FAC-003 Requirement R1 after R2 was reserved
Updated: Sep 21
FAC-003-5 reserved Requirement R2 and struck the clause limiting R1 to lines that were an element of an IROL or a Major WECC Transfer Path, so every applicable line is now an R1 line. Severity did not move: FERC had already raised R2's Violation Risk Factor to High in 2013.
A limb sits three feet six inches below the center phase of a 230 kV line in the Sierra foothills at 1,400 feet of elevation. Nobody has designated the line: it is not an element of an Interconnection Reliability Operating Limit, it is not on WECC's transfer path table, and the Planning Coordinator has never named it in a Planning Assessment. It is applicable to FAC-003 only because it operates above 200 kV.
Observed on March 28, 2024, that limb is a violation of FAC-003-4 Requirement R2, part 2.1. Observed on May 28, 2024, it is a violation of FAC-003-5 Requirement R1, part 1.1. The measurement is the same, the Minimum Vegetation Clearance Distance is the same 4.3 feet, the Violation Risk Factor is High in both cases and the Violation Severity Level is High in both cases. What changed on April 1, 2024 is the number the finding is filed under.
That makes the reservation of R2 sound like housekeeping, and at the level of a single encroachment it very nearly is. The part worth reading closely is what the standard stopped saying about the lines R2 used to cover, and the three or four places where the old distinction is still doing work.
What R2 said, and how little of it was different
FAC-003-4 opened its two performance requirements with lead-in sentences that differ by one word:
R1. Each applicable Transmission Owner and applicable Generator Owner shall manage vegetation to prevent encroachments into the Minimum Vegetation Clearance Distance (MVCD) of its applicable line(s) which are either an element of an IROL, or an element of a Major WECC Transfer Path; operating within their Rating and all Rated Electrical Operating Conditions of the types shown below
R2. Each applicable Transmission Owner and applicable Generator Owner shall manage vegetation to prevent encroachments into the MVCD of its applicable line(s) which are not either an element of an IROL, or an element of a Major WECC Transfer Path; operating within its Rating and all Rated Electrical Operating Conditions of the types shown below
The word is not. Below each lead-in sat four subparts, and those differ in two places across eight paragraphs. Part 1.1 reads "An encroachment into the MVCD as shown in FAC-003-Table 2, observed in Real-time, absent a Sustained Outage" where part 2.1 drops the table reference.
Part 1.4 reads "vegetation growth into the MVCD" where part 2.4 reads "vegetation growth into the line MVCD." Nothing else separates them. The footnotes are the same footnotes: R2's subparts carried "See footnote 4," "See footnote 5" and "Id." rather than text of their own. Measures M1 and M2 were the same sentence with the requirement number swapped.
FERC said so in as many words while reviewing the version that introduced the split:
The Commission observed that the substantive obligations set forth in Requirements R1 and R2 are identical, but the Violation Risk Factors differ based on whether a transmission line is an element of an IROL or Major WECC Transfer Path.
So the merger in version 5 did not combine two obligations into one. There was one obligation the whole time. What version 5 removed was a sorting step that ran ahead of it, and the burden that step imposed was on the entity: every applicable line had to be classified before a finding could be numbered.
FERC took the consequence out of the split in 2013
NERC proposed FAC-003-2 with a High Violation Risk Factor on R1 and a Medium on R2, on the reasoning that a non-IROL line poses less risk. FERC rejected it. In Order No. 777, issued March 21, 2013 in Docket No. RM12-4-000 and reported at 142 FERC ¶ 61,208, the Commission worked through the definitions and found the Medium designation unsupported:
As we explained in the NOPR, transmission lines that are not an element of an IROL or Major WECC Transfer Path have contributed to major cascading outages. This fact supports a "high" Violation Risk Factor designation for Requirement R2. Moreover, our Violation Risk Factor guidelines, which require, among other things, consistency within a Reliability Standard (guideline 2) and consistency between requirements that have similar reliability objectives (guideline 3), also support modifying the Violation Risk Factor assigned to Requirement R2 from medium to high.
The two events the Commission named are worth having in front of a Western program. One is the August 2003 Northeast blackout. The other is "an August 10, 1996 blackout in the Western Interconnection," which is the event that produced the institutional machinery a California transmission owner still lives inside.
WECC's own account sits in the process document that governs the transfer path table. It records that "in July and August of 1996, the Western Interconnection experienced two widespread outages resulting from inadequate vegetation management." The same document records that the WSCC trustees responded in March 1997 by creating the Reliability Management System.
