Patrol versus detailed inspection, and when each is required
Updated: Sep 21
GO 165 defines a patrol as a simple visual inspection for obvious structural problems, which may be done in the course of other company business. A detailed inspection requires that each piece of equipment be carefully examined and its condition rated and recorded. Table 1 requires both, on separate clocks. Neither is a vegetation inspection.
A rural joint use pole in Tier 2 of the High Fire-Threat District, carrying a 12 kV primary with a cable attachment three feet below it, is on four inspection clocks that run under two names. The supply conductor gets a patrol every year and a detailed inspection every five.
The communication line on the same pole gets a patrol every two years and a detailed inspection every ten. The words patrol and detailed mean different things in the two orders that set those four numbers, and none of the four inspections is a vegetation inspection. The oak growing toward the span belongs to a fifth clock that neither order contains.
The two definitions differ in four places, not one
General Order 165 defines both types in Section III.A, and the sibling page on the cycles carries the definitions in full. What matters here is where they part company, and it is in four separate places rather than on a single axis of thoroughness.
The standard of care. A patrol is "a simple visual inspection." A detailed inspection is one where individual pieces of equipment and structures are "carefully examined."
The method. A patrol is visual and nothing else. A detailed inspection is visual "and through use of routine diagnostic test, as appropriate," and, where practical and where useful information can be gathered that way, the equipment is opened.
The output. A patrol is "designed to identify obvious structural problems and hazards." A detailed inspection ends with the condition of each piece "rated and recorded." A patrol produces findings, which may be an empty set. A detailed inspection produces a row per asset whether or not anything is wrong with it.
The occasion. GO 165 says a patrol "may be carried out in the course of other company business." That sentence appears in the patrol definition and nowhere else in the order. The detailed definition has no equivalent, and the difference is not decorative.
Take the meter reader's route through a rural grid in Tier 2. That trip can lawfully carry the grid's annual patrol, because the order says so in as many words. The same trip cannot produce the detailed inspection due on the transformer at pole 14, because when it is over there is no rated condition for that transformer anywhere in the record. The test is not how long the inspector looked. It is whether the artifact the inspection was supposed to produce exists.
What each one can actually see
Neither definition names a platform. GO 165 does not say a patrol is done from the ground, from a truck, from a helicopter or from a drone, and it does not say a detailed inspection is done any particular way either. What it constrains is the result.
That leaves the platform question decided by the output requirement rather than by a rule about aircraft. A helicopter pass down a rural circuit can identify a leaning pole, a broken crossarm, a bird nest on a bank of cutouts.
It is a simple visual inspection designed to identify obvious structural problems, and it is a patrol. The same pass cannot open a transformer, cannot take an infrared reading of a connection it never stopped at, and cannot rate the condition of the twelve pieces of equipment on the six poles it flew past in eleven seconds.
The corollary is the part programs get wrong in the other direction. A detailed inspection does not require that everything be opened. The clause is conditional, "if practical and if useful information can be so gathered," and a padmounted switch that the utility's own procedure says is not to be opened in the field is still capable of a compliant detailed inspection. What is not conditional is the rating. There is no version of the definition in which the condition of a piece of equipment goes unrecorded.
A more thorough inspection is not automatically a detailed inspection
This is the failure mode with a price on it, and California has a published number for it.
In 2019 PG&E ran distribution pole inspections under its Wildfire Safety Inspection Program, an effort the Commission's citation describes as intended to perform "a more in-depth safety inspection based on wildfire risk." Under WSIP, PG&E inspected nearly 694,000 distribution structures in Tier 3, Tier 2 and Zone 1 of the High Fire-Threat District. It was, by volume and by intent, more inspection than GO 165 asked for.
It did not satisfy GO 165. The citation names two differences, and both are narrow:
1. PG&E did not require the WSIP inspectors to identify the lowest priority issues (F-tags), such as missing high voltage signs, guy markers, etc. PG&E's F-tags are approximately correlated with safety hazard level 3 under General Order 95, Rule 18(B)(1)(a)(iii) which allows corrective action to take place within 60 months. 2. PG&E did not require contracted qualified electrical workers (QEW) to pass ELEC-1000 GO 165 New Inspector Training course.
A missing high voltage sign is not a wildfire risk, which is exactly why a wildfire-scoped inspection was not looking for one, and exactly why the inspection could not stand in for the general one. PG&E expanded the WSIP criteria in 2020 to cover both gaps and merged the two programs into one enhanced inspection.
By then the 2019 gap existed: an internal review in May 2020 found that 54,755 poles had not received a GO 165 inspection, the 2020 work plan was not updated to catch them, and most were not inspected that year either. Of the 54,755, roughly 50,130 had at least had the 2019 WSIP inspection. The remaining 4,625 had neither.
