Avoid disrupting essential services with proper research and planning
This article looks at how to manage underground excavation work without interrupting essential services such as gas, water, sewerage, telecommunications and electricity. Here we discuss the Dial Before You Dig service, how to find buried utilities on site, and how to manage them during your project.
There’s also a list of reference links at the tail end of this article to help you locate specific information and regulations relating to your state.
UNDERGROUND EXCAVATION RISKS
One of the most important elements of pre-demolition planning is the disconnection of all essential services. Any underground excavation large or small has the potential to damage assets located around the work site. This can lead to power, phone, water or gas service interruptions, delays to the project and costly repairs.
High pressure gas mains, live cables, toxic refrigerant lines and other hazards can pose a safety risk to workers on site. These hazards need to be mitigated as much as possible.
In certain situations such as with high voltage underground cables, there is also the sobering possibility of serious injury or death.
Using Dial Before You Dig to obtain information on the whereabouts of live cables and high pressure mains lines significantly minimises these risks by providing information about the work site that is not immediately apparent from above ground.
WHAT IS DIAL BEFORE YOU DIG?
Dial Before You Dig is a national service that aims to reduce damage to Australia’s extensive underground pipe and cable networks. The service is free and assists civil contractors, builders, excavation and demolition workers, landscapers and drainage specialists. It enables you to locate buried services before any excavation or underground work takes place. This enables businesses and contractors to pinpoint and protect services in the excavation area.
Dial Before You Dig helps coordinate information from asset owners and service providers (such as water authorities). This includes information on essential services that may impact underground excavation plans.
Information might include the location and depth of pipes, cables or other associated plant. It can also include plans for any gas, water, sewerage, telecommunications, electricity, chemicals, fuel and refrigerant pipes or lines.
EXCAVATION AND THE LAW
Most state WHS legislation notes that you must seek to find out more information before beginning excavation works.
The model national WHS regulations state that “A person with management or control of the workplace must, before directing or allowing work to commence, take all reasonable steps to obtain current underground essential services information about the areas at the workplace where the excavation work is to be carried out. They must also obtain information about underground essential services in areas adjacent to the site of excavation and have regard for all of the information.”
This means that it is mandatory to locate pipes and cables before starting an excavation project. In short, you must:
- get information about the location and depth of underground cables, pipes and other essential services
- give the information to those carrying out the work
- make the information available for inspection, and
- keep the information until the work is complete, or for at least two years after a notifiable incident.
NOT JUST FOR DEEP EXCAVATIONS
This policy applies to all types of excavation work, including bulk excavations more than 1.5 metres deep, trenches, shafts and tunnels. Additionally, it’s good practice to never assume that pipes and cables run underground in a straight line or at a set depth. Often existing structures or natural features may result in changes to the direction or depth of pipes or cables.
FINDING OUT WHAT’S UNDER YOUR SITE
Dial Before You Dig acts as an agent on behalf of a myriad of utilities and services organisations. These organisations will normally release cable, pipe and network drawings to you on request.
It’s easy to call the 1100 Dial Before You Dig hotline, or to submit an online enquiry. The simple online services asks you to provide some basic project details. You can then mark out your area on the online map, and then view who owns the assets. Generally this will be electricity providers or water authorities, for example.
You can then contact the individual utility agency. The agency will provide as much information as possible to help you locate and avoid essential services pipes and cables. Occasionally the agency’s own representatives may need to get involved and excavation approval given.
It’s worth noting that available information may not always be 100% accurate. Therefore it’s important that excavation methods include an initial in-person examination of the area. With this purpose in mind, you may need to sample the area by exposing a short section of underground services. This is commonly done using water pressure and a vacuum system, known as potholing.
BEST PRACTICE PROJECT MANAGEMENT
Once you’ve got all the necessary plans and drawings, you can get to work on site. You can locate underground essential services using specialised underground locator tools. These include electromagnetic cable locators and ground penetrating radar.
A pipe or cable locator such as the Leica Digicat 550i available from Jaybro can be invaluable in avoiding underground cables and pipes. Used in conjunction with the information from Dial Before You Dig, these are a very handy tool. They assist you in estimating the depth of the underground infrastructure on your construction site.
