Grounding & Equipotential Bonding: Pump Station Protection

A surge protective device is only as effective as the grounding and bonding system connected to it. Whether protecting a pump station from lightning, utility switching events, motor starts, VFD operation, or internally generated transients, proper grounding and bonding help provide the reference path needed to divert surge energy safely.

For pump and lift stations, grounding and equipotential bonding are about more than meeting basic electrical code requirements. They are essential for protecting electrical equipment, maintaining reliable control systems, and supporting the performance of surge protection throughout the station.

DEHN helps utilities evaluate grounding, bonding, lightning, and surge protection as part of a coordinated protection strategy for pump and lift station reliability.

What Is Equipotential Bonding?

Equipotential bonding is the practice of electrically connecting conductive components so they remain at the same electrical potential during normal operation and transient events.

Without proper bonding, different parts of a pump station can develop significant voltage differences during a lightning strike or surge event. Those voltage differences can force current through control panels, communication equipment, instrumentation, or other sensitive electronics as the system attempts to equalize.

The objective is simple: create a common electrical reference that helps minimize damaging voltage differences throughout the station.

Grounding and Bonding Work Together

Although the terms are often used interchangeably, grounding and bonding serve different purposes.

Grounding provides a path for fault current and transient energy to dissipate into the earth.  Bonding connects conductive equipment and structural components together so they remain at the same electrical potential.

Both are required. A well-designed grounding system without proper bonding can still leave damaging voltage differences between interconnected equipment. Likewise, bonding alone cannot safely dissipate surge energy without an effective grounding system.

Why Grounding Determines SPD Performance

Surge protective devices do not absorb or eliminate surge energy. They divert it.

When an SPD operates, it redirects transient current to the facility's grounding system. If that grounding system has excessive impedance, poor continuity, or ground loops, the surge cannot be effectively discharged

Instead, residual voltage can remain on the electrical system, increasing the stress placed on downstream, sensitive equipment such as PLCs, RTUs, VFDs, telemetry devices, and instrumentation.

That is why grounding and bonding should be evaluated as part of the surge protection strategy — not treated as a separate issue. 

Grounding and Bonding Requirements at Pump and Lift Stations

Pump and lift stations combine power equipment, automation systems, communications, and exposed infrastructure within a relatively small footprint. Every major conductive component should be connected to a coordinated grounding and bonding network.

Typical components requiring  bonding include:

  • Pump motor frames
  • Electrical equipment enclosures
  • Control panel ground buses
  • Metallic conduit systems
  • PLC, RTU, and SCADA panels
  • Telemetry and communication equipment
  • Antenna masts and supports
  • Structural steel and other metal parts
  • Grounding electrodes and associated conductors

When these systems share a common electrical reference, the potential for damaging voltage differences during transient events is reduced.

Each protection stage reduces the transient energy passed to the next, improving the performance of the overall system.

A typical protection architecture includes:

Grounding Standards for Water and Wastewater Applications

Grounding design should follow recognized industry standards, project specifications, and authority having jurisdiction requirements. For industrial facilities, IEEE 142, commonly known as the Green Book, provides guidance for grounding system design and electrical safety practices.

NFPA 70 — National Electrical Code, Article 250 establishes grounding and bonding requirements for electrical installations, including equipment grounding, bonding methods, and grounding electrode systems. 

Together, these standards provide the framework engineers use when designing grounding systems for pump and lift stations and other water and wastewater infrastructure.

Grounding Should Be Evaluated Alongside Surge Protection

Installing surge protective devices without evaluating grounding and bonding may leave critical vulnerabilities unaddressed.

A coordinated review can help identify: 

  • Missing or inconsistent bonding connections
  • Grounding deficiencies
  • Unbonded antenna or telemetry equipment
  • Long  or high-impedance grounding paths
  • Improper shield termination practices
  • Separate grounding electrodes that are not bonded together
  • Electrical pathways that may reduce SPD performance.

Reviewing grounding, bonding, and surge protection together helps support a more complete protection strategy for pump and lift station reliability.

Evaluate Grounding & Bonding Before the Next Surge Event

Grounding and bonding issues are often hidden until a storm, switching event, or equipment fault exposes them. 

A Pump/Lift Station Surge Risk Assessment from DEHN helps identify exposed power, communication, grounding, bonding, and instrumentation pathways that may contribute to recurring SCADA outages, VFD trips, telemetry failures, instrumentation problems, and unplanned downtime.

The assessment helps utilities understand where grounding and bonding improvements may support better surge protection performance and long-term station resilience.

Ask About a Pump/Lift Surge Risk Assessment

Download the Water & Wastewater Protection Toolkit

The DEHN Water & Wastewater Toolkit includes engineering guidance, an electrical pathway audit checklist, and planning resources to help evaluate surge protection, grounding, and bonding across water and wastewater facilities.

Download the Toolkit

Frequently Asked Questions

What Is Equipotential Bonding?

Equipotential bonding is the process of electrically connecting conductive equipment and structures so they remain at the same electrical potential. This helps reduce damaging voltage differences during faults, lightning, and surge events.

What Is the Difference Between Grounding and Bonding?

Grounding provides a path for fault current and transient energy to dissipate into the earth. Bonding electrically connects conductive components together so they remain at the same electrical potential. Both are necessary for a safe and effective electrical system.

What Is Ground Potential Rise?

Ground potential rise — GPR —  occurs when lightning or fault current enters the earth and temporarily raises the electrical potential of the surrounding ground. Without effective grounding and bonding, this voltage difference can damage interconnected electrical and communication systems.

What Does IEEE 142 Recommend for Grounding at Pump Stations?

IEEE 142 provides guidance for grounding system design, bonding electrical equipment, reducing impedance, and improving electrical safety and system performance in industrial facilities. Pump station designs should also follow applicable codes, project specifications, and AHJ requirements. 

Can SPDs Work Without a Proper Ground?

Surge protective devices rely on a properly designed grounding and bonding system to divert transient energy safely. Poor grounding or inadequate bonding can limit SPD performance and leave sensitive electrical equipment exposed to damaging voltages.