The Hidden Risk In 90 Percent Of America’s Drinking Water – And How To Reduce It

Authored by Kimberly Drake via The Epoch Times (emphasis ours),

In the United States, 90 percent of Americans get the water they need from public drinking water systems that harbor disinfection byproducts, most of which are unregulated and understudied.

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Disinfection byproducts form as a result of chemical treatments that water companies use to keep water free of dangerous pathogens. Some byproducts may increase the risk of cancer.

In the United States, the Environmental Protection Agency (EPA) currently regulates four categories of disinfection byproducts for safety. However, researchers believe there may be hundreds—if not thousands—of unregulated byproducts lurking in the tap water that millions of people drink. The health effects of those chemicals are largely unknown.

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There are simple steps people can take at home to minimize these potentially harmful regulated and unregulated byproducts in their water.

Sourcing Public Drinking Water

In larger cities, water treatment plants typically pull water from surface water sources such as lakes, rivers, or reservoirs; groundwater; or a combination of both. Small towns tend to source drinking water from groundwater.

The U.S. Geological Survey estimated that in 2015, 70 percent of water used in the United States came from surface water sources, and 30 percent came from groundwater.

Some locations may use recycled water, which comes from municipal wastewater, stormwater, or agricultural runoff.

The water source that usually needs the least treatment is groundwater.

Treating Public Drinking Water

Regardless of where it comes from, water supplied to the public goes through several treatment processes involving the addition of chemicals to remove small particles and filtration to ensure it is safe to drink.

During the treatment process, water companies must strike a balance. They must add sufficient chemicals to the water to ensure safety, without exceeding EPA limits for treatment chemicals and their byproducts.

This process involves several steps, including:

1. Coagulation: Adding chemicals such as salts, iron, or aluminum to bind small particles.
2. Flocculation: Mixing the water to help particles form larger clumps, sometimes with the addition of other chemicals.
3. Sedimentation: Allowing large, heavy clumps to settle to the bottom of storage containers.
4. Filtration: Passing the remaining clear water through several filters to remove residual particles, parasites, bacteria, and viruses. Some water treatment plants may use reverse osmosis, especially when treating recycled water.
5. Disinfection: Using chemicals such as chlorine or chloramine to kill harmful germs and prevent waterborne illnesses such as cholera and typhoid.

While some treatment plants may use ultraviolet (UV) light or ozone during this step, disinfection chemicals are necessary because they continue to kill pathogens as the water travels to people’s homes. UV and ozone alone cannot provide that protection.

Health Concerns With Disinfection Byproducts

According to a 2024 EPA report, although disinfection chemicals are effective, they can react with compounds present in water and create harmful byproducts, which treatment plant operators must remove during the water treatment process. EPA disinfection rules require utilities to monitor treated water for four disinfectant byproducts, including:

• Trihalomethanes
• Haloacetic acids
• Chlorite
• Bromate

Treating recycled water is more challenging, as research suggests it needs more chemicals and advanced processes to clean it, which may lead to the creation of more byproducts.

“There are consistent associations between disinfection byproducts and bladder cancer, also some associations with colorectal cancer,” Susan D. Richardson, a professor of chemistry at the University of South Carolina, told The Epoch Times. She also cited associations between disinfection byproducts and miscarriage and birth defects.

Studies using hamster cells have shown that more than 100 disinfection byproducts are toxic to living cells and DNA.

While research is limited, the strongest evidence linking disinfection byproducts to cancer appeared in a study published in January in Environmental Health Perspectives. Results suggest that the byproduct trihalomethane increases the risk of bladder cancer by 33 percent in the highest versus lowest exposure groups, and colorectal cancer by 15 percent, even when levels are below current regulatory limits.

A review published in June in the Journal of Hazardous Materials found that long-term use of chlorinated drinking water and exposure to high levels of trihalomethanes are associated with an increased risk of bladder cancer, particularly in men.

Another 2024 study suggests there are more than 600 known disinfection byproducts, and potentially thousands more, most of which have no purified reference standard. This makes it difficult to determine how often they occur in drinking water or how harmful they may be.

