Drinking water quality in the United States
In 2016, over 90 percent of the nation's community water systems were in compliance with all published U.S. Environmental Protection Agency (US EPA) standards.
[6] These inequities underscore the need for more targeted investment and stronger enforcement of the Safe Drinking Water Act in vulnerable regions.
[22] EPA's Office of Enforcement and Compliance Assurance noted that the agency faced "a daunting list of challenges" in its continuing efforts, particularly with small systems that "lack the basic infrastructure, resources and capacity to provide clean drinking water.
Community water systems—those systems that serve the same people throughout the year—must provide an annual "Consumer Confidence Report" to customers.
[32] Studies have shown that there can be more than 80 common contaminants in treated drinking water that may pose a risk to human health.
A few common water-borne contaminants include aluminum, ammonia, arsenic, barium, cadmium, chloramine, chromium, copper, fluoride, bacteria and viruses, lead, nitrates and nitrites, mercury, perchlorate, radium, selenium, silver, and uranium.
The results of currently published studies do not provide convincing evidence that chlorinated water causes adverse pregnancy outcomes.
[43] EPA has issued standards for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, copper, cyanide, fluoride, lead, mercury, nitrate, nitrite, selenium and thallium.
The symptoms of lead poisoning may include abdominal pain, constipation, headaches, ADHD (Attention Deficit Hyperactivity Disorder), irritability, memory problems, inability to have children, and tingling in the hands and feet.
[50] A typical utility action is to adjust the chemistry of the drinking water with anti-corrosive additives, but replacement of customer pipes is also an option.
[58] In response to the Flint water crisis, EPA published revisions to the LCR on January 15, 2021, addressing testing, pipe replacement and related issues.
$11 billion in the bill allocated generally to drinking water infrastructure could also be spent on lead pipe removal.
[66] EPA published standards in 1991 to ensure that total chromium is limited to 0.1 milligrams per liter or 100 parts per billion in drinking water.
It can also be introduced to the environment through man made processes such erosion of natural chromium deposits, leakage, poor storage, or inadequate industrial waste disposal practices.
[67] In large doses human consumption or exposure can lead to adverse health effects including cancer, eye, stomach, and respiratory tract issues.
Groundwater contamination in Hinkley was caused by water containing hexavalent chromium being dumped on the ground by Pacific Gas and Electric (PG&E) from 1952 to 1966.
[70] EPA has issued standards for over 53 organic compounds, including benzene, dioxin (2,3,7,8-TCDD), PCBs, styrene, toluene, vinyl chloride and several pesticides.
[38] The presence of organic chemicals in water can cause an issues for human health and adverse effects on the environment will occur.
[73] Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic organofluorine chemical compounds which have been studied extensively due to potential human health concerns.
PFOA has been detected in the blood of more than 98% of the general US population in the low and sub-parts per billion (ppb) range, and levels are higher in chemical plant employees and surrounding subpopulations.
[75] In November 2017 the New Jersey Department of Environmental Protection announced plans to develop its own drinking water standards for PFOA.
A sample of very small PWS (serving less than 3,000 people), and all larger systems are required to monitor for 29 perfluorinated alkylated substances (PFAS) and lithium between January 2023 through December 2025.
[89] Perchlorate has been detected in public drinking water supplies of over 11 million people in 22 states at concentrations of at least 4 parts per billion (ppb).
According to patient advocate and writer Mary Shomon, people with thyroid conditions, as well as pregnant women and their fetuses are particularly at risk.
[93] The challenge of defining an acceptable level of perchlorate in drinking water sets two opposing groups with significantly different views against each other.
[96] In September 2020 the Natural Resources Defense Council (NRDC) filed suit against EPA for its failure to regulate perchlorate.
They have been found in tiny concentrations in the drinking water of several US cities affecting at least 41 million Americans, according to a five-month inquiry by the Associated Press published in March 2008.
Researchers do not yet understand the exact risks from decades of persistent exposure to random combinations of low levels of pharmaceuticals.
In 2010 EPA stated that "Further research suggests that certain drugs may cause ecological harm...To date, scientists have found no evidence of adverse human health effects from PPCPs in the environment.
[102] In 2010 it was reported that EPA had not finalized the proposal due to concerns raised by some utilities about high costs for controlling radon.
