The European Community Shellfish Waters Directive 79/923/EEC (the Directive), was adopted in 1979 to protect and, where necessary, improve the quality of waters where shellfish grow and to contribute to the high quality of directly edible shellfish products.

The Directive concerns the quality of shellfish growing waters. Along with other Member States, the UK has designated those coastal and brackish waters needing protection or improvement in order to support shellfish (bivalve and gastropod molluscs) life and growth and to contribute to the high quality of directly edible shellfish products. The Scottish Environment Protection Agency is the competent authority charged with the task of delivering the water quality standards laid down in the Directive.

The Directive prescribes the minimum quality criteria which must be met by shellfish waters, and guideline values which Member States must endeavour to observe. Details of these standards as applied in Scotland are given in the Annex to this introduction. The Directive also specifies the minimum sampling frequency and the reference methods of analysis which must be used. If the set environmental standards are not met, the Directive requires measures to be taken to ensure compliance within six years of waters being designated.

The Surface Waters (Shellfish) (Classification) (Scotland) Regulations 19971 establish classification and sampling criteria and confer a duty on the Scottish Environment Protection Agency (SEPA) to investigate and adopt appropriate measures where monitoring results indicate that the waters do not meet the quality standards specified in the Directive. An accompanying Direction, The Surface Waters (Shellfish) (Scotland) Directions 1997, instructs SEPA to endeavour to achieve guideline values specified in a Schedule to the Direction for designated waters.

The first Shellfish growing waters in Scotland were identified in 1981. By 1998, 22 waters had been officially designated by Direction4, with a further 11 designated in 20005. In 2002 an additional set of 75 waters were designated6, and the present report contains a Pollution Reduction Plan (PRP) for each of these most recently designated sites. Each PRP provides background information on the site, reports the results of compliance monitoring, identifies point source discharges and potential risks of diffuse pollution and highlights required improvement actions.

All the shellfish waters designated in 2002 have been demonstrated to be of excellent physicochemical status. In general, the physicochemical data collected to date from these sites are easily below the mandatory quality standards prescribed by the Directive. On a very few occasions the pH of a water body has been found to be just below neutral but, in each case, this has not resulted in failure of the Directive standard since Regulation 3 of the 1997 Regulations1 has been complied with.

The guideline physicochemical values are almost as well respected, though investigations have been initiated at a few sites to help ensure compliance with the Directive guidelines is achieved in the future.

More frequent exceedances of the bacteriological guideline standard have been recorded. The Directive only specifies a guideline value for faecal coliforms (FC) of not more than 300 FC per 100ml of shellfish flesh and intervalvular fluid. No clear relationship has been established between FC levels in shellfish tissue and the microbiological quality of the ambient waters, excepting those waters which are polluted2.

A full sampling regime was initiated in June of 2003 for the 75 newly designated sites and SEPA will report on a detailed analysis of all data collected from these sites once a full two years’ dataset has been generated. The full report will provide a definitive assessment of the compliance of these waters with all articles of the Directive. The PRPs presented in the present report are based on data collected up to the end of 2004.

In the absence of guidance on deriving a water quality objective that would achieve the guideline value set by the Directive, SEPA adopts a precautionary approach, as detailed in SEPA Policy 27a 3, whereby the discharger must demonstrate design to achieve no more than 100 FC/100 ml and 100 FS/100 ml for waters within the designated area or at the boundary of the shellfish water for any discharges made out with the designated area.

SEPA has established programmes for reducing pollution with the aim of ensuring that designated waters conform to the mandatory standards within 6 years of designation. The programmes also ensure that progress is made towards the achievement of guideline standards, depending on the risk from pollution sources. These plans identify consented discharges and potential risks of diffuse pollution, and highlight those areas requiring improvement. Relatively frequent non-compliance with the Directive’s guideline coliform concentration standard has been observed at these sites, in common with previously designated waters. Consequently, the pollution reduction programmes strongly emphasise measures being taken to reduce those sources of coliform bacteria which are controllable. SEPA recognises that faecal coliform (FC) levels in waters and shellfish flesh are influenced by complex factors and inter-relationships such as rainfall, diffuse pollution from agriculture as well as by direct/indirect sewage discharges. The two former are thought to be highly involved in the observed occasional failures of the G standard. Non linear bio-concentration of FC by shellfish in some seasons and in some environmental conditions is also implicated.

The plans detailed in this report are specific for each designated growing area and are aimed at identifying SEPA action and improvements directed to the appropriate source(s) identified for each water.

They frequently refer to Scottish Water’s sewerage and sewage treatment assets, particularly where these require upgrading. The capital investment needed to improve these assets is now identified and approved through a formal investment planning exercise for the water industry in Scotland. The Quality and Standards(Q&S) process is run by the Scottish Executive, in collaboration with Scottish Water, SEPA, SNH, the WIC and other stakeholders. The current investment programme, Q&SII, runs until 31st March 2006 and will deliver the majority of improvements specified in SEPA shellfish PRPs published in 2004. Those improvements still to be delivered have been incorporated as part of this PRP.

