Clearance achieved: what the auditor records after the crew leaves

Clearance achieved is the measured distance from a named conductor to the nearest vegetation, taken at a stated point in the span on a stated date after the crew left. GO 95 Rule 35 requires the Table 1 clearances to hold under normal conditions, so a reading that omits its position and conditions is impossible to grade.

A distance, a point in the span, and a date

Take one span. It is a 12 kV distribution circuit inside the High Fire Threat District, running from pole 14 to pole 15. The vegetation management inspector walked it on March 4, 2026. The tree crew worked it and released it on June 3. The auditor arrives on June 15, and the entry that says "clear" and stops there has recorded an opinion.

What goes in is a distance. It runs from a named conductor to the nearest wood or foliage. It was taken at a stated point along the span, on a stated date twelve days after the crew drove away. Each of those four fields carries weight.

The conductor tells a reviewer whether the reading ran to the primary or to a service drop. The point in the span lets the number be corrected for how the conductor moves. The date ties the reading to the work and to the growth that followed it.

The unit this entry attaches to, and the evidence file that carries it, are set out in what a QA/QC audit actually covers. This page is about the number itself: which one the span owes, how it is taken, and what has to sit beside it in the record for it to still mean something in April 2027.

The number the span owes was set before the auditor arrived

The auditor does not choose the acceptance criterion in the field. It is a function of where the span sits and what time of year it is. PG&E's distribution inspection procedure TD-7102P-01 defines the operating term:

Minimum Distance Requirement: Distance to maintain separation between vegetation and distribution conductors in Local Responsibility Areas (LRAs), State Responsibility Areas (SRAs) and California's High Fire Threat District (HFTD), in accordance with CPUC General Order (G.O.) 95, Rule 35 and Public Resource Code (PRC) 4293.

Appendix A of that procedure turns the two regulations into one table the field can carry. For primary conductors above 750 volts:

Jurisdiction	When it applies	Regulation named	Minimum distance
LRA, outside the High Fire Threat District	Year round	G.O. 95, Rule 35	18 inches
High Fire Threat District	Year round	G.O. 95, Rule 35	4 feet
State Responsibility Area	During fire season	PRC 4293	4 feet
Federal Responsibility Area, on USFS property	During fire season	PRC 4293	4 feet

Conductors below 750 volts get no distance at all. The appendix says to prune them "if strain or abrasion to the conductor is observed."

Poles 14 to 15 sit in the High Fire Threat District, so the span owes 4 feet on June 15 and would owe the same on December 15. A span in a State Responsibility Area outside the district owes its 4 feet under the Public Resources Code during fire season.

Section 4293 hands the timing to the fire agency, requiring the clearance "during such times and in such areas as are determined to be necessary by the director or the agency which has primary responsibility for the fire protection of such areas."

Which regulatory floor governs which ground is worked through in GO 95 versus PRC 4293, the boundary itself in SRA and LRA boundaries, and the underlying table in clearance by voltage. The auditor's job is to record which of those numbers was applied, so that a reviewer can check the arithmetic against the right one.

The reading is graded against normal conditions

Rule 35 of General Order 95 does not say to measure the gap. It says to maintain it:

Where overhead conductors traverse trees and vegetation, safety and reliability of service demand that certain vegetation management activities be performed in order to establish necessary and reasonable clearances, the minimum clearances set forth in Table 1, Cases 13 and 14, measured between line conductors and vegetation under normal conditions shall be maintained.

Table 1 attaches footnote (ddd) to both of those cases, and the footnote is the sentence an auditor needs most:

Clearances in this case shall be maintained for normal annual weather variations, rather than at 60 degrees, no wind.

Elsewhere in GO 95, Table 1 clearances are measured at a fixed benchmark. Rule 37 sets it at 60 degrees Fahrenheit and no wind. Footnote (ddd) removes Cases 13 and 14 from that benchmark and substitutes the weather the span will actually see across a year. A reading taken at 8:30 on a 62 degree June morning with still air is the most favorable measurement available on that span. It is a data point, and the criterion it has to satisfy is about a different set of days.

