How to Avoid Critical Utility Strikes While Digging
A shovel, fence auger, trenching machine, or mini excavator can turn a simple dig into an emergency in seconds. In Ontario, buried utilities can run through front yards, back lanes, farms, commercial lots, and construction sites. Some are shallow. Some sit where no one expects them. Some were installed decades ago and do not appear on old site drawings.
That is why every excavation should start with a locate request through Ontario One Call before the ground is disturbed. Utility marks are not just a formality. They help prevent injuries, service outages, repair bills, project delays, and environmental damage.
This guide covers the five most critical utility strikes in Ontario while digging, what makes each one dangerous, and what to do if a strike happens.
Gas line strikes can create an immediate fire or explosion risk
Natural gas is one of the most serious utilities to hit because the danger can spread quickly. A small nick, scrape, or puncture may release gas underground or into nearby structures. If gas reaches an ignition source, the result can be a fire or explosion.
Gas lines are common near:
Homes and cottages
Restaurants and commercial kitchens
Industrial buildings
Farm properties with heated outbuildings
Subdivisions with buried service lines
A gas strike may not always look dramatic at first. There may be a hissing sound, a rotten egg smell, blowing dust, bubbling water, or dead vegetation nearby. Sometimes the line coating is only scraped, but that still counts as damage. A damaged coating can lead to corrosion later.
If a gas line is struck:
Stop work immediately.
Move people away from the area.
Do not use phones, radios, vehicles, switches, or anything that could spark near the leak.
Call 911 from a safe distance if there is any sign of escaping gas.
Contact the utility owner and follow their instructions.
Do not try to bend, clamp, patch, or bury the line.
The safest response is to treat every gas contact as serious, even when the pipe still looks intact.
Electrical cable strikes can injure workers without direct contact
Buried electrical infrastructure may carry enough energy to cause severe shock, burns, arc flash, fire, or equipment damage. The risk increases when metal tools, wet soil, or machinery enter the area.
Electrical lines may feed:
Homes and garages
Streetlights
Parking lot lighting
Pumps and septic systems
Commercial signs
Industrial equipment
Temporary construction power
One of the most misunderstood risks is that you do not always need to cut through a cable to create danger. Crushing, scraping, or pulling on a service can damage insulation. An excavator bucket can also energize nearby equipment or the ground around it.
If a machine contacts an electrical cable, the operator should stay in the cab if it is safe to do so and warn others to keep away. People on the ground should not touch the machine. If fire or another immediate danger forces the operator to exit, they should jump clear without touching the machine and ground at the same time, then shuffle or hop away with feet close together.
Before digging near electrical marks, use careful daylighting methods. In many cases, that means hand digging or using approved vacuum excavation to expose the utility before mechanical digging continues.
Water main and water service strikes can cause flooding and soil collapse
A water strike may seem less dangerous than gas or electricity, but large volumes of pressurized water can cause major damage fast. A broken water main can flood trenches, undermine pavement, wash out soil, damage basements, and interrupt service to nearby properties.
Water lines may be found in:
Municipal road allowances
Front yards
Laneways
Industrial sites
Rural properties with private systems
New subdivisions under construction
The biggest hazard is often the ground movement that follows. Saturated soil can lose strength, especially around trenches or excavations. A trench that looked stable before the strike can become unsafe within minutes.
Signs of a water strike include sudden pooling, muddy water, pressure loss inside a building, sinking soil, or water spraying from the excavation.
If a water line is damaged:
Stop excavation.
Keep people out of the trench or low area.
Move equipment away if the ground is softening.
Contact the utility owner or municipality.
Protect nearby drains if sediment or debris may enter the system.
Do not assume the problem is minor because the water looks clean. Even a small service line can cause expensive property damage if it keeps running.
Sewer and storm line strikes can expose crews to contamination and drainage problems
Sewer and storm infrastructure can create health, environmental, and site stability problems when struck. These systems may not be pressurized like water mains, but they carry wastewater, storm runoff, or a mix of both depending on the area and system design.