The next Scottish Water investment programme, Q&SIII, is currently being finalized and will cover a double period running from 1st April 2006 to 31st March 2014. The Q&SIII planning process, which must address all current and future regulatory requirements on Scottish Water, has presented various investment options for consideration by Scottish Ministers. A minimum level of improvement has been specified as part of this process to ensure some movement towards guideline standards specified by the Shellfish Waters Directive. A prioritised list of all investment needs has been developed by taking account of the level of risk posed by Scottish Water assets. This has predominantly been achieved by looking at the scale and proximity of discharges to shellfish waters currently failing the guideline standard. This should ensure that, depending on the final option chosen by Ministers, the most significant risks are addressed first. The final decision on investment levels is expected by December 2005, once the WIC has completed the strategic review of charges. This PRP has been based on the indicative options proposed by Ministers in February 2005 for input this review.

Monitoring of these newly designated areas has produced limited data so far on the impact of human sewage. If subsequent data indicates that a new site requires urgent improvement to the sewage treatment, there is a mechanism within Q&S for substitution. Under substitution, planned investment can be diverted away from one site in order to finance infrastructure investment at another, if it is agreed that the second site has become a higher priority for improvement.

Where agricultural or urban diffuse inputs are suspected of causing or risking downgrade, SEPA is implementing “environmental improvement plans” to ensure such inputs are minimised.

Other relevant legislation

• EC Shellfish Hygiene Directive
  Compliance with the Shellfish Waters Directive (79/923/EEC) in itself will not ensure protection of public health. This is the objective of the Shellfish Hygiene Directive 1991, as transposed into the Food Safety (Fishery Products and Live Shellfish) (Hygiene) Regulations 1998.
  
  In the UK, the Shellfish Hygiene Directive and relevant Regulations are the responsibility of the Food Standards Agency (FSA). This includes responsibility for the designation of harvesting areas, setting standards and reporting the classification of harvesting areas according to the presence of faecal indicator organisms. The degree of shellfish contamination determines the degree of depuration (purification) required before the produce may be commercially marketed.
  
  SEPA has established direct liaison with the FSA to discuss issues of common interest, develop relevant research and exchange information. Results and information supplied by the FSA are taken into consideration in the PRP production process. In 2006 new regulations relating to the Hygiene Directive will come into effect that will provide SEPA with the opportunity to have greater involvement in the designation of new shellfish areas. This will help to ensure that new harvesting areas are located where the necessary water quality can reasonably be achieved without compromising existing and future social or economic activities.
  
  
• EC Water Framework Directive
  The Water Framework Directive (2000/60/EC) seeks to improve or maintain the ecological and physico-chemical quality of all waterbodies. When fully operational, this will achieve the level of protection afforded by a number of existing directives, including the Shellfish Waters Directive. These objectives will be achieved through operation of River Basin Management Plans, which will incorporate the improvement actions specified within the Shellfish Water PRPs presented here.
  
  
• SEPA’s core duties
  The environmental quality of designated shellfish waters is impacted by coastal water quality, freshwater inputs, groundwater quality within the catchment areas, direct discharges to the designated area, runoff from urban and agricultural land, offshore activities within the designated area, and aerial deposition of pollutants. Each of these present a route by which the environmental quality of a shellfish growing area might become compromised, and each is subject to control through SEPA’s core activities. These activities include enforcing legislation on planning development7, 8, the quality of discharges to surface waters9, 10, to groundwater10, 11 and emissions to air12, and through promoting guidelines for best practices for agriculture13-17, forestry18 and fisheries. These core duties are used to protect all of Scotland’s environment and, as such, help to maintain the high quality of shellfish growing waters.

References

1. Statutory Instrument 1997 No. 2470 (S. 162). Surface Waters (Shellfish) (Classification) (Scotland) Regulations 1997.
   
2. Investigation of the relationship between indicator bacteria in mussel flesh and intervalvular fluid and surrounding waters. Phase 3 SR97(07) F., Milne, D.P., Higgins, J.E. and Brodie, I.J. (1998). Scotland and Northern Ireland Forum for Environmental Research.
   
3. Policy No 27a Microbiological Standards and Design Criteria for Discharges to Shellfish Waters.
   
4. The Surface Waters (Shellfish) (Classification) (Scotland) Direction 1998 (as amended).
   
5. The Surface Waters (Shellfish) (Classification) (Scotland) Direction 2000 (as amended).
   
6. The Surface Waters (Shellfish) (Classification) (Scotland) Direction 2002.
   
7. Town and Country Planning (Scotland) Act, 1997
   
8. Town and Country Planning (General Development Procedure)(Scotland) Order, 1992
   
9. Control of Pollution Act, 1974
   
10. Surface Waters (Dangerous Substances) (Classification) (Scotland) Regulations, 1990, 1992, 1998 and associated Ministerial Directions.
    
11. Groundwater Regulations, 1998
    
12. Pollution Prevention and Control (Scotland) Regulations, 2000
    
13. Silage, Slurry and Agricultural Fuel Oil (Scotland) Regulations, 1991
    
14. Sludge (Use in Agriculture) Regulations, 1989, and amendment
    
15. Code of Practice – Prevention of Pollution from Agricultural Activities
    
16. Control of Pesticides Regulations, 1986
    
17. Plant Products Regulations, 1997
    
18. Forests and Woodlands Guidelines