Based on the information you provided and standard electrical code (NEC), splicing a GEC with a split bolt is generally permissible, but it must adhere to specific requirements.

Here's a breakdown

NEC Guidelines:
NEC 250.64(C)

This section specifically addresses the continuity and splicing of grounding electrode conductors (GECs). It allows for splicing of GECs.

NEC 250.64(C)(1) - (3)

This spells out the acceptable methods for splicing and connection:

Irreversible Compression-Type Connectors

The preferred method.

Exothermic Welding

Like a Cadweld connection.

Listed Connectors

Connectors listed for grounding and bonding.

Split Bolts

Historically split bolts were commonly used, but code changed with the 2020 NEC.

Analysis of Your Situation1. Existing GEC to Ground Rods

This is good. You have a continuous GEC to your ground rods, which is a primary requirement.2.

Short GEC to Water Pipe

This is the problem. Your GEC is too short to reach the service disconnect from the copper water pipe.3.

Split Bolt

The appropriateness of a split bolt depends on the connector's UL listing.4.

Irreversible Crimps

You don't have any. This would be an ideal solution but is not an option at this time.

Recommendations Use a Listed Connector

The ideal solution is to use a connector that is specifically listed for grounding and bonding. Look for connectors marked "Suitable for Direct Burial" or "DB" if the splice will be buried or exposed to moisture. The connector must be sized appropriately for the conductors you are joining. This is the code-compliant solution if you don't have access to irreversible crimps.

Important Considerations



Accessibility

Splices in GECs should ideally be accessible for inspection. However, this isn't always practical. If the splice is in the inaccessible crawl space, use the best possible connector and ensure it is properly tightened and protected from corrosion.

Corrosion Protection

All grounding connections, especially in damp environments like crawl spaces, should be protected from corrosion. Use a suitable anti-oxidant compound on the conductors before making the connection.

Inspection

Your work will be subject to inspection by your local electrical authority. Ensure that your installation meets their specific requirements.

Disclaimer: I am an AI chatbot and cannot provide professional electrical advice. Always consult with a licensed electrician for any electrical work to ensure safety and code compliance. Electrical work can be dangerous, and improper installations can create fire hazards or shock risks. Flag for review