In a State Responsibility Area, Public Resources Code section 4293 states its own condition in numbers:

In every case, such distance shall be sufficiently great to furnish the required clearance at any position of the wire, or conductor when the adjacent air temperature is 120 degrees Fahrenheit, or less.

GO 95 leaves both "normal conditions" and "normal annual weather variations" undefined. The utility's own program has to define them, write the definition down, and apply it the same way in Shasta County and in Kern County. The Commission has the last word when a specific tree is argued about. GO 95 says so in the one place where it allocates that risk.

Exception 4 to Rule 35 gives the Commission "final authority to determine whether the exemption applies in any specific instance," and leaves the utility carrying the risk of having decided that it did. An auditor who records a bare number and leaves the conditions blank has handed that argument to somebody else to lose.

Where in the span the tape went

PG&E's quality control standard SW-0003, Revision 03 of May 31, 2024, puts a number on conductor movement and places it directly in the specialist's assessment criteria:

Note: Depending on span length, facility construction and conductor material, potential sag and sway can range from 1' at quarter-span to 4' at mid-span.

Read that against a 4 foot requirement in the High Fire Threat District. A 48 inch reading taken at mid-span can be wholly consumed by movement the standard already expects. The same 48 inches taken at quarter-span leaves roughly 3 feet once a foot of movement is allowed.

The same 48 inches taken 10 feet off the pole is close to the worst case for that point, because the conductor moves least near the structure. One number, three different verdicts, and the field that separates them is the one a record most often omits.

SW-0003 lists what the specialist weighs alongside the reading:

Vegetation growth, tree canopy shift/sway, line loading, line sag, line blow-out, and foreseeable environmental factors under normal weather conditions such as wind and snow load for the location.

Tree canopy sway is on that list next to line sway, so the gap closes from both ends. A leader standing 5 feet off the conductor in still air at 8:30 stands closer in the first strong wind out of the northwest.

So the record names the position: at the pole, at quarter-span, at mid-span, or a measured distance from the nearest structure. Which conductor the reading ran to, and whether it ran to foliage or to wood, is a separate set of choices with its own consequences, and those are worked through in wire to vegetation versus wire to ground.

Which tool took the reading

SW-0003 lists three associated tools for the assessment: Field Maps, the Survey123 application, and "Measuring Tools." The standard does not say which measuring tool, and that silence is the program's problem to close. A tape reaches a leader at 8 feet. A laser rangefinder reaches a limb at 30 feet and returns a different kind of error. A trained estimate is free and travels with the specialist all day.

CAL FIRE's California Power Line Fire Prevention Field Guide, 2021 edition, is direct about one class of inspector. That guide governs fire agency personnel rather than the utility's own QC specialist, and it tells them:

Because of the danger of electrocution, fire agency personnel are NOT to attempt to physically or mechanically measure conductor clearances. Visual estimation is adequate.

The same guide states that the responsibility for inspecting power lines for compliance "rests exclusively with utilities." So the state's fire inspector estimates and the utility's auditor measures. The two can stand under the same span on the same afternoon, write down different numbers, and both be right. Approach limits bind the utility's auditor too, and they are covered in Cal/OSHA 2950 and minimum approach distance.

What follows for the record is small and is skipped constantly. The entry names the method. Tape, rangefinder, or estimate. Two auditors using two methods on one span produce a spread that looks like a quality signal and is really an instrument signal. Holding two raters to the same call is a calibration exercise, and it belongs to what a QA/QC audit actually covers. Measurements taken from a sensor rather than from the ground raise a different question about what the number represents, and that belongs to LiDAR sampled QA.

Six inches, and a pass from inside the number

Now a valley oak on the same span, with a major limb 8 inches from the 12 kV conductor. That is 40 inches inside the requirement. That reading can still pass.

Exception 4 to GO 95 Rule 35 carves out mature trees:

Mature trees whose trunks and major limbs are located more than six inches, but less than the clearance required by Table 1, Cases 13E and 14E, from primary distribution conductors are exempt from the minimum clearance requirement under this rule. The trunks and limbs to which this exemption applies shall only be those of sufficient strength and rigidity to prevent the trunk or limb from encroaching upon the six-inch minimum clearance under reasonably foreseeable local wind and weather conditions.

