Accident Prevention Begins Before Excavation

In the past decade, many positive steps have been taken to reduce accidental damage to underground utilities, yet construction crews still hit buried pipe and cable on a regular basis, causing service outages, work delays and sometimes serious injuries and death.

Following any utility hit is the question: Who was at fault?

If significant damages result and workers or others are injured, costly litigation is sure to follow, and when injuries are involved, OSHA will investigate and can levy fines where safety procedures were not followed. Legal fees and judgments against those found at fault can be hundreds of thousands of dollars and in some instances can force a contracting company out of business.

Accidents never are expected. But when a utility hit occurs, it is essential that the project foreman and personnel on site know exactly what to do and gather and document details for use in the investigation that will follow, says Ron Peterson, president, Utility Consulting Professionals Inc. Peterson has 17-years of industry locating experience, eight with a utility claims department, two as an insurance adjustor and seven years as a utility contractor. He is a member of the Common Ground Alliance and National Utility Contractors Locating Association and has been an expert witness in numerous utility damage lawsuits.

Accident prevention begins long before excavation starts, and Peterson says best practices steps taken during planning should be carefully documented and can play an important role in protecting the contractor from future claims.

This article is the first of a two-part series and covers pre-excavation documentation. The second will discuss investigation procedures to take immediately after an accident. In both reports, excavation means any activity that displaces the soil: excavation, trenching, directional drilling or vertical drilling. Facilities encompass any type of buried utility: pipe, cable, duct or conduit for water, sewer, natural gas, electrical power and communications.

A key to preventing utility hits is accurately locating and marking existing underground facilities, and the nation’s One-Call system is the starting point for arranging utility locates on a job site.

“Know the state’s One-Call law that applies to the area where the job is,” says Peterson. “Provide accurate marking instructions. Be as specific as possible, and make sure instructions are clear. If locating instructions are complex, conduct a meeting at the site where maps are provided. Walk the project with locating personnel. Obtain signatures of those involved. Do not over notify — request locates on an area much larger than the work site, causing the locator to mark more than what is necessary. If project details change, notify all involved, and if weather or other factors cause work to be rescheduled, recall the locate request and reschedule.”

Some states require the locator to provide a sketch of the locate to verify accuracy which many mean several sketches are needed, one for each facility.

“The excavator should make a simple drawing of the area that shows locations of buried facilities, using a map as the basis for the sketch,” Peterson says. “Take pictures, take videos. Document any discussions with locator personnel who may be representatives of the One-Call member or contractor locators hired by the utility provider. Note any questions about locates and answers provided by the locator.”

Many wireless smart phones carried by construction management and project supervisors have the capability to take photos, video and make audio recordings. When making a video, the device user or another person can explain images being captured. Satellite photos of the site also may be useful. This information should be transferred to an on-site computer, tablet or office computer to preserve the information and then stored by project number or in project files.

These records can be invaluable later if a dispute arises over responsibility for improperly located and marked facilities.

Before an underground utility installation begins, on-site personnel should be aware of tolerances required for depths of new installations and distances they should be away from existing facilities. Local codes and ordinances may be applicable.


“Locations of most utilities are measured from the outer edge,” says Peterson. “Required distances from existing facilities may be 18-inches, 24-inches or more. Questions to be answered include are tolerance zones regional or utility specific? Locations of most utilities are measured from the outer edge, assuming the width is represented accurately by marks or the size of utility is provided. Single painted lines should represent the center of the facility.

Many projects today involve potholing to visibly confirm the exact locations of buried facilities, sometimes required by the project owner or often because the excavator wants to confirm the exact location of buried pipe or cable where a crossing is to be made.

A locate is considered accurate at the point of a pothole, therefore keeping records of each pothole can be critical in the event of a disputed facility location.

Peterson recommends taking dated photos of each pothole, along with the information that identifies the utility, its depth at top and base, size, type, benchmark, distance from facility to benchmark and surface type. A simple form can be used to collect this information which should be signed and dated by a contractor representative. The form should include space for remarks pertaining to the potholed location.

Accurate locating and marking buried facilities and properly conducting a project reduces the risk of striking an underground utility. Efforts of the Common Ground Alliance and other organizations have initiated realistic programs to reduce underground facility accidents, and these measures are producing positive results.

Yet, utility hits still occur. The second part of this series covers how to investigate a utility strike.

Common Ground Alliance, (703) 836 1709,
National Utility Locating Contractors Association, (888) 685-2246,

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