Working near underground cables

• No mechanical excavation is allowed within 1 metre of the locate marks for underground distribution power lines. Workers must hand-expose or hydrovac all utilities within this zone. Download PDF on how to safely excavate near an underground power line.​​
• For underground distribution lines only, once the line is exposed, you can use mechanical digging equipment to dig near the line. Always use a spotter to make sure your equipment stays at least 30 cm (1') away from the line.
• The depth of buried utility lines and number of cables will vary. Freezing conditions in the fall and winter followed by the spring melt can impact the grading of soil. As a result, the soil can compact and cause power lines to migrate to shallower ground. Use caution and ensure the hand-dig zone is large enough to expose all cables in your dig area.
• If the dig site requires you to suspend large sections of distribution cable (greater than 2 metres), notify EPCOR's Power Emergencies at 780-412-4500 and they will put you in touch with a Safety Codes Officer. The cable may have to be de-energized or supported to prevent physical damage and ensure your safety.
• Be aware that high voltage equipment (such as a transformer or switching cubicle) has a ground grid around it that may not be marked by locators. Maintain a 2 metre safe zone around this equipment.
• Distribution cables must be covered with a minimum 30 cm of sand prior to backfilling procedures.
• For your safety do not handle or manipulate any underground cable. This may cause the cable to fail which may result in injury or death.

Transmission cables

If your proposed dig zone is within 30 metres of underground transmission lines, the following message should appear on your locate sheet: ""CONFLICT" NO GROUND DISTURBANCE UNTIL CLEARED BY EPCOR TRANSMISSION. ARRANGE FOR SUPERVISION".

• Absolutely no ground disturbance of any kind (hand, mechanical or hydrovac) is to take place within this 5 metres of a transmission cable before your work is cleared by EPCOR Transmission. EPCOR Transmission can be contacted at the phone number listed on your locate sheet.
• For underground transmission cables, contractors shall follow the direction provided by an EPCOR Transmission representative.
• The depth of buried utility lines and number of cables will vary. Freezing conditions in the fall and winter followed by the spring melt can impact the grading of soil. As a result, the soil can compact and cause power lines to migrate to shallower ground. Use caution and ensure the hand-dig zone is large enough to expose all cables in your dig area.
• If your work requires an underground transmission line be exposed more than 5 metres, EPCOR Transmission is to be contacted at the phone number listed on your locate sheet 30 days before the work is to start.
• Transmission cables may only be backfilled under the direct supervision of EPCOR Transmission and EPCOR's applicable standards. If you require specific instruction from EPCOR for backfill requirements, contact EPCOR Transmission at the phone number listed on your locate sheet.
• For your safety do not handle, manipulate or walk on any underground EPCOR Transmission cable. This may cause the cable to fail which may result in injury or death.​

Safe excavation requirements in Alberta

Find more information on the safe excavation requirements in Alberta in these sections of the Alberta Occupational Health and Safety Code, Part 32 Excavating and Tunnelling:

• Disturbing the ground (Section 441)
• Locating buried facilities (Section 447)
• Exposing buried facilities (Section 448)
• Consult the Alberta Electrical and Communication Utility Code for excavation work in the vicinity of underground power lines (Section 2-020).
  

Questions about digging around underground power lines?

Contact EPCOR at 780-412-4500 and ask for a referral to a Safety Codes Officer or fill out our online form for a safety consult or awareness session.