Ground Disturbance Level II flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Ground disturbance definition

Any activity that displaces or penetrates the ground, including excavation, trenching, augering, boring, and driving posts, and sometimes grading that alters soil structure.

Pre-job hazard assessment

A documented review before work begins that identifies buried facilities, soil conditions, utilities, traffic, adjacent structures, and environmental sensitivities, and records controls for each hazard.

Spoil pile setback

Spoil and materials must be kept back from the excavation edge, commonly at least 1 m, and never closer than the depth of the excavation, whichever is greater.

Trench protective system threshold

Any trench 1.2 m (4 ft) or deeper requires a protective system such as sloping, shoring, or a trench box before workers enter.

Exit distance rule

Trenches 1.5 m (5 ft) or deeper require a ladder, ramp, or other means of exit within 7.5 m (25 ft) of lateral travel for every worker.

Written ground disturbance plan

A document recording scope, locate status, crossing agreements, energy isolation, emergency response, and supervisory sign-off before ground is broken.

Crossing agreement

A written authorization from a pipeline or utility owner allowing the excavation to cross its right-of-way or corridor, specifying conditions and supervision requirements.

Reassessment triggers

The hazard assessment must be repeated when conditions change, such as a new crew, weather event, water ingress, or a change in depth or method.

One-Call notice period

Locate requests must be submitted before digging, typically 2 to 3 full working days ahead, and the ticket number and expiry date must be recorded.

Tolerance zone

The area within a set distance either side of a marked facility centreline, commonly 1 m, where hand or non-destructive excavation is mandatory.

Locate colour code

Red electric, yellow gas and oil, orange communications, blue potable water, green sewer, purple reclaimed water, and white proposed excavation.

Non-destructive excavation

Hand digging, vacuum excavation, or another approved method used to expose buried facilities within the tolerance zone without mechanical damage.

Locate ticket validity

Locate marks remain valid only for a limited period, often 10 to 30 days, and must be refreshed if the ticket expires or the marks are destroyed.

Locate is not a guarantee

Marks indicate approximate position only; the excavator must confirm depth and location by exposing the facility, and stop if unmarked facilities are found.

Contact or damage response

Stop work, notify the utility operator and the One-Call centre, make the area safe, and do not resume until the facility is repaired and cleared.

Private facility locating

Customer-owned facilities beyond the utility's responsibility may not be covered by the One-Call service, so the excavator must arrange separate locating.

Competent supervisor

A designated person who is trained, experienced, and authorized to supervise ground disturbance and to stop work when conditions become unsafe.

Atmospheric testing

Testing for oxygen deficiency, flammable gas, and toxic gas is required before entry where a hazardous atmosphere may exist, with continuous monitoring where the hazard persists.

Excavation inspection

A competent person inspects the excavation at the start of each shift, after rain or vibration, and after any change in conditions.

Perimeter protection

Barricades, signage, and lighting protect the excavation perimeter, and open excavations must be covered or guarded when left unattended.

Water control

Ditching, pumps, and sumps control water; standing water in a trench increases collapse risk and can hide hazards from view.

Undermining protection

The excavation must not undermine adjacent foundations, roads, or utility supports; spoil and equipment must not be stored over buried utilities.

Ladder placement

Ladders must extend above the excavation edge, be secured, and be spaced so no worker travels more than 7.5 m (25 ft) to reach one.

Soil collapse warning signs

Tension cracks, bulging sides, spalling, water seepage, and settlement of adjacent ground indicate instability and require workers to leave the excavation.

Employer duty

The employer must provide a safe work system, training, supervision, and resources so that the ground disturbance plan can be followed.

Supervisor duty

The supervisor verifies current locates, follows the plan, ensures worker training, and inspects the excavation before and during work.

Worker duty

Workers follow the plan, use required protective equipment, report hazards, and stop work when they believe conditions are unsafe.

Utility operator duty

The utility operator responds to locate requests, marks its facilities, and provides information about its infrastructure when requested.

One-Call centre role

The centre receives and transmits locate requests and maintains the ticket record; it does not perform the physical locating of facilities.

Compliance records

Locate tickets, hazard assessments, inspection logs, training records, and incident reports must be kept for the period required by regulation.

Incident notification

A contact, injury, or release requires notification to the regulator, the utility operator, and emergency services as required by law.

Ground disturbance authorization

A permit or written approval from the landowner, utility, or regulator may be required before work begins; working without it is non-compliant.