What is soil testing for a septic installation?
Soil testing determines whether your property's ground conditions are suitable for a drainage field — and if so, what size and type of drainage field your septic system will need.
The process involves two tests on your property. The first checks the groundwater level. The second measures how quickly water drains through your soil. Together, the results give a complete picture of what your site can support.
We carry out both tests. Our specialists document their findings and explain what they mean in plain language, so you can move on to the septic design stage with confidence.
How we carry out soil testing
Our technician carries out two tests on your site. The first checks the groundwater level and the second measures how quickly water drains through your soil.
Here's what to expect:
- We dig a trial hole
Using a mini digger, we excavate a hole on your property — typically to a depth of around 1.5 m, or until we reach the groundwater level.This tells us how high the water table sits on your site. We use this to determine whether a drainage field can be installed and at what depth. - We carry out the percolation test
If the trial hole confirms that your site can support a drainage field, we move on to a percolation test.We dig small holes in the proposed drainage area and fill them with water. We leave the holes to drain to ensure your soil is saturated before the test begins. We then refill each hole and measure how long it takes for the water level to drop.This tells us how well your soil absorbs liquid, which determines the size and layout of your drainage field. - We share the results with you
Once both tests are complete, we record our findings and share a full report with you. We explain what the results mean in plain language, so you can move on to the design stage of your project with confidence.
Transparent pricing and expert results
Our percolation test starts from £500, excluding VAT.
The price of a trial hole test depends on your site, so it's best to contact us for a quote.
Compared to the total cost of a septic installation, soil testing is a modest expense. But it's one worth getting right. Inaccurate results lead to an inaccurate design — and that means costly corrections down the line.
When we carry out your soil tests, you get results you can trust. Our technicians have done tests across the UK, covering a wide range of soil types and site conditions.
Soil testing you can rely on
We have been working with off-mains drainage systems across the UK for more than 50 years.
We don't just test soil — we design, manufacture, install, and service the systems that go in the ground. We understand the full picture in a way that other service providers can't.
When you request soil testing with us, you get:
- expertise backed by British Water accreditation
- results that meet the requirements of Approved Document H and the Environment Agency
- clear documentation you can use for your system design and regulatory submissions
- a team who can handle your installation from beginning to end, if you choose
