Electrical Safety and Arc Flash Mitigation Techniques for Water and Wastewater

Over the past few years more data and anecdotes have become available to illustrate the exact
nature of electrical injury or death. While the hazards from direct contact are widely known,
lesser understood is the injury potential from proximity to a fault event. The National Electrical
Code (NEC), Underwriters Laboratory (UL), and Occupational Safety and Health Administration
(OSHA) have recognized this hazard and implemented codes and standards to address this.
However, many water and wastewater utilities may not be aware of these requirements.
This paper examines basic safe practices a water and wastewater facility is required to implement
to minimize accident potential. Not only will this help a facility to protect staff from injury, but
it can help to prevent equipment outages that could cripple a utilities ability to treat water.
This paper is intended to be introductory in nature, and is not intended to be a working guideline
for an arc flash mitigation plan. Only a proper detailed engineering analysis of a utility can help
to develop a plan.
This paper is divided into four different interrelated areas. The first is an overview of arc flash,
its associated hazards, and what can happen when they are not addressed properly. The second
part illustrates what a municipalitie’s responsibility is, what it takes to fulfill these obligations,
and the challenge small municipality’s face. The third is the determination of what tools and
protective clothing (PPE) are required to protect workers from hazards, as well as safe working
distances. The fourth section looks at equipment and maintenance techniques that help minimize
the hazards.