Why Tap Water Seems Safe but May Not Be
Tap water is something that the majority of us take for granted, as we often overlook the common sources of its contaminants. You open a tap, fill your glass, and you suppose it is clean and safe, as it is treated and regulated. Unless you have a well or pump, all municipal water systems in the United States and other developed nations pass through many layers of federal regulation before water reaches your home.
However, the reality is this: what is "legally safe" is not necessarily what is "health-optimal," considering the various health issues that can arise.
The U.S. Environmental Protection Agency (EPA) regulates approximately 90 contaminants in the water supplies available to the people. Even so, the identified number of unregulated contaminants in tap water in the United States exceeds 160, as indicated by the Environmental Working Group (EWG). Most of these new pollutants lack an enforceable legal standard; that is, utilities are not under any obligation to clean them up.
Throughout this guide, we will examine closely what exactly is contained in your tap water, how it gets there, why the legal limits may not be the best health-based limits, and what you can do to protect yourself and your family from the contaminants contained in your drinking water, such as long-term filtration.
Common Contaminants in Tap Water
In the U.S., tap water is governed through the Safe Drinking Water Act, though this does not mean it is free from contamination with potentially harmful substances. Based on the National Tap Water Database maintained by the Environmental Working Group, numerous municipal systems have levels of the contaminants that are higher than what independent scientists say is safe.
The following are some of the most commonly found contaminants and why you should be concerned.
1. Lead
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Source: Lead gets into drinking water mainly as a result of corrosion in old lead pipes, solder, and plumbing fixtures, especially in houses constructed before 1986.
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Risks: Can damage children's brain development, reduce IQ, cause learning and behavior difficulties, and raise blood pressure among adults at very low levels. Pregnant women and infants are particularly at risk.
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Key fact: The EPA action level of lead is 15 parts per billion (ppb), although the CDC and EWG emphasized that there is no safe level of lead in drinking water.
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Prevention tip: Use an NSF/ANSI-certified lead filter to remove lead, run water for a few minutes before drinking or cooking, and consider replacing old piping.
2. Chlorine and Chloramine
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Source: Utilities add it to disinfect the water and kill the harmful microorganisms. People substitute chlorine with chloramine, which has a longer shelf life in the distribution pipes.
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Risks: Although necessary to address water-borne diseases, chlorine and chloramine may interact with organic materials to create disinfection byproducts (DBPs) such as trihalomethanes (THMs) that are associated with high cancer risk, reproductive health problems, and even potential developmental problems.
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Key fact: Chloramine may be more challenging to eliminate than chlorine and can irritate the skin, cause respiratory problems, or trigger asthma in sensitive individuals.
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Prevention tip: Use a high-quality activated carbon filter or a reverse osmosis system to minimize both disinfectants and byproducts.
3. Fluoride
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Source: Added to the drinking water of many municipalities to prevent tooth decay.
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Risks: At lower doses, fluoride is advantageous to tooth health, but when taken in large dosages, it leads to dental fluorosis in kids, and it may lead to thyroid dysfunction, low IQ for high exposures, and other developmental risks.
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Key fact: CDC recommends 0.7 mg/L to maintain the best dental health, but EWG suggests precautions against high fluoride when making baby formulas, particularly for infants.
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Prevention tip: If you are in a fluoridated community, you may use fluoride-free bottled water to mix up infant formula or even a reverse osmosis filter to prepare the infant formula.
4. Nitrates
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Source: Agricultural runoff, fertilizers, manure, and septic tank leakages are most commonly the source. More at risk are rural locations and neighborhoods around farms.
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Risks: High levels of nitrates are known to make children develop methemoglobinemia (“blue baby syndrome”), which lowers oxygen distribution in the blood. There have been associations between long-term exposure to cancer, thyroid disease, and developmental problems.
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Key fact: According to the EPA, the maximum contaminant level is 10 mg/L, although the health risk is likely at a lower level.
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Prevention tip: If you get your water supply through a privately-owned well and use a reverse osmosis or ion exchange filter to treat it, test it regularly to eliminate nitrates.
