Bathing water quality
The European Union sets standards for seaside bathing water in the EU area. Although European Law is not applied directly to the Island, the Government of the Isle of Man in 1990 took the decision to adopt the same standards, namely those set out in Directive 76/160/EEC which primarily was concerned with the contamination of bathing water by sewage.
The Government Laboratory tests seawater from 19 sites around the Island for compliance with the European Union Directive concerning bathing water quality. The sites that are monitored are not necessarily all bathing beaches in the sense of being beaches where people regularly swim, with facilities to support that activity, but they are beaches from which it is known that people do bathe or participate in sports that can involve or result in immersion and possible ingestion of water.
For 20 weeks each summer season (mid May to mid September) the results of testing are plotted on a chart showing the quality of the water in a traffic-light manner. This chart is displayed at the main bathing beaches and is updated each week during the season. The chart is also available for download (see downloadable documents), similarly updated weekly during the season.
In common with many places, a significant influence on bathing water quality on beaches around the Isle of Man is the discharge of untreated sewage or only partially treated sewage to sea, which releases large numbers of micro-organisms into the sea water. These micro-organisms include bacteria and viruses, some of which can be pathogenic with the potential to cause diseases, skin irritations and gastro-enteritis. The most abundant organisms in sewage are, however, the non-pathogenic coliforms, the detection and quantification of which is the basis of the regular testing of bathing waters.
Collection of the seawater samples from the beaches is arranged by the Department of Environment, Food and Agriculture's Environmental Protection Unit (EPU). More information about the Island's water quality is available on the EPU water quality page.
The regular monitoring does reveal an overall improvement in bathing water quality at the affected beaches from the time when former untreated sewage discharges were diverted to the ‘IRIS’ sewage treatment plant. It is noted, however, that not all of these beaches meet the best standards all the time, which is because human sewage is not the only source of bacterial contamination. Related to this, the quality of bathing water is widely accepted as being affected by weather, with extended periods of sunny, dry weather yielding better water quality than very wet periods, due to the dual effects of ultraviolet light from the sun killing bacteria coupled with less land run-off entering the sea – so summers with good weather tend to have a higher proportion of ‘good’ scores than bad weather summers.
Bathing water standards
The key requirements of the EU Directive set in 1976 are in respect of microbiological contamination, with mandatory limits set for total coliforms and faecal coliforms (95% of the samples taken throughout the bathing season required to have less than 10,000 total and less than 2,000 faecal coliforms per 100ml). That Directive also identifies a higher ‘guideline’ target standard (80% of samples having less than 500 coliforms and less than 100 faecal coliforms per 100ml). Subsequently in 2006 the EU issued a revised bathing water quality Directive which sets 3 standards instead of 2 – ‘excellent’ being approximately twice as stringent as the current Guideline standard, ‘good’ being broadly similar to the current guideline standard, and ‘sufficient’, a standard that sits between the current mandatory and guideline standards, however the classifications are based on at least 3 years’ data not individual years.
That standard will become mandatory for EU countries from 2015, and its more stringent requirements will impose challenges for many if it is to be met – however it does also allow adverse effects of weather to be taken into account, which may aid compliance in some cases, though at the expense of additional resources to monitor and greater effort to inform the public.
The Government Laboratory has been accumulating data appropriate to this new standard so that assessments can be made and information provided in due course. What is evident initially is that whilst, in common with the situation in the neighbouring isles, fewer Isle of Man beaches are likely to meet the minimum ‘sufficient’ standard than normally meet the current mandatory standard, more will meet the next level ‘good’ standard than meet the current ‘guideline’ target.
Other bathing water monitoring
Quite separate from the seasonal monitoring of bathing water from the sea, the Government Laboratory also undertakes bacteriological water quality testing of water taken from the various public swimming pools around the Island, including public baths and hotel swimming pools. These are variously submitted by the operator of the pool or by Environmental Health Officers, with reports given to the appropriate party.
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