Portobello’s West Beach is one of those where bacteria and viruses could pose risks to the health of anyone paddling, swimming or surfing, according to officers at the Scottish Environment Protection Agency (SEPA).
SEPA has provided initial estimates indicating that 21 bathing waters will be classed as “poor” under tough new European safety standards.
The list includes seven Seaside Award winners, such as East Beach at Dunbar in East Lothian.
Others include Fisherrow Sands in Musselburgh, East Lothian, Girvan in South Ayrshire and East Beach in Lossiemouth, Moray.
Under new laws, Scotland’s 84 officially designated bathing waters must be tested every four years for human and animal waste, e.Coli and intestinal bacteria.
Exposure can cause infections in ears, nose throat and stomach, and can be fatal.
Political figures said poor readings were grounds for caution but stressed the data for Portobello had always been highly weather-dependent.
Councillor Maureen Child, Labour member for Portobello and Craigmillar, said: “I think these tests are done at certain times in the year and if we’ve had very heavy rainfall then the results tend to come out poor – it does not mean to say they will be poor all of the time.
“If we’ve had torrential rain then, as I understand it, the sewers cannot cope and they overflow. However, in normal weather, you would have a good reading.
“When we’re talking about poor, it’s poor in comparison to the good results we’ve had in the past - and will have again.”
But Andy Cummins, of Surfers Against Sewage, has called for tough action.
“The tougher standards have been introduced to offer the public better protection against a wide array of significant health risks,” he said.
“Those beaches that fail urgently need to adopt new actions and measures to ensure public water quality is safe.”
It is thought that most beaches will be classified as excellent, good or sufficient, and that 22 will be rated “excellent”, with very low contamination.
They include Gullane Bents in East Lothian and Achmelvich at Lochinver in the Highlands.
SEPA chiefs stressed that recent years had seen a marked improvement in test results across Scotland.
Calum McPhail, environmental quality manager, said: “All the bathing waters originally designated in 1988 and 1994 reached the mandatory or guideline standard in 2014 under the former directive, a vast improvement from the first year of monitoring in 1988, when 13 of the then 28 designated sites failed.
“Our challenge, therefore, is to build upon the progress made under the previous directive to achieve corresponding improvements in 2015 and beyond through further investment and infrastructure improvements.”