Underground Utilities

Karen Schiltz - Friday, March 15, 2013

Most Alberta Communities and Industries are serviced by a complex network of underground facilities. Before you dig or excavate, find out what is buried below-through the free Buried Facilities Location Notification Service. Call toll free:1-800-242-3447

When you call to request locates, Alberta One Call will notify members in the area. Those members will then call you and arrange a meeting date and time on your site to mark the locations of the buried facilities.

Alberta One Call will give you the names of the member companies being notified. It is up to you to contact those utilities that are not members of Alberta One Call.

Remember to call at least three full working days before you want to dig.


Ground Disturbances

There are many activities that create a ground disturbance and have the potential for danger:

  • Excavating, Digging and trenching
  • Plowing (Cable, pipe), drilling, tunnelling, auguring and back-filling
  • Driving posts, topsoil stripping, land levelling and quarrying
  • Tree planting, rock picking, grading, blasting and clearing


There’s a Lot To Watch Out For!

When people think of underground facilities, they often think of power lines. But underground facilities include anything below the ground which transports or stores:

  • Water
  • Sewage
  • Electronic, telephonic, and telegraphic communications
  • Cablevision
  • Electric Energy
  • Oil
  • Gas

These may be contained in pipes, sewers, conduits, valves, manholes, cables, fibre optics lines, wires and catch-basins. There’s a lot to watch out for underground.


The Risks

If you hit an underground facility while digging, you could cause:

Injury to yourself and others:

  • Electrocution
  • Explosion
  • High pressure releases

Severe damage:

  • -Isolate entire communities
  • -Disrupt vital communication networks
  • -Render computer based business operations useless

Financial penalties:

  • Legal costs due to prosecution or litigation
  • Fines for violations of provincial legislation

Location Marks

Red- Electrical
Yellow- Gas, oil, petroleum and gaseous materials
Blue- Potable water
Green- Sanitary sewers, storm sewers and drain lines
Orange- Telephone, communications, cable TV, alarm and signals
White- Proposed excavation
Pink- Temporary survey markings
Purple- Reclaimed water, irrigation and slurry lines


Control Zones

Generally, a Control Zone is the one metre on either side of location marks. However, some special cases such as fibre optics and high pressure pipelines require a Control Zone of five metres.

Facilities must be exposed by non-destructive techniques before mechanical equipment is used within the Control Zone. Always use the method of exposure approved by the utility owner. This often means careful hand exposure before mechanical equipment is used within the Control Zone.

Hand exposure is stared at or near the location marks, working outward into the Control Zone until the buried facility is found. However, high voltage energized cables should never be hand exposed.

Make sure you know the Control Zones and hand exposure procedures for the underground facility you are working around.


Digging at Home

Homeowners often need to put in new fence posts, plant a tree, or build a garage pad or retaining wall. Remember: Call Before You Dig!

It’s easy to forget that just doing some work around the yard can be extremely dangerous. But it’s just as important to be careful at home as it is at work. In fact there are some special problems when digging at home:

  • Although utility lines are supposed to be buried at approved depths, conditions can change. Some shallow utilities may be less than 300mm (12 inches) below ground surface in residential areas.
  • There may be secondary services (such as electrical, telephone or gas lines) located between your house and garage.
  • Utility Rights of Way (URW) are becoming very common in urban areas. They are usually located across the front of residential properties. Your use of land within a URW is restricted.
  • You own the sewer and water services on your property. Municipalities will not locate these facilities (and they won’t pay for damage either)

For Further information, refer to current Occupational Health & Safety Legislation.

Information from The Alberta Construction Safety Association’s Brochure on Underground Utilities

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