Borehole Drilling and Private Water Supplies in West Sussex

Borehole Service Utilities Ltd drills water boreholes across West Sussex, from the coastal plain around Chichester and Bognor Regis to the Low Weald north of Horsham and the High Weald above East Grinstead. The company designs, drills and equips private water supply boreholes for homes, farms, estates and businesses, irrigation supplies for gardens, sports grounds, golf courses and nurseries, soakaway boreholes for surface water, off grid solar-powered pumps, filtration systems, and a maintenance and fault-finding service for boreholes that already exist.

West Sussex is a good county for a private water supply and an unusually varied one. The Chalk of the South Downs and the Lower Greensand belt through Midhurst, Petworth and Pulborough are both productive aquifers. A borehole at Storrington behaves nothing like one at Balcombe, though, and large parts of the Weald Clay will not give a usable supply at any sensible depth. The honest answer on any site starts with the geology beneath it and with a realistic figure for how much water the property actually needs.

Private water supply boreholes in West Sussex

A private water supply borehole is a drilled well that takes water from an aquifer beneath your own land, with a submersible pump lifting it to a storage tank or straight into the property. Borehole Service Utilities Ltd drills these across West Sussex for houses, farms, estates, equestrian yards, nurseries and commercial sites. Most customers are either off the mains completely, a long way from the nearest connection, or using far more water than a metered mains supply can deliver at sensible cost. Once the borehole is in, the water is drawn from your own ground, subject to the abstraction rules set out below.

The starting point is demand, not depth. A household of four uses a fraction of what a dairy unit, a glasshouse or a golf course irrigating greens in July gets through, and the whole design follows from that number: the diameter of the hole, the target formation, the pump duty, the size of the storage and the treatment train. Borehole Service Utilities Ltd works that out before drilling starts rather than after. An undersized borehole disappoints in a dry summer, and an oversized one is money spent on capacity nobody ever uses.

Borehole Service Utilities Ltd covers six areas of work across West Sussex:

  • Water well boreholes — private water supply for homes, farms, estates and businesses
  • Garden and sports grounds irrigation — gardens, pitches, golf courses, nurseries and farms
  • Off grid solutions — solar-powered down-hole borehole pumps and independent water supply for remote property
  • Soak away boreholes — deep borehole drainage where surface water will not percolate away at shallow depth
  • Filtration systems and maintenance — UV disinfection, sediment filtration, iron removal, pH balancing and limescale reduction
  • Borehole maintenance and trouble shooting — pump servicing, yield problems, water quality issues, CCTV inspection and rehabilitation

What is the geology under West Sussex, and what does it mean for drilling?

West Sussex has several distinct drilling environments, and which one a site sits in decides almost everything about the borehole. The Chalk Group forms the South Downs escarpment and dip slope and continues at depth beneath the coastal plain under Chichester, Bognor Regis, Littlehampton and Worthing. The British Geological Survey describes it as the major aquifer of the Chichester and Bognor district in terms of catchment area, storage capacity and yield. Chalk water is naturally hard. It is a fissured aquifer, so turbidity and bacteriological spikes after heavy rain are known behaviour, and filtration with ultraviolet disinfection is normally appropriate.

North and west of the Downs the targets change. The Upper Greensand forms a narrow belt at the foot of the chalk escarpment through Cocking, Duncton, Graffham and Heyshott and eastwards towards Amberley, Storrington and Washington, and BGS notes it as productive particularly in the Wiggonholt Syncline near Pulborough. The Lower Greensand Group carries the supply through Linchmere and Fernhurst, Midhurst, Petworth, Fittleworth, Pulborough and West Chiltington, with the Hythe and Folkestone formations as the water-bearing units. The Sandgate Formation between them is an aquitard rather than an aquifer, which is one reason a hole can pass through sand and still need to go deeper.

