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Ashentree excavator digging a drainage trench on a rural site
Berkshire · Hampshire · Oxfordshire · Wiltshire

Off-mains drainage, done properly from the ground up.

Percolation tests, drainage design and treatment plant installation for rural homes. One accountable person from the first test hole to the final sign-off.

How off-mains drainage works

Without a mains sewer, your wastewater has to be treated and returned to the ground on your own land. Every part of the system has to suit your soil.

Cross-section of a rural drainage system: wastewater flows from the house through an inspection chamber to a treatment plant, then into a drainage field where the cleaned water soaks safely into the ground.
  1. 1Wastewater drains and inspection chambers
  2. 2Sewage treatment plants and cleansing solutions
  3. 3Drainage fields and soakaways
  4. 4Ground investigations and percolation tests

What we do

Whether you're selling, buying, building or dealing with a system that's failed, we find out what the ground will take and give you a solution that meets the rules.

Tape measure dropped into a percolation trial hole beside the excavator bucket

Percolation testing and drainage design

Tests carried out to Building Regulations Part H, with a drainage field or soakaway designed and sized for your site. Ideal when planning or building control asks for results.

  • Trial holes and percolation tests
  • Drainage field and mound design
  • Foul drainage strategies for planning applications
Sewage treatment plant set level in its excavation, ready for backfilling

Treatment plant installation

We supply and install sewage treatment plants and drainage fields with our own plant, remove the old system and handle the building regulations sign-off.

Systems we install
  • Marsh
  • Kingspan Klargester
  • Graf
  • Tricel
  • WPL
  • Conder
  • Harlequin
Fenced, signed and managed excavation site with a tracked excavator

Compliance for property sales

If your septic tank discharges to a ditch or stream, it must be replaced or upgraded. We assess what you have and give buyers, sellers and lenders a clear, costed answer.

If an upgrade is needed, we install it and handle the building regulations sign-off, so you have the completion certificate solicitors ask for.

How it works

  1. 1

    Test the ground

    A site visit, trial holes and percolation tests to understand existing site characteristics and constraints.

  2. 2

    Design and approvals

    We design the system, submit the building regulations application and check it meets the Environment Agency rules.

  3. 3

    Install

    Our own diggers and crew fit the plant and drainage field, typically in a few days, and reinstate the ground.

  4. 4

    Keep it running

    We can arrange annual servicing and emptying through trusted local partners, so your system stays compliant and trouble-free.

Freshly excavated drainage field trench cut through topsoil into clay
Drainage field trench excavated and levelled, ready for gravel and distribution pipe.

Why choose us

We take care of the whole job professionally, from the first test to the final sign-off, and we keep you informed at every stage. You get clear advice, a fixed price and a system built to last.

Oak tree in a buttercup meadow in the Berkshire countryside
Honest, independent advice
We tell you whether your system really needs replacing, and explain your options in plain English.
Clear, transparent prices
Percolation tests are fixed-fee. Installations are fixed-price once we've tested the ground, with a written quote before any work starts.
One point of contact
Testing, design, approvals and installation handled by one team that answers the phone, with servicing arranged for you.
Care for your property
Tidy sites, reinstated ground and particular care on listed buildings and sensitive landscapes.

Where we work

Newbury, the Kennet Valley and the North Wessex Downs, across West Berkshire, north Hampshire, south Oxfordshire and east Wiltshire.

Just outside the shaded area? Call us and we'll let you know if we can help.

Common questions

Do I have to replace my septic tank before I sell?

If your septic tank discharges directly to a ditch, stream or other watercourse, it doesn't meet the General Binding Rules and must be upgraded or replaced. Buyer and seller should agree who does this as part of the sale, and lenders may refuse a mortgage until it's resolved. We can tell you where you stand and what the fix would cost.

What is a percolation test?

It measures how quickly your soil absorbs water. The result tells us whether a drainage field will work on your site and how large it needs to be. Building control, and increasingly planning officers, ask for it before approving a new system.

What if my ground doesn't pass?

Heavy clay or a high water table doesn't mean you're stuck. Options include a raised mound, a different location on the site, or a treatment plant discharging elsewhere with the right permit. We'll set out what's possible.

How long does an installation take?

Most domestic installations take a few days on site once approvals are in place. Very wet weather can delay work on clay ground, and we'll plan around it.

Get a quote

Tell us about your property and what you need. We'll reply within one working day, or call us on 020 7060 0602.

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