Operator Workflow

Patrolling the Line: Right-of-Way Checks and Leak Surveys on Pipelines

A pipeline can fail quietly. Small leaks, fresh digging, and shifting ground do not announce themselves. That is why operators put eyes on their lines on a regular schedule. Patrolling and leak surveys are the two ways those checks happen, and the difference between them matters.

Why operators patrol their lines

The purpose of a patrol is simple: see problems while they are still small. Left alone, a slow leak, a trench dug across the line, or a washout under the pipe can turn into a rupture, a fire, or a spill.

So the patrol hunts for the usual suspects. Leaks and seeps. Encroachment, meaning people building, planting, or storing things on the right of way without permission. Excavation activity near the pipe. Exposed pipe where soil has washed away. And ground movement that has left the pipe unsupported. Catch any of these early and the fix is routine. Miss them and the fix is an emergency.

One thing a patrol cannot do is see inside the pipe. Checking the pipe wall itself is a separate job done with tools that travel through the line, covered in our article on pigging and in-line inspection. A patrol watches the outside of the pipe; pigging watches the inside. Operators need both.

How a patrol is done

Patrols happen on foot, by vehicle, and by air, and sometimes with drones. The method follows the terrain. A river crossing gets walked or flown. A straight run across open ground can be driven.

On the ground, a patroller follows the right of way and checks the ground above the pipe and the markers that show where it runs. From the air, an observer looks down the line corridor for changes: a new road, new equipment, fresh dirt, anything that was not there last time. Drones give a closer look without putting a person into rough country.

Whatever the method, the patroller writes down what they saw. Operators keep a log of every patrol: date, route, conditions, and anything unusual. That log is the proof the work was done.

What a patroller looks for

Fresh digging is the biggest flag, because an excavator bucket is the fastest way to damage a buried line. If a patroller sees a trackhoe working near the right of way, they stop and find out who is digging and whether that crew called the one-call center first. That protection is covered in our article on one-call and line locating.

Odors matter on gas lines. Operators add a smell to gas so a human nose can find leaks, and a patroller who smells gas on the line stops and investigates. Discolored vegetation is another clue, since product leaking underground can yellow or kill the grass above it. So is standing water sitting over the line, which earns a closer look on liquid lines.

Construction and parked vehicles on the right of way are flags too. A bulldozer or a parked truck is often the first sign of work the operator never approved. And leaks or seeps, product actually showing at the surface, are the clearest sign of all. Those get called in immediately.

Patrols versus leak surveys

A patrol uses eyes. A leak survey uses instruments. They are different jobs, and the rules treat them differently.

Many leaks are too small to see or smell from the surface. A leak survey brings in gas detectors and other instruments that sample the air and soil above the line for trace amounts of product. Those instruments find a leak long before it shows up as dead grass or an odor.

Think of it this way. A patrol finds visible problems and early signs of work near the pipe. A leak survey finds the invisible ones, the small escapes that eyes miss. Both feed the same follow-up: the finding goes into the log, gets a ticket, and gets fixed on a schedule.

What the rules require

Federal rules set the baseline. For gas pipelines, the regulations in 49 CFR Part 192 require operators to patrol their transmission lines and to run leak surveys on a schedule. The patrolling rule and the leak survey rule sit side by side in the regulations because the two jobs are meant to work together.

For hazardous liquid pipelines, the rules in Part 195 require line patrol too, at intervals the operator sets based on each line's location and risk. A line through a crowded city is checked more often than one across empty country. The rules do not give everyone one fixed number of days. They tie how often a line is checked to where it runs and what it carries.

Two things matter to anyone supervising this work. First, operators document every patrol and every survey, because regulators expect to see the record, not just the claim. Second, the real work starts when a patrol finds something. Patrol logs, damage reports, and follow-up tickets are exactly the kind of field paperwork tracked in OpsFlo, the ticket, dispatch, timesheet, approvals, and document software built for field crews. A good find is only as good as the ticket that makes sure it gets fixed.

Sources and further reading

• eCFR 192.705: Patrolling (gas pipelines)
• eCFR 192.706: Leak surveys (gas pipelines)
• eCFR 195.412: Line patrol (hazardous liquid pipelines)