Assessing Scotland's water environment: use of environmental standards, condition limits and classification schemes

This document sets out how SEPA should implement the Water Environment and Water Services (Scotland) Act 2003, using Directions from 2014.

Section 2 Environmental Standards

2.1 Overview

Environmental standards and condition limits are key to the protection of our water environment and the achievement of our WFD objectives. They underpin assessments of whether waters are at risk of deterioration and what improvements would be needed to improve the status of waters that are not at good status.

The main work of developing environmental standards for use in the UK has been carried out by the UK Technical Advisory Group for the WFD ( UKTAG). This is a partnership of technical experts from the UK environmental protection and conservation agencies, as well as representatives from the Republic of Ireland. UKTAG is responsible for developing recommendations for standards and presenting these to the UK Administrations for consideration.

For surface waters, environmental standards have been identified for:

  • water plants and animals indicative of the ecological quality of surface waters

These biological standards help assess the extent to which the composition and abundance of water plant and animal communities has been affected by human activities. Such information enables us to identify where action is most needed to improve ecological quality and whether remedial action has been successful.

The scientific work to develop biological standards that are reflective of the impact of some pressures ( e.g. abstraction and engineering works) is still on-going. Progress has been made and we have now been able to introduce some ecological methods for assessing the impact of abstraction. We expect further standards to be progressively introduced as the necessary scientific work is completed.

Biological standards do not tell us what level of action is required to improve the status of our surface waters ( e.g. by how much an abstraction or discharge would have to be reduced to enable the achievement of good status) or the risk posed by development proposals (eg proposals to increase abstractions or discharges). For this, standards for the following are needed:

  • general chemical and physicochemical condition of surface waters

This includes standards for oxygen levels, acidity, temperature and nutrient concentrations. Together with the standards for toxic pollutants outlined below, they help assess whether water quality is of a sufficiently high standard to safeguard the ecological quality of surface waters.

  • toxic pollutants in surface waters
    Environmental standards have been set for:
    • priority substances and certain other pollutants identified at EU-level;
    • other specific pollutants identified at UK level.

Specific pollutants are toxic pollutants being discharged into surface waters in quantities significant enough to pose a risk to the ecological quality of those waters. We have introduced standards for 26 such pollutants. Further pollutants may be identified in future river basin planning cycles. Pollutants may also be removed from the list of specific pollutants if they cease to be discharged in significant quantities.

  • water flows and levels in surface waters

The ecological quality of our surface waters depends on the maintenance of the conditions necessary for healthy water plants and animal communities. These standards are used in assessing whether the right water flow and level conditions are present and whether proposed changes ( e.g. additional water abstraction) would pose a risk to ecological quality.

  • the condition of bed, banks and shores ( i.e. morphological conditions) of surface waters and the continuity of rivers for fish migration

These standards are used to assess the ecological risk posed by any alterations ( e.g. as a result of engineering works) to the beds, banks or shores of surface waters.

Many of the standards for surface water vary from one part of the water environment to another. This reflects the natural variation in the characteristics of the different parts of the water environment and the associated differences in their ecological sensitivity to pressures.

For groundwater:

  • threshold values have been identified for pollutants indicative of pressures placing bodies of groundwater at risk. Where a breach of a threshold value is identified, this acts as a trigger for investigations aimed at determining whether or not the conditions for good groundwater chemical status are being met (see section 3.4 for further details).
  • environmental standards are used in controlling inputs of pollutants into groundwater in order to:
    • protect surface waters associated with the groundwater and wetlands dependent on groundwater from pollution;
    • avoid deterioration of the quality of groundwater abstracted for human consumption;
    • safeguard the ability of groundwater to support human uses;
    • ensure ( i.e. by protecting against the development of pollution hotspots) that pollutant inputs do not cumulatively cause deterioration of the status of any water body.

The standards for protecting associated surface waters have been identified by UKTAG. We expect SEPA to use established drinking water standards to protect groundwater used for human consumption, safeguard the ability of groundwater to support human uses and avoid cumulative impacts on the status of groundwater bodies. These may include standards established under the Drinking Water Directive [1] , in World Health Organisation ( WHO) guidelines or by the United States Environmental Protection Agency.

Hazardous Substances

Whilst environmental standards underpin the way we manage the majority of pressures on the water environment, informing regulatory controls by identifying the quantities of particular pollutants that can be discharged into the water environment without causing harm, a different approach is required for certain hazardous substances. We have to stop them entering the water environment rather than just restricting their inputs in line with environmental standards.

