What the 2022 specification asks a surveyor to do
PAS 128:2022 is the current Publicly Available Specification for underground utility detection, verification and location in the United Kingdom. It organises work into survey types D, C, B and A and then assigns a quality level to each plotted segment so a reader can see how the line was obtained. That is the whole point of commissioning a PAS 128 survey rather than asking someone to “scan the site and mark the tarmac”.
Type D is the desktop utility study: statutory and private records are requested, compared and plotted with their uncertainty left visible. Type C is reconnaissance — covers, markers, scars and street furniture that either support or undermine those records. Type B is detection. Type A is verification by exposure. The CICES explanation of survey types and quality levels is the public companion to that hierarchy and is worth circulating to a project team that has only ever seen a coloured PDF of old plans.
Quality levels are not marketing grades. QL-D means the segment exists because a record said so. QL-C means someone saw supporting surface evidence. QL-B means geophysics produced a horizontal and, where possible, vertical position within a stated confidence. QL-A means the apparatus was exposed and measured. A competent PAS 128 drawing will mix those labels. A drawing that stamps every line QL-B1 without a method statement is a drawing you should query.
Type B detection is EML plus GPR, not a choice between them
PAS 128:2022 is unambiguous: a Type B survey includes electromagnetic locating and ground penetrating radar as a minimum, plus any other method the ground justifies. EML follows live cables and conductive pipes, including those that can be sonde-traced from an access point. GPR images dielectric contrasts — plastic water, many fibre ducts, voids, and abandoned features that no longer carry a signal. Using only a cable-avoidance tool and calling the result a PAS 128 Type B survey is not a compliant reading of the specification.
Methodology types M1 to M4P then set how intensively that pair is applied. Wider grids suit undeveloped land. Tighter grids and processed radar suit suburban boundaries and city-centre blocks. The “P” suffix means GPR data will be post-processed off site, which is often the only way to make sense of a reinforced slab or a cluttered urban section. The CICES client specification guide is written so a client can pick those levers without reprinting the PAS.
Where this work is used in the UK
We describe UK project environments, not invented appointments. The Elizabeth line corridor through central London is a textbook setting: a new railway, station boxes and later over-site development sitting above services that have been diverted more than once. Designers still commission PAS 128 surveys there because statutory records do not show every private connection or abandoned cable. HS2 enabling-works corridors posed the same problem at highway scale — compounds, diversions and protection slabs where an assumed alignment would have been a guess.
Those two settings are why a national practice talks about PAS 128 in the same breath as HSG47. The HSE’s Avoiding danger from underground services still expects planning, location and safe excavation. The specification is how the middle step is written down so a principal contractor in London and a designer in the Midlands can argue about the same quality levels rather than two different PDFs.
Deliverables that survive a progress meeting
A PAS 128 package from this practice is a quality-levelled utility mapping dataset, a method statement, photographs, and a residual-risk note. CAD is issued in the project grid. GIS is issued when someone other than the civils modeller needs the file. Chamber cards record what was visible when a cover was lifted. Trial-hole sketches are added only when Type A is instructed — we do not invent exposures.
Ground markings, where the surface allows them, help the excavator on day one. They are not the record. Paint fades, rain arrives, and a night shift will still need the drawing. If your team only wants spray on the road, say so; we will still keep the PAS 128 model because that is what an incident investigation will ask for.
To place a survey, use the quote form with a boundary, a target quality level, and any drawings you already hold. City notes for London and Manchester describe access and density. The blog post on what PAS 128:2022 changed is the shortest briefing you can send to a colleague who still thinks the 2014 edition is current.
A commissioning checklist that keeps the specification honest
Write the edition on the first line of the brief: PAS 128:2022. Then attach a boundary that a surveyor can price. Then say whether the working area is a live carriageway, a slab, a soft verge or a possession. Those four facts decide methodology type more reliably than a request for “the highest accuracy available in the UK”. Accuracy is a quality level after the work, not a slogan before mobilisation.
State that Type B includes electromagnetic locating and ground penetrating radar. If you want processed radar, name a P methodology rather than hoping the surveyor will guess. State how markings should be left, and state that markings are not the record. State CAD, GIS, or both. State who may lift covers. Leave a sentence that invites residual risk: services expected but not found, owners who did not reply, ground that defeated the antenna.
Insurance conversations belong in a later appointment document, not in invented certificate numbers on a marketing page. We will say what we can do on your ground. We will not list fictitious accreditations to look like a larger firm. If your framework requires named memberships, send the list; we will answer against facts.
Programme the desktop study first. Detection crews that arrive without a plotted Type D spend the opening hours reconstructing a paper trail that could have been finished in the office. On an Elizabeth line corridor plot or an HS2 enabling-works compound that wasted day is also a wasted possession. The specification is designed to prevent that, provided the client lets the sequence run.
Finally, keep HSG47 in the same pack as the PAS. The drawing is the locate-and-identify record. The permit, the competent person and the excavation method are still required on the morning you break ground. A PAS 128 survey that is treated as a licence to scrape is a survey that has been misunderstood.