Percolation Tests provides BRE365 soakaway percolation testing and foul infiltration testing across Leicester and the surrounding area.
We are based in Wolverhampton, about 42 miles away, and Leicester is well inside the area we cover as standard. We have carried out 23 tests within twenty-five miles of Leicester.
Ground conditions in Leicester
Leicester sits on a mix of Mercia Mudstone clay and river terrace deposits along the River Soar, with drainage performance varying between the low-lying valley floor and the higher, better-draining ground on the city’s outskirts. As with most cities, made ground from historic development is also a common consideration on individual sites.
Mudstone and clay drain slowly, so sites around Leicester more often return marginal or failing rates than free-draining ones. That is not automatically bad news — a measured rate, even a poor one, is what the drainage engineer needs to size the system or to justify a different approach. What causes problems is assuming a rate. River terrace gravels along the valleys can drain far better than the surrounding ground, and the only way to know which you have is to dig and time it.
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 Leicester
Applications in the Leicester area are dealt with by Leicester 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.
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. Plenty of rural sites around Leicester need both, and we can do them 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 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 Leicester city, Oadby, Wigston, Birstall, and the surrounding suburbs. Available Monday to Friday.
Get a quote
Contact us for a free, no-obligation quote for percolation or infiltration testing anywhere in Leicester. Call 01902 475653 or request a quote online.
Nearby areas we cover
Recent work near Leicester
Percolation testing around Leicester
Each dot is a site we have tested. 21 within twenty-five miles of Leicester.