The hazardous substances that we have to aim to prevent discharges, emissions and losses of into surface water are listed in the Priority Substances Directive (2008/105/ EC).

SEPA has published a list of the hazardous substances that must be prevented from entering groundwater to achieve the objectives of the 2006 Groundwater Directive. The list comprises those pollutants previously identified as hazardous for purposes of the 1980 Groundwater Directive. The work to identify these substances was overseen by the Joint Agency Groundwater Directive Advisory Group, whose members are the UK environment agencies (including SEPA), the Department of Environment, Food and Rural Affairs ( DEFRA), the Department of Health, and the Chemical Industry Association. The lists identified by this group have been subject to public consultation. Further details are available on the Environment Agency's website. The list will be updated as and when additional hazardous substances are identified. The scientific work to identify additional substances will continue to be coordinated at UK-level, and will be subject to consultation.

2.2 Phased introduction of environmental standards and condition limits

Environmental standards and condition limits have been introduced in phases. Further standards may be required as scientific knowledge increases, and as further data becomes available from monitoring and from work at a European level. This phased approach reflects our desire to ensure that all available scientific evidence is considered in developing the standards. Where an appropriate environmental standard has not yet been defined, SEPA will work with UKTAG to develop a standard and this will then be subject to consultation and Ministerial approval.

Equally, it is important that standards are proposed and introduced as early as possible where we have sufficient information and understanding. Timely introduction will give businesses and other water users sufficient time and certainty to plan for the future. As new standards are developed, there will be a phased transition from existing standards. SEPA manages that transition to ensure there is no deterioration in status of the water environment, whilst facilitating business and financial planning over the longer term.

Separation of Science and Policy

UKTAG's scientific recommendations are put forward to the UK administrations for Ministers to consider. This clear separation of science and policy has been adopted to emphasise that cost considerations should not influence the scientific development of standards; whilst recognising that the Directive allows flexibility to set less stringent objectives through the river basin management planning process where necessary on grounds of disproportionate costs or technical infeasibility.

2.3 Compatible approach across Europe

The environmental standards and condition limits introduced via the 2014 Standards Directions have been:

  • set to reflect definitions of environmental quality specified in the WFD;
  • developed in parallel with an EU exercise aimed at ensuring the biological standards Member States use in assessing good ecological status are comparable.

This EU exercise, known as inter-calibration, has been coordinated by the European Commission. Experts from Scotland and the rest of the UK have been, and continue to be, involved in the exercise.

2.4 How standards are used in Scotland

The RBMP and its associated legislation create a framework for SEPA and responsible authorities to follow in carrying out their functions. SEPA and the responsible authorities have a duty to protect the water environment but are also required to consider the social and economic impact of their actions, and to ensure that they act in the way best calculated to contribute to the achievement of the Scottish Government's strategic objectives including sustainable economic growth.

It is the responsibility of SEPA to regulate a wide range of activities that can adversely affect the water environment. Other regulators control certain activities that can have a significant impact on the water environment. For example, the Scottish Government is the competent authority for granting licences for engineering activities in coastal waters. All relevant regulators will be expected to adopt a similar approach to implementing the appropriate standards or condition limits in carrying out their regulatory functions.

Assessing current conditions against the environmental standards determines the available carrying capacity of the water environment to accommodate further activities or developments without significant risks to the quality of the aquatic ecosystem it supports. If, for instance, part of a river could accommodate some changes such as reduced water flow or alterations to the banks before an environmental standard or condition limit is breached, it still has available carrying capacity.

There are cases where more than one pressure contributes to an impact on the water environment. The most cost-effective combination of measures to address such impacts will be considered in implementing the programmes of measures identified in our river basin management plans. This issue is discussed in more detail in our policy statement on " Principles for setting objectives for the River Basin Management Plan".

2.5 Application of the standards in carrying out regulatory functions

For clarity and transparency, this paper sets out guiding principles for the application of water environment standards in Scotland. We expect SEPA and other regulators to have regard to these principles in their application of the environmental standards set out in the 2014 Standards Directions.

Guiding principles for applying environmental standards and condition limits in Scotland

SEPA and other regulators will normally be expected to use their powers to prevent a failure of an environmental standard or condition limit

This will include:

  • refusing to grant applications to undertake controlled activities that would (individually or cumulatively) result in failure of an environmental standard or condition limit;
  • granting authorisations subject to such conditions as they consider necessary to ensure controlled activities do not cause a failure of an environmental standard or condition limit; and
  • taking enforcement action where necessary to secure compliance with authorisation conditions that have been set to ensure an environmental standard or condition limit is met.

