The standard relating to underground utility detection, verification and location was updated. Called PAS 128: 2022, this British Standards Institution (BSI) moves the 2014 standard forward and changes the way underground utilities should be mapped. With an emphasis on enhanced accuracy, anyone involved in the planning and design of construction and infrastructure projects needs to be aware of the update and what is now required.
PAS 128 is the UK standard for surveying existing utilities and their surface features as well as planning for new infrastructure. It applies across the country, whether that is urban or rural areas, in public places or on private sites.
Clients, architects and contractors have duties under the Health and Safety Executive ‘Avoiding danger from underground services’ guidance known as HSG 47. Clients must make reasonable enquiries about underground services and pass relevant information to the designer and contractor. This is usually based on a PAS 128:2022
QL-D utility record search (desktop search) and potentially a QL-C site reconnaissance survey (visual inspection).
Designers in turn have a duty to reduce or ‘design out’ the risks arising from damage to underground services. Then, contractors must identify potential hazards, assess risk and put safe systems and clear
communication in place for their employees, which also safeguards against damage to essential services. This will be based on the findings of the QL-D and QL-C as well as a PAS 128: 2022 QL-B or QL-A
surveys for the benefit of safety.
Key updates – 2022
The survey process remains very much the same, but with more comprehensive desktop utility record searches leading to on-site visual inspections to geophysical techniques to detect underground utilities through observation, excavation or exposure. In short, data accuracy has become more prominent and there is more
consistency with less room for interpretation.
So, what are the changes? In undertaking the surveys, more detail is now specified on the search method and methodology:
- Incorporation of new technology to include GPR
arrays and their use in reconnaissance route
mapping prior to Type B survey works - Addition of guidance on training and qualifications
of practitioners – every survey practitioner should
be qualified to level 3 or 5 NVQ in underground
utility mapping - Greater emphasis on the importance of GPR post
processing by suitably trained operatives and the
recording of all raw data regardless of the post
processing requirement - Updates to the application of post processing in
detection surveys – M3P/M4P replacing M3/M4 - New guidance on the technical factors that
dictate the effort required for a detection survey
– 2 geophysical methods/full coverage of sites/
recording of all raw data regardless of the post
processing requirement - More effective planning and safer execution of street works, civil works and
ground works. - Providing clarity about the approach to surveys and a consistent approach to data
capture. - Sharing of data in one large data base (NUAR)
National Underground Asset Register has been
encouraged – this is to update or improve
any known utilities in any location where only
statutory, often inaccurate, records are available. - Read the full article here in Trenchless Works