“While previous studies have looked at the fate of regulated disinfection byproducts in distribution systems, very few have investigated the more toxic, unregulated byproducts,” Richardson said.

A Chinese population-based study found associations between prenatal exposure to nitrosamines, a group of unregulated disinfection byproducts, and lower birth weight among newborns, as well as a heightened risk of preterm delivery.

A 2021 study coauthored by Richardson suggests that disinfection byproducts are typically present at 100 to 1000 times higher concentrations than other water contaminants. The authors noted that it remains unclear which byproducts may be linked to bladder cancer, miscarriage, and birth defects.

The paper’s findings prompted Richardson and her colleagues to recommend that unregulated byproducts—specifically haloacetonitriles and iodoacetic acids—be considered for regulation, as they were the main drivers of toxicity in drinking water in this U.S.-based study.

Richardson told The Epoch Times her group’s latest research, expected to be published soon, investigated the fate of 66 disinfection byproducts as the treated water travels through pipes from the treatment plant to people’s homes.

She said that water distribution pipes are like reactors where disinfection byproducts can continue to form or degrade, and some transform into other byproducts over time.

The Epoch Times reached out to the EPA for comment on disinfection byproduct safety and unregulated byproducts revealed in studies, but did not receive a response.

Reducing Exposure to Disinfection Byproducts

A recent Environmental Working Group (EWG) study found that advanced per- and polyfluoroalkyl (PFAS) treatment technologies reduced trihalomethanes by 42 percent on average and lowered haloacetic acid levels by 50 percent.

However, only 8 percent of U.S. water treatment plants currently have these systems.

Steve Via, director of federal relations for the American Water Works Association, told The Epoch Times there are several technologies utilities use in combination with chlorine or chloramines to produce fewer byproducts.

However, he noted that there are no alternatives to chlorine or chloramines for maintaining water sanitation during distribution to homes, as mandated by the EPA’s Surface Water Treatment Rule. These methods are generally considered best practice for water systems.

While most people have no control over what happens to their drinking water at the treatment plant, reducing exposure to potentially harmful byproducts at home is possible.

Richardson said her group’s research showed that activated carbon filters can remove some of the disinfection byproducts, although ongoing studies are investigating this in more detail.

Reverse osmosis systems are another option. A 2017 paper in the Journal of Environmental Health Science and Engineering found that reverse osmosis can simultaneously remove both organic and inorganic byproducts and their precursors.

Richardson noted that reverse osmosis is particularly effective for charged byproducts such as haloacetic acids and for larger molecules.

Water pitcher filters can also help reduce exposure.

* AHEM *

Via advised that before purchasing a water treatment device, consumers should confirm it is certified to NSF standards for the contaminant of concern and install and maintain the device according to the manufacturer’s instructions.

Activated carbon filters are typically installed where the water pipe enters the house (point of entry) or in the pipes leading to a faucet. Reverse osmosis systems are usually installed under a sink and connected to the faucet. Most commercially available filter systems combine carbon filtration and reverse osmosis to maximize chemical removal.

Installing filtration systems or using pitcher filters may help reduce disinfection byproducts, but these options can be costly. However, there are low- or no-cost ways to lower exposure.

“Setting aside drinking water in a pitcher in the refrigerator allows disinfection byproducts to dissipate, so that is one option,” Via said.

Storing water with or without a lid can reduce trihalomethanes by up to 47 percent, and boiling water for one minute and then storing it can lower the level of these byproducts by up to 92 percent, according to a 2019 study published in Science of The Total Environment.

People who want to learn more about what’s in their water can access water quality reports by calling their local water utility company, visiting the utility’s website, or searching for the report on the EPA’s Consumer Confidence Reports webpage.

Reports typically show levels of the four regulated byproducts, and inorganic contaminants like arsenic, fluoride, and nitrate. They may also reveal lead and copper levels, PFAS, and radioactive contaminants like uranium. Reports often indicate whether the water came from surface water, ground water, or recycled water.