Generally, which pipe materials are ranked by utilities as the most favorable for maintaining water quality?

• A. Cast Iron, Steel, PVC
• B. PVC, Concrete Pressure, Lined Ductile Iron
• C. HDPE, Copper, Fiberglass
• D. Asbestos Cement, Steel, PVC

Answer: (B)

The most favorable pipe materials for maintaining water quality are chosen because they minimize interactions with the water—reducing corrosion, leaching of metals, and taste/odor changes. PVC is highly inert and non-reactive with drinking water, so it doesn’t corrode or impart metals or taste. Concrete pressure pipe is also very stable and non-reactive, providing long-term durability without introducing contaminants. Lined ductile iron uses a cement lining to protect the metal from water contact, effectively preventing corrosion and metal leaching while still offering the strength of iron. This combination—PVC, concrete pressure pipe, and lined ductile iron—offers the best balance of inertness and structural reliability, which utilities view as most conducive to maintaining water quality.