Borehole Drilling and Private Water Supply Across Surrey

Borehole Service Utilities Ltd drills water boreholes across Surrey for homes, farms, estates, sports grounds and businesses. The company is Surrey based, on the 01428 dialling code that covers Haslemere and Hindhead in Waverley, and works right across the county from Farnham and the Hog's Back in the west to Oxted and Lingfield in the east. Work covers water well boreholes, garden and sports grounds irrigation, off grid solar-powered pumps, soakaway boreholes, filtration systems and borehole maintenance. Ring 01428 735013 to talk a site through.

Surrey is good borehole country. Two principal aquifers run across it: the Chalk of the North Downs through Guildford, Leatherhead, Dorking, Reigate and Oxted, and the Lower Greensand through Farnham, Godalming, Haslemere, Hindhead, Shere and Godstone. Both hold water at depths a domestic or agricultural borehole can reach. South of them the Weald Clay around Cranleigh, Dunsfold and Lingfield is poor for supply but is exactly the ground where surface water will not soak away, which is where a deep soakaway borehole earns its place. The right answer depends on what sits under your land.

Water well boreholes and private water supply in Surrey

A water well borehole is a private water supply drilled into the rock under your own land, giving you water that does not come from a mains connection. Borehole Service Utilities Ltd drills them across Surrey for houses, farms, stables, estates, nurseries and commercial sites. The usual reasons are the same ones every year: no mains in the lane, a mains connection quote that means a long run of new pipe, a large garden or paddock that costs a fortune to water on metered mains, or a business that needs more water than the existing supply will give.

Surrey is well suited to it. Much of the county sits on one of two principal aquifers, and there is a long history of private supply on the farms, estates and off-mains houses of the Greensand and the Downs. Four different water companies supply Surrey — Thames Water, SES Water, Affinity Water and South East Water — and no single one covers the county, so mains options vary sharply from parish to parish. A borehole takes that variable out. Once it is drilled, tested and commissioned, the water comes from your own ground.

Yields depend on the formation, not on the postcode. On the Lower Greensand, BGS records small-diameter boreholes in the Hythe Formation typically giving 0.5 to 1.25 litres per second, and a 300mm borehole in the Bargate and Hythe Beds near Haslemere that gave 50 litres per second. That is the spread on one aquifer alone. A site visit and a look at the local records is the only honest way to say what your land is likely to give.

Water well boreholes are drilled in Surrey for:

  • Houses and cottages with no mains water, or where a mains connection would need a long run of new pipe
  • Farms, smallholdings and livestock units needing stock water
  • Stud farms, livery yards and private paddocks around the Horsleys, Effingham, Cobham and the Weald Clay belt
  • Country estates and large gardens where watering on metered mains is the biggest running cost
  • Nurseries and growers on the lighter Greensand and Wey valley soils
  • Commercial premises and sports grounds needing more water than the existing supply gives

What lies under Surrey, and what it means for drilling

Surrey has two principal aquifers and they run in parallel bands across the county. The Chalk Group of the North Downs is the northern band: the Hog's Back between Farnham and Guildford (GU1 to GU4), then Merrow, the Horsleys and Effingham (KT24), Leatherhead (KT22, Surrey side), Box Hill and Dorking (RH4 and RH5), Betchworth, Reigate (RH2), Redhill and Merstham (RH1), Oxted and Limpsfield (RH8). BGS and Environment Agency Baseline Report 5 records the Chalk dipping gently northwards at around 2 degrees, steepening to as much as 55 degrees at the Hog's Back where deep faults have been reactivated.

South of the Chalk runs the Lower Greensand, the second principal aquifer, through Farnham (GU9 and the Surrey part of GU10), Tilford, Frensham and Churt, Elstead, Milford and Witley (GU8), Godalming (GU7), Haslemere (GU27) and Hindhead (GU26), Albury and Shere (GU5), the Holmwoods, Reigate, Redhill, Bletchingley, Godstone (RH9) and Oxted. Only two of its formations are the water-bearing units: the Hythe Formation and the Folkestone Formation. The Sandgate and Bargate Beds between them act as a leaky aquitard and the Atherfield Clay confines the base. Groundwater levels in the Lower Greensand stay essentially constant through the year, with the seasonal swings seen elsewhere largely absent.