The exception is the Commission's. The field test that decides whether it reaches this oak is the utility's, and SW-0003 section 3.1 writes one out. Where the specialist identifies a tree meeting the criteria of a Major Woody Stem, the standard has them verify each of the following:

• Wood is more than 6 inches from the high voltage conductor.

• There is no evidence of prior contact between any portion of the branches or trunk and the conductor, including abrasion and incidental contact.

• The tree has been established in its current location for at least 10 years.

• The tree is at least 10 inches in diameter at breast height.

• The tree or limb at the conductor level is at least 6 inches in diameter.

• The tree is not resprouting at the conductor level at the time of inspection.

• The tree is not easily climbable, with scaffold branches present below 8.5 feet from the ground.

The standard adds one further condition in a line of its own: the tree is not hazardous under PG&E's priority tag procedure, TD-7102P-17. Every item on that list is an observation somebody can write down, and one of them is a measurement taken in inches rather than feet. Where any of them fails, SW-0003 directs the specialist to "initiate a PTT record and create a Veg survey for the priority tree deficiency finding in the QC Map."

Two things follow for the record. The entry has to say that an exemption was claimed and name it, because a bare 8 inch reading against a 48 inch criterion reads as a failure to every downstream system. And the entry has to carry the observations rather than the conclusion, because Exception 4 puts the risk of the call on the utility and the final say with the Commission. A file that records "MWS" alone keeps the verdict and throws away the evidence for it.

The secondary conductor has no number to measure

The same span carries secondary below the primary. The tape stays in the bag for that one. Rule 35 sets no distance for circuits at 750 volts or less and switches to a condition test:

When a supply or communication company has actual knowledge, obtained either through normal operating practices or notification to the company, that its circuit energized at 750 volts or less shows strain or evidences abrasion from vegetation contact, the condition shall be corrected by reducing conductor tension, rearranging or replacing the conductor, pruning the vegetation, or placing mechanical protection on the conductor(s).

SW-0003 section 3.4 puts the same test in the specialist's hands, and excludes the service drop:

Verify the secondary conductor(s) (excluding service drop) are free of significant strain and/or abrasion.

Rule 35 also settles what does not count, in a sentence worth keeping close: "Contact between vegetation and conductors, in and of itself, does not constitute a nonconformance with the rule." A branch resting on triplex is not a finding on its own. Friction damage to the insulation is abrasion. Scuffing and polishing sit outside that definition. Strain is present when the contact significantly compromises structural integrity.

So the clearance record for the secondary is an observation and a photograph. It says what was seen at the point of contact, and on what date. An auditor who leaves the secondary blank for want of a distance leaves the most common vegetation contact on the span undocumented.

When the reading comes back inside the number

On June 15 the auditor measures 30 inches to a live limb at quarter-span, against a 4 foot requirement. Three things happen, in order, and each leaves a trace.

The tree gets marked. SW-0003 is specific about how: "QC Specialist will use pink/black pattern flagging to indicate each QC vegetation finding." A crew arriving in August needs to find the same stem the auditor found, and a flag pattern reserved for QC keeps that stem distinguishable from the inspector's paint.

The finding gets a clock. TD-7102P-01 defines a priority as a condition that may result from encroachment into the minimum clearance requirement or from potential tree or limb failure, and attaches a time limit to each level. Priority 1 tags "must be mitigated within 24 hours of identification when reported," and Priority 2 tags "within 20 business days, unless constrained." The priority assigned at the moment of the reading is what sets the date the file will be measured against later.

The finding gets an owner. SW-0003 asks the specialist to name the work group likely responsible for the finding. A limb at 30 inches that is missing from the prescription is a different failure from one that was prescribed and left.

Attribution is worked through in trim type correct, the corrective action and its due date in what a QA/QC audit actually covers, and what happens to the span after the crew returns in rework. Who may accept the span once the number is right, and what their signature attests to, is who signs off on a span.

