The space between the inner casing and the outer casing of a well should be filled with cement grout to a minimum of how many feet?

Cement grout is used in well construction to create a barrier that prevents contaminants from entering the well and maintains the integrity of the water source. Filling the space between the inner and outer casings with cement grout is crucial for protecting the well from surface water and other potential pollutants.

The minimum requirement for the depth of cement grout in this space is typically set at 10 feet. This depth is intended to ensure that the seal is effective in preventing any surface drainage or contaminants from infiltrating the well. A minimum of 10 feet helps establish a physical barrier that provides adequate protection to the water supply by preventing migration of surface water, which could carry pathogens or other harmful substances.

While other answers might suggest deeper grout levels, the established minimum requirement is specifically 10 feet, reflecting industry standards and best practices for well construction and groundwater protection.