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Chapter six
CONTROL OF DIFFUSE POLLUTION

Directive's Requirements

6.1 The Water Framework Directive explicitly requires the control of diffuse pollution as one of the mandatory measures to protect the water environment. These controls may take a number of forms including prior authorisation (licensing) or registration based on general binding rules.

Environmental Impacts of Diffuse Pollution in Scotland

6.2 Point-source pollution is easily defined and understood, it is pollution from the end of a pipe. However, indirect or diffuse pollution is more difficult to define. Table 6.1 sets out some of the characteristics of diffuse pollution.

6.3 We can see that diffuse pollution includes many things. It includes runoff of rainwater partially contaminated with oils and other toxic substances from roads, industrial estates and car parks. It also includes the runoff and seepage from agricultural premises and fields of water contaminated with manure, slurry and chemicals such as pesticides. Runoff from forestry and other land uses provide other potential sources of diffuse pollution. Diffuse water pollution is closely related to land-use and is directly affected by the weather. All the evidence suggests that the relative impact of diffuse pollution is increasing all the time. Indeed, SEPA estimate that diffuse agricultural pollution alone will be the most significant contributor to water pollution by 2010.

Table 6.1: Diffuse Pollution

Controls

6.4 Unlike point source pollution there is no single piece of legislation that deals more effectively with diffuse pollution. There are a number of domestic and European provisions that tackle particular impacts but their effect is not comprehensive. The Nitrates Directive is one example. It targets one particular type of diffuse agricultural pollution - excessive nitrates from manures and fertilisers. The Nitrates Directive requires the establishment of codes of good agricultural practice and the designation of Nitrate Vulnerable Zones (NVZs) in catchments where the waters are affected by or at a particular risk from nitrate pollution. In these areas particular rules must be followed. The Nitrates Directive also controls nitrate pollution to groundwaters. The Integrated Pollution Prevention and Control (IPPC) Directive concentrates on specific intensive practices which lead to diffuse pollution - intensive poultry or pig farming units - rather than particular pollutants. It does so by requiring that units limit pollution through the employment of the Best Available Technology (BAT). In the UK this is being done by the development of general binding rules appropriate to different types of farming units.

6.5 There are other statutory and non-statutory mechanisms designed to tackle diffuse pollution. The Control of Pollution (Silage, Slurry and Agricultural Fuel Oil) (Scotland) Regulations 1991 have been an effective tool in reducing pollution from these sources. The chemical industry sponsored initiative to tackle the environmental effects of pesticides is an example of the alternative voluntary approach. So is the SUDS (Sustainable Urban Drainage Systems) approach to limiting the adverse environmental impact of urbanisation on the water environment. A detailed design manual was published by a group including the construction industry, SEPA, Local Authorities and the Scottish Executive last year.

6.6 The EC Rural Development Regulation provides that farmers receiving agri-environment or LFA support payments must comply with standards or use "good farming practices". The standard of Good Farming Practice is set out for Scotland in the Scotland Rural Development Plan. It has three elements. Firstly, compliance with existing environmental legislation (for example, the Control of Pollution Act 1974, the Clean Air Act 1993 and the Wildlife and Countryside Act 1991). Secondly, compliance with a list of "verifiable standards" which include disposal of sheep dip, trimming of hedgerows and protection of field boundaries. Thirdly, farmers are encouraged to comply with the recommendations in other relevant codes of good practice. Failure to comply with the standards of Good Farming Practice will be likely to lead to withholding of payments.

6.7 However, it is clear that, even taken together, these schemes do not satisfy the requirement of the Water Framework Directive to have controls in place to tackle diffuse pollution on a comprehensive basis.

6.8 Developing such controls will not be simple. We have to balance the need to protect the environment with the need to promote economic development and wealth creation. We believe the following factors should inform our thinking about diffuse pollution control:

Need for supplementary measures - the Directive provides for supplementary measures - over and above those that are mandatory - to be set out in the RBMP as a means of obtaining the environmental objectives set. We think that there will be a particular need for supplementary measures in relation to diffuse pollution. In particular, training and education in how to avoid diffuse pollution will be of crucial importance. This is true for both urban and rural sources of diffuse pollution.

Implementation of already established Good Practice - we already have a good technical and scientific grasp of what causes diffuse pollution and of how its impact can be reduced. In the built environment the work already done on SUDS has demonstrated how soft-engineering solutions can have a positive benefit. Similarly, on the agricultural side, good practice in nutrient and waste management as well as farm yard and field drainage mitigation following the principles and guidance set out in the Prevention of Environmental Pollution from Agricultural Activity Code (PEPFAA) can be effective in tackling diffuse pollution. The Forestry and Water Guidelines have also been shown to be an effective tool in tackling diffuse impacts from forestry. The task therefore is to secure the adoption of this good practice across the board.

Need for means of tackling persistent problems where they exist - in common with other impacts that the Water Framework Directive requires to be controlled, diffuse pollution only needs to be controlled where it is having a detrimental effect on the environment. Controls should be proportionate to the situation in the local area. If we can secure good practice across the board much will have been achieved but there will clearly still be a need for measures to tackle particular problems as they arise. There may, for example, be particular areas where diffuse polluters are resistant to or have to go beyond the minimum standards of good practice. That resistance may result in environmental harm and, if that is the case, it will need to be tackled. To allow this we believe that the regulator will require to be given powers to take action to prevent diffuse pollution where it is identified and no other measure is effective. Such powers could involve giving the regulator the power to issue notices requiring that the diffuse pollution be stopped, the contravention of which would be a criminal offence.

6.9 We believe that we should aim to build on the good practice that already exists in tackling diffuse pollution. We believe this would best be done by giving statutory force to updated codes of practice that developers, farmers, foresters and anyone else causing diffuse pollution would require to comply with. We also believe that such an arrangement would require to be underpinned by powers available to the regulator to take enforcement action where necessary. However, we are aware that there are other models we could use to tackle diffuse pollution. Environmental licensing of particular activities - farming and forestry for example - could be established. We would be grateful for your views about how diffuse pollution would best be tackled. How do we achieve the best balance between the requirements of the Water Framework Directive and the interests of those whose activities cause diffuse pollution?

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