Which specification governs this dig
Gas, electricity and water asset owners each publish their own plant-protection specification, and the clause that applies depends on which network you are near.
Contact us →Nine questions, one document behind each answer
A buyer checking a technique against a gas asset, pricing a day of suction excavation, or working out who pays after a strike is not looking for a summary. They need the clause, the paragraph number and the edition date, because that is what goes into a scope of works or gets read out on a call with a contractor who disagrees.
Nine questions like these recur across this kind of work, and each one has its own page here, built the same way. The governing document is named first, with its reference and edition, then the clause or paragraph itself, then what it changes about the decision in front of the reader.
What each page gives you to work with
- The document name, reference and edition date, stated in the same sentence as the fact drawn from it
- The clause or paragraph itself, quoted where the source allows it
- What that clause changes about a scope of works, a price or a site decision
Some of these questions sit under a document that binds the job, such as an asset owner's plant-protection specification. Others sit under guidance that is not compulsory, such as HSE's HSG47, or under an industry code such as CPA's SAVESIG guidance, and the difference between the two matters when a contractor pushes back on a requirement. Each page states which kind of document it is dealing with before it says what that document requires.
Hydro Excavators is an independent UK publisher. It does not sell, hire or operate excavation equipment, so the pages follow the order a buyer or specifier actually needs the answers in, not a service list.
Where most buyers start
Before a scope of works can be written, these are the points a contractor will be held to.
What HSG47 actually says
HSE HSG47 (3rd edition, 2014) is guidance, not law, and its paragraphs sit alongside whichever asset owner specification actually binds the job.
Contact us →What it costs and why
No independent rate book exists for this work, so every published figure needs to be attributed to the company that published it.
Contact us →Which technique suits this ground
Suction, air-lance and water-lance excavation suit different ground conditions and asset types, and the wrong choice risks the asset or the spoil.
Contact us →Where the spoil goes
Excavated arisings carry a waste classification and a disposal route that depend on the asset, the technique and the reinstatement class required.
Contact us →Four more questions before you specify
Liability, operator competence, scope-of-works wording and survey level each turn on a different document, cited with its clause.
Who pays when a service is struck
Liability falls under NRSWA 1991 section 82 and separately under ordinary negligence, with the two duties handled differently on site.
Check the position →What the operator must hold
The competence duty sits in HSWA 1974 section 2. CPCS A78 and NPORS N021 are the cards the industry uses as proxies for it.
Verify the requirement →Writing the scope of works
Clause-level wording for technique, nozzle, operator card level, banksman and spoil route, marked as a starting point for review against the asset owner's specification.
See the wording →Which PAS 128 level applies
PAS 128:2022 sets out quality levels built from the survey method used to reach each one, current since the 2022 edition.
Check the level →What a provenance class tells you before you use a number
A cost figure for this kind of work rarely arrives with its source attached, and that is the difficulty a buyer runs into first: a number is repeated across search results and quotes with nobody saying who counted it or why.
The five classes a figure can fall into
- Rate-book: the figure comes from an independent rate book or a published pricing framework.
- Statutory: the figure is set by legislation or a statutory fee schedule.
- Trade-body: the figure is published by an industry association representing its members.
- Supplier: the figure is published by a company selling the excavation work it describes.
- None: no independent source stands behind the figure, and it cannot be traced to a rate book, a statute or a trade body.
Why the class changes what you do with the number
A supplier figure tells you what one company charges. Pricing a scope of works against it alone means anchoring on a single seller's rate card. A figure with no independent source is not wrong for that reason alone, but it is not usable on its own either: what matters at that point is the drivers behind the price, not the price itself, because there is nothing to check the number against.
Wherever a figure is quoted here, its class travels with it, so a buyer taking a number to a contractor knows straight away whether they are holding a market rate, a statutory fee or one company's asking price.