Order No. 777 directed the change "within 45 days of the effective date of the Final Rule." The NERC Board of Trustees adopted it on May 9, 2013, and the standard's own Version History records the closing entry for November 22, 2013: "Updated the VRF for R2 from 'Medium' to 'High' per a Final Rule issued by FERC."
From that date forward, whether a line was an IROL element decided nothing about what an MVCD encroachment cost. Both requirements carried a High Violation Risk Factor, and both ran on a Real-time Time Horizon. Both used the same two Violation Severity Levels: High for an encroachment observed in Real-time absent a Sustained Outage, Severe for a fall-in, a blowing together or a grow-in that caused one. Version 5 removed a distinction that had been drained of consequence ten years and four months earlier.
The clause R1 lost, and the sentence the VSL gained
Set the two versions of R1 next to each other and the edit is visible in one line.
Text after "of its applicable line(s)" | |
FAC-003-4 R1 | "which are either an element of an IROL, or an element of a Major WECC Transfer Path; operating within their Rating and all Rated Electrical Operating Conditions of the types shown below" |
FAC-003-5 R1 | ", operating within their Rating and all Rated Electrical Operating Conditions of the types shown below" |
The qualifying clause is struck and nothing replaces it. Four things came through unchanged:
The four subparts.
The footnote 4 carve-out for circumstances beyond the entity's control.
The footnote 5 rule that a later Fault confirmation counts as the equivalent of a Real-time observation.
The footnote 6 rule that multiple Sustained Outages from the same vegetation within 24 hours count as one.
The Violation Severity Level table changed in the same motion, and its new wording is the more useful of the two edits for anyone writing a finding. FAC-003-4's High column described a failure "of a line identified as an element of an IROL or Major WECC transfer path." FAC-003-5's reads:
The responsible entity failed to manage vegetation to prevent encroachment into the MVCD of a line identified in the Applicability section 4.2 and 4.3 and encroachment into the MVCD as identified in FAC-003-5-Table 2 was observed in real time absent a Sustained Outage.
The VSL now points at the Applicability section rather than at a class of line. That makes the first question in any R1 finding an applicability question, and which lines parts 4.2.1 through 4.2.3 and 4.3 actually reach is where the answer comes from. A span that fails the applicability test is not a lesser finding under FAC-003-5. It is not a finding at all.
One phrase in the Severe column survived the edit and is worth knowing about before it turns up in a dispute. R1 parts 1.2 and 1.3 place the fall-in and the blowing together "inside the ROW," which is a defined NERC Glossary term. The Severe VSL describes the same two cases as occurring "inside the active transmission line ROW."
The word active appears nowhere else in FAC-003-5, in the requirements, the definitions or the supplemental material. It is a version 4 phrase carried forward into a table that is used to grade severity, not to establish the obligation, and the obligation is the one written in R1.
The paragraph that was deleted rather than moved
The substantive change in version 5 is not in Section B at all. It is in the supplemental material, where FAC-003-4 explained why the two requirements existed:
The separation of applicability (between R1 and R2) recognizes that inadequate vegetation management for an applicable line that is an element of an IROL or a Major WECC Transfer Path is a greater risk to the interconnected electric transmission system than applicable lines that are not elements of IROLs or Major WECC Transfer Paths. Applicable lines that are not elements of IROLs or Major WECC Transfer Paths do require effective vegetation management, but these lines are comparatively less operationally significant.
Neither sentence is in FAC-003-5. The heading above them, "Requirements R1 and R2," became "Requirements R1," and the discussion beneath it now reads, with the seam from the edit still showing in the grammar:
R1 is a performance-based requirements. The reliability objective or outcome to be achieved is the management of vegetation such that there are no vegetation encroachments within a minimum distance of transmission lines R1 requires each applicable Transmission Owner or applicable Generator Owner to manage vegetation to prevent encroachment within the MVCD of transmission lines. R1 is applicable to lines that are identified as an element in the Applicability section 4.2 and 4.3.
Two things follow. The first is that FAC-003-4 kept publishing the ranking sentence for eight years after FERC declined to accept the reasoning behind it. The version 4 supplemental material carries a Board of Trustees adoption date of February 11, 2016, more than two years after the Commission had rejected a Medium Violation Risk Factor built on exactly that premise. Version 5 finally reconciled the narrative with the risk factor.
The second matters more in a program document. FAC-003-5 contains no statement that any applicable line is less operationally significant than any other. The standard never authorized a reduced service level on non-IROL lines in the first place, because R6 has always required a Vegetation Inspection of 100 percent of applicable lines and R7 has always required 100 percent completion of the annual work plan.
