Service lines that are more than 2 in. in diameter are usually made of

• A. Copper
• B. PVC
• C. Cast iron
• D. The same material as water main material

Answer: (D)

When a service line is larger than about 2 inches, utilities commonly run it in the same material as the water main. This practice keeps the main and service sections mechanically compatible, so you use the same jointing methods, maintain the same pressure capabilities, and avoid the complexities and potential corrosion concerns that can come from mixing dissimilar metals. It also reduces the number of special fittings and transitions required, which lowers the risk of leaks and simplifies maintenance and future upgrades.

Copper is typically favored for smaller-diameter services because of ease of workmanship and install, while PVC is common for many new installations, but for larger services the cost and complexity of using a different material from the main make matching the main material the more practical approach. Cast iron might be used for certain mains, but the overarching rationale is to ensure compatibility by mirroring the main’s material.