CountyClean Environmental Services Ltd
Based in Eastbourne, East Sussex · Covers London and the South of England Accreditation not yet checkedOwn website
02 · Building Regulations · Part H
Percolation and soakaway tests in London
28 providers offering percolation and soakaway tests in or across London, including national firms. A drainage specialist, groundworks contractor or consultant able to run and write up the test.
Who needs oneAnyone building a new home, outbuilding or extension that cannot connect rainwater or foul drainage to a public sewer
Who can do itA drainage specialist, groundworks contractor or consultant able to run and write up the test
WhenBefore the drainage is designed and before building control signs off the plans
28 drainage and ground testing specialists for London
Featured (paid) listings first, then A–Z · How we check listings
Showing all 28 providers
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Based in or covering London (12)
Create Consulting Engineers
Based in Norwich, Norfolk (also London, Glasgow, Chelmsford, Milton Keynes) · Covers UK-wide (England and Scotland, from five offices) Accreditation verified 12 October 2026Own websiteUK-wide
EMS Geotech
Based in Hereford, Herefordshire · Covers Offices in Hereford, Worcester, London and Cardiff Accreditation not yet checkedOwn website
Geosphere Environmental Ltd
Based in Brightwell, Suffolk · Covers Nationwide; most work in Suffolk, Essex, Norfolk, London, Bedfordshire and Kent Accreditation not yet checkedOwn websiteUK-wide
Jomas Associates
Based in Uxbridge, London · Covers Nationwide; names London, Surrey, Kent and Wales Accreditation not yet checkedOwn websiteUK-wide
Lucion Group
Based in Gateshead, Tyne and Wear · Covers Head office Team Valley, Gateshead; offices in Aberdeen, Preston Brook, Manchester, Hull, Leeds, South Yorkshire, Lincoln, Peterborough, Coventry, Surrey, Stroud, Bristol, London and Northern Ireland Accreditation stated by provider: UKAS-accredited inspection body No. 0263 (asbestos), CIEEM-accredited ecologistsOwn website
Lustre Consulting
Based in Chatham, Kent · Covers Kent, Essex and London Accreditation stated by provider: CHAS, AGS memberOwn website
Nimbus Engineering Consultants
Based in East Calder, West Lothian · Coverage not stated, so check with the provider Accreditation not yet checkedOwn website
PRP UK Ltd
Based in Enderby, Leicester · Covers Across the UK; offices in Leicester, Northampton and London Accreditation not yet checkedOwn websiteUK-wide
Sevenoaks Environmental Consultancy Ltd
Based in Pembury, Kent · Covers South East including London and the Home Counties; nationwide support Accreditation not yet checkedOwn websiteUK-wide
Southwest Environmental Limited
Based in Taunton, Somerset · Covers UK-wide, with offices in Taunton, Exeter, Plymouth, Bristol, London, Manchester and Edinburgh Accreditation not yet checkedOwn websiteUK-wide
Sub Surface Ltd
Based in Preston, Lancashire · Covers Nationwide from offices in Preston, Ossett, Tipton and High Wycombe Accreditation not yet checkedOwn websiteUK-wide
National providers (check they cover your area) (16)
Abbeydale Geoscience Limited
Based in Wakefield, West Yorkshire · Covers Yorkshire and the wider UK Accreditation not yet checkedOwn websiteUK-wide
Below Ground Solutions Ltd
Based in Taunton, Somerset · Covers UK-wide for percolation tests Accreditation not yet checkedOwn websiteUK-wide
Betts Associates (Betts Hydro)
Based in Sealand, Flintshire, Wales · Covers UK-wide Accreditation stated by provider: Not confirmed on siteOwn websiteUK-wide
Castledine Environmental
Based in Leeds, West Yorkshire · Covers Yorkshire and the Humber; also works nationally Accreditation not yet checkedOwn websiteUK-wide
Earth Environmental & Geotechnical
Based in Stockport, Greater Manchester · Covers UK-wide Accreditation stated by provider: Not statedOwn websiteUK-wide
Earth Science Partnership Ltd
