Dudley is on our doorstep, a short run from our base in Wolverhampton. We carry out BRE365 soakaway percolation testing and BS 6297 foul infiltration testing across Dudley and the surrounding area.
We have tested 13 sites within five miles of Dudley, 47 within ten and 187 within twenty-five, so the ground here is familiar to us. Of the 47 tests within ten miles, 45 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 Dudley
Dudley is built on some of the most worked ground in the country. The Coal Measures here carried the Thick Coal, and the Silurian limestone of the Wren’s Nest and Castle Hill was mined underground, which is why the borough has canal tunnels and limestone caverns beneath it.
For a soakaway that means two things. Natural ground varies quickly between sandstone, mudstone and clay, and a large part of the borough is covered in made ground of unknown depth. Infiltration can look promising in fill and then stop dead at the natural clay beneath. The Council will also want to know that surface water is not being directed towards old workings, so a properly logged BRE365 test is worth having before the design is fixed.
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 Dudley
Planning in Dudley, Stourbridge, Halesowen and Brierley Hill is handled by Dudley Metropolitan Borough Council, which is also the Lead Local Flood Authority. Drainage conditions requiring infiltration testing are routine on new dwellings and extensions that cannot connect to a surface water sewer.
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 Dudley, including Sedgley, Gornal, Coseley, Netherton, Brierley Hill and Kingswinford. 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 Dudley
Each dot is a site we have tested. 47 within ten miles of Dudley, 187 within twenty-five.
Also serving the West Midlands
This page is part of our coverage across the West Midlands, which also includes: