Call before
you dig
Call before you dig
Contacting utilities is
the first step in safe excavation
There is more to safe excavation than simply calling before you dig. That's only the first step in safeguarding underground utilities from damage and construction workers from harm.
Use Ontario One Call
As an excavator, you are responsible for determining any utilities located in your work area. Phone Ontario One Call at 1-800-400-2255. The operator will tell you which utilities will be contacted in your work area. But don't stop there.
A little more investigation on your part may save time, money, and aggravation later. It may also save your life. Look for posted signs identifying buried utilities. Look for evidence of unmarked utilities. Maintenance holes, catch basins, pedestals, junction boxes, water and gas meters, valve chambers, conduit affixed to wood poles, test posts, sunken ground -- these may indicate the presence of underground structures.
Allow Time
Most utilities try to provide a locate within two business days of your request. This isn't mandatory and may take longer. For federally regulated pipelines a locate is legally required within three business days. Realistically, two or three business days is the time you should allow for a locate to be scheduled rather than done.
If you don't receive an all-clear locate within a reasonable time -- say, one week -- call the manager of Ontario One Call or the utility directly. Don't start excavating until locates are completed. To start without locates is negligent and almost impossible to defend if something goes wrong.
Locates are available for genuine emergencies. But failing to plan ahead or failing to allow time for utilities to do their job isn't a valid reason for an emergency locate.
Comply with Stake-Out Report
Many utilities have out-sourced their locating service to contractors who mark buried services in the work area with paint, stakes, or flags and then leave. Utilities are identified by an international colour code. Some excavators rely on this code alone; others require direct contact with the utility to confirm locates. The stake-out report given to an excavator should be legible, clearly understood, and signed by both parties. The report may include special instructions such as "Erect a snow fence at this point" or "Hand dig to expose utility." Excavators should comply fully with these instructions.
Excavate with Caution
The surest, safest way to confirm the location of any buried structure is to expose it by hand excavation. This means excavation by shovel alone, not picks or spud bars. New technology now allows for vacuum excavation as well.
Most utilities prohibit mechanical excavation within one metre on either side of painted marks. Some utilities are less specific. Confirm the location of all utilities before bringing in heavy equipment.
Stake-out marks are eventually destroyed by excavation. To protect against possible damage claims, many excavators photograph or videotape the staked-out site before digging.
If the stake-out report requires a utility inspector on site during excavation, make sure the inspector is there before you start digging. Ensure that all of the inspector's instructions are carried out during excavation.
Expect the Unexpected
There's always the possibility that utilities have been staked out inaccurately or not at all. Utility locators are sometimes confused by contradictory signals in urban settings where tramp iron, abandoned services, changes in elevation, parallel fences, and overhead wires may interfere with detection equipment. Information on utility depth is especially unreliable.
Keep an eye out for evidence of previous excavation. Virgin ground is usually harder than disturbed ground. Soft ground may indicate a utility trench, backfill material, and buried services otherwise unmarked.
Trans-Northern Pipelines Inc. in preparing this article.
