WA3 Development and Groundwater Protection Policy
In considering proposals for development, the Local Planning Authority will have regard to the need to protect sources of groundwater. The Local Planning Authority may require consultation with the Environment Agency and may impose conditions and obligations directed at preventing derogation in terms of both quality and quantity. Particular attention will be paid to proposals for mineral extraction, waste disposal, industrial and chemical processes.
Reasoned justification :
19.11 Much of Wirral is founded on sandstone which forms a major aquifer. Groundwater sources within this aquifer need to be protected, to maintain water supplies from aquifers (13% of water abstracted in Wirral and Ellesmere Port and Neston), to feed surface waters through springs and by base flows to rivers.
19.12 However, groundwater is often at risk not only from point sources but from diffuse sources of pollution which accumulate over many years, such as from the landfilling of wastes and the application of fertilizers and pesticides. If groundwater becomes polluted, it is difficult to rehabilitate because slow rates of groundwater flow and low microbiological activity limit any self-purification. It is, therefore, better to prevent or reduce the risk of groundwater contamination than to deal with it’s consequences. Mineral extraction and changes in land-use may also affect the availability of groundwater resources by restricting recharge and diverting flow.
19.13 The Environment Agency has extensive powers over the protection of such areas and these are supported by the control of potentially polluting development through the UDP. Development and the use of land is one consistent element in the list of potential threats to the quality of groundwater; land-use planning policies can, therefore, play a significant role in effective groundwater protection.
19.14 The concept of groundwater vulnerability recognises that risks of pollution from a given activity are greater in certain hydrological, geological and soil situations than others. The Environment Agency has mapped groundwater vulnerability for the Wirral and has identified major aquifers within these, high vulnerability or “principle recharge areas”. These are illustrated on Map 7. These areas are particularly vulnerable to pollution by agricultural and industrial activities and by urban development in general.
19.15 Policy WA3 attempts to complement Environment Agency powers and duties by using land-use planning powers to assist in protecting the groundwater resource as a whole and in particular these principal recharge areas. A distinction needs to be made between the general protection of the groundwater resources and the specific protection which may be needed for individual sources. It is possible to define the source catchment area of an aquifer. This is the area of land needed to sustain groundwater abstraction by natural recharge. The Environment Agency is in the process of defining groundwater source protection zones. These can rarely be regarded as definitive and maps will not be published, although information will be available from the Environment Agency. Consideration of source protection zones should therefore be regarded as additional to the general consideration of groundwater vulnerability