Vegetation Maintenance Standards

Read below to learn more about industry-wide standards we adhere to in order to keep everyone safe.

ANSI Requirements (Z-133.1)

ANSI Z-133 is the American National Standard for Arboricultural Operations, which includes safety requirements for brush cutting, pruning, repairing, maintaining and removing trees. Documents from these requirements are referenced when identifying safety violations of personnel engaged in utility vegetation maintenance work. Therefore, it is considered the definitive safety standard for arboricultural operations by which PEC’s vegetation maintenance department abides.

Diagram showing tree clearance around power lines

ANSI Z-133 defines an electric hazard to exist anytime a tree worker, tool, tree or any other conductive object is closer than 10 feet from an energized conductor with a voltage of 50,000 volts or less. This drives our commitment to safely maintain a 10-foot clearance from electric lines with our cyclical feeder maintenance (see image). ANSI Z-133 provides tables that outline minimum approach distances for both qualified and non-qualified tree workers based on voltage and elevation.

ANSI A-300 Standards

ANSI A300 standards are the generally accepted industry standards for tree care practices. Pedernales Electric Cooperative and its approved vendors abide by these performance standards in order to promote healthy growth away from electric lines, embody professionalism, improve communication and education to our membership, and eliminate hazards. The A300 standards consist of ten parts from which PEC has developed pruning standards, integrated vegetation management and tree risk assessment practices.

OSHA Standards (1910.269)

OHSA 1910.269 is the Occupational Safety and Health Administration’s vertical safety standard pertaining to the generation, transmission and distribution of electricity. A specific section of OHSA 1910.269 requires that everyone performing tree work in proximity to electric hazards must be trained and qualified to distinguish exposed live parts from other parts of electric equipment, 1910.269(a)(2)(iii)(A,B,C).

Qualifications also include skills necessary to determine minimum approach distances specified in this section corresponding to the voltages to which the employee will be exposed and the skills and techniques necessary to maintain those distances.

All PEC trimming contractors are trained and qualified to determine minimum approach distances and are certified to work within those distances. This ensures the right pruning methods are performed safely within our service area.