GO 165 inspection cycles, and the one thing they do not cover
Updated: Sep 21
GO 165 caps distribution inspection intervals: patrols yearly in urban areas and every two years in rural areas, raised to yearly on overhead equipment in High Fire-Threat District Tiers 2 and 3; detailed inspections every five years overhead and three underground; wood pole intrusive inspection every ten years. It sets no vegetation interval.
A rural 12 kV circuit inside Tier 2 of the High Fire-Threat District carries three clocks on the same poles. A patrol every year, because the fire-threat footnote pulls the rural interval in from two years to one. A detailed inspection of the overhead conductor and the equipment hung on it every five. And on any wood pole past its fifteenth birthday that has never been bored, an intrusive inspection every ten.
None of those three is the vegetation cycle. General Order 165 is the order everyone reaches for when asked how often a distribution line gets inspected in California, and the words vegetation, tree, trim and clearance do not appear anywhere in it.
What GO 165 actually requires
General Order 165 is titled "Inspection Requirements for Electric Distribution and Transmission Facilities." It was adopted March 31, 1997 and took effect the same day, by D.97-03-070 in I.95-02-015 and R.96-11-004. It has been amended four times:
Amended | Decision | Proceeding |
August 20, 2009 | D.09-08-029 | R.08-11-005 |
January 12, 2012 | D.12-01-032 | R.08-11-005 |
June 27, 2013 | D.13-06-011 | R.08-11-005 |
December 14, 2017 | D.17-12-024 | R.15-05-006 |
The December 2017 text is the current one, and it runs to seven pages including a blank and a cover.
Section I states the purpose in a sentence: to establish requirements for electric distribution and transmission facilities, excluding those contained in a substation, "regarding inspections in order to ensure safe and high-quality electrical service."
The operative obligation is one sentence in Section III.B:
Each utility subject to this General Order shall conduct inspections of its distribution facilities, as necessary, to ensure reliable, high-quality, and safe operation, but in no case may the period between inspections (measured in years) exceed the time specified in Table 1.
Two duties, not one. The first is open ended and judgment based: inspect as necessary for safe operation. The second is a ceiling. Table 1 is not a schedule the utility is asked to hit, it is a maximum the utility may not exceed, and a program that inspects on the table's intervals and nothing more has satisfied only the second half of that sentence.
Who the order binds, and who it does not
Section II is short and each clause does work:
This General Order applies to all electric distribution and transmission facilities (excluding those facilities contained in a substation) that come within the jurisdiction of this Commission, located outside of buildings, including electric distribution and transmission facilities that belong to non-electric utilities. The requirements of this order are in addition to the requirements imposed upon utilities under General Orders 95 and 128 to maintain a safe and reliable electric system. Nothing in this General Order relieves any utility from any requirements or obligations that it has under General Orders 95 and 128. This General Order does not apply to facilities of communication infrastructure providers.
The reach into non-electric utilities is not theoretical. The Commission's own GO 165 audit file for the 2014 reporting year holds a "SoCal Gas General Order 165 Compliance Maintenance Report." It sits alongside the filings from PG&E, SCE, SDG&E, PacifiCorp, Liberty, Bear Valley, Anza, Valley Electric, Plumas-Sierra, Surprise Valley, Modesto Irrigation District, Roseville, Lompoc and Silicon Valley Power.
A gas utility that owns electric distribution facilities files under this order. The order then carves back out in a note at the foot of Table 1: it does not apply to cathodic protection systems associated with natural gas facilities.
The last sentence of Section II is the one that matters most on a shared pole, and it runs the opposite way from the vegetation rule. GO 165 does not reach the facilities of communication infrastructure providers. GO 95 Rule 35 does, stating on its face that its requirements apply to all overhead electrical supply and communication facilities covered by that General Order.
So on a jointly used pole in a rural grid, the electric conductor and the transformer are on a GO 165 clock, the telecom attachments beneath them are not, and both are inside Rule 35's vegetation obligation. Who owes what on a pole with two owners is its own question, but the first half of the answer is that these two orders draw their boundaries in different places.