Between the two sits the Gault, and it is not a thin bed here. Baseline Report 5 records the Gault reaching up to 85 metres thick in Surrey and the Upper Greensand reaching 35 metres near Guildford, so the clay is a substantial barrier that decides which aquifer a given site can actually reach. Further south the Weald Clay of Cranleigh (GU6), Dunsfold (GU8), Ockley, Capel, Newdigate and Lingfield (RH7) is a poor water-bearing formation, with supply depending on striking a sandstone or shelly limestone band. In the north-west, the Bagshot Formation sands around Bagshot (GU19), Chobham and Bisley (GU24) and the Woking heaths give reliable yields but need careful construction.

The formations that matter for borehole drilling in Surrey are:

  • Chalk Group (North Downs) — principal aquifer; hard calcium bicarbonate water moving through fissures, with rapid recharge
  • Lower Greensand, meaning the Hythe and Folkestone Formations — principal aquifer; fresh, low-mineralisation water, steady levels year round
  • Weald Clay of the Low Weald — mudstone with thin sandstones and shelly limestone bands; poor for supply and poor for percolation
  • Bagshot, Windlesham and Camberley Sand Formations — the secondary aquifer of north-west Surrey; soft but iron-bearing water, easily mobilised fine silt
  • London Clay — effectively unproductive for supply; cased through to reach the Chalk beneath in the north of the county
  • Upper Greensand and Gault — the Gault is an aquitard up to 85 metres thick separating the two principal aquifers
  • Ashdown Formation — only the far south-eastern corner around Dormansland, Felbridge and Lingfield

What happens on site, from survey to commissioning

A borehole is drilled in stages, and on a straightforward domestic job the drilling itself is usually the shortest part. It starts with a desk study and site visit: what the geology says should be under the plot, what nearby borehole records show, where the rig can stand, where the water has to get to, and where a borehole can sit clear of drains, soakaways, oil tanks, slurry and any other pollution risk. Access matters more than most people expect. The rig, support vehicle and water need a route in and a working area, and that is worth checking early.

Drilling, construction and testing then follow a set order. Each stage produces a record: the strata log, the depth water was struck, the rest level, and the drawdown and recovery measured during test pumping. Those figures are what the pump is then sized against, and they are the reason a borehole should never be finished by guesswork. A borehole that has not been test pumped is an unknown quantity.

Timescales vary with depth and ground, but the pattern is consistent: the rig is on site for days rather than weeks on a domestic borehole, then there is a gap while the water sample goes to a laboratory, then the pump, controls and any treatment are installed. Deep boreholes in north Surrey that have to be cased through the London Clay to reach the Chalk beneath take longer than a shallow Greensand borehole at Godalming or Haslemere.

A typical water borehole runs through these stages:

  • Site survey and desk study — geology, nearby borehole records, access, and a safe distance from contamination sources
  • Drilling through the overburden first, then into the target formation
  • Casing set through the upper ground and grout sealed so surface water cannot run down the outside of the borehole
  • Screen and gravel pack where the formation is sand rather than rock, sized to hold back fine material
  • Development and airlifting to clean out drilling debris and fine sediment
  • Test pumping to measure yield, drawdown and recovery, with a water sample sent for laboratory analysis
  • Pump selection and installation, with the down-hole pump set at the right depth for the tested yield
  • Controls, pressure vessel, pipework, storage where needed and a headworks chamber
  • Chlorination, flushing and commissioning, with any treatment set up and handed over

Off grid water: solar-powered borehole pumps for remote properties

Off grid solutions mean a borehole that runs on its own power rather than on a mains electricity connection. Borehole Service Utilities Ltd fits solar-powered down-hole pumps so a water supply can work at properties with no practical power supply at the wellhead. It suits field troughs, remote paddocks, woodland holdings, smallholdings and houses well away from services — the kind of ground found on the Greensand around Hindhead (GU26) and Haslemere (GU27), the Chobham and Bagshot heaths, and the scattered farms of the Low Weald.

