50% of US Water Pollution Could be Caused by the Entry of Contaminants in Ephemeral Streams Endangering Communities, Aquatic Life [Study]

Water pollution in the United States is an ongoing environmental and public health threat. It was during the 19^th century that the problem of the country's water quality reached a critical level, endangering not only human population centers but also local ecology. The underlying issue stems from various anthropogenic factors, including mining, agricultural development, and industrial chemical emissions.

In recent years, the US Government has acknowledged contamination affecting water supply in some parts of the country. In 2023, the presence of "forever chemicals" or PFAS (per- and polyfluoroalkyl substances) was detected in the nation's tap water, according to the U.S. Geological Survey (USGS). These hazardous toxic chemicals are used to manufacture consumer products worldwide.

Now, a new study led by researchers from the University of Massachusetts and Yale University has determined half of the US water pollution may have come from ephemeral streams, rivers that only flow after a rain event or snowmelt. The study also highlights that contaminants can "legally" enter these inland bodies of water, meaning the pollution comes from chemical residues from industrial establishments.

US Water Pollution

Water contamination can happen in both developed and developing nations, threatening not only local communities but also aquatic life. In the US, agricultural pollution is a major cause of water pollution, along with sewage or wastewater, oil pollution, and radioactive substances, as reported by the National Resources Defense Council (NRDC). These contaminants are in addition to the pollution caused by microorganisms.

Over the past decade, there have been various surveys regarding the impact of water pollution on human health, which can result in moderate to severe symptoms or even death. In 2015, scientists estimated that water pollution killed a total of 1.8 million people, based on a 2017 study cited by the non-profit environmental advocacy group published in The Lancet journal.

Forever Chemicals and Ephemeral Streams

In the US, forever chemicals were detected in at least 45% of the nation's tap water and identified 32 types of PFAS, according to a USGS announcement in July 2023. USGS scientists spotted the forever chemicals by sampling tap water from kitchen sinks.

Meanwhile, the University of Massachusetts and Yale University found that ephemeral streams (which are not protected by the Clean Water Act) potentially contribute to 50% of the US water pollution. These findings may explain as to why the entry of PFAS into the water supply continues. Their findings were published in the journal Science on Thursday, June 27.

It was in 2023 when the Supreme Court ruled that these rivers were not included in the Act. This means that such streams are not protected by US law even if they are polluted. The US water pollution is not only limited to mainland communities. Previously, scientists found that river pollution spreads into the oceans, harming marine life and their ecosystems.