Sampling and results

Overview

Water quality samples are taken at each bathing water throughout the bathing season, from 1 June to 15 September. A pre-season sample is taken during the last fortnight in May.

Bathing water results for a specific site can be accessed by selecting the geographic region of interest from the menu on the left, or using the map below.

Most bathing waters will be sampled 20 times during the season. Some geographically remote sites will be sampled 10 times. Sites which have consistently demonstrated excellent water quality (typically every sample meeting guideline criteria for a number of years) are sampled five times. This reduction in water quality sampling allows more resource to be put into the investigative work required to eliminate or minimise the sources of pollution which still have an intermittent adverse affect on several designated bathing waters.

The overall compliance outcome for each designated bathing water is determined by the results over the full season. We will provide this on or shortly after 15 September.

The revised Bathing Water Directive: changes prior to 2015

The revised Bathing Water Directive (2006/7/EC) came into force on 24 March 2006 and was translated into Scottish law by The Bathing Waters (Scotland) Regulations 2008. The directive introduces a new classification system with more stringent water quality standards and puts an emphasis on providing information to the public. Whilst we will first report water quality classifications under the revised directive in 2015, other parts of the directive must be implemented earlier and some are already in place.

2011 2012 2015
  • Publication of bathing water profiles
  • Publication of monitoring calendar
  • Action, where required, on cyanobacterial (blue-green algae) blooms, macroalgae (seaweed), marine phytoplankton and other waste
  • Switch to new parameters
  • Summary information to be posted at beach locations
  • Implementation of signage and discounting
  • New abnormal situation rules to apply                 
  • Report water quality standards against the revised Bathing Water Directive

What we measure

Changes have now been made to the bacterial entities monitored. These arise from recommendations from the World Health Organization (WHO). In place of the current coliform and faecal streptococci standards, the revised directive sets standards for Escherichia coli and intestinal enterococci. While slightly altering the microbiological analytical techniques necessary, the differences in the values obtained are considered to be minimal. During the period 2012 to 2014 we report against the standards prescribed in Directive 76/160/EEC using these new parameters.

Sampling program

Sampling schedules (the monitoring calendar) are set and fixed in advance of the bathing season as required by Regulations.

At sites which have daily real time forecasting of bathing water quality and electronic beach message signage we may use the allowed 5 day sampling window to avoid sampling when the sign gives a poor water quality warning and we have actively advised against bathing.

At all other sites we sample on the date in the monitoring calendar unless there is an unexpected operational reason e.g. vehicle breakdown.

Short term pollution

Our electronic signage network at 23 sites across Scotland provides real-time predictions of bathing water quality. These electronic signs enable us to remove (from the overall classification dataset) samples collected during short-term pollution events, when there is a public warning system in place to inform prospective bathers of potentially poorer water quality. A separate closure sample must have been taken to demonstrate that the event has ended and management measures must be in place to prevent, reduce or eliminate the causes of the pollution. The directive says that a maximum of 15% of the samples used to assess the classification of a bathing water can be disregarded from the assessment and, if necessary, replaced.

Abnormal situations

An abnormal situation is defined by the revised Bathing Water Directive as an event or combination of events impacting on bathing water quality at the location concerned and not expected to occur on average more than once every four years. During an abnormal situation the monitoring calendar can be suspended so that samples which assess compliance of the bathing water are not taken. This is because they are unrepresentative of the water quality of a bathing water. When an abnormal situation is in force, signs must be put up by the beach controller warning the public of the nature and expected duration of the pollution.

How results are determined, 2012 to 2014

During the period 2012 to 2014 we will continue to report compliance against the standards in the 1976 directive, as in pervious seasons. During this time, we will be monitoring the new bacterial entities. The table below shows how compliance will be determined.

Table 1: Interpretation of microbiological values for bathing waters in the period 2012 to 2014.

  Escherichia coli 
(previously faecal coliforms)    
Intestinal enterococci
(previously faecal streptococci)
Mandatory pass (M)

95% of samples should not exceed 2,000 E. coli per 100 ml

 

If a site is sampled 20 times, at least 19 samples must meet this criteria.

 

If a site is sampled less than 20 times, all samples must meet this criteria

The 1976 directive contains no mandatory standard for this parameter
Guideline pass (G)

80% of samples should not exceed 100 E. coli per 100 ml

 

If a site is sampled 20 times, at least 16 samples must meet this criteria

 

Proportional reductions apply at sites with reduced sampling

90% of samples should not exceed 100 intestinal enterococci per 100 ml

 

If a site is sampled 20 times, at least 18 samples must meet this criteria

 

Proportional reductions apply at sites with reduced sampling

Bacteriological analysis

Bacteriological analysis is carried out in SEPA’s specialist microbiological laboratories at East Kilbride, Aberdeen and Edinburgh. All of these laboratories operate to United Kingdom Accreditation Service (UKAS) quality systems for their analytical work. We also participate in external inter-laboratory testing schemes such as those run by the Public Health Laboratory and Aquacheck. The inter-laboratory testing has demonstrated consistent high accuracy of SEPA's bacteriological test results.