The three inspections, in the order's own words
Section III.A defines its terms, and the definitions are shorter than most people expect:
(3) "Patrol inspection" shall be defined as a simple visual inspection, of applicable utility equipment and structures, that is designed to identify obvious structural problems and hazards. Patrol inspections may be carried out in the course of other company business. (4) "Detailed" inspection shall be defined as one where individual pieces of equipment and structures are carefully examined, visually and through use of routine diagnostic test, as appropriate, and (if practical and if useful information can be so gathered) opened, and the condition of each rated and recorded. (5) "Intrusive" inspection is defined as one involving movement of soil, taking samples for analysis, and/or using more sophisticated diagnostic tools beyond visual inspections or instrument reading.
A fourth definition sets up everything downstream. "Corrective Action" means "maintenance, repair, or replacement of utility equipment and structures so that they function properly and safely." Vegetation work is not maintenance, repair or replacement of equipment, and it is not what this definition describes.
Two phrases in the patrol definition carry most of the practical weight. "Obvious" sets the standard of care, and "may be carried out in the course of other company business" means a patrol does not have to be a dedicated trip. Neither phrase appears in the detailed definition, which instead requires that "the condition of each" piece be "rated and recorded."
A patrol produces observations. A detailed inspection produces a rating per asset. What each type can realistically close on a span follows from that difference and belongs to its own page.
Table 1, and the one interval that moves with location
Table 1 is headed "Distribution Inspection Cycles (Maximum Intervals in Years)."
Facility | Patrol urban | Patrol rural | Detailed urban | Detailed rural | Intrusive |
Transformers, overhead | 1 | 2 (1) | 5 | 5 | --- |
Transformers, underground | 1 | 2 | 3 | 3 | --- |
Transformers, padmounted | 1 | 2 | 5 | 5 | --- |
Switching/protective devices, overhead | 1 | 2 (1) | 5 | 5 | --- |
Switching/protective devices, underground | 1 | 2 | 3 | 3 | --- |
Switching/protective devices, padmounted | 1 | 2 | 5 | 5 | --- |
Regulators/capacitors, overhead | 1 | 2 (1) | 5 | 5 | --- |
Regulators/capacitors, underground | 1 | 2 | 3 | 3 | --- |
Regulators/capacitors, padmounted | 1 | 2 | 5 | 5 | --- |
Overhead conductor and cables | 1 | 2 (1) | 5 | 5 | --- |
Streetlighting | 1 | 2 | x | x | --- |
Wood poles under 15 years | 1 | 2 | x | x | --- |
Wood poles over 15 years, no intrusive inspection yet | 1 | 2 | x | x | 10 |
Wood poles which passed intrusive inspection | --- | --- | --- | --- | 20 |
Footnote (1) is the only thing in the table that moves with geography. The December 2017 amendment is what put it in its current form:
Patrol inspections in rural areas shall be increased to once per year in Tier 2 and Tier 3 of the High Fire-Threat District. (See GO 95, Rule 21.2-D).
Read the footnote markers, not just the footnote. The uplift attaches to four rows only, and all four are overhead: overhead transformers, overhead switching and protective devices, overhead regulators and capacitors, and overhead conductor and cables. It does not attach to any underground or padmounted row, and it does not attach to streetlighting or to any of the wood pole rows.
A rural streetlight in Tier 3 stays on the two year patrol interval that the same table gives a rural streetlight in the Central Valley. SCE's 2022 annual report reads the table the same way. It describes its obligation as "annual patrols of all urban streetlights, and biennial patrols of all rural streetlights" with no fire-threat qualifier. It treats grid patrols as annual in urban areas and all high fire hazard areas.
What that footnote said before is worth knowing, because inspection records predating 2018 were built against it. The June 2013 text raised rural patrols to annual only in "Extreme and Very High Fire Threat Zones" in eight named counties, Imperial, Los Angeles, Orange, Riverside, Santa Barbara, San Bernardino, San Diego and Ventura. Those zones were mapped by the CAL FIRE Fire and Resource Assessment Program map or SDG&E's modified version of it adopted in D.12-01-032.
D.17-12-024 replaced all of that with a pointer to the statewide High Fire-Threat District. A rural grid in the northern Sierra was on a two year patrol interval under the old footnote and is on a one year interval under the new one, with no change on the ground and no change to its assets. Which tier a given circuit sits in is therefore a compliance fact with a date attached to it.
