Hand Me My Pick- I Need To Hand Dig! HAND DIGGING? HOW DO I DO THAT?
We have a complex utility locate system in Ontario with many regulations, standards, guidelines and best practices that employers and workers must follow to ensure they are working safely near buried utility lines. Many of these documents state that you must hand dig within the tolerance zone or hand expose zone without giving clear direction of HOW to hand dig or hand excavate.
The purpose of using hand digging or vacuum excavation techniques is to prevent damage to a buried facility. While vacuum excavation requires a trained operator that knows the regulations and rules to follow when vacuum excavating around each type of buried facility, hand digging can be performed by anyone without knowing or using proper hand digging techniques. You must be aware that hand digging, if done incorrectly, can cause damage to a buried facility.
Each utility owner has their own set of rules on how you should excavate around their buried infrastructure. Even if the regulations and/or best practices state that you must do it a certain way, if a utility owner has a procedure of how to work safer near their buried infrastructure, it must be followed. You must consult with each utility or their published guidelines to determine what their acceptable method of excavation is near their buried facilities. Below is an outline of the most applicable standards and guidelines, and what I believe should consist of a best practice when hand digging around every buried facility.
Recently in August 2016, the Canadian Standards Association released a standard entitled, “Damage Prevention for the Protection of Underground Infrastructure” (CAN/CSA-Z247-15). This standard is typically referred to as “Z247”. In February 2018, the Technical Standards & Safety Authority (TSSA) amended Ontario Regulation 210/01 (Oil and Gas Pipeline Systems) to adopt and require all persons whom O. Reg 210/01 applies to comply with the standards, procedures and other requirements within Z247. It replaced the “Guideline for Excavation in the Vicinity of Utility Lines” that was shared with the Electrical Safety Authority (ESA). In short, you must comply with Z247 when working near buried oil and gas pipeline systems.
Z247 states that hand digging is “any movement of earth using a hand shovel”, and “this does not include using picks, bars, stakes, or other earth-piercing devices”. It also defines the hand expose zone as the “area around the underground infrastructure where ground disturbance by mechanical equipment cannot take place until the underground infrastructure has been exposed by safe ground disturbance practices such as hand digging or vacuum excavation”. Z247 does not provide a hand digging procedure, rather it states you must use a hand shovel and no other earth-piercing devices. Unfortunately, most hand shovels are pointed, potentially “earth-piercing”, which can cause damage to a buried facility if used incorrectly.
When exposing a buried electrical distribution line, the ESA’s “Interim Guideline for Excavating in the Proximity of Underground Distribution Lines” (Version 2.0, Jan 2019) is very clear on initial exposure of a distribution line with test holes and how to excavate after test holes are completed. However, it does not define hand digging either.
There are commonly used practices within the excavation industry when exposing a buried facility and the procedures below can help reduce damages when hand digging a test hole to expose a buried facility.
Hand Digging Test Holes Directly on Top of a Buried Facility
Use a blunt nose shovel.
Hand dig parallel to the line. If you dig across the buried facility, you risk striking it.
The shovel angle should not be greater than 45 degrees. You want the shovel to slide along the buried facility in the event that contact is made.
Do not use any more pressure than your arm strength with the shovel. Foot pressure or stabbing motions with the hand shovel can cause damage to a buried facility.
If you need to remove the remainder of the soil within the hand expose zone once the buried facility is found, check with the utility owner to determine what (if any) is an acceptable mechanical method other than hand digging or vacuum excavation. The ESA Interim Guideline for electrical lines, as well as some other pipeline and telecom guidelines, are very specific when using mechanical equipment in parallel with an exposed facility within the hand expose zone.
Hand Digging to the Side of the Buried Facility
Machine excavate a trench parallel to the buried facility outside the hand expose zone to a depth greater than the presumed depth of the facility. Provided you have clearance from other buried facilities.
From within the trench, provided you follow safe trenching practices, use a blunt nose shovel and dig parallel with the buried facility along the trench sidewall in a prying motion until you reach the buried facility.
Once again, the shovel angle should not be greater than 45 degrees. You want the shovel to slide along the buried facility in the event that contact is made.
Do not use any more pressure than your arm strength with the shovel. Foot pressure or stabbing motions with the hand shovel can cause damage to a buried facility.
As the soil is pried away from the sidewall of the trench, and as the soil piles up in the bottom of the trench, a machine bucket can remove the soil safely from the trench outside the hand expose zone.
After researching this topic for many years, I have not yet come across a published procedure for how to properly hand dig in Canada. If you know of a published procedure, please message me at grant.piraine@ownyoursafety.com. Thanks, and safe digging everyone!