A damaged sanitary sewer can expose workers to sewage and harmful bacteria. A broken storm line can redirect water where it should not go, including into foundations, road bases, landscaped areas, or neighbouring properties.
Sewer and storm strikes often happen during:
Fence and deck installations
Pool excavation
Landscaping and grading
Driveway work
Foundation repairs
Road and sidewalk construction
Older properties can be especially tricky. Private laterals may not follow a straight path. Additions, old tanks, abandoned services, or previous repairs can make the underground layout harder to predict.
If a sewer or storm line is hit, stop work and keep people away from exposed flow. Avoid entering confined spaces or trenches where gases may collect. Contact the utility owner, municipality, or qualified contractor. If sewage is present, use proper protective equipment and cleanup procedures.
The repair may involve more than patching the pipe. Crews may need to check slope, bedding, joints, and downstream blockages so the system works after the excavation is restored.
Telecommunications and fibre strikes can disrupt homes, businesses, and emergency systems
Telecommunications lines are often smaller than other utilities, but they are not harmless. Cutting a copper, coaxial, or fibre optic line can interrupt internet, phone, security systems, payment terminals, traffic systems, and other connected services.
Fibre lines are especially easy to damage because they may be thin and flexible. They can also serve many customers from one point. A single strike may affect more than the property where the digging happens.
Telecom strikes commonly occur during shallow work because people assume the dig is not deep enough to matter. That assumption is risky. Some lines sit closer to the surface because of grading changes, erosion, landscaping, resurfacing, or older installation practices.
Watch for telecom routes near:
Property lines
Utility poles
Pedestals and cabinets
Driveways
Road crossings
Multi-unit buildings
Commercial plazas
If a telecom line is hit, do not pull on it or coil it out of the way. Fibre strands can be fragile, and broken fibre may present a hazard if handled incorrectly. Stop work, secure the area, and contact the utility owner.
The real cost of a telecom strike is often downtime. For a business, that may mean lost transactions, no phones, no internet, or interrupted monitoring systems.
Use locates as a guide, not a guarantee
Utility marks are essential, but they do not remove the need for careful digging. Marks show the approximate horizontal location of known underground infrastructure. They do not show exact depth. Soil conditions, frost, grading, past construction, and private lines can all affect what crews find.
A safer dig plan includes:
Request locates before work starts
Review the paperwork
Respect the tolerance zone
Look for private utilities
Keep marks visible
Train the crew
Use Ontario One Call and wait for the required responses before digging.
Check which utilities have cleared the site and which have provided marked locates.
Use hand digging or approved soft digging methods near marked utilities.
Lines to pools, lights, sheds, gates, irrigation, and outbuildings may not be covered by public locates.
Protect flags and paint. Refresh or renew locates when needed.
Make sure everyone knows the emergency steps before equipment starts.
Private utilities deserve special attention. A locate request may cover member-owned infrastructure, but it may not identify everything installed privately on the property. That can include electrical feeds to detached garages, gas lines to barbecues or pool heaters, irrigation lines, and drainage systems.
What to do after any utility strike
A utility strike is not the time to guess, hide damage, or keep working. Even a scrape, dent, kink, or coating damage should be reported. Small damage can become a larger failure later.
Use this basic response for any suspected strike:
Stop digging.
Move people to a safe location.
Shut down equipment if it is safe to do so.
Keep the area clear.
Call 911 if there is danger to people, property, or the public.
Contact the utility owner.
Report the damage according to site procedures.
Do not backfill until the utility owner or qualified repair crew gives direction.
Photos, notes, and location details can help with reporting, but safety comes first. Do not re-enter an unsafe excavation to document damage.
The safest dig starts before the shovel hits soil
Most utility strikes are preventable with planning, patience, and respect for buried infrastructure. Gas, electrical, water, sewer, storm, and telecom lines all carry different risks, but the best first step is the same: request locates before digging and follow the marks in the field.
A clean project is not just one that finishes on time. It is one where crews go home safely, neighbours keep their services, and the ground is restored without an emergency along the way.
Comments