Excavation Safety: Preventing Utility Strikes
The Problem
Excavation work presents serious risks—striking underground utilities is one of the most dangerous. Hitting gas, electrical, water, or telecommunications lines can result in injury, death, environmental harm, or major service disruptions. Today, we’ll identify these hazards and outline practical solutions to prevent utility strikes and keep everyone on site safe.
Identify the Hazards
- Striking Buried Utilities: Making contact with live services can cause electric shock, gas leaks, flooding, or data loss.
- Tolerance Zone Damage: Excavating too close to marked services can rupture or damage underground assets.
- Collapsing Exposed Utilities: Once uncovered, unsupported utility lines can sag or collapse under their own weight.
- Heavy Machinery Damage: Using mechanical diggers near utilities without proper clearance increases the risk of damage.
- Unreported Utility Damage: Even minor damage (e.g. scratched insulation) can become a serious safety risk if left unreported.
- Backfilling Risks: Improper backfilling can crush or stress exposed utilities, causing failure.
Safety Practices and Preventative Measures
1. Pre-Digging: Mark All Utilities
Solution: Always request utility location services before excavation begins. In New Zealand, contact BeforeUdig at www.beforeudig.co.nz.
- Allow at least 2-3 working days for utilities to be located and marked.
- Colour-coded markers (flags, spray paint, pegs) identify different services.
- Do not begin digging until you’ve verified all markings on site.
2. Tolerance Zones and Hand Digging
Solution: When working within 0.5 metres either side of a marked utility, use hand digging or vacuum excavation to avoid striking the service.
- Always follow BeforeUdig guidelines and consult the Competent Person for site-specific tolerances.
- Never assume the depth or position of a buried service—expose it carefully before proceeding.
3. Supporting Exposed Utility Lines
Solution: Use timber or non-conductive supports to prevent sagging or damage to exposed utilities.
- Support the utility line with suitable materials and tie it securely without creating strain.
- Confirm all support methods with the Competent Person before continuing work.
4. Caution When Digging Near Utilities
Solution: Reduce risk by slowing down and taking extra care when working near marked services.
- Avoid sudden or forceful digging.
- Lower mechanical equipment settings when working near or around known utilities.
5. Reporting Utility Damage
Solution: All utility strikes or suspected damage must be reported immediately—even if it seems minor.
- Notify the Supervisor or Competent Person.
- Stop work and evacuate the area if the damage involves gas or electricity.
6. Caution When Backfilling
Solution: Protect exposed utilities during backfilling:
- First, place firm soil beneath the utility for full support.
- Then, backfill over the line gently and in layers, compacting carefully.
Real-Life Case or Scenario
A crew failed to log a BeforeUdig request before starting excavation. Within minutes, the bucket of an excavator punctured a gas main, leading to an emergency evacuation. Authorities shut the site down for several days, and the repair costs were substantial. This incident could have been prevented with a single phone call and proper planning.
Employee Responsibilities
- Always request utility locates through BeforeUdig before beginning excavation.
- Use hand digging or non-destructive methods within tolerance zones.
- Immediately report any signs of damage—don’t assume it’s minor.
- Take care during backfilling and when working near marked lines.
Employer Responsibilities
- Provide training on safe excavation practices and utility strike prevention.
- Ensure all utility locations are completed and marked before work begins.
- Provide guidance on safe working distances and tolerance zones.
- Assign a Competent Person to manage utility risk and approve work near live services.
Discussion & Questions
- “Has anyone here had a near-miss or strike with a buried utility? What happened?”
- “What do you find most challenging about working near underground services?”
Encourage everyone to share experiences and raise concerns—they help the whole team learn.
Commitment/Action Plan
Let’s commit to always checking for buried utilities before digging. From today on, we’ll ensure every excavation job begins with a BeforeUdig request, and we’ll work with care around any marked services. If something doesn’t feel right—stop and report it.
Wrap-Up
Striking underground services is entirely preventable. By making smart choices—planning ahead, digging safely, and reporting issues early—we can prevent injuries, delays, and service outages. Let’s make safe digging standard practice on every site. Thanks for putting safety first.
Standards Overview
Under the Health and Safety at Work Act 2015 (HSWA) and WorkSafe NZ guidelines:
- PCBUs must identify and manage risks associated with excavation and buried services.
- All underground utilities must be located and marked before work begins.
- Safe digging techniques, such as hand digging or vacuum excavation, must be used near identified services.
- Utility strike incidents must be reported immediately and investigated.
Disclaimer
These toolbox talks are provided for informational and educational purposes only and are not a substitute for professional legal, health and safety, or regulatory advice.
The content reflects recognised best practices and general industry standards as at the date of publication. However, it may not be applicable to all workplace environments or specific operational contexts.
It is the responsibility of the Person Conducting a Business or Undertaking (PCBU), as well as officers, workers, and other duty holders under the Health and Safety at Work Act 2015 (HSWA), to ensure compliance with all relevant laws, regulations, and WorkSafe New Zealand guidance.
The authors, presenters, and distributors of this toolbox talk disclaim all liability for any loss, damage, or injury arising from the use or reliance on the information provided. Users should seek advice from a suitably qualified health and safety professional or legal advisor for guidance tailored to their specific circumstances.
Always follow your organisation’s policies, procedures, and safe work practices to manage risks and maintain a safe and healthy workplace.
All Rights Reserved Site App Pro 2025