Two areas call for caution. Across the Low Weald — Horsham, Southwater, Billingshurst, Slinfold, Itchingfield, Cowfold, Shipley, West Grinstead, Shermanbury, Henfield and the Adur valley — the Weald Clay is predominantly mudstone. Any usable water comes from thin sandstone and limestone bands within it, the Horsham Stone and the Large and Small Paludina limestones, and those are unpredictable in position and yield. In the High Weald around East Grinstead, West Hoathly, Turners Hill, Balcombe, Ardingly, Horsted Keynes and Cuckfield, the Hastings Group alternates sand and clay, so a borehole there can reasonably be expected to be deeper than an equivalent Chalk or Lower Greensand hole elsewhere in the county.

Indicative ranges only. Every depth below has to be confirmed by test drilling on the actual site and should never be quoted from a map:

  • Chalk Group, Downs and coastal plain: roughly 40 to 120 metres for a domestic or agricultural supply, shallower where the water table is close to the surface, considerably deeper beneath the high downland where the unsaturated zone is thick
  • Upper Greensand at the scarp foot: roughly 30 to 80 metres at outcrop, deeper where it is targeted beneath the Chalk, and easily missed because the unit is thin
  • Lower Greensand, Hythe and Folkestone formations: roughly 30 to 90 metres, varying with which formation is targeted and whether it is at outcrop or confined beneath the Gault
  • Weald Clay of the Low Weald: no depth range can honestly be published, and some sites will not produce a usable supply at any sensible depth
  • Hastings Group in the High Weald: no published range, and expect to work through interbedded clay to reach a productive sand
  • Palaeogene beds and superficial deposits on the coastal plain: not a first-choice target, and normally cased and grouted through rather than screened within

Where Borehole Service Utilities Ltd works in West Sussex

Borehole Service Utilities Ltd covers the whole of West Sussex. The north-west of the county is the closest ground to the company's Surrey base: Fernhurst and Linchmere (GU27), Midhurst with the Western Rother valley parishes of Bepton, Cocking, Easebourne, Heyshott, Stedham and Woolbeding (GU29), and Petworth with Duncton, Graffham, Lodsworth, Lurgashall, Northchapel and Tillington (GU28). Much of that sits inside the South Downs National Park, which covers 1,627 square kilometres in total, of which 807 lie in West Sussex, with Chichester District holding the largest single share at 544 square kilometres.

Eastwards, the work runs through Pulborough, Storrington and Sullington, Washington, Thakeham, Ashington and West Chiltington (RH20), Billingshurst with Kirdford, Loxwood, Plaistow and Wisborough Green (RH14), and Horsham with Warnham, Rusper, Rudgwick, Slinfold, Itchingfield, Southwater, Nuthurst, Cowfold, Shipley and Lower Beeding (RH12 and RH13). Crawley's rural fringe at Worth and Turners Hill is useful ground too (RH10 and RH11). Several of these outcodes cross a county or district boundary, so the county is confirmed on each address before a site visit rather than assumed from the postcode.

The rest of the county works the same way. In Mid Sussex that means East Grinstead and West Hoathly (RH19), Cuckfield, Balcombe, Ardingly and Handcross (RH17), Haywards Heath and Lindfield (RH16), and the scarp-foot villages of Hurstpierpoint, Hassocks and Albourne (BN6). Along the Adur it means Henfield and Woodmancote (BN5) and the downs gap villages of Steyning, Bramber, Upper Beeding and Wiston (BN44). On the coastal plain it means Arundel with Amberley and Slindon (BN18), Littlehampton, Angmering and Rustington (BN16 and BN17), Worthing's downland fringe at Findon, Clapham and Ferring (BN11 to BN14), Bognor Regis with Barnham and Felpham (PO22), Chichester and Fishbourne (PO19), and the Manhood peninsula at Selsey, Sidlesham, Tangmere and the Witterings (PO20).

What happens on site, from survey to commissioning

A water borehole is a short job on a small footprint, not a building project. It starts with a desk study and a site visit: what the geology beneath the site is, what nearby boreholes have found, where the rig can stand, where the water is going, and where the headworks can sit clear of contamination risks such as drains, fuel stores, slurry and septic tanks. Access matters more than most landowners expect. A drilling rig, a support vehicle and a water tanker all need a route in and a working area, and reinstatement of the ground surface is planned before anything is drilled.

