Fig. 1: Surface water dominates urban water supply.
From: Comparison of potential drinking water source contamination across one hundred U.S. cities
Relative contributions of surface water and groundwater to total water supply across 116 United States cities with population exceeding 150,000 people (city locations shown on map, top right). Vertical positioning of each point within each Census region (West/South/Northwest/Midwest) is random to avoid overlap.
