Which condition is the reason to install Styrofoam insulation above a buried water main?

• A. High turbidity
• B. Inadequate burial depth
• C. Low chlorine residual
• D. High total dissolved solids

Answer: (B)

Protecting a buried water main from freezing. When the burial depth isn’t deep enough to keep the pipe insulated from cold ground, the water inside can freeze in winter. Installing Styrofoam insulation above the buried main slows heat loss from the pipe to the surrounding soil, helping to keep the water from freezing and preventing service disruptions or damage.

Other factors like turbidity, chlorine residual, or total dissolved solids relate to water quality, not temperature and freezing risk, so they aren’t reasons to add insulation.