Drilling a domestic borehole usually takes a few days on site once the rig is set up, depending on depth and on what the formation does. The hole is cased and grouted through the superficial deposits and any shallow water-bearing layers so that surface water and perched water are sealed out rather than allowed into the supply. BGS records that the coastal plain superficials — brickearth, raised beach and river terrace gravels and alluvium — give only limited supplies and mainly support perched water above impermeable bedrock, which is exactly why they are sealed out. Screened construction is used where the formation is uncemented sand, which covers a good deal of the greensand work.

Once the hole is complete it is developed and test pumped, which establishes what it will actually yield and how far the water level draws down under load. That test sets the pump duty and the setting depth, not the other way round. A water sample goes to a laboratory and the results decide the treatment train, then the pump, rising main, pressure vessel, controls, storage and filtration are installed and commissioned. GOV.UK is explicit that abstractors and their contractors are responsible for making sure boreholes are designed, constructed, tested, operated and decommissioned without polluting groundwater, so the headworks detail matters as much as the depth.

Filtration, water testing and borehole maintenance

Treatment is set by a laboratory analysis of the finished borehole and never predicted from a geological map. Borehole Service Utilities Ltd installs and services filtration systems across West Sussex, covering sediment filtration, iron removal, pH balancing, limescale reduction and ultraviolet disinfection. On the Chalk the water is naturally hard, so limescale reduction is a common requirement, and because the Chalk is fissured, turbidity and bacteriological spikes after heavy rain are behaviour the system has to be designed around rather than a fault in the borehole.

Elsewhere in the county there is no honest prediction to be made from the formation alone. Iron is a reasonable thing to test for in the High Weald, where the clay ironstone in the Wadhurst Clay weathers to limonite and gave the Wealden iron industry its raw material, but the treatment train still follows the sample. On the coastal plain, BGS flags that the Palaeogene sands can carry high concentrations of sulphate and iron, which is one of the reasons the Chalk beneath them is usually the better target for a private supply in the first place.

Boreholes also need servicing. Pumps wear out, rising mains corrode, screens silt up, water chemistry shifts and yields fall away. Borehole Service Utilities Ltd services and repairs existing boreholes anywhere in West Sussex, including boreholes drilled by somebody else. If a supply has lost pressure, gone cloudy or started failing samples, the first useful step is finding out whether the problem is the pump, the treatment or the borehole itself, because all three produce similar symptoms at the tap and only one of them is cheap to fix.

Maintenance and trouble shooting work includes:

  • Pump servicing, testing and replacement, including rising main and control gear
  • Falling yield investigation and borehole rehabilitation
  • Water quality problems, including sampling and treatment upgrades
  • Downhole CCTV inspection of the casing, screen and water level
  • Filtration and UV servicing, cartridge and lamp changes

Irrigation boreholes for gardens, sports grounds, farms and nurseries

An irrigation borehole gives a landowner water at the point of use on the day it is needed, without a metered bill or a mains restriction dictating the programme. Borehole Service Utilities Ltd drills and equips irrigation supplies across West Sussex for gardens, sports pitches, golf courses, nurseries and farms. Commercial growing in the county is concentrated on the Chichester coastal plain, where the West Sussex Growers Association is an active network of more than 50 members growing in both open field and glasshouse settings, and where field-scale cropping runs across the Manhood peninsula through Sidlesham, North Mundham, Runcton and Tangmere.

Turf, estate and vineyard irrigation is the other half of the work. West Sussex has downland and heathland golf courses, polo grounds at Cowdray Park near Midhurst, showjumping at Hickstead in Twineham parish (RH17), and a substantial sparkling wine sector on the chalk and greensand slopes around West Chiltington, Washington and Bolney. These are the kinds of site where demand concentrates into a handful of dry weeks in summer, which is precisely when a mains connection is least able to deliver volume and when restrictions are most likely to bite.

