In the site investigation industry the biggest risk to the safety of operatives is arguably that of striking buried services, and unlike many theoretical or perceived risks this is real. A JCB of cable percussive drill rarely loses an argument with a buried pipe or cable and the implications of ripping through a gas main and electricity supply together are only too obvious.
Prior to starting an intrusive site investigation, ground investigation crews need to be aware of any buried services underlying the site so that the services are all found to be exactly at the location and depth expected, and exploratory holes can be completed without incident.
Ideally crews should arrive on site with detailed plans of the buried services. The electricity and telecommunications can be readily confirmed with a Cable Avoidance Tool (CAT), and the route of the gas main, sewer and water main can be visually located through pavement scarring and covers. For exploratory holes close to the services, an inspection pit can by hand dug to confirm it is safe to continue.
On many sites, the information provided in respect of buried services before a ground investigation, is limited. Usually, a utilities desk study search often shows the electricity, water and sewerage plans in detail, for the roads surrounding your site. The power loops to on-site street lighting and the installations for telecommunications are seldom shown on such drawings and remain to be discovered.
The CDM regulations clearly set out the duties of designers, particularly in taking “all reasonable steps to provide with his design sufficient information…”. This leads to the question as to whether sufficient attention is being given to acquiring detailed and accurate services information prior to breaking ground. In most developments it would appear that gathering this information is of low priority and reliance is placed on the site crew to CAT scan and dig a 1.2 m deep inspection pit.
Obviously detailed information concerning buried services is going to be required at some stage in the project – it is just when, rather than if the information is to be obtained. A number of commercial providers will obtain all of the services information relatively rapidly and relatively economically. Going back to responsibilities under CDM; is gathering this information in advance of breaking ground, a ‘reasonable step’?
Responsible designers should be advising their clients that detailed current services information should be acquired at the very earliest opportunity. It must be seen as an equally important and “routine” activity, as a topographic survey of a site and will be of benefit to all parties as the design progresses. Crucially, however it significantly contributes to reducing the risk of serious injury to the ground investigation contractor.
How can we help?
An experienced in-house team of land quality specialists help agb Environmental’s clients ensure they can achieve the objectives for ground conditions in a safe way. The team has significant experience of managing various ground investigation projects for developments. To discuss how these projects risks may effect your development project, contact Simon Pike, Principal Consultant, on 01638 663226 or firstname.lastname@example.org.