An awareness of key standards and specifications affecting the UK ground investigation industry

November 17, 2018

As anybody involved in the UK ground investigation industry knows our day to day works are very heavily influenced by numerous UK and European standards and specifications – and given that the works we undertake are of such importance to the success and prosperity of the country you can see why this is necessary.

Without appropriate ground investigations there is an increased risk of project build cost and time over runs, ineffective design or over engineered solutions, none of which benefit the ultimate clients.

And it is important that the end users of the data that we ultimately produce can rely on its integrity and repeatability, it goes without saying that it’s necessary that all in-situ testing, lab testing etc. is always preformed to the same standards whichever individual or company undertakes it. Without this standard approach it would be impossible for correlation or delivery of large infrastructure projects if all companies undertook works in a different manner. The work done by the Association of Geotechnical & Geoenvironmental Specialists (AGS) has greatly influenced this with their standard AGS Data Format providing a standard way to transfer ground investigation, laboratory testing and monitoring data between the contributing parties of a project which involves geotechnical or geoenvironmental elements.

But if we take a step backwards form this end product compliance and consistency it is the following specifications, regulations and standards that affect the fundamentals of our industry:

UK Specification for ground investigations second edition: 2012 (the Yellow Book), BS5930:2015 Code of Practice for ground investigations, BS EN 1997-2:2007 Eurocode 7 – Geotechnical design – Part 2: Ground investigation and testing, BS EN ISO 22475-1:2006 Geotechnical investigation and testing. Sampling methods and groundwater measurements. Technical principles for execution, BS 22475-2:2011 Geotechnical investigation and testing. Sampling methods and groundwater measurements. Qualification criteria for enterprises and personnel, BS 22475-3:2011 Geotechnical investigation and testing. Sampling methods and groundwater measurements. Conformity assessment of enterprises and personnel by third party, BS EN ISO 14689:2018 Geotechnical investigation and testing. Identification, description and classification of rock. Part 1: Identification and description, CDM 2015 and BS 1377-1:2016 Methods of test for soils for civil engineering purposes – General requirements and sample preparation.

With the later standard first published in 1948 and the 2016 edition being the first update since 1990 some may say we are an industry slow to change alternatively if it isn’t broke don’t fix it may be more appropriate.

There seem to be a few aspects of these standards and specifications that are all to regularly overlooked, for example in the UK GI specification there is a requirement that under clause 3.14.3 Qualification of site operatives (Boring and drilling operatives) that “All boring and drilling operatives, including Lead Drillers and Drillers (Drilling Support operatives), employed on the contract shall hold and NVQ in Land Drilling and hold a valid and current audit card of competence, for example as issued by the British Drilling Association Ltd (BDA) or an equivalent body in a state of the European Union.???

BS 22475-3 requires that the competency of operatives be verified at regular intervals to ensure ongoing competence e.g. the annual BDA Audit.

BS 22475-2 states in Notes 3.2 qualified operator “person who has documented competence to perform specified parts of sampling and/or groundwater measurements in accordance with BS EN ISO 22475-1. NOTE 1 Qualified operators can include Lead Drillers on boring and rotary drills. NOTE 2 Documented competence for Lead Drillers may be membership of a relevant competence-based scheme such as BDA Audit.”

Unfortunately these very similar and intertwined requirements are all too often not enforced. The British Drilling Association website ( has an up to date list of all individual audited drillers – the current number of lead Driller and Drilling Support Operatives with in date certification is around 250 individuals.

One way to draw attention to the qualification of the individual drillers is perhaps rather than listing the drillers’ initials on the log to state the individuals’ registration number in the same way that a laboratory would state its UKAS number on all of its test result sheets. This would very quickly demonstrate compliance with the appropriate standards and allow traceability years down the line when an individual driller may be long forgotten. This would hopefully lead to an uptake in compliance and in the same way that when you have your gas boiler serviced at home you should ask to see the gas safe card, specifiers and clients will ask to see drillers Audit Card – we can but hope.

Of course there are numerous other standards and specifications that effect the works undertaken by the wider UK drilling industry be that geothermal drilling, water well drilling or associated with mineral extraction and all come with their own specific requirements. Even the base depth of a machine excavated trial pit is defined in the UK Specification for ground investigation, its 1.5m2 in case any eagle eyed QS’s want to check they are getting what they have paid for.

It’s important that everyone involved in the drilling industry has access to and understands the requirements of all the relevant standards, specifications and regulations that effect their work and takes time to familiarise themselves with these.

Recently the Federation of Piling Specialists (FPS) has quite rightly highlighted the need for better site investigation associated with pile design. The FPS has established a working group to quantify the quality of the site investigations its members typically receive with a view to producing clear concise guidance on the minimum site investigation information required for effective piling solutions. This promotion complements the recent BDA quality matters campaign, promoting the need for better quality designed and implemented site investigation.

Both drives for improvement within the ground investigation industry do not necessarily mean that most holes being drilled now do not comply with the relevant standards, in terms of how they are formed, in-situ tests undertaken or how the samples are taken.

It does though appear to highlight that perhaps these site investigations are not being designed, specified or supervised appropriately from the outset. As an industry we all have a collective responsibility whenever we encounter this to make our clients aware that proposals are not fit for purpose to avoid not only ineffective, inappropriate over designed solutions but also to improve the image of the site investigation industry at the forefront of the construction sector, providing high quality, appropriate, reliable AGS data.

Author: Mark Toye, Chair BDA Technical and Standards Sub-Committee

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