Volume is where irrigation differs from a household supply. A single home uses far less than 20 cubic metres a day, but a working farm, a commercial nursery, a golf course or a full sports ground scheme can pass that threshold, and above it an abstraction licence from the Environment Agency is required. The arithmetic has to be done per site at design stage rather than assumed, and it is far better done before the borehole is drilled than after the pump is running.

Soakaway boreholes and off grid solar-powered pumps

A soakaway borehole disposes of surface water down a drilled hole into permeable ground below, and is used where shallow percolation fails. On the Weald Clay of the Low Weald that is a common problem: a conventional soakaway pit dug into mudstone simply will not empty. A deeper borehole can pass through the impermeable material and discharge into a permeable layer beneath, taking roof and yard water away from a building. Borehole Service Utilities Ltd drills soak away boreholes in West Sussex for houses, farm buildings, yards and hardstanding, and a soakaway borehole of 15 metres or more must be notified to the British Geological Survey before drilling.

Off grid solutions mean a water supply that runs without a mains electricity connection. Borehole Service Utilities Ltd installs solar-powered down-hole borehole pumps for remote property across West Sussex: field troughs and livestock water, isolated Wealden farmsteads across RH13 and RH14, downland farms in GU28, GU29 and BN44, holiday and caravan sites on the Manhood peninsula, and large-plot rural houses in RH17 and RH19 with no practical mains route. The pump fills a storage tank through the day and the tank carries the property overnight and through dull weather, so storage is sized for the worst week rather than the average one.

Do you need a licence for a borehole in West Sussex?

You need an abstraction licence from the Environment Agency if you intend to abstract more than 20 cubic metres of groundwater a day. A typical single household sits well below that figure, so most domestic boreholes in West Sussex are not licensable. A working farm, a large estate, a commercial nursery, a golf course or a sports ground irrigation scheme can exceed it and should be assessed against the threshold at design stage. Not all abstraction activities need a licence, and the detail changes, so current GOV.UK guidance is the thing to check on each project.

Two further permissions catch people out. Before applying for a groundwater abstraction licence you are likely to need a groundwater investigation consent under section 32 of the Water Resources Act 1991, obtained before drilling. Separately, under the Water Resources Act 1991, any water borehole of 15 metres or more in depth must be notified to the British Geological Survey before drilling begins, with a daily record of the operation kept and the resulting data deposited on completion. The Environment Agency also publishes an Arun and Western Streams abstraction licensing strategy, published on 22 June 2022, which sets out where water is available for further abstraction in this part of the county.

Drinking water quality on a private supply is dealt with by the local authority. In West Sussex that is the district or borough council environmental health team — Chichester, Horsham, Mid Sussex, Crawley, Arun, Adur or Worthing — which carries out risk assessment, sampling and monitoring, working to guidance published by the Drinking Water Inspectorate. Requirements depend on the type of supply and are revised from time to time, so confirm the current position with your council before a new supply is put into use. Much of the county also lies within the South Downs National Park, the High Weald National Landscape or Chichester Harbour National Landscape, so check access and reinstatement with your local planning authority as well.

Borehole drilling by town and postcode in West Sussex

These are the 20 main towns and postcode districts Borehole Service Utilities Ltd covers in West Sussex. 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.

  • Chichester – PO19, PO20
  • Midhurst – GU29
  • Petworth – GU28
  • Fernhurst and Linchmere – GU27
  • Pulborough – RH20
  • Storrington – RH20
  • Billingshurst – RH14
  • Horsham – RH12, RH13
  • Crawley – RH10, RH11
  • East Grinstead – RH19
  • Cuckfield and Balcombe – RH17
  • Haywards Heath – RH16
  • Hurstpierpoint and Hassocks – BN6
  • Henfield – BN5
  • Steyning, Bramber and Upper Beeding – BN44
  • Arundel – BN18
  • Littlehampton, Angmering and Rustington – BN16, BN17
  • Worthing – BN11, BN12, BN13, BN14
  • Bognor Regis – PO21, PO22
  • Selsey and the Witterings – PO20

Borehole Questions from West Sussex Property Owners

Depth depends entirely on which aquifer is being targeted. As an indication only, a Chalk borehole on the South Downs or the coastal plain often falls in the range of 40 to 120 metres, and a Lower Greensand borehole around Midhurst, Petworth or Pulborough often falls between 30 and 90 metres. High Weald boreholes near East Grinstead or Balcombe are usually deeper, because the Hastings Group alternates sand and clay. The real figure is confirmed by test drilling on site, never read off a map.

