Sewer and water lines are often thought of as modern conveniences in the United States as many rural areas of Appalachia continued to use outhouses and wells until the 1930s. Water and sewer lines have undergone a shift in preferred material selection. Before 1900, most water lines were made from cast iron pipes – a material that was relatively inexpensive, strong enough for pressurized water lines, and capable of being buried under roads other structures. While construction of brick sewers was labor intensive, the refractory materials used to form bricks were naturally resistant to erosion and corrosion, though the same could not be said for mortar. When the growth of sewer systems exploded in the United States, concrete was the go-to material for large-diameter interceptors as it was thought to resolve many of the issues inherent to brick construction.