5. PFAS ("Forever Chemicals")
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Source: Industrial processes, firefighting foam, stain-resistant fabrics, food packaging, and nonstick cookware manufacturers.
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Risks: PFAS are persistent, bioaccumulative, and toxic, which are associated with cancer, immune system suppression, liver damage, hormonal disruption, and developmental damage.
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Key fact: They are exceptionally hard to eliminate because they can stay in the environment and human body for several years, and it is hard to eliminate them without exceptional filtration.
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Prevention tip: Invest in a reverse osmosis system or an activated carbon filter certified to remove PFAS, and avoid products treated with stain-, water-, or grease-blocking chemicals.
Ever wondered what's in your tap water? Go to the EWG tapwater database, type in your ZIP code, and see an in-depth report on what is in your local water system.
How Contaminants Enter Municipal Water
Municipal water systems are often unable to eliminate all possible contaminants, even with high-technology treatment options. Most pollutants enter the water supply before it reaches a water plant, while others occur after treatment and as the water travels through the distribution system pipes to your tap.
Before Treatment
The contaminants may find their way into the source water, either rivers, lakes, or groundwater, much before the treatment process starts:
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Industrial discharges: manufacturing plants and factories could have heavy metals, solvents, and other toxic waste, which are released into the local water sources. EPA guidelines on Industrial Wastewater Discharge describe how these pollutants reach the public's sources of water.
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Agricultural runoff: Nitrate and phosphate fertilizers, as well as pesticides, may dissolve and move to rivers and underground water with water runoff. It is one of the most significant factors of nitrate pollution in a rural setting that has been related to health problems such as blue baby syndrome and cancer.
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Natural contamination: Certain hazardous materials are naturally present. An example is arsenic, which might leach into healthy water and aquifers, particularly in the western United States, in some rock formations.
After Treatment
Although water exits the treatment plant with safeguarded levels, it might become polluted before it reaches your faucet:
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Pipe corrosion in old pipes: Lead and copper may leach into pipes that are decades old and part of the typical home plumbing or service lines. The EPA states in the Lead and Copper Rule that this poses one of the biggest threats to the safety of tap water in the U.S.
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Leaching plumbing fixtures: Older brass faucets, solder, and fixtures can release lead and other metals into your drinking water.
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Biofilm accumulation: Bacterial growth may also create biofilms within the pipes, which occasionally leak bacteria or byproducts of disinfection back into the water.
The Aging Infrastructure Problem
The aging water infrastructure in America is one of the greatest challenges it faces. Most municipal systems are over 50 years old, with some dating back to the early 20th century, and their pipes are similarly aged. Old systems are more likely to break, leak, or even corrode- this continually poses a risk of contamination. Although in its most recent Report Card for America's Infrastructure, the American Society of Civil Engineers (ASCE) rated the U.S. drinking water infrastructure a grade of C from C-.
Legal Limits vs. Health-Optimal Levels (EPA vs. EWG)
In the case of water safety, what the law says and what is safe are two different things.
The U.S. Environmental Protection Agency (EPA) establishes Maximum Contaminant Levels (MCLs) on the water supply at the national level, which are binding. However, these limits are not entirely based on healthcare science; they also consider the cost of treatment, the ability to detect the problem, as well as political factors (EPA Drinking Water Standards).
This means:
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The regulation level might be significantly larger than the amount that is believed to be safest concerning health.
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Several MCLs are outdated, and some remain unchanged from decades ago, despite new findings indicating risks at a lower scale.
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Certain chemicals, such as the so-called forever chemicals PFAS, do not have a federally regulated limit yet despite their demonstrated detrimental health effects.
In comparison, the Environmental Working Group (EWG) establishes Health Guidelines that are strictly based on health considerations and apply the latest data on toxicology and epidemiology without considering the cost of treatment. In many cases, their results are much more stringent than EPA levels, reflecting the best available science.
