American Water's breakdown of water supply 2023, by major state

In 2023, around 91 percent of the water supplied to American Water's customers in Pennsylvania was sourced from surface water. Surface water is collected from bodies of water found on the surface of the earth, such as rivers and lakes. In comparison, California was heavily more reliant on groundwater and purchased water. Ground water is extracted from below the Earth's surface between rocks and soil. California is reliant on this type of water source due to the dryness of the state, with concerns rising over the increased occurrence of droughts. Groundwater is most used in agriculture in California, especially in the dry farmlands of the San Juan Valley, where increasing groundwater pumping for irrigation has led to the area sinking as much as two meters in recent years.