Science and Technology Committee Inquiry: Water Quality
The House of Commons Science and Technology Committee has launched an inquiry into Water Quality. The submission produced by the Geological Society of London can be found below. You can read the terms of reference for the inquiry here: http://bit.ly/Z2YURP.
Submitted 7th February 2013
- The Geological Society is the UK’s learned and professional body for Geoscience, with more than 10,500 Fellows (members) worldwide. The Fellowship encompasses those working in industry, academia and government with a broad range of perspectives on policy-relevant science, and the Society is a leading communicator of this science to government bodies and other non-specialist audiences.
- We have not attempted to answer all the questions raised in the Terms of Reference for the inquiry, many of which are outside our area of competence. We have focused on relevant geoscientific considerations which we believe the Committee may find helpful in its deliberations. The main points raised below are:
i. The importance of an integrated and holistic approach to water quality and remediation.
ii. The benefits of a catchment based approach in line with the EU’s Water Framework Directive.
iii. The importance of a joined up approach to water remediation innovation and technology sharing.
iv. The importance of water quality protection in safeguarding drinking water for the future and preparing for likely water scarcity challenges.
What should the acceptable thresholds be and how are these chemicals currently controlled?
- The monitoring of toxic chemicals in the environment and establishing of thresholds is essential for improving the ecological status of our waterways in line with the European Water Framework Directive. The basis for establishing acceptable thresholds is clearly open to debate. The geoscience community is not directly involved in setting such thresholds, but has an important role offering advice on aspects of complex and variable water systems at a national and EU level.
- Surface water exists as part of a wider system encompassing groundwater, oceans, water in the atmosphere and water stored in ice. These sub-systems are pervious to water and the chemicals contained within them, so the impact of a contaminant should be considered for the whole system when defining threshold limits. It is important to consider the impact and behaviour of contaminants in the sub-surface and in the shallow sea for the provision of clean drinking water and ecosystem services. An unchecked build up of these chemicals may have long term impacts on fisheries, sub-surface and coastal fauna and tourism, for instance.
- Currently, limits are applied on a national or international (EU) basis. In line with the EU’s river basin-based approach to water management, we suggest that because of the geochemistry of water systems and their interactions with the environment, the application of blanket thresholds may not be the optimal way to manage toxic chemicals in the environment. Thresholds are usually set by taking a classical risk-based approach to contamination that cannot always capture the variability of different systems. Local geochemistry may have a considerable impact on levels of risk or harm, as properties of water bodies such as pH, dissolved organic carbon and particulates can have significant effects on concentrations of dissolved chemicals. The varying residence times of water in different parts of a system is also significant in considering behaviour of contaminants in that system. Changes caused by disequilibrium and external effects can significantly affect the amount of contaminant bioavailable (that is, the degree to which an organism has access to the chemical). Different water catchments are affected by different microclimates and geological heterogeneity, which give rise to distinct geochemical environments. This can significantly affect the behaviour of potentially toxic chemicals. The US Environmental Protection Agency, recognising the heterogeneity of water systems, has developed a policy of assigning of site-specific threshold limits due to the wide variability in behaviour of contaminants.
- Parts of the UK rely heavily on groundwater for the provision of safe drinking water, so the quality of this water resource should not be overlooked. The potential for build up and extended residence times in sub-surface aquifers should be taken into consideration. As a result of environmental change and population growth, pressure on safe drinking water and water scarcity is set to increase in future, adding to the need to safeguard these valuable resources.
To what extent is innovation in water treatment supported in the UK?
- Water treatment technology development occurs in both the academic and industrial sector, but is principally developed in private sector companies seeking to design and sell economic materials and technologies. Whilst private sector development is important, reliance on this sector alone may reduce consideration of the water system and environment as a whole, and of the long term environmental impacts of remediation materials and technologies. A more joined up approach between government, academia and industry would support the generation of technologies which address water quality more holistically.
What likely impacts could the Commission’s proposal have in the UK? How could any adverse effects be mitigated?
- We welcome the Water Framework Directive’s approach to addressing river quality and management in terms of catchment basins, as this functions as a better demarcator for considering ecological status. Such a holistic localised approach could reduce the need for excessively low blanket thresholds, which have been criticised in the past and are likely to impose a greater financial cost on emitters.
- Long term impact on delicate ecosystems and on ecosystem services such as fisheries should be considered when setting limits. Insufficient or inappropriate control of new, perhaps poorly understood contaminants could result in unforeseen long term impacts on surface and groundwaters. Acting now will also help the future challenge of securing safe, clean drinking water in the coming years when water scarcity will be more keenly felt.