Urban and rural are defined by population density and nothing else. Urban is "those areas with a population of more than 1,000 persons per square mile as determined by the United States Bureau of the Census." Rural is areas with "a population of less than 1,000 persons per square mile" on the same authority.
The order names no census vintage, no geographic unit to measure the density over, and no rule for a place sitting at exactly 1,000. Those choices are made in the utility's own program, and they are worth finding in writing before an audit rather than during one.
The detailed columns for streetlighting and for every wood pole row print an x rather than an interval, and the order contains no legend defining it. In practice those assets are inspected as part of the detailed inspection of the pole. PG&E's GO 165 report says so directly.
It defines an overhead unit as a pole supporting its equipment or conductors under 60,000 volts. It notes that PG&E "also patrols and inspects the PG&E-owned overhead equipment, overhead conductors, and streetlights on those poles, but these facilities are not counted as additional overhead units for the purposes of this report."
What a year means here, and why late is not outstanding
The interval is measured in years, and the order defines the word. This note sits under Table 1 and came in with D.13-06-011:
For the purpose of implementing the patrol and detailed inspection intervals in Table 1 above, the term "year" is defined as 12 consecutive calendar months starting the first full calendar month after an inspection is performed, plus three full calendar months, not to exceed the end of the calendar year in which the next inspection is due. A required inspection may be completed any time before the expiration of the associated inspection interval using this definition of "year," but not after. The completion of an inspection starts a new inspection interval that must be completed within the prescribed timeframe using this definition of "year."
So an inspection performed on April 12, 2025 starts its clock on May 1, 2025, runs twelve months to April 30, 2026, takes three more to July 31, 2026, and is capped by December 31, 2026. The three month allowance is real but it is not a rolling grace period: completing the inspection resets the interval, and the cap on the calendar year stops the allowance from walking a program's due dates later every cycle.
The same note carries one extension, and it is narrow. Intervals "may be extended by up to six months in areas where the Governor of California or the President of the United States has declared an emergency or a disaster following a major earthquake or other catastrophe," using the procedure in D.13-06-011. The extension "shall not exceed six months from the date that an emergency is declared or the date that a disaster is declared, whichever is earlier."
PG&E's report for 2017 shows exactly how that definition bites, and it is the cleanest published example of the distinction. In the Stockton Division, clerical staff printed map K31 instead of map package KK31, so the area in KK31 went uninspected. A division specialist found the error while physically validating map packages.
PG&E completed the detailed inspection of 215 overhead units on August 18, 2017, against a CPUC due date of July 13, 2017. Those 215 units appear in the report as late and not as outstanding, because outstanding is defined against the calendar year and late is defined against the Table 1 due date. Both numbers are true, they answer different questions, and a program that tracks only one of them cannot say which it is reporting.
Wood poles, and the only age trigger in the order
Every other row in Table 1 keys on what a facility is. The wood pole rows key on how old it is and what has already been done to it, and they are the only place GO 165 does that.
A wood pole under fifteen years gets patrols and nothing intrusive. Once it is over fifteen years and has never been subject to intrusive inspection, it goes on a ten year intrusive interval. Once it has passed an intrusive inspection, it moves to twenty, and the patrol and detailed columns for that row read "---".
For intrusive inspections the definition of a year changes too: a separate note states that for wood pole intrusive inspections, "the term 'year' is defined as a calendar year." No first-full-month start, no three month allowance.
The record obligation changes with it. Section III.C requires patrol and detailed records to be kept for at least ten years, and intrusive inspection records for "the life of the pole." A pole set in 1974, first bored in 1998, and bored again in 2018 carries a file that has to survive as long as it is standing. That is longer than any other retention period in the order and longer than the ten years GO 95 Rule 18A requires for corrective action records.
Real programs run tighter than the table, and their reports say so. SCE aligns wood pole cycles by grid, inspecting every pole in a grid rather than only the poles due. So in 2022 it had 2,193 poles due for intrusive inspection and performed 105,212 intrusive borings plus 28,469 visual pole inspections.
A visual pole inspection is sounding the pole with a hammer and examining it rather than boring it. That visual pole inspection is not a category in Table 1 at all. PG&E likewise runs padmounted detailed inspections on a three year cycle where the table permits five, and reports its padmounted units as due against its own three year cycle rather than against the order's five.
