Britain’s coastline is one of its abiding glories. The sea has played a central role in our history and has a tight grip on the nation's imagination. Nowhere in the UK is more than 72 miles from the ocean and at some stage everyone has felt compelled to go down to the sea and even occasionally plunge into it.

Yet despite this fascination we treat our coastal waters with scant respect. Thirty years ago this newspaper campaigned to clean up our beaches, leading to a law to stop the dumping of garbage from ships. Twenty years ago we highlighted our polluted rivers in the river rats campaign. However, as we report today, the water companies are still pumping large amounts of raw sewage into rivers and the sea despite spending £10 billion on infrastructure since privatisation. One in four beaches fails to quality for the European Union’s top category and hundreds of people contract diseases every year from swimming in polluted waters. Children are playing in streams on beaches in which raw sewage flows into the sea.

Many believed that the much publicised expenditure on improved sewage treatment, which led to higher water bills, had solved the problem. This is clearly not so. Even the coveted blue flag status of beaches is no insurance against illness; it is quite possible to discharge sewage onto these beaches and for it not to be discovered by random testing.

True, there has been a steady clean-up in the past 20 years and the levels of pollution are much better than they were. But that was from a shockingly low base. Britain used to treat coastal waters as an unfiltered national U-bend and paid little attention to the sewage flowing into the sea. Even a polio outbreak in the 1950s was not enough to convince the government to take action.

In part we can thank the European Union for imposing better standards. In 1976 limits were set on faecal coliforms in “designated bathing waters”, which now number more than 500. This means they are monitored but it does not stop many other beaches from being positively hazardous.

Surfers and swimmers are three times more likely to contract hepatitis A and there is a 14% risk of contracting a gastrointestinal illness in minimum standard European designated water. Sometimes the risk can be up to 5% for every swim. As The Sunday Times Magazine said last year, “imagine that strawberry yoghurt carried a 5% risk of diarrhoea and vomiting. It would be off the shelves before you could say ‘Food Standards Agency’.”

Instead we show a remarkably cavalier attitude to this risk. The Environment Agency, under pressure from the Marine Conservation Society, has admitted there are still 3,500 overflow outlets that frequently pump raw sewage into the sea. These are not monitored and there have been no prosecutions. Even when the agency has prosecuted the water companies for illegal dumping from other registered outlets, the fines have been minimal. There is no deterrent to the companies to continue to save money by pumping sewage into the sea and damning the consequences.

This is clearly a case for decisive action. More people are using our coastal waters than at any time in the past and they have a right to demand higher standards of cleanliness. No one, not even water company executives, wants to swim or surf through raw sewage. It is time for the government and concerned members of parliament to take decisive action. They should start by demanding that the water companies stop this pollution. They could then urge the Environment Agency to get tough and give it greater powers to impose massive fines. Punitive measures may be the only effective means of stopping this violation of our national heritage.