Pipeline right-of-way and ground disturbance

Damage by people digging, boring, plowing and driving over pipelines is one of the leading causes of pipeline failures in both countries. The pipe itself may be in excellent condition, well coated and cathodically protected, and still be holed in seconds by an excavator bucket or an auger. Most of these strikes happen on the right-of-way, the strip of land over the pipeline where the operator has the legal right to build, operate and maintain it. HSE-330 introduced ground disturbance on leases: locating buried facilities, the zones around them, hand exposure and hydrovac, and what to do if a line is hit. This lesson looks at the pipeline right-of-way from the operator's side and from the side of anyone working near it: what the right-of-way is, the rules that protect it, how crossings and third-party work are managed, the hazards that pipeline crews face while working on rights-of-way and how a strike becomes an emergency.

What a right-of-way is

Pipeline companies rarely own the land their lines cross. Instead they hold easements or right-of-way agreements with landowners, who keep ownership and most uses of the land, such as farming and grazing, but agree not to build on or disturb the strip over the pipe without the company's permission. Rights-of-way are usually marked where they cross roads, railways, fences and watercourses with signs that name the operator, the product and an emergency telephone number. Markers show the approximate route, not the exact position or depth of the pipe, and several pipelines may share one corridor.

A right-of-way needs to stay clear. Trees and buildings on it block patrols and access for repairs, and roots and foundations can damage coatings and pipe. Encroachments, such as sheds, fences, dugouts, stockpiles or new roads built without permission, are found on patrols and resolved with the landowner. Changes in land use, such as a farm field turning into a subdivision, may also change the pipeline's class location, as Lesson 9 explained.

The legal framework for work near pipelines

In the US, every state has a one-call law that requires anyone excavating to call 811 or submit an online ticket a set number of business days, typically two or three, before digging, so that operators can mark their facilities. Excavators must wait for the marks, respect a tolerance zone on either side of them, commonly 18 to 24 inches depending on the state, and expose the line by hand or vacuum excavation within that zone. PHMSA's damage prevention rules require pipeline operators to run damage prevention programs and allow PHMSA to enforce against excavators in states whose enforcement it has found inadequate. Common Ground Alliance best practices are widely adopted, and its annual DIRT report summarizes damage data. Many operators also have crossing and encroachment standards that require written permission for heavy equipment crossings, new roads and construction near their lines.

Damage statistics show why these rules exist. PHMSA's April 2026 advisory bulletin on excavation damage reported that since 2005, excavation damage to regulated pipelines had caused more than 875 incidents, 40 deaths and 166 serious injuries. For gas distribution systems in 2025 alone, operators reported 85,606 damages from about 35.8 million locate tickets, with excavator practices, notification failures and locating errors as the leading root causes. Canadian one-call centers and the CER publish similar data showing that most strikes involve work done without a locate request or without hand exposure near the marks.

Crossings and third-party work

Pipelines are crossed constantly: by roads, other pipelines, power and communication cables, drainage tile, fences and, most often, by vehicles and farm equipment. Each crossing is a chance for damage, so operators manage them through crossing agreements and procedures. A typical crossing request includes the location, the type of work, the equipment and its weight, the depth of the pipeline and the protection proposed, such as minimum clearances between the pipeline and a new cable, minimum cover over the line, or mats and ramps to spread a heavy load.

Heavy loads crossing a shallow pipeline can overstress it, especially if the soil cover is thin or wet, the pipe is old or thin-walled, or the load passes repeatedly. Operators use engineering methods to check crossings. The program below uses a classic simple estimate, Boussinesq's equation for a point load on the surface, to show how the vertical stress reaching the top of a pipe depends on the wheel load and the depth of cover, and how a crane mat that spreads the load over a larger area helps. It is a teaching calculation; real crossing assessments follow industry methods and the operator's standards.

