Case Studies

Southern Water Authority (Public Water Utility) - Construction of a series of boreholes using cable tool percussion method was undertaken to provide water for pumping into the River Itchen at times of low water levels to maintain river level and flow.

Portsmouth Water PLC (Public Water Utility) - A series of boreholes were drilled to investigate a new public water source. Boreholes were drilled using a combination of rotary mud flush and cable tool percussion drilling methods through 100 metres of clay into the underlying Chalk. Yield testing of the wells was undertaken and acidisation was used to improve the water supply. Up to 1.5 mega litres per day (approximately 62 m3/hr) was achieved from one borehole.

Wessex Water (Public Water Utility) - Projects undertaken for Wessex Water have included drilling a water supply production borehole for a biosolids treatment works and a series of groundwater monitoring boreholes around a sewage treatment site to monitor groundwater quality. In addition a water well through tertiary deposits into the underlying Chalk was constructed to prove yield and quality in the groundwater. Acidisation of the Chalk was completed successfully followed by a 4 week continuous pump test.

Water Bottling Companies - Construction of boreholes and associated testing for mineral or spring water production for several well known water bottling companies in the UK.

Hall & Woodhouse Brewery Water Supply, Dorset - A water supply borehole was drilled for the brewery through chalk to 50 metres using cable tool percussion method. Test pumping was undertaken and a water supply of 3.5 mega litres per day (approximately 145 m3/hr) was achieved.

Addington Palace Golf Club, Surrey - A borehole was drilled through Chalk to 60 metres depth using rotary foam flush method for a water supply to irrigate the golf course.

Mitchum Golf Club, Surrey - A borehole was drilled through 90 metres of London Clay overlying Chalk to a total depth of 140 metres using rotary foam flush method for a water supply to irrigate the golf course.

Environment Agency - Wardle Drilling & Geotechnical Ltd was awarded the Environment Agency's (southern region) Framework Contract in 2004. Projects completed include various Hampshire Observation Borehole Contracts and Sussex Chalk Groundwater Investigation Scheme, where observation boreholes were drilled to monitor groundwater levels and movement.

Arreton Valley Nurseries - Two boreholes were drilled through sands using rotary mud flush to supply 70 acres of glass houses growing tomatoes and peppers. Johnson continuous slot stainless steel screen with a graded filter sand pack was installed. The permanent pump installation was completed and provided a water supply of 1 mega litre per day (approximately 42 m3/hr).

London Underground, Jubilee Line Extension - Dewatering boreholes were drilled using rotary mud flush method through London Clay into chalk to lower the groundwater table and allow tunnelling to progress.

Dorchester Hospital - A 170 metres deep borehole was drilled through clay overlying chalk using rotary mud flush method to provide a new hospital water supply. Yield testing was also undertaken.

St Richards Hospital, Chichester - Replacement borehole was drilled to supply the hospital laundry. The borehole was drilled through sands/clays overlying Chalk to a depth of 125 metres. A submersible pump was installed and pump testing completed to the Environment Agency's requirements.

Poole Hospital, Dorset - A borehole was drilled to 120 metres through sands using rotary mud flush for a new hospital water supply. Johnson continuous slot stainless steel screen complete with a graded filter sand pack was installed. Pump testing of the borehole to Environment Agency's requirements was undertaken.

Royal Naval Hospital, Hasler - A borehole was drilled to 112 metres through sands using rotary mud flush for a new hospital water supply. Johnson continuous slot stainless steel screen complete with a graded filter sand pack was installed. Pump testing of the borehole to Environment Agency's requirements was undertaken. The permanent pump was installed to provide a 25 m3/hr water supply.

RHS Wisley Gardens, Guildford - Refurbishment of an existing borehole was undertaken involving cleaning out the borehole to 241 metres depth and then installing screen and sand pack. A new pump installation was then undertaken to complete the work.

Water Sampling Boreholes for an International Airport - Observation boreholes of 300mm diameter were drilled using the cable tool percussion method at various locations around the airport to allow water sampling to be undertaken as part of the Airport's on-going environmental monitoring requirements.