Here's a table for comparison:
Contaminant |
EPA Legal Limit |
EWG Health Guideline |
Common Sources |
Health Concerns |
Lead |
15 ppb |
0 ppb |
Aging pipes, plumbing fixtures |
Developmental delays, learning problems, and kidney damage |
Nitrate |
10 ppm |
0.14 ppm |
Fertilizer runoff, septic systems |
Blue baby syndrome, possible cancer risk |
Arsenic |
10 ppb |
0.004 ppb |
Natural deposits, industrial pollution |
Skin lesions, cancer, cardiovascular disease |
PFAS (“forever chemicals”) |
No federal limit |
1 ppt (proposed) |
Non-stick cookware, firefighting foam, and manufacturing waste |
Hormone disruption, cancer, and immune suppression |
Chromium-6 |
No federal limit |
0.02 ppb |
Industrial discharge, erosion of natural deposits |
Why this matters: Your water may still be contaminated with levels of EPA-regulated contaminants that are still unsafe in the long term and which can be particularly harmful to vulnerable populations like infants, pregnant women, and individuals with weaker immune systems. To learn more about health risks and safer options, see our article on drinking water filtration systems and the CDC's Drinking Water and Health.
How to Research Your Local Water Quality (Without DIY Testing)
You may not necessarily have to spend money to purchase a home water test kit to determine the contents of your tap water, because there are several trusted and free resources you can use to get appropriate information concerning your local water supply. Knowing where to inquire can help guide you on whether to filter or leave alone water, bottled water consumption, and even local advocacy issues.
1. Check Your Utility’s Annual Consumer Confidence Report (CCR)
The Safe Drinking Water Act (SDWA) requires all water systems in the U.S. to publish an Annual Consumer Confidence Report by July 1 of each year. This document enumerates:
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All water contaminants found in your water over the last year
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A comparison of the levels with the EPA legal limits
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Potential health impacts of any of the contaminants.
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Where your source water comes (e.g., river, reservoir, well)
How to access:
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Visit your local water utility website and search for "Water Quality Report" or CCR.
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You can call your utility and ask them to send you a copy of it, just in case it is not up to date online.
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In case of small community systems, you might get the CCR through the mail.
2. Use the EWG Tap Water Database
One of the most user-friendly resources is the Tap Water Database offered by the Environmental Working Group. Type in your ZIP code, and it will access information contained in official utility reports and show:
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All the pollutants found in your local source
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The comparison of levels with both the EPA-recommended limits and the more health-protective limits of EWG
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Even though contaminants may be well below modern research-based safety standards, they may still be above the outdated federal regulations.
It is beneficial because EPA regulations on many pollutants have not been revised in decades, so your water may be technically legal, but still not perfect in terms of health.
3. Review State Environmental Agency Reports
Most states carry out additional testing on emerging contaminants that are not yet federally regulated, such as:
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PFAS (forever chemicals)
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Chromium-6
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Uranium
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1,4-Dioxane
To access these reports:
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Enter your state name with "[Your State] Department of Environmental Quality" or "[Your State] Water Resources Department" and check under Water Quality Reports.
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In other states, there are interactive maps or databases on which you can compare results on a county or municipality basis.
As an example, the State Water Resources Control Board of California has a water quality database that individuals can search and find specific contaminant information in their communities.
4. Search the EPA’s Safe Drinking Water Information System (SDWIS)
The EPA maintains an SDWIS database where you can find violations, enforcement actions, and monitoring histories of any of the U.S. public water systems. This can inform how your provider was recently involved in safety breaches or compliance.
How to use it: Type your state and the name of your water system to access inspection outcomes, enforcement activities, and contaminant observation listing.
5. Check Local News & Community Environmental Groups
Investigative journalists at the local level frequently publish long-form coverage about water quality issues, most often following water contamination incidents. Search for “[Your City] water quality site:[localnewsdomain].com” and it can turn up a detailed and relevant coverage.
You can also engage local advocacy groups, such as Clean Water Action, which monitor water safety in the area and provide independent reports.
6. Look at School or Hospital Water Testing Data
Public schools, universities, and hospitals also independently perform lead and contaminant testing in older structures in many cases. These results are often public records and will provide you with area-by-area images, which can vary from the utility-wide average.
7. Review USGS Water Data for Your Region
The U.S. Geological Survey Water Data portal provides raw test data for wells, rivers, and reservoirs. If your community’s source water comes from these bodies, the data show upstream contamination trends before they end up in drinking water.
