On March 21, 2013, FERC issued a final rule approving the North American Electric Reliability Corporation’s (“NERC”) modified reliability standard for vegetation management along transmission right-of-ways.  The modified reliability standard, FAC-003-2, makes several revisions to the current standard, FAC-003-1, by (1) expanding the applicability of the standard; (2) requiring a minimum vegetation clearance distance (“MVCD”) regardless of whether an outage occurs or not; and (3) implementing a new annual vegetation inspection and work requirement.  FERC previously issued a Notice of Proposed Rulemaking regarding NERC’s proposed vegetation management reliability standard on October 18, 2012 (see October 29, 2012 edition of the WER).

First, the revised reliability standard now applies to all transmission lines that operate below 200kV that are required for system reliability.  FERC explained in its order that the transmission lines are required for reliability if they are an element of an Interconnection Reliability Operating Limit or an element of a Major Western Electric Coordinating Council Transfer Path.  In approving the modified reliability standard, FERC noted that this approach “reasonably balances enhanced applicability of the standard with unreasonably increasing the burden on transmission owners without commensurate reliability gains.”

Second, the reliability standard now imposes a “zero tolerance” approach to vegetation management and requires owners to prevent vegetation encroachment within the MVCD regardless of whether the encroachment results in a sustained outage.  The reliability standard defines MVCD as the “calculated minimum distance stated in feet to prevent flash-over between conductors and vegetation, for various altitudes and operating voltages.”  NERC stated that the standard is intended to prevent vegetation encroachment by incorporating a specific MVCD into the standard itself.  However, encroachments beyond the owners’ control, such as natural disasters and certain human or animal activity, other than those of the transmission owners’ employees or contractors, are exempt from the MVCD requirement.

Finally, transmission owners are now required to conduct annual inspections of all transmission lines subject to the reliability standard.  Additionally, transmission owners are required to complete 100% of their annual vegetation management work plans.  This annual minimum inspection rule also mandates that no more than 18 months pass between inspections.

FERC approved the final rule and required transmission owners to comply with the modified reliability standard in accordance with NERC’s implementation plan for the new reliability standard.  The final rule is effective 60 days after publication in the Federal Register.  A copy of the final rule is available here.