The legal framework for the licensing of groundwater abstraction or pumping in England and Wales dates, in principle, from the 1960s. Abstraction licences are required from the Environment Agency (EA) when groundwater is to be put to beneficial use (for example for process or potable use).
However, because of the need to pump groundwater to maintain the stability of underground works (such as mines, quarries and excavations), dewatering or groundwater control works were generally exempt from the need for an abstraction licence.
This created the anomaly that a water supply well would require licensing but a dewatering system at the same site pumping from the same aquifer would not.
The licence for the well would not automatically be granted, the application might need to be advertised to allow other water users to object, and limits would be set on the permissible flow rates.
In contrast, the mechanism for EA control of dewatering works is less straightforward. Under Section 29 of the Water Resources Act 1991, the EA must be notified in advance of any dewatering works, but it does not have the authority to directly license or consent to the works.
On sites where groundwater resources may need protecting, restrictions can be imposed indirectly using conservation notices under Section 30 of the Act.
The authorisation procedure for dewatering abstractions, together with the procedures for Discharge Consents for water disposal, is outlined in the forthcoming CIRIA Report Groundwater Control: Design and Practice, due to be published later this year.
However, the government has announced that the system will change and that groundwater abstractions for dewatering will be more closely regulated. The proposed changes to the water abstraction licensing system are outlined in a recent DETR report Taking Water Responsibly.
The changes are wide ranging, and are intended to provide the EA with additional tools to manage water resources.
For licensed abstractions, the main change is that all future licences will have a time limit and, during a transitional period, existing licences will be converted to time-limited status.
The report indicates that, in many cases, licences will have a duration of 15 years, with a presumption of renewal provided no significant environmental concerns have arisen.
Of direct relevance to the ground engineering industry, the DETR report proposes that all abstractions above a threshold amount, for whatever purpose, will require prior authorisation from the EA.
Current exemptions on grounds of use will be removed, and two new forms of authorisations - permits and consents - will apply to dewatering works (see box).
The proposed threshold is very low, 20m3/day or 0.2l/s in continuous 24 hour pumping. This implies that almost all dewatering works, even small sump pumping jobs, will require authorisation - a significant change from the present circumstances.
The DETR report indicates that the EA will be required to deal rapidly with applications for consents and permits.
It is proposed that a permit will be deemed to have been issued without conditions if the EA has not otherwise determined within 15 working days of its receipt.
The system is intended to allow 'emergency' or 'one-off' abstraction to proceed without impediment, although there is no definition of 'emergency'.
However, the Environment Agency must be informed of the circumstances within five working days of the commencement of abstraction.
A time scale for the introduction of the legislation has not yet been set and, in any case, it is likely that a transitional period will apply.
Nevertheless, in the near future dewatering abstractions will come under closer regulatory control. Hopefully this will contribute to continuing improvements in good practice in the planning and execution of dewatering works of all types.
Dr Martin Preene is groundwater group leader at Ove Arup & Partners.