Boreholes

In order to drill a borehole you will need to gain permissions from the Environment Agency, therefore, it is advisable to contact them before you start looking for water to discuss your proposal.

After establishing if you have a potential water source you will also need to consider where you are going to locate your borehole. It is good practice to site a borehole as far away as possible, and preferably upslope from any potential sources of pollution such as septic or fuel tanks, soakaways, slurry pits and areas of intensive grazing. A minimum distance of 50m between a water borehole and any form of pollutant is recommended.

This can be undertaken by the British Geological Survey. The report will indicate the likely geological and groundwater conditions on your farm with possible yields and flows. The current cost of a British Geological Survey report is from £235 (ex VAT – Jan 2013) and takes about 6-8 weeks to complete.

If the water prognosis report confirms that a borehole is suitable, consent to drill and test pump an exploratory borehole must be sought from the Environment Agency.  The consent will set out general conditions which will include how to keep the Environment Agency informed as works progress. Specific conditions particular to your borehole could include dimensions of the borehole, any monitoring required, details of required test pumping, and where to discharge water. You should be aware that any development close to environmentally sensitive sites will require testing over a longer period to estimate the effects of abstraction.

After consent to investigate is granted by the Environment Agency, you can drill and test pump your exploratory borehole. Water quality samples should be taken at the end of the test to determine whether the source is contaminated and whether the water will fit the use that you intend. As well as quality sampling, it is important that the pumping rates and water levels are measured accurately before, during and after the pumping period.

Information obtained from the test can be used to decide on the specifics for the permanent pumping equipment. It is also a measure of the borehole performance, at the time of drilling. However, you will need to ensure that works do not introduce waterborne diseases in to the ground water and that any wastes including drill cuttings are disposed of correctly.

If you want to find out more about drilling companies you could contact the Well Drillers Association which provides a useful source of information on the construction of water supply boreholes.

If you are planning to abstract more than 20m³ (4,400 gallons) a day for use on your farm then you will need to apply for an abstraction licence from the Environment Agency.

An abstraction licence will give you permission to take a given amount of water from your local source and specify how you can use it. It will protect your right to abstract so that other users in the same area will not have access to your share of water. The licence is valid for a period of 12 years, after which you will need to reapply to the Environment Agency. The licence will take two to three months to approve. There are three licence options:

• Full abstraction licence -for most types of abstractions over 20m3per day
• Transfer licence – moving water from one location to another with no intervening use
• Temporary licence – for abstractions over 20m3 per day over a period of less than 28 consecutive days

In order to apply for your licence you will need to:

1. Contact the Environment Agency and fill out a WR42 Water abstraction or impoundment preliminary enquiry form. It should take about 15 minutes to complete
2. Complete the application form and provide all supporting information that is required
3. If you are proposing a new borehole you will need to submit your pumping test results with your application

The Environment Agency may stipulate a maximum drilling depth and you will need to ensure that the correct casing is installed and sealed in order to protect your water supply from any polluting substances. Your local drilling company should be able to advise you on design and construction including:

• Depth and width
• The minimum working area which is generally 20 metres by 15 metres and is suitable for a large lorry mounted drilling rig
• Disposal of excavated materials which arise from construction activities. Those that are uncontaminated and naturally occurring can be reused on site assuming they require no further treatment. If no use can be found it on your holding they should be taken away as a waste by a registered waste carrier.

NB: If the borehole is going to be deeper than 15 metres, there is a statutory requirement for the driller to supply the full information to the British Geological Survey at the Wallingford Office to be entered into the National Well Record archive.

Costs of boreholes vary greatly and are dependent on many variables such as geology of the land, the nature of the water and the depth of the borehole. It is also dependent on the yield required and the access to the borehole location. For more information contact the Well Drillers Association.