Pipe or cable locators are of great help, but to establish the exact location of all underground infrastructure, you may need to pothole the area. All electric, gas, water, sewer, steam and other service lines not required in the demolition process should be shut off. You should ensure you cap them or otherwise control them at or outside the building line, before you begin demolition.
Ensure you pothole precisely following the utility owner’s prescribed method. Then, protect the infrastructure by erecting barriers and marking the location of the exposed pipes, cables or wires. This will ensure you keep the services safe until the project is complete.
You should also ensure all workers are aware of the potholed area and that it is clearly fenced off, for example with temporary fencing or a pit guard.
Underground Excavation Essentials
Jaybro can offer advice and assistance in choosing the right tools and products to assist you in performing a successful underground excavation. With a team of specialists with extensive knowledge in underground civil works, drainage and geosynthetics, we’re here to lend a hand if you need a specific product to help you get the job done, fast.
Click on the products below to learn more about these essential tools of the trade. All of these products are conveniently available to order online from Jaybro.
If you’ve identified infrastructure clues such as grates, pits and marker posts on your site, check them closely for marker tapes that indicate buried water mains, electricity mains or sewer mains below ground.
Signs noting any dangers such as ‘Danger – Underground Cables’ offer a clear indication. A danger underground cables sign or ‘Danger – Services Buried Below‘ sign makes it clear that a hazard is present.
PIT LIDS, PIT LIFTERS & LID LIFTERS
You may need to use a lid lifter to access communications pits and isolate cables. Jaybro carries a range of lid lifters for Telstra pits and communications pits.
MAINS MARKER TAPES
Within the pit, mains marker tapes indicate major services such as gas mains, or in shared trenches you might find communications, gas and electricity together, flagged with 3-way mains marker tapes.
Jaybro’s range of non-detectable mains marker tapes includes: Green – Buried Water Main | Blue – Danger Stormwater Main | Red – Danger Firefighting Main | White – Communication Cable Below | Beige – Sewer Main Below | Yellow – Buried Gas Main
Network cables are generally surrounded by a conduit such as fibreglass snake or communication rod.
Our communication rod is available with a heavy duty galvanised dispenser, and is available in different sizes with both detectable and non detectable versions.
PIT GUARDS & MANHOLE GUARDS
DETECTABLE MARKER TAPES
Underground mains are ordinarily marked with detectable marker tapes. These warning tapes are sandwiched around a stainless steel tracer wire and are used to label communications, electricity, gas, water, sewer and stormwater mains. Designed to stretch when caught by an excavators bucket, they are durable and able to withstand underground condition over extremely prolonged periods.
Mains marker tape is typically laid above underground services evenly between the service and the surface, providing a warning to machine operators before any damage to the service is caused. Jaybro’s detectable mains tape is available for all common services including: Orange – Electricity Below | Yellow – Buried Gas Main | Blue – Stormwater Main | White – Communications Cable Buried Below | Beige – Sewer Main
PITS AND RISERS
Jaybro can supply strong plastic moulded pits for P2, P5 and P6 applications, each with a unique side wall design that offers the necessary structural integrity. This enables them to withstand the loads applied by the compaction of the surrounding soil, while still supporting the vertical loads required in general use.
DIAL BEFORE YOU DIG STICKERS
The Dial Before You Dig program is an essential service for underground and civilcontractors. Safety stickers that promote Dial Before You Dig act as a great reminder on site and help create a safer working environment. Applied to heavy plant equipment, first aid kits and vehicles, they encourage workers to be mindful of underground services. Jaybro can supply a 5-pack of vinyl Dial Before You Dig stickers for you to stick on your equipment.
Education and awareness are key and all staff should be familiar with regulations and proper procedures.
Once you have located the pipes and cables that exist under your site, you need to take great care in managing how to proceed. Always refer to your local regulations and authorities for more information on how to control and safety manage existing services at your site.
WHERE CAN I FIND MORE INFORMATION?
AUSTRALIA WIDE – Safe Work Australia Model Code of Practice for Excavation Work
QUEENSLAND – Work Health and Safety Regulation 2011, Section 304
WESTERN AUSTRALIA – Western Australia OH&S Act Section 3.21
SOUTH AUSTRALIA & NORTHERN TERRITORY – Excavation Work Code of Practice, Section 3.5
NEW ZEALAND – Worksafe NZ Excavation Safety Good Practice Guidelines