Percolation Testing in Stourbridge

Stourbridge is within half an hour of our base, and we test regularly across the Stour valley. We carry out BRE365 soakaway percolation testing and BS 6297 foul infiltration testing across Stourbridge and the surrounding area.

We have tested 7 sites within five miles of Stourbridge, 43 within ten and 203 within twenty-five, so the ground here is familiar to us. Of the 43 tests within ten miles, 42 gave a usable result and 1 showed infiltration too poor for a soakaway, which is exactly why a test is needed before the design is fixed.

Ground conditions in Stourbridge

Stourbridge sits where the Coal Measures give way westwards to the red Permian and Triassic sandstones of the Stour valley. The town’s fireclay, once used for glass-making crucibles and refractory bricks, is a reminder that parts of it stand on dense clay, while the river terraces and sandstone to the west can drain freely.

That split is the reason we test rather than assume. A plot on sandstone or river gravel near Wollaston may pass comfortably; a plot on clay a mile east may not take water at all. Where both are possible, we set the pits at the proposed soakaway position so the result applies to the design.

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 Stourbridge

Stourbridge is covered by Dudley Metropolitan Borough Council, which is also the Lead Local Flood Authority. Some sites to the south and west, such as Hagley, fall under Bromsgrove or Wyre Forest instead, so it is worth checking which council issued your permission.

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 Stourbridge, including Wollaston, Amblecote, Pedmore, Norton, Lye, Wordsley and Hagley. 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.

Also serving the West Midlands

This page is part of our coverage across the West Midlands, which also includes:

• Kidderminster
• Bromsgrove
• Dudley
• Halesowen