Scotland's bathing water season is upon us once again, and as we head to beaches to enjoy the summer sun, we want to be sure that the quality of the water we swim and paddle in is high. SEPA is responsible for monitoring Scotland's 60 identified bathing waters. But how are these samples taken, what can the scientists tell from them, and are Scotland's beaches improving year on year? Caroline Budge spent a day with SEPA senior microbiologist Brian O'Keefe to find out how the water quality is tested.

Spending your days visiting some of Scotland's most beautiful beaches seems like an idyllic job. When Brian and I spent the day travelling along the coast of East Lothian and down into the Scottish Borders on a glorious September day last year, we visitedstunning locations such as Coldingham, Pease Bay and St Abbs. But the work Brian and other SEPA microbiologists throughout the country do is vital for ensuring the quality of our bathing waters is not only reaching the standards set down in European legislation, but improving all the time.

Last year's results were, SEPA admitted, disappointing, and efforts are continuing to try and understand why some waters are consistently failing, and what can be done to improve their quality. In Scotland, the first bathing waters were identified in 1987 when the then Secretary of State identified 23, based on the EC Bathing Waters Directive. In 1998 a review panel of a wide variety of interested parties added another 37 waters to the list, including two freshwater locations.

Every summer, between June and September, SEPA officers take water samples 20 times at each site. These are analysed in SEPA's microbiology laboratories and the results published, usually within three days, on SEPA's website. A final report for the year is produced after the end of the season.



Sampling

Brian is based at SEPA's Edinburgh laboratory, which covers 27 identified beaches in the south east of the country, as well as another 27 waters that are not designated, but are sampled and analysed to the same standard.

Collecting the samples is quite straightforward - SEPA staff collect water from about 30 centimetres below the surface in a sterilised bottle, being careful not to contaminate the sample. These are kept in a cool-box and taken back to the lab for testing within six hours. Staff also take a note of the conditions at the time, such as the weather, water and air temperature, wind direction, high or low tide, and whether there's any sewage debris present. The latter can indicate a problem with the sewage system somewhere.

There are two standards for bathing waters to pass - the mandatory standards and the stricter guideline values which, if achieved, indicate excellent bathing water quality. In 2001, 24 of the 60 identified bathing waters passed the guideline standards, 27 passed the mandatory standards, and nine failed.

But what do the tests in the laboratory look for, and what constitutes a pass or a fail? In the UK, the Bathing Waters Directive standards are largely based on three groups of bacteria - faecal coliforms (FC), total coliforms (TC) and faecal streptococci. These are often called indicator bacteria because their presence in water usually indicates faecal contamination from sewage or animal droppings. A high concentration of the indicator bacteria usually means a greater amount of contamination. To achieve a mandatory pass, at least 19 of the 20 samples collected over the season must not exceed set limits. For the guideline passes, even stricter limits must be met. Changes to the Directive, however, are being proposed, including testing for just one bacteriological indicator - a subgroup of the faecal streptococci called intestinal enterococci. Brian and his staff took part in trials in 2000 to test for the proposed indicator.



Improvements

The south east area of Scotland has seen some major improvements in bathing water quality in recent years. However SEPA staff are not complacent about what is still to be done.

Improvements to wastewater treatment works have had a positive impact on water quality, explained Brian. Eyemouth Beach, for example, achieved a mandatory pass last year, having failed in the previous three years. This was due, Brian believes, to the installation of a new sewage outfall. Another beach, Portobello Central near Edinburgh, had made the guideline standard – quite an achievement, he felt, when you consider the waste from almost half a million people is treated just two kilometres away.

SEPA works closely with Scottish Water (formerly the East of Scotland Water Authority in this area, see page 19) to improve water quality. The former Scottish water authorities had invested substantial amounts of money to deal with the problem of poor bathing water quality, explained Brian.

Being proactive

The area is one he knows very well – as a microbiologist with the Forth River Purification Board prior to SEPA's formation in 1996, he has 20 years experience of testing the beaches of Fife, the Lothians, Angus, Tayside and the Borders. "In this area, bathing water quality is mostly related to the size of the human population, and how that population's waste is processed. In other areas though, run-off from farms, especially in intensive cattle raising zones, can be just as important. Same faecal problem, different source," he pointed out.

In large conurbations sewage has to be treated before discharge and the greater the population, the more intense the treatment level.

High quality results of bathing water could only be achieved as long as there are no short circuits to the system, Brian explained.

"That's the biggest worry when you have a large population living in close proximity to the bathing water. One faulty operating combined sewer overflow or storm overflow can very easily ruin an otherwise perfect system, and cause a bathing water to fail. For this reason it is very important not just to monitor the actual bathing water quality, but also to look at what's behind the beach as possible causes of pollution."

This detective work to try and get to the root of the cause of any pollution is something SEPA's staff are trying to do more of. There is now more emphasis on how to predict what may cause a bathing water to fail.

So, the next time you take advantage of a nice day and visit one of Scotland's coastal beaches, or the bathing waters at Luss in Loch Lomond and Dores in Loch Ness, remember all the work going on behind the scenes to improve our bathing water quality.



SEPA's bathing water quality results can be seen on its website at: www.sepa.org.uk/bathingwaters