The Water Framework Directive and the legislative picture around pollution of groundwater
Groundwater is an important receptor in the context of land contamination. In the first years of the Part IIA regime the circumstances under which groundwater contamination could result in the designation of land as being ‘Contaminated’ was any pollution of controlled waters which has subsequently been altered to ‘significant’ pollution of controlled waters, in line with a risk-based approach.
There are however other pieces of legislation which cross over Part IIA, and these can create a confusing picture. For example:
The Water Resources Act 1991. This allows the use of Works Notices to carry out remediation where other regimes (such as Part IIA) do not apply or where the pollution would not be dealt within an appropriate timescale using that other regime.
Groundwater Regulations 1998. These facilitate the issue of Notices to prevent pollution of groundwater by listed substances. They also require an authorisation for the discharge or disposal of listed substances to groundwater.
The Water Framework Directive (WFD) 2000/60/EC which replaces the earlier Groundwater Directive (80/68/EC) and in turn is to be repealed in 2013.
The Water Framework Directive and its daughter directives aim to establish a consolidated and consistent way of managing water quality with the stated aim of achieving a ‘Good’ quantitative status with no deterioration in status evident. Much of this centres on surface water but regarding underground water resources it also brings with it an obligation to:
• Classify all groundwater bodies to determine whether they have ‘good’ status.
• Identify any trends that represent a significant risk of harm to the quality of aquatic or terrestrial ecosystems, human health or the legitimate use of the water environment
These two obligations, because of the large spatial context, are mainly influenced by large scale effects such as significant abstractions and widespread or diffuse pollution. They therefore require an extensive and protracted monitoring programme. The targets regarding water quality status (chemical) are detailed in the River Basin Districts Typology, Standards and Groundwater Threshold Values (Water Framework Directive) (England and Wales) Directions 2009. These cover protection of human health (based on drinking water standards) and the protection of aquatic ecosystems (based on environmental quality standards). The results of these measurements need to be reported to the European Commission in the River Basement Management Plans with the first set of quality objectives to be met in 2015.
The third obligation is associated with a ‘Prevent or Limit’ duty which is aimed at preventing pollution, causing deterioration in status or any significant and sustained upward trend in the extent of contamination. This is also a current obligation of the Groundwater Directive (80/68/EC), and is the key element which links the WFD to the issue of land contamination. Overall the Directive, and in particular its daughter directives maintain the UK’s risk-based approach to contaminated land and continue to enable groundwater contamination issues, insofar as they are related to contaminated land, to be managed through a tiered an iterative approach, as described in CLR11. In a general sense these impacts tend to be local as they arise from point source inputs. For this reason they may have little or no impact on the overall quality status of the groundwater body and it is quite possible that an aquifer with overall good chemical status has localised pollution. However, the more widespread the pollution becomes the more likely the groundwater body will be at ‘poor’ status. With this in mind the daughter directives of the WFD place an obligation on member states to carry out additional trend assessments in order to verify that plumes from contaminated sites do not expand and worsen the overall groundwater quality with regard to the classification and trend obligations outlined above. Member states are further required to summarise their assessments in their River Basin Management Plans which are submitted from time to time to the European Commission. In practise this may mean that an ongoing monitoring programme is required at a contaminated site post remediation, making close out difficult to achieve.