More than 90% of Americans access drinking water through public water systems, which are regulated at the state and local level, according to the government-standardized data portal USA FACTS.
During 2021, there were 153,501 total water quality violations across all U.S. states and territories. Of the total violations, more than 63% were found because of issues with monitoring and reporting by regulatory agencies.
The high proportion of monitoring, reporting and public notification violations raises questions about how well tens of thousands of public water supply systems test for and report potential health violations to EPA and the public, according to a USA FACTS report released in November 2022.
While the total number of violations in 2021 is lower than the 10-year average, the frequency of drinking water violations does not appear to be decreasing over time, according to the report.
In states such as Iowa and other big agricultural states — with extensive crop production and livestock farming, which involves the use of fertilizer, pesticides and manure — runoff from these activities contributes to water pollution.
These pollutants, particularly nitrates and phosphates, can enter water bodies, causing problems such as harmful algal blooms, oxygen depletion and degradation of aquatic ecosystems.