But a maintenance strategy under R3 that justifies a longer cycle or a thinner inspection on undesignated lines by quoting that paragraph is quoting text that is not in the standard in force. The justification now has to come from the entity's own analysis of growth rates, control methods and inspection frequency, which is what R3.2 asked for all along.
There is a further reason not to lean on the designation as a proxy for risk in the West. WECC's own table revision process, in the footnote attached to the table's title, says this about the word in the name:
For purposes of this document and those documents specified herein, the word "major" is used only as a title and not as an adjective. Its legacy use as a title does not indicate the importance of the path or its impact on reliability.
And, two sentences later: "Beyond this feature found in the RMS there are no known technical studies explaining why the specified paths are listed in the Table."
The current standard still names R2 in four places
Section A.6, the Background, was not conformed when R2 was reserved. FAC-003-5 as posted still contains all three of these:
Requiring that vegetation be managed to prevent vegetation encroachment inside the flash-over clearance (R1 and R2);
For this standard, the requirements have been developed as follows: Performance-based: Requirements 1 and 2
Requirements R1, R2, and R7 serve as the second line of defense by requiring that entities carry out their plans and manage vegetation.
None of that revives R2. The Background sits in Section A and describes the standard; the requirements are in Section B, and Section B says "[Reserved for future use]." The supplemental material was updated and the Background was not, which is an editorial gap rather than an ambiguity.
It does create one practical trap. Utility vegetation procedures frequently reproduce the defense-in-depth list verbatim, because it is the clearest short statement of what the standard is trying to do. A procedure that carries that list forward into a 2026 revision is telling its own crews and its own auditors that R2 is a live requirement. The fix is a search for the string "R2" across the procedure set, not a rewrite.
The fourth place is the audit worksheet. The Reliability Standard Audit Worksheet for FAC-003-5, issued March 27, 2024 and revised August 16, 2024, retains an R2 row in its findings table and a section headed "R2 Supporting Evidence and Documentation" whose entire content is the two reserved lines.
Its Regulatory Language section records the FERC letter order of March 4, 2022 in Docket No. RD22-2-000, then closes with a paragraph about MVCD values being added for elevations up to 15,000 feet, which describes the change from version 3 to version 4. The worksheet an auditor works from does not explain the reservation of R2 anywhere.
Where the old split still lives
Three things survived R2, and a California program touches all three.
Applicability part 4.2.3. A Major WECC Transfer Path element below 200 kV is inside FAC-003 only because WECC designated it. The current table, effective January 1, 2025, carries eight paths that run in or into California.
Path | Name |
15 | South of Los Banos or Midway to Los Banos |
24 | PG&E to SPP |
26 | Northern to Southern California |
45 | SDGE to CFE |
46 | West of Colorado River |
61 | Lugo to Victorville 500 kV |
65 | Pacific DC Intertie |
66 | COI |
The designation no longer decides which requirement applies. It still decides whether the standard applies.
The quarterly outage report. The periodic data submittal kept the two-tier structure that R1 and R2 gave up, and it kept it in the same document that reserved R2. Sustained Outages are still sorted into Category 1A and 1B for grow-ins, 2A and 2B for fall-ins from within the ROW, 3 for fall-ins from outside it, and 4A and 4B for blowing together.
How the categories are built and filed is a separate subject, but one edit inside them belongs here, because it is the same edit that was made to Applicability part 4.2.2.
FAC-003-4 defined the A categories by the old test. Category 1A covered grow-in outages on applicable lines "that are identified as an element of an IROL or Major WECC Transfer Path." FAC-003-5 replaced that phrase throughout with a description of the consequence:
Category 1A: Grow-ins: Sustained Outages caused by vegetation growing into applicable lines, that are identified by the Planning Coordinator, per its Planning Assessment of the Near-Term Transmission Planning Horizon
The rest of the sentence repeats the instability, Cascading and uncontrolled separation language that Applicability part 4.2.2 carries, and closes with "by vegetation inside and/or outside of the ROW." Read the opening clause against the applicability section it was conformed to and a gap opens. Part 4.2.2 admits lines identified by "the Planning Coordinator or Transmission Planner." Part 4.2.3 admits lines identified by WECC. The A categories name only the Planning Coordinator's Planning Assessment.
