Extraction Methods

All mineral workings have the potential to affect the water environment in one way or another. The original Guide to Good Practice⁷⁸ provides a detailed review of the relevant characteristics of each of the main types of surface mineral working encountered in Great Britain.

Because of their size, hydrogeological characteristics, environmental settings or particular methods of working, certain types of mineral extraction are more likely to cause problems than others. In this respect, particular attention needs to be given to opencast coal extraction (because of the very high volume of total extraction, including overburden, and the associated risk of both natural and industrial contamination); large scale quarrying of limestone and chalk from major karstic aquifers (because of the importance of the water resources involved and the uncertainty of hydrogeological conditions) and sand and gravel workings in river fIoodplains (because of the increased risks to surface water quality, river flows and floodplain hydraulics).

At a strategic level, there may be a need for more detailed planning guidance relating to these types of sites. There may also be a need for the implications of these forms of mineral working on water resources and the water environment to be considered in both regional planning guidance and strategic development plans.

At the more detailed level of preparing development plans, determining individual applications, or reviewing the conditions attached to old minerals permissions, these types of sites are already subject to more detailed scrutiny (with respect to potential impacts on the water environment) than other types of surface mineral workings, and it is appropriate that this should continue.