# Vertical soil stress at the top of a pipe from a wheel load (Boussinesq point load, teaching only).
import math

def stress_psi(load_lb, depth_ft):
    return 3 * load_lb / (2 * math.pi * depth_ft ** 2) / 144   # psi directly under the load

wheel_lb = 20_000.0    # one heavy wheel, invented
for cover in (2, 3, 4, 5):
    print(f"Cover {cover} ft: about {stress_psi(wheel_lb, cover):5.1f} psi at the pipe")

# A mat spreads the wheel load: approximate it as four smaller loads 2 ft apart.
cover = 3.0
spread = sum(3 * (wheel_lb / 4) * cover ** 3 / (2 * math.pi * (cover ** 2 + r ** 2) ** 2.5) / 144
             for r in (1.0, 1.0, 1.0, 1.0))
print(f"With a mat at {cover:.0f} ft cover: about {spread:4.1f} psi (vs {stress_psi(wheel_lb, cover):.1f} psi)")

Cover 2 ft: about  16.6 psi at the pipe
Cover 3 ft: about   7.4 psi at the pipe
Cover 4 ft: about   4.1 psi at the pipe
Cover 5 ft: about   2.7 psi at the pipe
With a mat at 3 ft cover: about  5.7 psi (vs 7.4 psi)

Halving the depth of cover roughly quadruples the stress at the pipe, which is why shallow lines need special care and why operators measure depth of cover before approving heavy crossings. Spreading the load with mats reduces the peak stress noticeably. Cover can also change over time: erosion, plowing, leveling and river scour can leave a pipeline far shallower than it was built, which is one reason operators run depth-of-cover surveys.

Third-party work, such as road building, utility installation, farm drainage or a neighbor's oilfield construction, is supervised by the pipeline operator when it is close to the line. A pipeline company representative may be required on site to confirm the pipe's location, watch excavation within the controlled zone, check that the pipe is exposed by hand or hydrovac where required, and inspect the pipe and coating if they are exposed. The representative has the authority to stop work that threatens the line.

Hazards for pipeline crews on the right-of-way

Pipeline technicians, patrol crews and contractors who work on rights-of-way face hazards of their own, often far from help.

Induced voltage deserves a closer look because it surprises people. A long metal pipeline running beside a high-voltage power line for kilometers can pick up an alternating voltage through electromagnetic induction, high enough in some cases to give a dangerous shock to someone touching a test post, valve or exposed pipe while standing on the ground. Fault currents during a power line failure can raise the voltage much higher for a short time. Operators install AC mitigation, such as grounding cables and gradient control mats, and technicians measure AC voltage before touching pipeline appurtenances in shared corridors. Workers should never assume a buried pipeline is electrically dead.

When a pipeline is struck

A strike on a pipeline can range from a scrape on the coating to a full rupture. HSE-330 described the immediate response to a line strike on a lease. On a pipeline right-of-way the response follows the same principles with some additions.

• If gas or liquid is escaping, stop work, shut down equipment where it is safe to do so without creating sparks, leave the equipment and move upwind and uphill, and keep others away.
• Call the emergency number on the pipeline marker and 911, and give the location, what was hit and what is escaping. Do not try to stop the leak or bury the line.
• If nothing is escaping, stop work and still call the pipeline company. A scrape, dent or gouge that does not leak today can fail later, and the coating damage must be repaired.
• Do not backfill a damaged line. The operator will inspect it, which may mean reducing the line's pressure first.
• Expect the operator to isolate and depressure the line, control the area and notify regulators.

Many jurisdictions treat failure to report a strike as a serious offense, because the hidden damage from an unreported contact is exactly what leads to later ruptures. A strike reported at once can be repaired for the cost of a dig; one hidden under backfill can become a fatal failure years later.

Patrols and what they look for

Operators patrol rights-of-way on a schedule set by regulation and their integrity programs, using ground crews on foot or in vehicles, aircraft and, increasingly, drones and satellite imagery. A patrol is not a sightseeing trip; patrollers look for specific signs that the pipeline or its cover is threatened. These include excavation, construction or survey stakes on or near the right-of-way that nobody has told the operator about; exposed pipe or loss of cover at creek crossings and in cultivated fields; erosion, washouts, slumping, tension cracks and leaning trees on slopes; dead or discolored vegetation, frost patches, bubbling water or stains that may indicate a leak; damaged or missing markers, test posts and fences; and new buildings, dugouts or roads that could change the class location or block access. Each observation is recorded with a location and photographs and passed to the integrity or damage prevention team for follow-up.

Landowners, farmers and nearby residents are often the first to notice a problem, because they are on the land every day. Pipeline companies maintain contact with landowners through land agents and public awareness mailings required under API RP 1162, and they print their emergency and inquiry numbers on every marker. A landowner who calls about a wet spot, a new contractor or a strange smell is part of the damage prevention system, and every such call should be answered and followed up. Landowners and farmers are also excavators under state one-call laws when they dig, install drain tile or build fences, and some states exempt routine farming activities only to limited depths.