Such action will help protect Scotland's water environment and the interests of other users of the water environment; and contribute to achieving the WFD's objectives of preventing deterioration of status of any water body.

SEPA and other regulators will be expected to use their powers to minimise the impacts of hazardous substances

This will include:

  • requiring hazardous substances to be prevented from entering groundwater unless one or more of the conditions for exemption identified in the 2006 Groundwater Directive is met;
  • contributing to the objective of aiming to cease or phase out discharges, emissions and losses of priority hazardous substances.

Under certain circumstances, SEPA and other regulators may grant an application for authorisation even though they expect that the proposed activity will cause an environmental standard or condition limit to be failed

SEPA and other regulators are required to have regard to the social and economic costs and benefits of their regulatory decisions and will be expected to strike the right balance between the protection of the water environment and the social, economic and environmental benefits we gain from its sustainable use. This means that SEPA and other regulators may decide it is appropriate to authorise an activity which would cause a failure of environmental standard or condition limit where they consider the benefits to sustainable development, human health or human safety would outweigh the adverse social, economic and environmental consequences and provided the activity does not lead either directly or indirectly to increased pollution of surface waters.

Where the authorisation of a proposed activity would threaten the status of a water body, regulators may only grant authorisation if the WFD's provisions for exemption from its objective of preventing deterioration of status are satisfied, in line with the provisions of the Water Environment (River Basin Management Planning: Further Provision) (Scotland) Regulations 2013 Justification for any such exemption must be recorded and presented in the River Basin Management Plans.

SEPA and other regulators will normally be expected to grant authorisation for activities that would not individually or in combination with other pressures cause an environmental standard or condition limit to be failed

However regulators should be satisfied that granting such authorisations would not:

  • result in the achievement of environmental objectives, including those for Protected Areas, being compromised;
  • unnecessarily limit opportunities for future sustainable development by authorising inefficient use of the water environment; or
  • have unacceptable adverse impacts on the interests of other users of the water environment

SEPA and other regulators will normally be expected to require action to improve the water environment only where they are confident that the condition of the water environment is such that there is a significant risk that an environmental objective will not be achieved

In assessing the condition of the water environment, SEPA and other regulators will:

  • compare monitoring or modelling results against environmental standards and condition limits;
  • assess the confidence of the result; and
  • if no one piece of evidence provides sufficient confidence about the condition of the water environment, consider the weight of all the available evidence including, in particular, ecological evidence of adverse impacts. Such evidence is particularly important in the case of failures of plant nutrient and river flow standards.

SEPA and other regulators are expected to ensure that any improvements they seek are also sufficient to:

prevent the environmental standard subsequently being failed again as a result of fluctuations in environmental quality that cannot readily be controlled; and

provide environmental capacity for future development by securing good environmental practice in terms of efficient and sustainable water use where development is currently constrained because of the lack of such capacity.

Environmental standards define the point at which the carrying capacity of the water environment is exceeded and hence at which there is a significant risk of adverse effects. Environmental carrying capacity is defined as the capacity of the water environment to accommodate changes resulting from human activities without significant risk to plants and animals it supports.

SEPA and other regulators will not normally require improvements for the purposes of achieving the WFD's objectives for the status of water bodies where making the necessary improvements would be technically infeasible or disproportionately expensive

Where an operator considers that making an improvement to the water environment would be disproportionately expensive or technically infeasible, the regulator will be expected to take into account information provided by the operator and interested third parties before determining whether to require that improvement and to explain the reasons for the determination.

2.6 Practical application of guiding principles

In applying the above principles in seeking improvements to the status of the water environment, Ministers expect the following steps to be applied:

  • relevant regulators identify the activity or activities responsible for causing the significant adverse impacts on a water body;
  • the regulator seeks the necessary improvements by encouraging or initiating a variation of the relevant authorisation or authorisations for the activity or activities, or issuing a remediation notice;
  • where taking the necessary action to deliver the environmental improvements may be disproportionately expensive or technically infeasible:
    • the proposed variation or variations will be advertised to enable third parties to express their views on the case;
    • the regulator will confirm with the operator that the most cost-effective option for delivering the required environmental improvements has been considered; and
    • the regulator will determine whether the action necessary to deliver the environmental improvements would be disproportionately expensive or technically infeasible;
  • if achieving a standard necessary to enable the achievement of good status standards by is determined to be disproportionately expensive or technically infeasible, the regulator should identify what improvements, if any, would be technically feasible and proportionate and over what timescale; and
  • the regulator issues an appropriately varied authorisation for the activity or activities.


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