A solar borehole pump is sized around daily demand rather than instantaneous flow. The array runs the pump when there is light, the pump fills storage, and the storage covers the rest. That is why storage volume, not pump size, usually decides whether the system copes with a dull week. Steady groundwater levels help here: in the Lower Greensand, levels stay largely constant through the year, so the pump setting does not have to allow for a big seasonal fall.

Much of this ground is in the Surrey Hills National Landscape, designated in 1958 and one of the most wooded of the UK's protected landscapes at 47 per cent tree canopy cover, or within the Metropolitan Green Belt. That affects what can sensibly be built above ground. A wellhead chamber, a discreet panel array and a buried run to a storage tank keep the visible kit to a minimum.

Filtration, maintenance and fault finding on Surrey boreholes

Surrey borehole water usually needs some treatment, and what it needs is set by the aquifer. Chalk water is hard: Baseline Report 5 records it as dominantly calcium bicarbonate, with calcium in outcrop groundwaters ranging from 62 to 220 mg/l, so limescale is the normal outcome and softening is the usual answer. Where the unconfined Chalk lies under farmland, nitrate is elevated, reaching up to 28 mg/l as nitrate-nitrogen, and Nitrate Vulnerable Zones are designated across a significant part of that outcrop. Where the Chalk is confined beneath the Palaeogene cover of north Surrey, nitrate falls away and iron, manganese and ammonium rise instead.

Greensand and Bagshot water is the opposite problem. Lower Greensand groundwater is fresher than water from most other UK aquifers, with a median pH of 7.2, but the aquifer has little carbonate cement and so buffers acid poorly, which gives water at pH 6.5 or below in places — particularly at the base of the Lower Greensand and in parts of the unconfined Hythe Beds. Iron and manganese are the usual filtration problem on both the Greensand and the Bagshot sands, where the water is soft but ferruginous. Baseline Report 5 makes the point that high iron and manganese are generally only a problem for private abstractors.

Boreholes also need servicing, and most faults show up as one of three things: less water than there used to be, water that has changed in colour or taste, or a pump that will not run. Borehole Service Utilities Ltd services pumps and controls, investigates falling yield, chases water quality problems, runs CCTV surveys down the borehole and carries out rehabilitation where a screen or the surrounding formation has silted or encrusted. On the Bagshot sands the classic cause is fine silt drawn in from the formation; on the Chalk it is more often headworks or fissure-borne contamination.

Treatment fitted and maintained on Surrey private supplies includes:

  • UV disinfection, the standard answer to bacteriological risk on shallow, fissured or otherwise vulnerable ground
  • Sediment and particle filtration for fine sand and silt
  • Iron and manganese removal, the usual requirement on the Greensand and the Bagshot sands
  • pH balancing where poorly buffered Greensand water sits at the acidic end and starts attacking pipework
  • Limescale reduction and softening for hard Chalk water
  • Annual servicing, filter and lamp changes, and repeat water sampling

Irrigation boreholes for gardens, sports grounds, farms and nurseries

An irrigation borehole replaces metered mains water for watering, which is where the running cost of a large garden, pitch or nursery usually sits. Borehole Service Utilities Ltd drills and equips irrigation supplies for private gardens and estate grounds, sports pitches, golf courses, nurseries and farms across Surrey. Demand is concentrated where you would expect it: the estate grounds along the Mole around Cobham (KT11), the large gardens of Hook Heath, Mayford and Pyrford in Woking (GU21 and GU22), the stud and livery land around the Horsleys and Effingham (KT24), and the nursery ground of the Wisley, Ockham and Send corridor (GU23).

Surrey has a strong concentration of championship golf, and course irrigation is a direct fit. Wentworth at Virginia Water, St George's Hill at Weybridge, Walton Heath at Tadworth and Woking Golf Club are all in the county. Vineyards need water too, for irrigation and frost protection: Denbies Wine Estate at Dorking (RH5 6AA) describes itself as England's largest single-estate vineyard, with 265 acres under vine. Racing and equestrian land at Epsom Downs, Lingfield Park and Sandown Park sits on three different geologies, which is a reminder that two neighbouring sites can need very different boreholes.