The Problem with TDS Obsession (Debunked Simply)
Total Dissolved Solids (TDS) is defined as the concentration of the total volume of dissolved minerals, salts, metals, and other solids in the water, which may be beneficial and/or harmful. Although most individuals tend to think that a high or low TDS value represents that a given water is good or bad, this is not the case.
Here’s why:
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Good minerals, like calcium, magnesium, and potassium, are necessary nutrients in human beings, and the reading of TDS is naturally higher with these minerals. That is why mineral spring water can contain large amounts of TDS yet be perfectly safe and even helpful.
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Possible contaminants may remain undetected. Hidden impurities such as lead, PFAS (forever chemicals), arsenic, or microbial pathogens may be present in tiny proportions that barely have any impact on the TDS values. They can, however, be potentially dangerous to health (EPA: Drinking Water Contaminants).
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Taste does not equal safety. Taste is not a good measure of protection, and some people think that water with a low TDS will taste less polluted. Most contaminants are colorless, odorless, and tasteless.
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RO systems and TDS misunderstanding. RO systems typically reduce the TDS drastically by eliminating both harmful chemicals and healthy minerals. That is why post-filtering remineralization is sometimes suggested to regain taste and a proper mineral balance.
To sum it up: TDS informs you of the quantity, not of the quality. Rather than relying on it as a safety determinant, focus efforts on testing and eliminating known contaminants, regardless of whether this is achieved through certified home water filters, municipal water treatment records, or independent laboratory reports.
Once you've identified the contaminants in your water, the next step is to find the right filter for your needs.
Not every water filter is necessarily designed to remove every possible water contaminant; some aim to eliminate only chlorine and make the water taste good, and others are constructed to eliminate serious health hazards such as lead, PFAS, or microbial contaminants. Understanding what to look for can be the difference between a filter that will make your water taste better and one that will protect your health.
What to Look for in a Reliable Water Filter
Choosing the proper water filter is not just a matter of taste; it is a matter of matching a specific water quality issue with the right technology. Regardless of the primary purpose behind chlorine removal to add flavor, safeguard your family against lead or PFAS, or make sure the water is safe in case of emergencies, the following are the key points to remember:

1. Contaminant Removal Range
All filters are not created equal; while one might remove only the taste and odor, another can reduce serious health risks. Consider models that will eliminate or reduce:
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Heavy metals like lead, mercury, and arsenic
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PFAS (per- and polyfluoroalkyl substances) are associated with chronic health risks
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Agricultural runoff includes pesticides & herbicides
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Chlorine & chloramine, which influence the taste and potentially lead to the formation of harmful byproducts
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Microbial contaminants: Bacteria, viruses, and cysts
2. Independent Certification
Make sure that the filter is NSF/ANSI tested by a reputable, independent third-party organization. For example:
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NSF/ANSI 53- Reduces health-related contaminants such as lead and cryptosporidium
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NSF/ANSI 42- Enhances taste, smell, and reduces chlorine
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NSF/ANSI 401 -Removes emerging contaminants such as pharmaceuticals and microplastics
It makes sure the manufacturer's claims are science-based and not mere marketing.
3. Capacity & Lifespan
The lifespan of the filters affects the long-term and maintenance costs. A filter with a larger capacity (in gallons) may help save money and reduce waste.
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For families, consider systems that last 6 months to several years, depending on use.
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Consider the accessibility and cost of obtaining replacement filters.
4. Maintenance & Ease of Use
The harder a filter is to maintain, the greater the chance it falls through the cracks and decreases performance. Select the systems that have:
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Tool-free filter replacement
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Easy-to-clean housing
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Easy-to-follow guidelines as well as visual indicators for replacement signs
5. Design & Portability
Consider where and how you will use it:
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Countertop/ Under-sink filters that can be used daily at home
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Portable filters or gravity-fed travel, camp, or emergency filters
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Compact, no-power-required systems in the off-grid lifestyle or disaster preparedness
Why Berkey Filters Stand Out
Berkey Water Filters has gained numerous loyal customers because of its unique combination of broad-spectrum performance and a practical design.
