By Malcolm Abernethy
Executive Officer, NZ Contractors' Federation
As projects are being prepared for tender and construction, it is timely to consider the importance of site investigations and, in particular, who is responsible for locating services in the road reserve, or that cross any construction site.
There is a trend for tender documents to require the tenderer to determine the existence of services on or about the site and protect them during construction. In city centres there may be a large number of services that need to be worked around, protected or relocated. Tender documents that require contractors to determine the existence of services at the time of tender can be a significant waste of resources.
There are a large number of utility provider asset owners that may need to be contacted by every company tendering the project, for example, telecommunication companies, energy providers in the vicinity of the works (including electricity, gas and petroleum pipe lines) and local authorities who may be supplying water and the extensive networks for the disposal of sanitary and stormwater waste services.
BeforeUdig provides a free service to contractors and engineers, providing plan locations of services on a site. The service reduces time and costs for engineers and planners when determining what services may be on a site. The service notifies asset owners of the proposed construction activity and the company will contact the enquirer as to how they want any excavations to be managed.
Determining the existence of services on a site should form part of the site investigation process as the information provided may determine design outcomes and costs of construction. It is considerably more efficient for the construction industry when the consultant or principal determines the existence of services on a site with the information being used for design purposes. In recognition of this New Zealand Standard Conditions of Contract NZS 3910:2003 in clause 5.13.1 requires:
“The principal shall arrange for the searching of records to determine the existence and position of pipes, cables and other utilities on or about the site, and the position of such utilities shall be indicated in the contract documents as accurately as the information permits.”
Many of the records held by utility owners may be incomplete or of limited accuracy as a result of changes in level of roads, boundary adjustments – particularly when original locating methods were from structures or buildings that have been demolished since the service was first mapped.
Once construction work starts NZS 3910 recognises that there may be inaccuracies and allows for this in clause 5.13.2: “The contractor shall be responsible for physically locating the position of all such utilities and shall arrange with the controlling authorities for any necessary exploratory work, location, protection, isolation, offsetting, reinstatement or alterations required. The contractor shall record any alterations which it makes to such utilities.”
This means the contractor remains responsible for protecting all utilities whether indicated or not and for arranging reinstatement or repair of any damage caused to the utilities (NZS 3910 clause 5.13.3).
The contractor is required to physically locate the utilities indicated by pot holing in the near vicinity of the location provided – generally using hand excavation methods. It is though unreasonable for the contractor to use these methods over large areas of the site.
If a utility is not in the location provided in the contract documents the contractor should request the utility owner to assist in determining its exact location.
When the actual location of a utility is different from the information provided in the contract documents then a variation occurs. NZS 3910 clause 5.13.4 covers this situation:
“Where a utility is not indicated or is not substantially in the position indicated in the contract documents any extra work in physically locating its position or altering or protecting or offsetting or reinstating it shall be a variation.”
I believe it is necessary for the principal and its consultants to identify any services on the site and record their location during the investigation and design phase of a project. The utility owners receive one inquiry rather than all tenderers seeking the same information.
The costs for determining the existence of services are then borne by the principal as part of the investigation and design phase of the project (where the costs should lie).
By requiring contractors to determine the existence of utilities at the time of tender may result in increased construction costs to cover the expense associated with determining what services may exist on the site.
Costs for any work required to locate, protect, isolate, offset, reinstate or alter services need to be included in the schedule of prices as separate items, and the consultant needs to determine these during site investigations, design and preparation of the contract documents.
Contractor Vol.34 No.1 February 2010
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