Irrigation demand is seasonal and peaky, which changes the design. A garden or sports ground may need a large volume over a few hours on a summer evening and almost nothing in winter, so storage and a booster set are usually a better answer than a bigger pump running the borehole hard. It is also the service most likely to take a site over the abstraction licence threshold, so the daily figure needs working out before anything is drilled, not after.

Soakaway boreholes where surface water will not drain

A soakaway borehole is a deep, narrow shaft drilled to carry surface water down through impermeable ground into a formation that will take it. It is the answer where a conventional soakaway fails a percolation test, which in Surrey happens on two large areas of ground. The London Clay of the north — Woking, Byfleet, Weybridge, Esher, Cobham (KT11), Addlestone, Chertsey and Egham — has an average hydraulic conductivity of about 0.001 metres per day, so water simply does not move through it. The Weald Clay of the south does the same job in the opposite corner.

Cranleigh (GU6), Dunsfold (GU8), Ockley, Capel, Newdigate, Blindley Heath and Lingfield (RH7) sit on Weald Clay, and the same low permeability that makes a water supply hard to find there makes surface water disposal hard as well. Farmyards, new buildings, stable blocks, arenas and hardstanding all have to put their run-off somewhere. A soakaway borehole drilled through the clay into a permeable horizon beneath takes the water away in a footprint far smaller than a crate or trench system, which matters on a tight yard.

Discharging to ground has to be done without putting the aquifer at risk, so what goes down a soakaway borehole matters as much as the hole itself. Clean roof water is a different proposition from a yard that drains vehicles or livestock. Design, silt traps, any required treatment and the depth the water is released at all follow from that. Environment Agency permission may be needed depending on what is being discharged, and that should be established before drilling.

Do you need a licence for a borehole in Surrey?

Most private boreholes in Surrey do not need an abstraction licence. GOV.UK guidance is that if you plan to take more than 20 cubic metres — 20,000 litres — a day, you are likely to need an abstraction licence from the Environment Agency. Below that figure a licence is generally not required. If you abstract from the same source at more than one point, the exemption only applies if the combined total of all abstractions is 20 cubic metres or less a day. Exemptions exist for particular activities, so a specific case is worth checking rather than assuming.

There is a separate notification duty. Section 198 of the Water Resources Act 1991 applies where someone proposes to sink a well or borehole intended to reach more than fifty feet below the surface, which is about 15.2 metres, for the purpose of searching for or abstracting water. Notice must be given before the work begins, to UK Research and Innovation, and in practice the British Geological Survey receives these notifications and the resulting data. There is also a duty to keep a journal of the work recording strata and water levels, to send completion records and to provide particulars of flow tests.

Drinking water from a private supply is regulated by your district council under the Private Water Supplies (England) Regulations 2016. A local authority must risk-assess every private water supply, though for a supply serving a single dwelling that duty applies only where the supply forms part of a commercial or public activity; otherwise the council must carry out the assessment if the owner or occupier asks for one. Surrey has eleven districts: Waverley, Guildford, Mole Valley, Tandridge, Reigate and Banstead, Woking, Surrey Heath, Elmbridge, Runnymede, Epsom and Ewell, and Spelthorne.

Borehole drilling by town and postcode in Surrey

These are the 21 main towns and postcode districts Borehole Service Utilities Ltd covers in Surrey. The surrounding villages and outlying farms in each of these districts are covered too, so it is worth ringing even if your own village is not named here.

  • Guildford – GU1, GU2, GU3, GU4
  • Farnham – GU9, GU10
  • Godalming – GU7
  • Haslemere – GU27
  • Hindhead – GU26
  • Cranleigh – GU6
  • Dunsfold – GU8
  • Shere – GU5
  • Ripley – GU23
  • West Horsley – KT24
  • Woking – GU21, GU22
  • Chobham – GU24
  • Bagshot – GU19
  • Cobham – KT11
  • Leatherhead – KT22
  • Dorking – RH4, RH5
  • Reigate – RH2
  • Redhill – RH1
  • Godstone – RH9
  • Oxted – RH8
  • Lingfield – RH7

Borehole Questions from Surrey Property Owners

Borehole depth in Surrey depends on which formation the water is in. As an indication only, a domestic or agricultural borehole on the Chalk of the North Downs is often in the region of 30 to 100 metres, and one on the Lower Greensand roughly 30 to 80 metres at or near outcrop. Boreholes are deeper where the Chalk is confined beneath London Clay in the north of the county. No honest figure can be given for a specific site before a survey.