Based in Taff's Well, Cardiff · Covers Wales, England, Scotland, Northern Ireland and Ireland Accreditation stated by provider: ISO 9001, ISO 14001Own websiteUK-wide
G&J Geoenvironmental Consultants Ltd
Based in Barrow-upon-Soar, Leicestershire · Covers Throughout the UK from a Midlands base Accreditation not yet checkedOwn websiteUK-wide
Geocon Site Investigations Ltd
Based in Marple, Stockport · Covers Nationwide; Newcastle office covers North East, North Yorkshire, Humberside and Scotland Accreditation stated by provider: RISQS approvedOwn websiteUK-wide
Geoinvestigate
Based in Newcastle upon Tyne, Tyne and Wear · Covers Newcastle, County Durham, Northumberland and across the UK; head office in North Yorkshire Accreditation not yet checkedOwn websiteUK-wide
GeoSmart Information
Based in Shrewsbury, Shropshire · Covers Not explicitly stated; serves planners, architects and developers nationally Accreditation stated by provider: Not confirmed on siteOwn websiteUK-wide
GRM Development Solutions
Based in Burton-on-Trent, Staffordshire · Covers Across the UK Accreditation not yet checkedOwn websiteUK-wide
Ian Farmer Associates (1998) Ltd
Based in Washington, Tyne and Wear · Covers Throughout the UK from hubs in Glasgow, Washington, Warrington, Coventry and Hemel Hempstead Accreditation stated by provider: UKAS, ISO 9001, ISO 14001, ISO 45001, AGS member, Constructionline Gold, CHAS, RISQSOwn websiteUK-wide
JNP Group
Based in Amersham, Buckinghamshire (offices across the UK) · Covers National coverage; offices in Amersham, Belfast, Brighouse, Bristol, Hartlepool, Sheffield and Warwick Accreditation not yet checkedOwn websiteUK-wide
Micro Geotechnical Ltd
Based in Hevingham, Norfolk · Covers Nationwide Accreditation stated by provider: CHAS, Building Trust, SafeContractorOwn websiteUK-wide
Solmek
Based in Stockton-on-Tees, County Durham · Covers Across the UK; offices in Stockton, Chesterfield, Glasgow and Reading Accreditation stated by provider: UKAS (ISO/IEC 17025 laboratory), ISO 9001, ISO 14001, ISO 45001, CHASOwn websiteUK-wide
Unda Consulting
Based in Crawley, West Sussex · Covers Nationwide Accreditation stated by provider: CIWEMOwn websiteUK-wide
Percolation and soakaway tests in other regions
South East (17) East of England (8) South West (12) West Midlands (11) East Midlands (12) Yorkshire and the Humber (10) North West (10) North East (9) Wales (8) Scotland (10) Northern Ireland (7)
Percolation and soakaway tests in London
This page lists drainage and ground testing specialists covering the 32 London boroughs and the City of London. Sign-off under the Building Regulations comes from council building control or a registered building control approver, either of which can ask for this evidence before issuing a completion certificate.
We list 12 firms for percolation and soakaway tests in London. All of them also cover other regions. Another 16 firms say they cover the whole UK.
Of the 12, 3 state an accreditation or membership. We have verified 1 of the 12 listings; the rest are as each firm states. See how we check listings.
Nearby regions for percolation and soakaway tests: South East and East of England. Other reports in London: drainage strategy (SuDS), flood risk assessment, contaminated land report, structural engineer’s report and noise impact assessment.
About percolation and soakaway tests
A percolation test measures how quickly water drains away into the ground on your site. Building control may ask for the result to show that a soakaway for rainwater, or a drainage field for a septic tank or small treatment plant, will work. The two uses are tested and judged differently, so it helps to know which one you need.
Getting signed off in England
In England, your council’s building control team or a registered building control approver checks the work. They issue a completion or final certificate once they have the reports they need, such as the as-built SAP, EPC, air test and any sound or ventilation test results.