So a grow-in outage on a sub-200 kV element of Path 26, applicable through 4.2.3 and never separately named by a Planning Coordinator, was a Category 1A outage under FAC-003-4 and reads as a Category 1B outage under the words of FAC-003-5. The same is true of a line that only a Transmission Planner identified.
The standard does not resolve it. A program that files quarterly reports across a Western footprint should decide which reading it uses, write the reasoning down once, and apply it the same way every quarter. The category letter is the only place in the current standard where that distinction still produces a different entry.
The Facility inventory. The audit worksheet asks the entity, as the first question under R1: "Does the applicable entity have any Facilities meeting the criteria in Applicability Sections 4.2. and/or 4.3?" If yes, it asks the entity to "provide a list and quantity Facility types as shown in Applicability Sections 4.2 and /or 4.3." That is a list broken out by 4.2.1, 4.2.2, 4.2.3 and 4.3. R1 stopped caring which subsection a line arrived through. The evidence request did not.
One more artifact sits alongside these. WECC's table revision process, effective January 1, 2025, lists the NERC and WECC documents it governs, and the first entry reads "FAC-003-4, Transmission Vegetation Management referencing the 'Major WECC Transfer Path in the Bulk Electric System by WECC'." The reference is to a standard that was retired nine months before that document took effect. The table itself is unaffected, and FAC-003-5 part 4.2.3 points at the same list under the same name.
M2, the evidence file, and what an audit asks for now
M2 was reserved with R2, and nothing was lost with it. M1 and M2 named the same three examples of acceptable evidence: dated attestations, dated reports containing no Sustained Outages associated with encroachment types 2 through 4, and records confirming no Real-time observations of any MVCD encroachments. An entity that maintained two parallel attestation sets, one per requirement, now maintains one.
The evidence retention list changed by one character. FAC-003-4 required the entity to retain evidence "with Requirements R1, R2, R3, R5, R6 and R7, for three calendar years." FAC-003-5 requires it "with Requirements R1, R3, R5, R6 and R7, for three calendar years."
The period did not move, the R4 carve-out for operator logs and voice recordings did not move, and neither did the rule that an entity found non-compliant holds the related material until it is found compliant, or for the retention period, whichever runs longer. What the state stack expects of the same crew's records, and for how long is the longer obligation on a California file in most cases.
Under R1 the worksheet now asks two yes or no questions and requires an explanation either way. The first is the Facility inventory question above. The second: "Did the applicable entity have any encroachment (Types 1.1-1.4) into the MVCD of its applicable line(s) in the audit period?
If Yes, describe the encroachment(s). If No, explain how the entity made this determination." Both questions are answered once, for the whole applicable population. Before April 1, 2024 the equivalent exercise ran twice, on two line lists that had to be built and kept current.
A finding on a span that used to be an R2 line
Return to the 230 kV line in the foothills. Undesignated, applicable under part 4.2.1 alone, and carrying an MVCD of 4.3 feet in the band over 1,000 up to 2,000 feet. Where that 4.3 comes from and what altitude does to it is a Table 2 question, and Table 2 is identical in versions 4 and 5.
Observed March 28, 2024 | Observed May 28, 2024 | |
Standard in force | FAC-003-4 | FAC-003-5 |
Requirement cited | R2, part 2.1 | R1, part 1.1 |
Violation Risk Factor | High | High |
Violation Severity Level | High | High |
Time Horizon | Real-time | Real-time |
MVCD applied | 4.3 ft | 4.3 ft |
Measure | M2 | M1 |
Report category if it had caused a grow-in outage | 1B | 1B |
Evidence retention | 3 calendar years | 3 calendar years |
One row moved, and it moved because the standard did, not because the risk did.
The date boundary is the part that needs handling rather than understanding. FAC-003-4 was retired immediately prior to the effective date of FAC-003-5, so there is no overlap and no transition window. A compliance monitoring period covering calendar year 2024 is measured against FAC-003-4 through March 31 and FAC-003-5 from April 1.
Two encroachments three months apart on the same span, under the same procedure, by the same inspector, are cited under two different standards and two different requirement numbers. With a three calendar year retention period, the FAC-003-4 portion of 2024 is still reachable in a 2027 audit. A tracking system that stores a finding as "R1" or "R2" without storing the standard version and the observation date has thrown away the information needed to reconstruct which was which.
What this does not change in California
Nothing in the state stack moved on April 1, 2024, and the federal number is still the smallest number on the span.
GO 95 Rule 35 and its Table 1 were not touched by a NERC standard revision and could not have been. Case 13 and Case 14, and the 120 inches that Case 14 requires inside the High Fire-Threat District, are unchanged. PRC 4293's radial clearance bands are unchanged, and so is the fact that they are measured a different way from the MVCD.
