The Well Drillers Association was first formed some 70 years ago and acts as a forum for interested parties in the design and construction of water wells and boreholes. Its membership consists of companies and individuals engaged in well construction, test pumping, maintenance and rehabilitation. A number of its members also act as distributors for well related equipment including pumps.

The Association meetings allow members to discuss the industry, technical specifications, contract problems, training and the potential impact of legislation on the industry. It also maintains close contacts with the Environment Agency, the British Geological Survey and the various Water Authorities and Water Companies.

Since very early days the supply of water for drinking and washing purposes has been critical to the survival of businesses and communities. In early days water was taken from adjacent streams and rivers or from from shallow holes simply dug into the ground. Evidence exists that in Roman times wells or boreholes with their associated pipelines became very sophisticated.

Over the last 100 years the original cable percussive drills used to construct deep and large diameter boreholes have been joined but not replaced with rotary drills using air, water and biodegradeable drilling fluids with both direct and reverse circulation techniques. Water well construction can now be carried out up to depths of 500 metres with less deep boreholes having diameters in excess of one metre.

Before any decision is made on the economics of developing underground water resources for commercial benefit it is important to discuss with the local regional office of the Environment Agency or the Scottish Environment Protection Agency (SEPA) the potential for extracting groundwater at the site. Currently in England and Wales any abstractions above the threshold limit of 20 cubic metres per day have to be licenced by the Environment Agency. Some types of abstractions are exempt altogether, such as abstractions for irrigation other than spray irrigation and abstractions for dewatering (ie in construction works).

In Scotland an application for authorisation must be made to SEPA for abstractions above 10 cubic metres per day. Abstractions of less than 10 cu m per day for the purpose of dewatering and abstractions for the purpose of extracting geothermal energy are covered by a General Binding Rule and provided the rules are complied with no application for authorisation to SEPA is required.

It is also necessary to investigate the expected geology and groundwater regime at the site and this can be carried by the client, engineer or experienced drilling contractor contacting the Records Section of the British Geological Survey at Wallingford, Oxfordshire. They can for a small fee prepare a groundwater assessment report related to the National Grid Reference of the site based on information available to them in their borehole data base. If both these reports are favourable in terms of quality and quantity then in England and Wales a consent to drill and test pump an exploratory borehole must be sought from the Environment Agency.
In Scotland an authorisation to drill and test pump a borehole is generally required from SEPA for boreholes intended for the purpose of abstracting more than 10 cu m per day.

At this stage and subject to the Environment Agency consent, or SEPA authorisation drilling contractors with experience in the area should be consulted either directly or through an experienced consultant on the estimated cost of constructing and testing the proposed borehole, which may also be the permanent extraction borehole. A detailed written estimate should be obtained and if acceptable should be confirmed in writing. With the construction and testing completed it is then necessary to submit the results to the Environment Agency or SEPA with an application for a licence to extract the prescribed quantities of groundwater for commercial purposes.

Reference should be made to The Well Drillers Association publication "Guidance Notes for the Construction of Boreholes for Water Supply" covering contract arrangements, general matters including pollution precautions, equipment and materials specifications and legislation.

Malcolm Gamble the Chairman of the Well Drillers Association has been active in the drilling industry for some 45 years initially on Geotechnical Investigations but becoming increasingly involved in Groundwater Projects both in the United Kingdom and Overseas. He is a past Chairman of the British Drilling Association and currently works with well drilling contractors and consultants as a Specialist Consultant on groundwater and contract matters.