PG&E filed a voluntary self-identified notification on May 7, 2021. On November 22, 2021 the Safety and Enforcement Division issued Citation D.16-09-055 E.21-11-002 to PG&E, utility number U 39 E, for $2,500,000, signed by SED Director Leslie Palmer. The poles broke down as 49,042 in Tier 2, 5,241 outside the High Fire-Threat District, 471 in Tier 3 and one in Zone 1, and amounted to about 2.3 percent of the poles PG&E detail inspects.
Two things about that citation are worth carrying into any program design. First, the cited provision is GO 165 Section III.B, Standards for Inspection, not Table 1. The violation was framed as a failure to conduct detailed inspections, not as a failure to hit an interval.
Second, the Commission stated the purpose the detailed inspection serves in one line: it "allows the utility to monitor the condition and degradation of its infrastructure ensuring reliable and safe operation." Degradation over time is what a per-asset rating measures and what a list of findings cannot.
The record is where the two types stop looking alike
GO 165 Section III.C sets a single content standard for all inspections. It is the same five elements whether the trip was a patrol or a detailed inspection:
what was inspected
who inspected it
the date
any problems or items requiring corrective action
the scheduled date of that corrective action
A patrol record that carries those five elements is complete. Nothing in III.C asks a patrol for more.
The rating requirement does not come from III.C. It comes from the definition in III.A(4), which is why a program can produce records that pass a Section III.C read and still fail to be detailed inspections. Ten years of retention applies to both types under III.C, and the corrective action itself falls under GO 95 Rule 18A(1)(b), which is a separate record with separate contents.
The practical shape of it, on one pole: the patrol file for pole 14 in 2025 should say the circuit, the inspector, the date, and either nothing found or a finding with a correction date against it. The detailed file for pole 14 in 2027 should say all of that and also carry a condition for the pole, the crossarm, the transformer, the cutouts and the conductor, including the ones that were fine.
If the 2027 file looks like the 2025 file, the 2027 inspection did not happen, whatever the work management system says. Which retention clock each of those files runs on is its own question.
What a patrol can start, and what it cannot finish
A patrol finding and a detailed finding enter the same machinery. GO 95 Rule 18A(2) requires all companies to "establish an auditable maintenance program for their facilities and lines" with a timeline for corrective action, and sorts every Safety Hazard and GO 95 nonconformance into three levels. The level is assigned "at the time of identification by a qualified company representative," and nothing in Rule 18A makes that assignment depend on which type of inspection produced the finding.
Level 1 is an "[i]mmediate safety and/or reliability risk with high probability for significant impact," corrected immediately or temporarily repaired and reclassified down. Level 2 is variable risk, corrected within a period the qualified representative sets, "but not to exceed" four ceilings:
Level 2 nonconformance | Corrected within, not to exceed |
(1) Nonconformances that create a fire risk located in Tier 3 of the High Fire-Threat District | six months |
(2) Nonconformances that create a fire risk located in Tier 2 of the High Fire-Threat District | 12 months |
(3) Nonconformances that compromise worker safety | 12 months |
(4) All other Level 2 nonconformances | 59 months |
Level 3 is "[a]cceptable safety and/or reliability risk," where the company is to "[t]ake action (re-inspect, re-evaluate, or repair) as appropriate."
So a patrol can open a six month fire risk clock on a Tier 3 span. What it cannot do is close the detailed inspection interval on the assets it flew past. The two clocks are unrelated: correcting every finding a patrol generated leaves the Table 1 detailed row exactly where it was.
Rule 18A also lists the circumstances under which correction times may reasonably be extended, and the list is short: third party refusal, customer issue, no access, permits required, and system emergencies such as fires or severe weather. Vegetation work runs into the first and the third of those constantly, and what a refusal actually does to the obligation is not the same question as whether the clock pauses.
One duty attaches to the inspection itself rather than to the finding. Under Rule 18B, a company that discovers a safety hazard on or near another company's facility while inspecting its own must notify that company "no later than 10 business days after the discovery."
Where the owner cannot be determined, the pole owners must be told and must pass it on, "normally not to exceed five business days." All parties preserve that documentation for at least ten years. A patrol triggers that duty as readily as a detailed inspection does, and the ten day clock starts at discovery, not at the end of the patrol cycle.
The same two words, redefined for the attachment below
GO 95 Rule 80.1 sets inspection requirements for communication lines, and it defines both terms again. The patrol definition in Rule 80.1-A(3) tracks the GO 165 one, substituting communications facilities for utility equipment. The detailed definition does not track it at all:
Detailed Inspections. For the purpose of this rule, Detailed Inspection shall be defined as a careful visual inspection of Communication facilities and structures using inspection tools such as binoculars and measuring devices, as appropriate. Detailed inspections may be carried out in the course of other company business.
