Walsall is fifteen minutes from our base in Penn, so it is some of the most local work we do. We carry out BRE365 soakaway percolation testing and BS 6297 foul infiltration testing across Walsall and the surrounding area.
We have tested 13 sites within five miles of Walsall, 53 within ten and 179 within twenty-five, so the ground here is familiar to us. Of the 53 tests within ten miles, 51 gave a usable result and 2 showed infiltration too poor for a soakaway, which is exactly why a test is needed before the design is fixed.
Ground conditions in Walsall
Walsall sits on the eastern edge of the South Staffordshire coalfield, where Coal Measures mudstones and sandstones meet the Silurian limestone that was quarried and mined around the town for centuries. The lakes in the Arboretum are flooded limestone workings, and there are old limestone mines under parts of the borough.
That history matters for a soakaway. Where the ground is clay-rich mudstone or boulder clay, infiltration can be slow. Where there is made ground over old workings, it can be fast in one pit and negligible in the next, and the Council will want to see that a soakaway is not discharging into or near old mine voids. Testing where the soakaway will actually go is the only reliable answer.
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 (SuDS) support for planning applications
How the test is carried out
BRE Digest 365 sets out the procedure. A single filling of a single hole proves very little.
- Trial pits are dug at the proposed soakaway position, taken below the level the soakaway will sit at.
- Each pit is filled to at least 75% of its effective depth, where the timed measurement starts.
- Each pit is filled and timed three times, measuring the fall from 75% to 25% of the effective depth.
- The slowest run is used in the calculation, which keeps the design conservative.
Planning conditions in Walsall
Applications are decided by Walsall Council, which is also the Lead Local Flood Authority for the borough. Drainage conditions asking for BRE365 testing and a soakaway design are common on extensions, infill plots and small developments, particularly where there is no surface water sewer to connect to.
Testing early is worth it. If infiltration is not viable the drainage strategy has to change, and finding that out after the groundworks are priced is an expensive surprise.
Foul drainage and septic tanks
If the site is not on mains foul drainage, that is a separate test. Drainage fields for septic tanks and package treatment plants are sized by the method in BS 6297, referenced by Part H of the Building Regulations, and that figure is not interchangeable with a BRE365 result. We can carry out both on the same visit.
What you receive
- A full report with the recorded times for every pit and every fill
- The calculated infiltration rate, ready for 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 cover the whole of Walsall, including Aldridge, Bloxwich, Brownhills, Darlaston, Willenhall, Pelsall and Streetly. Available Monday to Friday.
Get a quote
For a free, no-obligation quote, call 01902 475653, send an enquiry, or if you know where the pits need to go, use our detailed quote request.
Percolation testing around Walsall
Each dot is a site we have tested. 53 within ten miles of Walsall, 179 within twenty-five.
Also serving the West Midlands
This page is part of our coverage across the West Midlands, which also includes: