Betts Associates (Betts Hydro)
Based in Sealand, Flintshire, Wales · Covers UK-wide Accreditation stated by provider: Not confirmed on siteOwn websiteUK-wide
02 · Building Regulations · Part H
Percolation and soakaway tests in Wales
26 providers offering percolation and soakaway tests in or across Wales, including national firms. The rules in Wales differ from England’s, so see the notes below.
The rules in Wales
Wales publishes its own version of Approved Document H. Since 7 January 2019, a new development of more than one dwelling, or with a construction area of 100 m² or more, also needs its surface water drainage approved by the council’s SuDS Approving Body (SAB) before work starts, separately from planning permission.
26 drainage and ground testing specialists for Wales
Featured (paid) listings first, then A–Z · How we check listings
Showing all 26 providers
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Based in or covering Wales (8)
C & L 24hr Emergency Drainage Ltd
Based in Welshpool, Powys · Covers Shropshire and Mid-Wales Accreditation not yet checkedOwn website
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
EMS Geotech
Based in Hereford, Herefordshire · Covers Offices in Hereford, Worcester, London and Cardiff Accreditation not yet checkedOwn website
Jomas Associates
Based in Uxbridge, London · Covers Nationwide; names London, Surrey, Kent and Wales Accreditation not yet checkedOwn websiteUK-wide
Tankology Services Ltd
Based in Newport, Gwent · Covers South Wales, including Cardiff, Swansea, Bridgend, Llanelli, Abergavenny and Brecon Accreditation not yet checkedOwn website
Unda Consulting
Based in Crawley, West Sussex · Covers Nationwide Accreditation stated by provider: CIWEMOwn websiteUK-wide
National providers (check they cover your area) (18)
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
Castledine Environmental
Based in Leeds, West Yorkshire · Covers Yorkshire and the Humber; also works nationally Accreditation not yet checkedOwn websiteUK-wide
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
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
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
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
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
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
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
Percolation and soakaway tests in other regions
London (12) 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) Scotland (10) Northern Ireland (7)
Percolation and soakaway tests in Wales
This page lists drainage and ground testing specialists covering all 22 Welsh local authority areas, with cities such as Cardiff, Swansea, Newport and Wrexham. Wales has its own Building Regulations. Sign-off comes from council building control or a registered building control approver.
We list 8 firms for percolation and soakaway tests in Wales. Of these, 2 work only in this region and 6 also cover other regions. Another 18 firms say they cover the whole UK.
Firms that work only here are based in Newport (1) and Taff's Well (1).
Of the 8, 3 state an accreditation or membership. We have not verified any of them yet, so these are as each firm states. See how we check listings.
Nearby regions for percolation and soakaway tests: South West, West Midlands and North West. Other reports in Wales: drainage strategy (SuDS), flood risk assessment, contaminated land report and structural engineer’s report.
Getting signed off in Wales
Building control in Wales works much like England. Your council or a registered building control approver checks the work and issues a completion or final certificate. Wales has its own Approved Documents, and all new and converted homes must have sprinklers.