The Environment Department (DEFRA) has published its final consultation document on the methods that the Environment Agency will use to define and classify surface waters and groundwaters under the EU’s water framework Directive.1
Responses are required by 19 December. After completion of the consultation, ministers will finalise the legislative Directions instructing the Agency on how to proceed.
The aim is to produce an objective, reproducible and scientifically robust system of standards consistent with the Directive’s aims and aligned - as far as possible - with biological and ecological standards. The classifications proposals have been developed by the water framework UK Technical Advisory Group, which has published recommendations on surface waters, groundwaters and heavily modified or artificial water bodies over the last year.
DEFRA first consulted on the proposals along with the costs of implementing the Directive in February this year (ENDS Report 398, pp 47-48 ). Ofwat and Water UK were concerned that the standards were over-precautionary and too much of the costs would be met by water firms and their customers (ENDS Report 401, p 47 ). DEFRA published a summary and consideration of all responses to the consultation in August (ENDS Report 404, p 39 ).
The current consultation concerns the two legislative Directions the government will issue under Section 40 of the Environment Act 1975 to instruct the Agency.
Annex A includes the draft River Basin Districts Surface Water Typology and Environmental Standards (Water Framework Directive) (England and Wales) Direction 2008 plus a schedule with six parts.
Part I specifies the criteria for classifying the types of rivers, lakes and transitional and coastal waters. Part II specifies the standards for high, good, moderate, poor and bad quality in each type.
Part III deals with chemical environmental quality standards for 18 pollutants such as zinc, arsenic, copper, chromium and various pesticides. Part IV sets maximum admissible concentrations of the 33 priority substances cited in the daughter of the water framework Directive finalised in 2007 (ENDS Report 390, pp 47-48 ).
Part V deals with ‘biological element status boundary values’. These specify the degree to which the abundance of plant or animal taxa may vary from those expected to be present in the various types of water under ideal ‘reference conditions’. These are given as ‘ecological quality ratios’, which are close to one for high-quality waters and lower for poor-quality waters.
This is the element of the Directive that is the subject of an intercalibration exercise between member states conducted by the European Commission. The results are due to be published in spring 2009 after consideration by the European Parliament.
Part VI details ‘groundwater threshold values’ that will be used by the Agency in judging whether groundwaters achieve good chemical status. There are a large number of these reflecting the varied geochemistry of aquifers in England and Wales.
Threshold values are not simply limits that define good status, although a groundwater body will achieve good chemical status if threshold values are not exceeded at any monitoring point. A breach of a threshold value triggers an investigation to assess the impact of the breach on receptors - such as drinking water boreholes -using a number of tests set out in Annex B.
The first of these sets out the methodology for classifying the ecological and chemical status of surface waters, the ecological potential of heavily modified and artificial water bodies and how to assess morphological and flow characteristics. It specifies how all the characteristics of a water body - biological, physico-chemical and hydromorphological - will be combined in a single ecological classification.
The Agency will monitor or model values for the relevant biological and physico-chemical quality elements and compare them with the corresponding values set out Annex A of the consultation. The quality element most severely affected by human activity will determine the overall ecological status, which is described as the "one out - all out principle".
For heavily modified or artificial water bodies, the physical characteristics made to accommodate uses like navigation, water storage and flood defence can prevent the attainment of good ecological status. Such waters may be designated as artificial or heavily modified where the objective is to achieve good ecological potential and good chemical status.
Maximum ecological potential is the best ecological quality that can be achieved without making changes to the modified or artificial physical characteristics. Other classes of ecological potential are defined in terms of how far the quality deviates from maximum ecological potential.
The Environment Agency will assess whether all feasible measures have been put in place to reduce the adverse effects of the physical characteristics of the water body on ecology. If this has been done and there are no failures of standards that are not caused by the modification itself, the water body will be classified as good or maximum ecological potential.
Ecological potential will be seen as less than good where all feasible and effective measures are not in place or a quality factor unaffected by the modification does not meet the required standard. The chemical status of heavily modified and artificial water bodies follows the same methods as for unmodified surface waters.
The second schedule of Annex B concerns the method for determining the chemical and quantitative status of groundwaters.
Groundwater bodies are classified on chemical and quantitative standards, each of which is either good or poor. The lower classification decides the overall classification of the groundwater. Details of the criteria for groundwaters to meet good chemical quality status and good quantitative status are given in the annex.