You do not need an abstraction licence for most private boreholes in Surrey. GOV.UK states that if you plan to take more than 20 cubic metres, or 20,000 litres, a day you are likely to need a licence from the Environment Agency. Where you abstract from the same source at several points, the exemption only applies if the combined total is 20 cubic metres or less a day. Exemptions apply to some activities, so check your own case.

Yes. Section 198 of the Water Resources Act 1991 requires notice before sinking a well or borehole intended to reach more than fifty feet — about 15.2 metres — below the surface for searching for or abstracting water. Notice goes to UK Research and Innovation, and the British Geological Survey receives these notifications and the data in practice. A journal of the work must be kept recording strata and water levels, with completion records and flow test particulars supplied.

Yield depends on the formation, not the postcode. On the Lower Greensand, BGS records small-diameter boreholes in the Hythe Formation typically giving 0.5 to 1.25 litres per second, while a 300mm borehole in the Bargate and Hythe Beds in the Haslemere area gave 50 litres per second. The Bagshot Formation of north-west Surrey has high effective porosity and storage and gives reliable yields. Only test pumping on your own borehole gives a figure you can design around.

Borehole water in Surrey is usually safe to drink once it is properly treated and tested, but it should never be assumed safe untreated. The Chalk carries water through fissures with rapid recharge — 25 active swallow holes have been identified in the Mole Valley — and the Lower Greensand is described as relatively vulnerable to pollution. UV disinfection, filtration and a proper wellhead seal are the standard answer. Your district council regulates private supplies and can arrange sampling.

Drilling a domestic borehole usually takes days rather than weeks on site, but the full programme is longer than the drilling. After drilling come casing and sealing, development, test pumping and a water sample sent to a laboratory, then pump and control installation, any treatment, chlorination and commissioning. Deep boreholes cased through the London Clay of north Surrey to reach the Chalk beneath take longer than a shallower Greensand borehole near Godalming or Haslemere.

Yes. A borehole can run alongside a mains connection, and on many Surrey properties that is the sensible arrangement. The borehole covers irrigation, stock water, washdown or process water, while the mains stays as the drinking supply or as backup. Keeping the two systems physically separate is essential, with no cross-connection between them. Surrey is supplied by four different water companies, so mains cost and reliability vary from parish to parish.

It depends on the aquifer. Chalk water across the North Downs belt is hard, dominated by calcium bicarbonate, with calcium in outcrop groundwaters recorded between 62 and 220 mg/l, so limescale is the expected outcome. Lower Greensand water is fresher and less mineralised, with a median pH of 7.2 but a poor ability to buffer acid, so some sites give water at pH 6.5 or below. Bagshot Formation water in north-west Surrey is soft but ferruginous.

A soakaway borehole is a deep, narrow borehole that disposes of surface water through impermeable ground into a formation that will accept it. You are likely to need one where a percolation test fails — common on the London Clay of north Surrey, which has an average hydraulic conductivity of about 0.001 metres per day, and on the Weald Clay around Cranleigh, Dunsfold and Lingfield. It uses far less ground than a crate or trench system.

Talk to Borehole Service Utilities about your Surrey site

Borehole Service Utilities Ltd drills, equips and maintains water boreholes across Surrey — Guildford, Farnham, Godalming, Haslemere, Hindhead, Cranleigh, Dorking, Leatherhead, Reigate, Redhill, Godstone, Oxted, Lingfield, Woking, Chobham, Bagshot, Cobham and the villages between them. Ring 01428 735013, or use 07970 573840 or 07517 151270, or email info@boreholeservice.co.uk. Tell us where the site is and what the water is for, and you will get a straight answer on what is likely to be under the ground and what the next step should be.