This GBCA Toolbox Talk was developed in collaboration with the Pennsylvania One Call System. This toolbox talk discusses Safe Digging on Construction Sites and summarizes the responsibilities of contractors doing work involving digging.

GBCA members can use PA One Call for free. Learn more about this GBCA Membership Benefit by clicking below:


Click below to download the Toolbox Talk as a handout (includes Sign-In Sheet).



Safe Digging on Construction Sites

The following toolbox talk, created in a collaboration between GBCA and Pennsylvania 811, summarizes the responsibilities of contractors doing any work that involves digging, such as excavation, trenching, or demolition. Before you dig, contractors need to ensure that they know if and where any utility lines may be buried. The responsibilities of excavators are outlined in PA Act 287, the Underground Utility Line Protection Act (UULPA).


Notify the PA One Call System Before Digging

Verify if, what, and where utility lines are buried underground by calling 811 to notify the One Call System. After notification, facilities will send out locators to mark their utility lines before the start of the project.

The lawful start date of any digging project is three business days through ten business days following notification of the One Call System. This provides locators enough time to mark the utility lines before the start of the project.

A business day is any day except Saturday, Sunday or a legal state holiday prescribed by state statute. Business days begin at 12:00:00am and end at 11:59:59pm.

Notifications that come in on a Saturday, Sunday, or legal state holiday will be processed on the following business day.

The lawful start date starts on the third business day after the processed notification.


Dig Carefully and Safely

See the GBCA Safety Toolbox Talk, “Identify and Mark Utility Lines Before Digging,” for information about utility line marks.

If you must dig within the tolerance zone of a marked line, use prudent techniques such as hand digging to expose the utility line. Contact the facility owner If you are unsure on how to provide
support or mechanical protection for the line.

Remember that most trench accidents happen in trenches 5 feet to 15 feet in depth.

A competent person must evaluate excavations daily. Excavations should be re-evaluated after events such as rain.

Use a Protective System for excavations greater than 5 feet in depth or less when deemed necessary by the competent person. Protective Systems include using,

  • Shoring equipment,
  • Shielding, and/or
  • sloping or benching systems.

Examine protective systems in accordance with manufacturer’s recommendations and remove damaged systems from service.

Consider the following issues when selecting the best protective system to prevent cave-ins:

  • Depth of cut
  • Water content of soil
  • Weather and climate (rain, frost)
  • Other operations in the area (heavy equipment, sources of vibrations)
  • Soil classification


Soil Type Classification

Stable rock: Natural solid mineral matter than can be excavated with vertical sides and remain intact while exposed.

Type A: Cohesive soils including clay, silty clay, sandy clay, clay loam.

Type B: Granular cohesionless soils including angular gravel (similar to crushed rock), silt, silt loam, sandy loam.

Type C: Granular soils including gravel, sand, and loamy sand, submerged soil or soil from which water is freely seeping, submerged rock that is not stable.

If the soil is part of a sloped, layered system where the layers dip into the excavation, then you may need to select a protective system that is not designed strictly for just one soil type.


Responsibility to Report Issues and Violations of the UULPA

Excavators must report any type of damage done to an underground line such as a nick or a scrape to the facility owner. Call 811 to report line damage if you do not have the facility owner’s
contact information.

Call 911 immediately if you are digging and strike a line resulting in the escape of any flammable, toxic or corrosive gas or liquid which endangers life, health, or property. After calling 911, the
excavator should also contact/phone the facility owner, or call 811 if the facility owner’s contact information is unknown.

Report incidents when a person or company, by action or inaction, fails to fulfill their obligations under PA Act 287, as amended by submitting an Alleged Violation Report (AVR) to the Public Utility Commission (PUC) through the One Call System.

The AVR form is available in the enforcement section of the PA One Call website (requires login access).

Excavators and Project Owners have no more than 10 business days to file an AVR of an alleged violation.

Designers and Facility Owners have no more than 30 business days to file an AVR for an alleged violation.


Remember to record the attendees of your toolbox talk!


Access GBCA’s full library of toolbox talks: