How do you clean a well screen clogged with lime scale?

• A. Use aggressive hydrochloric acid to dissolve lime scale
• B. Use diluted bleach to dissolve scale
• C. Flush with high-velocity water to dislodge scale
• D. Inhibited acid, because it does not harm other parts of the well

Answer: (D)

When lime scale builds up in a well screen, you need a treatment that dissolves calcium carbonate without harming the well components. Lime scale is primarily calcium carbonate, so acids are effective at dissolving it. An inhibited acid is formulated for well use: it contains corrosion inhibitors and other additives that protect metal casing, screens, cement seals, and surrounding materials while the acid dissolves the scale. That balance—chemically dissolving the scale while minimizing damage to the well infrastructure—is why inhibited acid is the preferred option.

Using straight hydrochloric acid would be more aggressive and could corrode metal parts and seals. Diluted bleach isn’t capable of dissolving calcium carbonate, so it won’t effectively clear the scale. Flushing with high-velocity water might remove some loose debris but doesn’t reliably dissolve or remove the scale that adheres to and inside the screen. Inhibited acid provides the chemical action needed to dissolve the scale with precautions to protect the well components.