What the inspection record has to name
Section III.C sets the content standard in one sentence, and it is a list of five things:
For all inspections records shall specify the circuit, area, facility or equipment inspected, the inspector, the date of the inspection, and any problems (or items requiring corrective action) identified during each inspection, as well as the scheduled date of corrective action.
What is inspected, who inspected it, when, what was found, and when the fix is scheduled. The fifth element is the one that gets left off, and it is what turns an inspection record into an auditable program: a finding with no scheduled correction date has no clock on it, and there is nothing to audit against.
Note what this covers and what it does not. GO 165 III.C is about the inspection. GO 95 Rule 18A(1)(b) is about the work that follows, requiring that on completion of corrective action the records show "the nature of the work, the date, and the identity of persons performing the work."
A vegetation file that names the span, the date and the crew satisfies Rule 18A and still says nothing about the inspection that generated the finding. Both halves have to exist, and they are usually produced by different people on different systems. What a working clearance record contains and which retention clock each piece of it runs on are their own subjects.
Records "shall be made available to parties or pursuant to Commission rules upon 30 days notice," and Commission staff may inspect them consistent with Public Utilities Code section 314(a).
The annual report, and the officer who signs it
Section III.D is the part of GO 165 that produces a public document every year:
By July 1st each utility subject to this General Order shall submit an annual report for the previous year under penalty of perjury.
Four categories, no more: Patrols, Overhead Detailed, Underground Detailed and Wood Pole Intrusive. For each, the total units of work due in the reporting period and the number outstanding. Note 1 of the sample template leaves the denominator to the filer: "Each utility will define its reporting unit basis (e.g., circuit, grid, facility / equipment)."
That note is why the numbers in two utilities' reports cannot be compared. SCE counts patrols by grid, where a grid is "a defined geographical area averaging about three quarters of a square mile."
For 2022 it reported 17,315 grid patrols due with 110 outstanding, 181,204 overhead detailed inspections due with 9,035 outstanding, and 2,193 wood poles due for intrusive inspection with 434 outstanding. PG&E counts overhead units by pole and reported 1,158,288 overhead patrols due for 2017. The two filings are both correct and describe systems of comparable size. Only the reporting unit differs.
The verification page is worth reading before the tables. SCE's 2022 report was filed July 3, 2023 and verified on June 29, 2023 at Pomona by Tracy Sanders, Vice President of Vegetation, Inspections and Operational Services, Transmission and Distribution, declaring under penalty of perjury that the foregoing is true and correct.
The officer who signs the inspection numbers at that utility is the officer who owns the vegetation program. The signature is a good reason to treat GO 165 counts as a records question rather than a field question: what is being sworn to is what the system says was done.
The same report shows what happens when the system and the field disagree. SCE found that overhead detailed inspection records from 2020 through 2022 held potential discrepancies, where its work management system showed an inspection complete while an enhanced inspection survey showed it could not be completed. Roughly 10,000 structures in 2020 and 5,000 in 2021 appeared affected.
SCE reclassified them as not completed, reassigned them for inspection, self-reported to the Safety and Enforcement Division on April 25, 2023 and to the Office of Energy Infrastructure Safety on May 5, 2023, and proposed amended GO 165 reports for both prior years. Which body would have done what with that is worth knowing in advance.
Transmission gets two sentences and no table
Section IV, in full:
Each utility shall prepare and follow procedures for conducting inspections and maintenance activities for transmission lines. Each utility shall maintain records of inspection and maintenance activities. Commission staff shall be permitted to inspect records and procedures consistent with Public Utilities Code Section 314 (a).
There is no Table 1 for transmission, no urban and rural split, no patrol or detailed or intrusive interval. The enforceable frequency on a 115 kV line is whatever the utility's own written procedure says it is, and the enforceable obligation is to follow that procedure and keep the records. "Prepare and follow" makes the utility's document the standard it will be measured against, which means an internal procedure that promises more than the utility does is a self-inflicted finding.
Above 200 kV a second regime applies on top, and it does set an interval and does name vegetation. NERC FAC-003 requires annual vegetation inspections of applicable transmission lines, on a standard enforced by a different body under different authority. Which transmission lines are actually in FAC-003's scope decides whether that second regime is live on a given circuit.
