Which two factors can contribute to well screen clogging?

Well screen clogging can occur from several factors, and iron bacteria and calcium hardness are two significant contributors.

Iron bacteria thrive in environments where iron is present. They form slimy biofilms that can accumulate on well screens, reducing flow rates and clogging the screens. When they grow in substantial numbers, they can effectively create a barrier that restricts the movement of water through the screen, leading to operational problems in the well.

Calcium hardness, or the concentration of calcium ions in water, can also play a crucial role in clogging. High levels of calcium can lead to scale formation, which can build up on the interior surfaces of the well screen and further reduce the efficiency of water extraction. The combination of biofilm from iron bacteria and scale from calcium contributes heavily to clogging issues in well screens.

While the other options present factors that can affect water quality or well operation, they are less directly related to the specific mechanism of well screen clogging compared to iron bacteria and calcium hardness.