Three departures from GO 165, all of them consequential. There is no requirement that a condition be rated and recorded, so the deliverable is a careful look rather than an asset register. The named tools are binoculars and measuring devices, so a compliant detailed inspection of a communication attachment can be performed from the ground without touching the pole. And the sentence about other company business, which GO 165 confines to patrols, is attached here to the detailed type as well.
The intervals differ too. Rule 80.1-A(1) caps the intervals for communication lines on joint use poles carrying supply circuits, and on poles within three spans of one, in Tiers 2 and 3 only:
Inspection | Tier 2 | Tier 3 |
Patrol | 2 years | 1 year |
Detailed | 10 years | 5 years |
Set that against the pole in the opening paragraph. In Tier 2 the supply owner owes an annual patrol and a five year detailed inspection on the overhead conductor. The communications owner on the same pole owes a two year patrol and a ten year detailed inspection. Two inspections of the same physical structure, both correctly called detailed, five years apart and to different standards.
Outside Tiers 2 and 3 the communications side has no numeric interval at all. Rule 80.1-A(2) requires each company to "prepare, follow, and modify as necessary, procedures for conducting patrol or detailed inspections for all of its Communication Lines throughout the State." The type, frequency and thoroughness are set, consistent with Rule 31.2, by five listed factors:
fire threat
proximity to overhead power line facilities
terrain
accessibility
location including whether the lines are in the High Fire-Threat District
The same subrule requires that the company's procedures "include a checklist for patrol inspections," a document GO 165 never asks an electric utility for.
The record contents differ by one element in each direction. Rule 80.1-A(4) requires ten year records naming the location, the date of each inspection, the results, the personnel who performed it, the date and description of each corrective action, and the personnel who performed each corrective action.
GO 165 III.C asks for the scheduled date of corrective action and does not ask who performed it. Rule 80.1 asks who performed it and does not ask for a scheduled date. Reconciling the two files on a shared pole is its own exercise.
Neither type is a vegetation inspection
Both GO 165 definitions are written over "equipment and structures," and the order's definition of corrective action in III.A(6) is maintenance, repair or replacement of utility equipment and structures. A tree is none of those things, and the order contains no vegetation interval anywhere.
The route by which that becomes a live problem runs through GO 95 itself. Rule 31.2 states the general inspection duty: "Lines shall be inspected frequently and thoroughly for the purpose of insuring that they are in good condition so as to conform with these rules." Those rules include Rule 35, the vegetation clearance rule.
Rule 31.2-B then disposes of the frequency question in one line: "Supply Lines shall be inspected in compliance with the requirements of General Order 165." A duty to inspect for conformance with the vegetation rule, satisfied by compliance with an order that has no vegetation row in it.
What fills the gap is the utility's own program, and the vocabulary is its own too. PG&E's Utility Procedure TD-7102P-01, Revision 2, effective June 20, 2023, has its vegetation management inspector perform "a Level 1 visual inspection of the vegetation surrounding the facilities." The inspector looks for growth that has encroached or will encroach the minimum distance requirement before the next annual work cycle, and for whole trees or portions of trees that may fall into the line.
If the inspector sees, or suspects, one of the defect conditions the California Power Line Fire Prevention Field Guide lists, the procedure escalates: "THEN PERFORM a Level 2 assessment of that tree."
That is a patrol and a detailed inspection in everything but name, keyed to a trigger rather than to a calendar, and neither of the two names GO 165 defines appears in it. Until 2023 the same document was titled the Vegetation Management Distribution Routine Patrol Procedure, which is where the word patrol went when vegetation programs borrowed it.
The frequency for that work is committed in the wildfire mitigation plan under Public Utilities Code section 8386(d), not in a general order, which is why two utilities can both be current on GO 165 and be running vegetation inspections a year apart. What sets that interval is a separate subject.
On transmission there is no patrol and no detailed
GO 165 Section IV is two sentences long and contains neither term. It requires each utility to write its own transmission inspection and maintenance procedures, to follow them, and to keep records of the work. There is no table, no urban and rural split, and no definition of any inspection type. On a 115 kV line, whether an inspection is a patrol or a detailed inspection is answered by the utility's own procedure, and the enforceable obligation is that the procedure is followed.
Above 200 kV a second regime arrives with its own single inspection type. NERC FAC-003-5 Requirement R6 requires each applicable Transmission Owner and Generator Owner to:
perform a Vegetation Inspection of 100% of its applicable transmission lines (measured in units of choice - circuit, pole line, line miles or kilometers, etc.) at least once per calendar year and with no more than 18 calendar months between inspections on the same ROW.