You need an abstraction licence from the Environment Agency if you abstract more than 20 cubic metres of groundwater a day. Most single households use well under that, so a domestic borehole in West Sussex is usually not licensable. Farms, estates, nurseries, golf courses and sports ground irrigation schemes can exceed the threshold. Where a licence will be needed, you are also likely to need a groundwater investigation consent under section 32 of the Water Resources Act 1991 before drilling starts.

It depends on the aquifer and is only properly known after test pumping. A well-sited domestic borehole in West Sussex will normally supply a house comfortably, with storage smoothing out peak demand. Large published figures are not domestic figures: BGS records maximum borehole yields of up to 100 litres per second in the Chichester and Bognor district, but those are public-supply scale abstractions from the Chalk. In the same district BGS records a maximum of 0.4 litres per second for the Greensands.

Borehole water is usually safe to drink once it has been tested and properly treated, and it should never be assumed safe without a laboratory analysis. Chalk water in West Sussex is naturally hard and otherwise of generally good quality, but the Chalk is fissured, so turbidity and bacteriological spikes after heavy rain are known behaviour. A typical drinking water train combines sediment filtration with ultraviolet disinfection, plus iron removal, pH correction or limescale reduction where the analysis shows they are needed.

Drilling a domestic borehole usually takes a few days on site once the rig is set up, though depth and ground conditions change that. The full programme is longer: desk study and site assessment, drilling, casing and grouting, development and test pumping, laboratory water analysis, then installation and commissioning of the pump, controls, storage and treatment. Allow time for the water sample turnaround and for any consents or notifications that have to be in place before drilling begins.

Yes. Many West Sussex boreholes are drilled on properties that already have a mains connection, usually because the volume needed for irrigation, livestock, a nursery or a commercial process is expensive on a metered supply. The private supply and the mains are kept entirely separate, with no cross-connection between them. Mains drinking water in the county comes from more than one company depending on the address, while Southern Water is the sewerage undertaker throughout the region.

Sometimes, but it cannot be promised. The Weald Clay across the Low Weald, taking in Horsham, Southwater, Billingshurst, Slinfold, Cowfold, Shipley and the Adur valley, is predominantly mudstone. Any usable water comes from thin sandstone and limestone bands within it, such as the Horsham Stone and the Paludina limestones, and those are unpredictable in both position and yield. Some Weald Clay sites will not produce a usable supply at any sensible depth, and that should be said before drilling.

A soakaway borehole is a drilled hole used to dispose of surface water where the ground will not percolate at shallow depth. It passes through the impermeable material, usually clay, and discharges into a permeable layer beneath it. They are used across the Low Weald for houses, farm buildings, yards and hardstanding where a conventional soakaway pit will not empty. A soakaway borehole of 15 metres or more must be notified to the British Geological Survey before drilling.

Yes. A solar-powered down-hole pump runs a borehole with no mains electricity connection, which suits remote farms, field troughs, livestock water, holiday sites and isolated rural houses across West Sussex. The pump fills a storage tank during daylight hours and the tank carries the property overnight and through dull weather. Storage is therefore sized for the worst week rather than the average one, and the pump duty is set by the yield established during test pumping.

Talk to a borehole contractor who knows West Sussex ground

Borehole Service Utilities Ltd drills, equips and maintains water boreholes right across West Sussex, from the Manhood peninsula and the Chichester coastal plain to the High Weald above East Grinstead. Tell us where the site is, what the water is for and roughly how much you need, and you will get a straight answer about what the ground beneath you is likely to do. Call 01428 735013, 07970 573840 or 07517 151270, or email info@boreholeservice.co.uk.