Yes, the copper water line needs to be connected to the grounding electrode system (GES). Here's why: NEC (National Electrical Code) Requirement

The NEC (specifically, section 250.52(A)(1)) generally requires a metal underground water pipe to be used as a grounding electrode if it's in direct contact with the earth for 10 feet or more, and is electrically continuous. In your case, with a 1" copper water line buried underground for a distance of 160 feet, it easily meets this requirement.

Supplementary Grounding Electrode

If the grounding electrode conductor (GEC) to the water pipe isn't continuous or the connection to the water pipe is questionable, it is still required to supplement it with another grounding electrode, such as your ground rods.

Bonding to the GES

Since you have the ground rods established at the service disconnect, you'll need to run a grounding electrode conductor (GEC) from the service disconnect to the copper water pipe. This ties the water pipe into the overall grounding electrode system.

Purpose of Grounding

The purpose of grounding is to provide a low-impedance path for fault current to return to the source (the transformer). This helps to quickly trip a breaker or blow a fuse during a fault, minimizing the risk of electric shock and fire.

Size of GEC

The size of the GEC to the water pipe is determined by the size of your service entrance conductors as described in the 2020 NEC Table 250.66.

Bonding Jumper Around the Water Meter

When connecting to a metallic water piping system, the NEC also requires a bonding jumper to be installed around any insulated joints or equipment that may interrupt the electrical continuity of the system. Typically, this would be the water meter. This bonding jumper should be sized per NEC Table 250.102(C)(1), based on the size of the GEC to the water pipe.

Corrosion Concerns

The connection to the water pipe must be made within 5 feet from its point of entrance to the building per NEC.

Aluminum Considerations

Aluminum and copper are dissimilar metals that can cause corrosion when they come into direct contact with one another. Therefore, it is essential to use the proper listed connector when bonding the GEC to the copper water line.

How to Connect


Determine the GEC Size

Consult NEC Table 250.66 based on the size of your service entrance conductors to determine the correct size of the grounding electrode conductor (GEC).
2.

GEC Installation

Run the GEC from the service disconnect to the copper water pipe. The GEC can be copper or aluminum. It must be protected if it's subject to physical damage.3.

Approved Connector

Use a listed connector that is suitable for direct burial and for connecting the GEC material (copper or aluminum) to the copper water pipe. The connector should be corrosion-resistant.4.

Bonding Jumper

Install a bonding jumper around the water meter, as close to the water meter as practical. Size this jumper according to NEC Table 250.102(C)(1).
5.

Point of Connection

Connect to the water pipe within 5 feet of where the water pipe enters the building.

Important Considerations



Local Codes

Always check with your local electrical inspector or building department for any specific requirements or interpretations of the NEC that may apply in your area.

Qualified Electrician

This type of work is best performed by a qualified and licensed electrician to ensure compliance with all applicable codes and safety regulations. Incorrect grounding can create a dangerous situation.

Disclaimer: This information is for general guidance only and should not be considered a substitute for professional electrical advice. Always consult with a qualified electrician for specific recommendations based on your particular circumstances. Flag for review