Vegetation Inspection is a defined term in the NERC Glossary:
The systematic examination of vegetation conditions on a Right-of-Way and those vegetation conditions under the applicable Transmission Owner's or applicable Generator Owner's control that are likely to pose a hazard to the line(s) prior to the next planned maintenance or inspection. This may be combined with a general line inspection.
That last sentence is the FAC-003 analogue of GO 165's "in the course of other company business," and it is deliberate: the standard's supplemental material says the definition was revised to allow maintenance inspections and vegetation inspections to be performed concurrently. Note what the requirement counts.
Not assets and not findings, but percentage of applicable line, in units the owner chooses, against a calendar year and an eighteen month ceiling between passes on the same right of way. Which lines are actually applicable decides whether any of that is live, and the rest of the standard is its own page.
What the record has to name
For any inspection a program claims as compliant, four facts settle which type it was, and all four should be visible without asking the inspector.
Which order the interval came from.
What is being inspected | Where the interval comes from |
Supply equipment | Table 1 of GO 165 |
A communication attachment in Tier 2 or Tier 3 | The Rule 80.1-A(1) table |
Transmission above distribution voltage | The utility's own transmission procedure |
An applicable transmission right of way | FAC-003-5 R6 |
Vegetation | The wildfire mitigation plan |
Five sources, and a record that does not name one of them cannot be audited against anything.
Which definition the work was performed to. GO 165 III.A(3) and (4), Rule 80.1-A(3), or a numbered internal procedure with a revision date on it. The PG&E citation turned on the answer to this question and nothing else.
Whether the artifact the definition demands exists. For a GO 165 detailed inspection that is a rated condition per piece of equipment, including the pieces that were fine. Its absence is the finding, and no volume of adjacent inspection cures it.
What clock each finding started. A Rule 18A level assigned at the time of identification by a qualified company representative, with the correction date it implies, and a Rule 18B notification within ten business days if the hazard sits on somebody else's facility. Those clocks run from a patrol exactly as they run from a detailed inspection, which is the one respect in which the two types are genuinely interchangeable.
Further reading
GO 165 inspection cycles, and the one thing they do not cover: The intervals each type runs on, and the definition of a year that decides whether one is late.
Joint use attachments and who owes what: The second owner on the pole, running a different inspection clock under different definitions.
What a clearance record has to contain: Where an inspection finding goes once it exists, and what the file has to prove.
Frequently asked questions
What is the difference between a patrol inspection and a detailed inspection under GO 165?
Four things. A patrol is a simple visual inspection; a detailed inspection requires that equipment be carefully examined. A patrol uses the eye; a detailed inspection adds routine diagnostic testing as appropriate and opening equipment where practical and useful. A patrol identifies obvious structural problems and hazards; a detailed inspection produces a condition for each piece of equipment, rated and recorded. And GO 165 says a patrol may be carried out in the course of other company business, a sentence it does not attach to the detailed definition.
Can an enhanced wildfire inspection count as a GO 165 detailed inspection?
Only if it does everything the detailed definition requires. In 2019 PG&E inspected nearly 694,000 distribution structures under its Wildfire Safety Inspection Program and treated some of that work as covering its GO 165 obligation. The Commission cited it $2.5 million on November 22, 2021 for 54,755 poles, because the WSIP criteria did not require inspectors to identify the lowest priority issues and did not require the contracted workers to have passed PG&E's GO 165 inspector training course. A broader inspection that drops one category of finding is not a superset of the detailed inspection.
Does a GO 165 patrol satisfy a vegetation inspection requirement?
No. Both GO 165 definitions are written over utility equipment and structures, and the order's definition of corrective action is maintenance, repair or replacement of equipment and structures. The words vegetation, tree, trim and clearance do not appear in General Order 165. GO 95 Rule 31.2 requires that lines be inspected frequently and thoroughly so as to conform with the GO 95 rules, and then routes supply lines to GO 165 for the requirement, so the frequency question lands in an order with no vegetation row in it. The vegetation inspection frequency comes from the utility's wildfire mitigation plan under Public Utilities Code section 8386(d).
Do communication companies use the same patrol and detailed definitions?
The patrol definition in GO 95 Rule 80.1-A(3) matches the GO 165 one with communications substituted for utility equipment. The detailed definition does not match. Rule 80.1 defines a detailed inspection as a careful visual inspection using tools such as binoculars and measuring devices, with no requirement that any condition be rated and recorded, and it says such inspections may be carried out in the course of other company business. The intervals differ too: on a joint use pole in Tier 2 the communications detailed interval is ten years where the supply detailed interval is five.
