Percolation Tests provides BRE365 soakaway percolation testing and foul infiltration testing across Stoke-on-Trent, supporting planning applications throughout the Potteries area.
We are based in Wolverhampton, about 29 miles away, and Stoke-on-Trent is well inside the area we cover as standard. We have carried out 18 tests within fifteen miles of Stoke-on-Trent and 68 within twenty-five, so the ground around the town is familiar to us.
Ground conditions in Stoke-on-Trent
Stoke-on-Trent’s ground is heavily influenced by its industrial and mining history, sitting on the North Staffordshire coalfield with substantial made ground, colliery spoil, and marl clay across much of the city. This combination means percolation rates can be unpredictable and highly site-specific, and testing needs to account for potential historic ground disturbance in addition to the natural clay-dominant geology.
The bigger complication around Stoke-on-Trent is made ground. Generations of industry, quarrying and shallow coal working have left fill of very variable depth and composition, and it is a common reason for a soakaway design being questioned at planning. Infiltration through made ground can be quick in one trial pit and negligible in the next, so testing where the soakaway is actually going matters more here than almost anywhere. It is worth testing early: if infiltration is not viable, the whole drainage strategy has to change.
What we test for
- BRE365 percolation testing for surface water soakaway design
- Foul effluent infiltration testing (Part H) for septic tanks and treatment plants
- Drainage strategy support for planning submissions
What a BRE365 test involves
The method comes from BRE Digest 365, and it takes longer than most people expect. It is not one hole and a stopwatch.
- Trial pits are dug where the soakaway is proposed and taken below its intended base. How many depends on the size of the site and what the drainage design needs.
- Each pit is filled to at least 75% of its effective storage depth before timing begins.
- Each pit is then filled and timed three separate times, recording how long the water takes to fall from 75% to 25% of the effective storage depth.
- The slowest result is the one used, so the design is based on the worst case rather than a flattering one.
Because every pit is tested three times and has to drain fully in between, a proper test is not an hour’s work. We would rather tell you a site is unsuitable than hand over a figure that will not stand up at planning.
Planning conditions in Stoke-on-Trent
Applications in the Stoke-on-Trent area are dealt with by Stoke-on-Trent City Council, and drainage conditions are attached routinely — particularly on rural plots, barn conversions and self-builds with no mains surface water connection. The condition normally asks for infiltration testing to BRE365 and a soakaway design based on the result, approved before work starts.
Testing early is worth the trouble. If infiltration turns out not to be viable the drainage strategy has to change, and discovering that after the groundworks are priced is an expensive surprise.
Septic tanks and foul drainage
Surface water and foul drainage are tested differently, and the results are not interchangeable. A drainage field for a septic tank or treatment plant is sized using BS 6297, which Part H of the Building Regulations refers to. If your site near Stoke-on-Trent needs both a soakaway and a drainage field, we can carry out both tests in one visit rather than two.
What you receive
- A full report with the recorded times for every pit and every fill
- The calculated infiltration rate, ready to hand to your engineer or planner
- Trial pit locations and depths
- Photographs of the testing on site
- A clear statement of whether a soakaway is viable, and if not, why not
Coverage
We test across Hanley, Burslem, Tunstall, Longton, Fenton, and the wider Stoke-on-Trent and Newcastle-under-Lyme area. Available Monday to Friday.
Get a quote
Contact us for a free, no-obligation quote for percolation or infiltration testing anywhere in Stoke-on-Trent. Call 01902 475653 or request a quote online.
Nearby areas we cover
Recent work near Stoke-on-Trent
Percolation testing around Stoke-on-Trent
Each dot is a site we have tested. 4 within ten miles of Stoke-on-Trent, 59 within twenty-five.