What one reading has to carry

Everything above reduces to a row. These are the fields that let somebody re-grade the span from the office:

Field	What it holds
Location and span	The circuit and the two structures the reading sits between
Conductor	Which conductor the reading ran to, and its voltage class
Criterion applied	18 inches or 4 feet, and the rule the number comes from
Measured distance	The reading, in the units it was taken in
Point in the span	At the pole, quarter-span, mid-span, or feet from the structure
Target of the reading	Wood or foliage, and the species
Method	Tape, rangefinder, or visual estimate
Date and time of the reading	With the elapsed days since the crew released the span
Conditions at the reading	Temperature and wind, because the criterion is not set at 60 degrees and no wind
Exemption claimed	Which one, and the observations that support it
Verdict and tag	Pass, or the tag type recorded
Auditor	The name against the reading

Two of those fields are the ones that get dropped and the ones that get asked about: the point in the span, and the conditions at the reading. A file full of distances that omits both is a column of numbers waiting to be argued with.

Who reads the number after you

The reading has a second life. If that span produces an ignition in September, the investigation will pull the last measurement anybody took on it, and the useful version is the one that says 30 inches at quarter-span at 2:10 on a 94 degree afternoon rather than "compliant."

It has a third life in the regulator's file. The Independent Evaluator working for California's Office of Energy Infrastructure Safety states that its aim includes verifying PacifiCorp's "control (QA/QC) programs." The audit method is inspected alongside the numbers it produces.

Three neighboring questions are settled elsewhere:

• Where this record meets the inspection obligations around it: what a QA/QC audit actually covers.

• The content standards a clearance entry is written to: documenting clearance work.

• How long the entry has to survive: recordkeeping and retention.

The clearance established at time of trim and the clearance that has to hold between visits are two different numbers, and they are separated in time of trim versus maintained clearance.

None of those readers were standing under the conductor on June 15. The record is the only thing that was.

Further reading

• What a QA/QC audit actually covers in utility vegetation work: The unit, the evidence file, auditor calibration, and the rates this measurement rolls up into.

• Trim type correct: the audit against the prescription, cut by cut: The other half of the grade on the same span, and why a clear span can still fail.

• Who signs off on a span, and what that signature means: Who accepts the measurement, and how an exception is attested instead.

Frequently asked questions

Does 48 inches measured at mid-span on a calm morning prove the span is compliant?

No. GO 95 Table 1 footnote (ddd) requires the Case 13 and Case 14 clearances to be maintained for normal annual weather variations rather than at 60 degrees and no wind. PG&E's QC standard SW-0003 tells the specialist that potential sag and sway can range from 1 foot at quarter-span to 4 feet at mid-span. A 48 inch reading taken at mid-span on a still morning can be consumed entirely by conductor movement the rule already accounts for.

Can the auditor use the 60 degrees, no wind benchmark that GO 95 applies to other clearances?

Not for vegetation. That benchmark sits in GO 95 Rule 37 and governs the Table 1 clearances generally. Footnote (ddd) attaches to Cases 13 and 14 and replaces it with normal annual weather variations. In a State Responsibility Area during fire season, Public Resources Code section 4293 adds its own condition: the distance must furnish the required clearance at any position of the wire at 120 degrees Fahrenheit or less.

A limb sits 8 inches from a 12 kV conductor inside the High Fire Threat District. Is that automatically a finding?

Not automatically. Exception 4 to GO 95 Rule 35 exempts mature trees whose trunks and major limbs are more than six inches from primary distribution conductors but closer than the Case 13E or 14E clearance, provided the wood has the strength and rigidity to stay outside six inches under reasonably foreseeable local wind and weather. The exception also states that the utility bears the risk of deciding the exemption applies and that the Commission has final authority. The auditor records the observations, not a conclusion.

What does the auditor measure on a secondary conductor?

Nothing, with a tape. GO 95 Rule 35 sets no distance for circuits at 750 volts or less and instead requires correction once the company has actual knowledge that the circuit shows strain or evidences abrasion from vegetation contact. PG&E SW-0003 section 3.4 asks the specialist to verify that secondary conductors, excluding service drops, are free of significant strain and abrasion. Rule 35 also states that contact alone is not a nonconformance.