Percolation Tests carries out BRE365 soakaway percolation testing and foul infiltration testing across Bridgnorth and the surrounding rural Shropshire area.
We are based in Wolverhampton, roughly 13 miles away, so Bridgnorth is genuinely local work rather than a long trip. We have carried out 97 tests within fifteen miles of Bridgnorth and 210 within twenty-five, so the ground around the town is familiar to us.
Ground conditions in Bridgnorth
Bridgnorth is built on sandstone cliffs above the River Severn, and this sandstone geology generally percolates well across much of the town and surrounding high ground. Low Town, closer to the river, and some of the surrounding rural clay-influenced farmland can behave quite differently, so testing on a site-by-site basis remains important.
In practice that means results around Bridgnorth are rarely uniform. Sandstone can take water well, but where glacial till, boulder clay or made ground sits over it the picture changes within a very short distance — one corner of a plot can drain freely while another barely moves. Ground water matters here too: BRE365 requires the base of a soakaway to stay clear of the water table, and a site can fail on that alone however well the soil itself drains. None of it can be read off a map, which is why the test is asked for.
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
How the test is carried out
BRE Digest 365 sets out the procedure, and it is more demanding than it sounds. A single filling of a single hole proves very little.
- Trial pits are excavated at the proposed soakaway position, taken down below the level the soakaway will sit at. The number depends on the site and the design.
- Each pit is filled to at least 75% of its effective storage depth, which is where the timed measurement starts from.
- Each pit is then filled and timed three times over, measuring the fall from 75% to 25% of the effective depth.
- The slowest of those runs is carried into the calculation, which keeps the resulting design conservative.
The three fills and the draining time between them are why this cannot be rushed. A number produced quickly is a number that tends to get challenged.
Planning conditions in Bridgnorth
Applications in the Bridgnorth area are dealt with by Shropshire 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 Bridgnorth 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 Bridgnorth and the surrounding rural Shropshire villages. Available Monday to Friday.
Get a quote
Contact us for a free, no-obligation quote for percolation or infiltration testing anywhere in Bridgnorth. Call 01902 475653 or request a quote online.
Percolation testing around Bridgnorth
Each dot is a site we have tested. 29 within ten miles of Bridgnorth, 166 within twenty-five.
Also serving Shropshire
This page is part of our coverage across Shropshire, which also includes:
Recent work near Bridgnorth