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Eliminates known contaminants - Eliminates more than 200 contaminants, including heavy metals, PFAS, pesticides, pharmaceuticals, and pathogens, making it one of the most comprehensive systems on the market.
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Gravity-fed usage- No plumbing or electricity required, ideal for everyday or emergencies.
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Durable filter components- The Black Berkey Elements have a long usable life of up to 6,000 gallons per pair, and will frequently render years of clean, safe drinking water to a family.
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Flexibility of use- It works best at home, in RVs, for travel, and in off-grid systems.
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Proven history - Relief organizations, outdoor enthusiasts, and families throughout the world use it.
Specific Actions Families Can Take to Reduce Exposure
To ensure your family's safety against the dangers of tap water contamination, consider implementing some minor daily routines. Aging pipes, industrial runoff, or farm methods introduce many contaminants into drinking water, including lead, PFAS or forever chemicals, pesticides, and nitrates. Although there are federal standards, studies indicate that such thresholds do not necessarily coincide with the newest health recommendations.
These are the tested methods of limiting the exposure of your household:
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Drink and cook with filtered water. Use drinking water filters that are certified to remove the contaminants of concern in your region. To illustrate, you should prefer a type that is effective in combating nitrates if you reside in an agricultural area. To do so, look for a good water filter that has a capacity for the amount of water you consume.
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Flush taps before use. In the morning or after non-use, allow cold tap water to flush through a tap for about 1-2 minutes. This helps to eliminate stagnant water, which might have increased contaminant levels.
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Never drink hot tap water, as it tends to dissolve metals, mainly lead, in the plumbing system. Instead, boil cold filtered water in a pan or use a kettle.
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Upgrade aging plumbing. Use non-lead faucets, fittings, and pipes that are NSF/ANSI-approved.
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Safely store water for later use. Since bacteria can multiply, filtered or bottled water should be stored in clean bottles or food-quality containers.
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Mind your ice. An ice maker should always be attached to a tap and water filtration system.
Regions Where Tap Water Is More Likely to Be Unsafe
Although the U.S. Environmental Protection Agency (EPA) upholds standards of the water systems accessible to people, certain areas are more vulnerable because of geography, infrastructure, and local industry.
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Industrial areas: More likely to have PFAS, solvent, and chemical discharges. The exceptional ones are segments of Michigan and West Virginia, where manufacturing has constantly affected the quality of water.
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Farm lands, or agricultural belts: These are rural Midwest communities with high fertilizer runoff and elevated levels of nitrate.
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Legacy lead pipes are a significant risk to older cities like Newark, Pittsburgh, and Flint.
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Areas at risk of droughts: Low water levels will lead to increased concentrations of contaminants in specific parts of California and Arizona.
How to Advocate for Stricter Water Safety Standards
When it comes to water quality, you may not feel you can do much, but you can use your voice to influence safer policies.
✔ Participate or volunteer in local organizations like Clean Water Action or state advocacy networks.
✔Attend the city council or water board meetings to learn about testing time schedules, infrastructure projects, and the removal of contaminants.
✔Contact your state and federal legislators and ask them to support more demanding EPA standards and funding to support upgrades in the public water systems.
✔Educate the neighborhood on how to avoid infection by posting reliable information, such as the CDC's Water Safety page or local health department reports and news.
✔Encourage PFAS bans and other preventative policies that put an end to contamination before it starts, instead of treating it once it has already happened.
No matter how active the families may be, the quality of municipal water and private wells can never be entirely under their control. This is why one of the most valuable methods of defending your household throughout the year is to have a stable filtration system.
Empowerment Through Knowledge and Effective Filtration

The safety of tap water is a complicated matter; not only does it involve the personal responsibility to make educated decisions, but it also needs to be advocated on a group level. Although public systems struggle to provide clean water, they continue to be polluted in our taps. The existing legal limits are not always in line with the most recent science, and most pollutants are not regulated.
The great news is that there are alternatives, especially for residents in urban areas.
With some knowledge about the content of local water, with some home prevention measures, and a good long-term investment in a water purification system like Berkey, you can significantly minimize the exposure of your family and relax in the peace of knowing that you are doing the proper protection.