What GO 165 does and does not require of transmission inspections is unchanged. Which body can issue what against whom is unchanged: the CPUC and CAL FIRE do not enforce FAC-003, and WECC as Compliance Enforcement Authority does not enforce GO 95.
The one operational consequence in a California file is narrow. Any internal artifact that sorts applicable spans into R1 lines and R2 lines is sorting on a distinction the current standard does not make. That includes QA forms with a requirement field, clearance specifications with separate sections for IROL and non-IROL circuits, contractor scopes of work that reference R2 by number, and the applicability matrix in a compliance program document. None of them is wrong about the clearance. All of them will produce a finding written against a reserved requirement.
What the record has to name
Four things, and three of them are dates.
The standard version, on every finding and every attestation. "FAC-003 R1" is ambiguous across the April 1, 2024 boundary in a way that "FAC-003-5 R1" and "FAC-003-4 R2" are not. Both citations are correct within their own periods, and a record that names the requirement without naming the version cannot be sorted later.
The applicability basis, per line, with the subsection. The audit worksheet asks for the Facility list broken out by Applicability sections 4.2 and 4.3, so the file has to carry which of 4.2.1, 4.2.2, 4.2.3 or 4.3 put each line in scope, and for a designated line, who designated it and when. R1 no longer needs the answer. The evidence request does, and the report category letter depends on it.
The reading applied to the A and B categories, written once. For any line applicable through 4.2.3 or through a Transmission Planner rather than a Planning Coordinator, the program has to decide whether a Sustained Outage on it is an A or a B, and record the reasoning. Consistency across quarters is the checkable property here, since the standard supplies no answer.
The date the internal procedure set was swept for R2. The Background of FAC-003-5 still names R2 three times and the audit worksheet still has a section for it, so a procedure that quotes either one is not obviously stale on its face. A dated note that the sweep was done, and what was changed, is faster to produce than the argument that nothing needed changing.
The same discipline that makes a clearance record checkable by a stranger two years later applies to the citation itself: name the version, name the date, name the subsection, and the record survives the next time a requirement number moves.
Further reading
NERC FAC-003-5: transmission vegetation management after April 2024: The standard as a whole, its live requirements, and the arithmetic behind April 1, 2024.
Which lines FAC-003 actually applies to: Parts 4.2.1 through 4.2.3, and how a sub-200 kV designation arrives and leaves.
The FAC-003 quarterly vegetation outage report: The A and B category letters that kept the split R1 and R2 gave up.
Frequently asked questions
Was FAC-003 Requirement R2 deleted?
No. It was reserved. Section B of FAC-003-5 still carries R2 and M2, each reading only [Reserved for future use], which is why R3 through R7 kept their numbers. The change took effect April 1, 2024, when FAC-003-5 became enforceable and FAC-003-4 was retired immediately prior.
Is a violation more serious now on a line that used to fall under R2?
No. R2 carried a High Violation Risk Factor from November 22, 2013, the same as R1, after FERC directed the change in Order No. 777. The Violation Severity Levels for the two requirements were also identical in structure, High for a Real-time observation absent a Sustained Outage and Severe for a fall-in, blowing together or grow-in outage. Consolidation into R1 moved the citation number and nothing about the exposure.
Do we still need to know whether a line is an element of an IROL or a Major WECC Transfer Path?
Not for Requirement R1, which no longer mentions either. The determination still matters in two places. Applicability part 4.2.3 brings sub-200 kV elements of a Major WECC Transfer Path into the standard at all, and the quarterly outage report still sorts Sustained Outages into A and B categories, though FAC-003-5 rewrote that test to reference the Planning Coordinator's Planning Assessment rather than IROLs and WECC paths.
Can a compliance finding still be written against FAC-003 R2?
Not against FAC-003-5. It can still be written against FAC-003-4 R2 for conduct before April 1, 2024, and the three calendar year evidence retention period means a 2026 audit can still reach into that window. A monitoring period covering calendar year 2024 is measured against two different standards on either side of April 1.
Did the MVCD, the inspection interval or the work plan requirement change with R2?
No. FAC-003-Table 2 is identical between versions 4 and 5, and R3 through R7 came through Project 2015-09 with their text, Violation Risk Factors and Time Horizons intact. The only requirement-level changes in version 5 are the reservation of R2, the qualifying clause struck from R1, and the rewrite of Applicability part 4.2.2.