Where the vegetation cycle actually comes from
GO 165 is the inspection order, and a vegetation program still has to get its interval from somewhere else. Three places, and they are worth keeping straight.
GO 95 Rule 35 supplies the standard and not the schedule. It requires that the Table 1 Cases 13 and 14 clearances "shall be maintained," which is a condition that has to hold continuously rather than an interval to be met. Nothing in Rule 35 or in its four exceptions names a number of months, and nothing in Table 1 of GO 95 does either.
GO 95 Rule 18A supplies the machinery. It requires every company to establish an auditable maintenance program with a timeline for corrective actions, sorts findings into three priority levels, and sets a correction period for each level. It sets no inspection frequency at all.
Rule 18A(3) then hands the question back: "Companies that have existing General Order 165 auditable inspection and maintenance programs that are consistent with the purpose of Rule 18A shall continue to follow their General Order 165 programs." That sentence is why a GO 165 program is where a vegetation finding is usually born and where its clock usually starts, even though the order that governs the program never mentions vegetation.
The vegetation interval itself is set in the wildfire mitigation plan. Public Utilities Code section 8386(d) requires an electrical corporation's plan to include, at paragraph (9), "plans for vegetation management," and at paragraph (10), "plans for inspections of the electrical corporation's electrical infrastructure." The section was most recently amended by Stats. 2025, Ch. 119, Sec.
53, which is SB 254, effective September 19, 2025. That is where an annual patrol of a Tier 3 circuit's vegetation, or a second inspection pass in a given year, is actually committed to, and it is a commitment made in a filed plan rather than a duty imposed by a general order. What species growth rate does to that interval and the gap between the figure a crew trims to and the figure an audit measures are separate questions with separate answers.
The practical consequence for anyone reconciling a vegetation file against an inspection file is that the two are keyed differently. GO 165 counts units of work against a maximum interval and reports them once a year under oath. Rule 35 measures a distance on a span at whatever moment it is measured. A circuit can be current on every GO 165 interval in Table 1 and carry an uncorrected clearance nonconformance on the same poles, and neither record will say so unless somebody built it to.
Further reading
Patrol versus detailed inspection, and when each is required: What each of GO 165's inspection types can actually see, and what it can close.
CPUC GO 95 Rule 35: the vegetation clearance rule, explained: The clearance obligation a GO 165 program is the machinery for.
How growth rate sets the trim cycle: Where the vegetation interval comes from, since GO 165 does not supply one.
Frequently asked questions
What are the GO 165 inspection cycles for distribution facilities?
Table 1 sets maximum intervals in years. Patrols are annual in urban areas and every two years in rural areas. Detailed inspections are every five years for overhead transformers, switching and protective devices, regulators and capacitors, and overhead conductor and cables, and every three years for the underground equivalents. Wood poles past fifteen years that have never been intrusively inspected are on a ten year intrusive cycle, and poles that passed intrusive inspection go to twenty.
Does GO 165 set a vegetation inspection or trim cycle?
No. The words vegetation, tree, trim and clearance do not appear anywhere in General Order 165, and Table 1 has no vegetation row. The order governs inspection of equipment and structures. The clearance obligation is GO 95 Rule 35, which requires clearances to be maintained and names no interval, and the vegetation inspection frequency an electrical corporation actually works to is set in its wildfire mitigation plan under Public Utilities Code section 8386(d)(9) and (d)(10).
What does a year mean in GO 165 Table 1?
For patrol and detailed intervals, twelve consecutive calendar months starting the first full calendar month after an inspection is performed, plus three full calendar months, not to exceed the end of the calendar year in which the next inspection is due. An inspection may be completed any time before that expiration but not after. For wood pole intrusive inspections, a year means a calendar year.
Does GO 165 apply to transmission lines and to communication attachments?
Transmission is in scope but gets no table. Section IV requires each utility to prepare and follow procedures for inspecting and maintaining transmission lines and to keep records of that work, with no interval prescribed. Communication attachments are out of scope entirely: the order states that it does not apply to facilities of communication infrastructure providers, which is the opposite of GO 95 Rule 35, whose requirements reach communication facilities on their own terms.
