Fig. 5: Source diversity and reliance matters.
From: Comparison of potential drinking water source contamination across one hundred U.S. cities
a Displays the impact of watershed weighting on nonpoint PPCS, while b displays the impact of watershed weighting on point PPCS. These results show the % impact on Point and Nonpoint PPCS relative to the same metrics but calculated assuming equal weighting of supply across sources. Results are shown for cities with >5% average nonpoint contamination and cities with >0.5% average point contamination across contributing watersheds. This analysis excludes the influence of groundwater. Point color gives U.S. Census division (see map insert).
