was not tested for antimicrobial resistant bacteria or microplastics.
Surfers Against Sewage added that there was only one designated bathing site on an English river – which was rated poor – meaning people who swam in rivers had no idea of the threat to their health.
Hugo Tagholm, the charity’s chief executive, said: “Not only is the progress to improve the water quality at our favourite spots slowly grinding to a halt but the testing regime which is designed to protect us is actually failing to give us a clear picture of the state of our waters.
“If we are to restore our blue spaces for the good of people and the planet, we need a rapid overhaul of the testing regime to ensure it tests water quality for all kinds of pollutants all year round.
“Crucially we also need to see the expansion of the number of bathing rivers in the UK to ensure everybody has access to waters fit to swim in.”
A report published by Parliament’s Environmental Audit Committee on January 13 said England’s rivers were struggling with a “chemical cocktail” of sewage, agricultural waste and plastic.
It blamed “outdated, underfunded and inadequate monitoring” and called for urgent regulatory action, investment from water companies as well as tougher sanctions for providers who breached the rules.
On Tuesday, the Environment Agency’s chief executive Sir James Bevan called for the bosses of the nation’s worst corporate rule-breakers to face custodial sentences.
A spokesman for Water UK, the industry body representing UK water companies, said current water quality levels were the result of “decades of water company investment and different sectors and regulators working towards a common goal”.
The spokesman said the industry supported the creation of a network of inland bathing sites in rivers across England, adding “we must not allow complacency to reverse this positive trend” on water quality.
“This will not happen overnight but with targeted investment, effective regulation and the co-operation of other sectors we believe we can do for inland bathing what we have done for coastal bathing,” Water UK added.