Percolation Testing in Herefordshire

Percolation Tests carries out BRE365 percolation testing and foul infiltration testing across Herefordshire, supporting rural planning applications, self-builds, and agricultural developments.

Ground conditions in Herefordshire

Much of Herefordshire sits on Old Red Sandstone geology, which generally offers reasonable percolation in many areas, though overlying clay and loam soils in the river valleys of the Wye and Lugg can slow drainage considerably. Herefordshire’s predominantly rural character means a very high proportion of properties rely on private drainage — septic tanks and treatment plants — rather than mains sewerage, making foul infiltration testing under Part H a particularly common requirement in the county.

What we test for

• BRE365 percolation testing for surface water soakaway design
• Foul effluent infiltration testing (Part H) — especially relevant given Herefordshire’s high proportion of off-mains drainage
• Drainage strategy support for planning submissions

Coverage across Herefordshire

We test across Hereford, Leominster, Ross-on-Wye, Ledbury, Bromyard, and the surrounding rural county. Testing is available Monday to Friday; rural and agricultural sites where access needs planning are a large part of our work here.

Why get a percolation test

With so much of Herefordshire off the mains drainage network, a properly conducted infiltration or percolation test isn’t just a box-ticking exercise for planning — it directly determines whether your proposed treatment plant or soakaway will actually function long-term.

Planning authorities in Herefordshire

Drainage conditions on Herefordshire planning permissions are set by the district or unitary council, and for larger schemes the Lead Local Flood Authority is consulted on the surface water strategy. Both expect infiltration to be considered first in the SuDS hierarchy and both expect the evidence to be a BRE Digest 365 test carried out on the site, not a figure taken from a map or a neighbour’s result. The authorities we most often write reports for in Herefordshire are:

• Herefordshire Council — the single unitary authority for the county, which also acts as the Lead Local Flood Authority. One planning department and one set of standard drainage conditions, so what is asked for is consistent across the county.

If your decision notice asks for ‘infiltration testing in accordance with BRE 365’, ‘evidence of soakaway feasibility’ or ‘percolation test results to BS 6297’, that is what we produce, laid out so the case officer can find what they need without asking again.

Ground conditions in more detail

The Old Red Sandstone that underlies most of Herefordshire is really a sequence of sandstones and marls, and the marls — the red mudstones — are what most gardens are dug into. They weather to a heavy red clay that drains slowly, which is why so many Herefordshire results come back marginal. The exceptions are the river terraces along the Wye, Lugg, Arrow and Frome, where sands and gravels can drain very well indeed, and the higher ground where the sandstone is closer to the surface. The Woolhope Dome and the western flank of the Malverns bring older, harder rocks with thin soils. A site near Leominster and a site near Ross-on-Wye can be on the same map colour and behave completely differently.

Which test does your site need?

A BRE 365 test sizes a surface water soakaway — roof and driveway run-off — and is what Approved Document H3 and the SuDS hierarchy point to. A BS 6297 test sizes a foul drainage field for a septic tank or package treatment plant under Approved Document H2. They use different pits, different procedures and different calculations.

Herefordshire has one of the highest proportions of off-mains properties in England, and it shows in our order book: foul infiltration testing to BS 6297 is asked for here more often than in any other county we cover. If you are installing or replacing a septic tank or treatment plant, the Environment Agency’s general binding rules require a properly sized drainage field, and that size comes from the BS 6297 test — not from a BRE 365 soakaway result, which measures something different. Where both are needed we do them together.

What our testing in Herefordshire shows

We have carried out more than 90 tests within a dozen miles of the Herefordshire towns listed below since 2018. Of the sites where we recorded an outcome, roughly two in three did not achieve an infiltration rate that would support a conventional soakaway. That is not a reason to skip the test — it is the reason to do it early. A measured rate, even a poor one, is what your engineer needs to size attenuation or justify a different discharge, and it is what the authority will accept. A guessed rate is what gets a scheme sent back.

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

Get a quote

Contact us for a free, no-obligation quote for percolation or infiltration testing anywhere in Herefordshire. Call 01902 475653 or request a quote online.

Towns and areas we cover in Herefordshire

• Hereford — Wye terrace gravels in and around the city, red marl beyond; 31 tests within ten miles
• Leominster — Lugg and Arrow valley alluvium over marl; 17 tests within ten miles
• Ross-on-Wye — sandstone closer to the surface, often better draining; 24 tests within ten miles
• Ledbury — marl and the western edge of the Malvern rocks; 18 tests within ten miles
• Bromyard — higher ground on sandstone and marl; 27 tests within ten miles

Recent work near Herefordshire