Tap water flows from faucets or other water outlets in homes connected to the municipal water system. It’s often juxtaposed against well water and primarily comes from two sources: surface water and groundwater. Surface water includes lakes, rivers, and reservoirs, while groundwater is accessed through wells. Both sources are rich in naturally occurring elements, including beneficial minerals and potentially harmful contaminants like lead and coliform bacteria.
Depending on the treatment methods used by water suppliers, the quality of tap water can vary significantly. It’s almost impossible to have contaminant-free tap water without proper treatment since both of its sources can contain pollutants.
Let’s explore where tap water in the United States, Canada, and Australia comes from, the common contaminants found in it, and more.
Where Does Tap Water Come From?
The United States gets its tap water from surface water and groundwater. Canada’s tap water comes from these two water sources too.
Surface water refers to streams, rivers, lakes, and other natural sources. It’s essentially any body of water that is visible to you. Precipitation and run-off are the two major suppliers of surface water.
Groundwater refers to the water below the ground. Water seeps through the ground and pools in any cracks and crevices in the soil below to form aquifers. Groundwater constitutes about 51% of the drinking water supply of the United States. While surface water is relatively easy to access, groundwater requires some work to get to.
To reach groundwater, municipalities and private water suppliers have to drill big wells. Individuals, for the most part, are required to hire contractors to drill into the ground to create a well.
Where Does Australia Tap Water Come From?
Australia’s tap water comes from stored surface water that resides in reservoirs.
Australia is a dry continent/country, so it’s susceptible to droughts. Moreover, there isn’t enough water below the surface to supply Australian residents, so the country only uses a small amount of groundwater for tap water.
As climate change worsens, Australia’s drinkable water supply is decreasing. As a result, Australia is getting creative and finding other ways to make water drinkable. Seawater desalination is one of these ways, and it has so far played a large role in Australia’s drinkable water supply.
In this process, ocean water goes through a filter to remove solids. Then, the water is moved into a tank where the reverse osmosis process takes place. The final step involves conditioning or treating the water to make it suitable for consumption.
Since Australia is surrounded by ocean water, so desalination provides access to an endless supply of potentially drinkable water. There are quite a few desalination plants set up across Australia to aid in water supply replenishment.
Where Does Sydney Tap Water Come From?
Sydney’s tap water mostly comes from surface water sources such as Lake Burragorang, the Warragamba Dam, and some other smaller lakes and rivers. These sources make up 80% of the city's water supply.
The remaining 20% is desalinated seawater. Sydney sources water from the Tasman Sea and processes it in the Sydney Desalination Plant. This plant is especially beneficial to Sydney residents when there is a drought.
Which Countries Have the Best and Worst Tap Water?
According to the 2024 Environmental Performance Index report prepared by Yale Center for Environmental Law & Policy, countries that have the best and safest drinking water are:
- Estonia
- Luxembourg
- Germany
- Finland
- United Kingdom
- Sweden
These countries provide clean drinking water for all citizens. Moreover, none of them have had a water-related death in the last year.
The report goes on to state that the following countries have the lowest tap water quality:
- India
- Myanmar
- Laos
- Pakistan
- Vietnam
What is in Tap Water?
Some common minerals and contaminants found in tap water are:
- Minerals such as iron, sodium, calcium, magnesium, manganese, chloride, bicarbonate, and sulfate
- Sediment
- Small amounts of metals such as lead, copper, cadmium, and arsenic
- Human waste
- Chemicals such as nitrate, mercury, and fluoride
Some of these compounds are completely safe for consumption, while others are detrimental. The minerals in water are healthy for you as long as they’re not present in high amounts, and fluoride is good for your teeth as it keeps their enamel strong. However, heavy metals like lead, arsenic, copper, and chemicals like mercury can lead to severe health problems (You can learn more about these from our article on water contaminants).
Is It Safe To Drink Tap Water?
While tap water is typically treated and safe for consumption, as city water treatment is well-regulated, its content can vary depending on your location, the water source it comes from, the treatment method, and other factors. The same can’t be said for well water treatment, as the well owners are responsible for its safety.
That said, whether you own a well or not, there are two things you can do proactively to ensure the water you’re drinking is safe.
One is to check your local water quality reports regularly. The other is to test the water from your tap. You can periodically collect a water sample from your faucets and send it to an EPA-certified lab for analysis.
Doing these two things keeps you informed about the quality changes in your tap water and can help you identify whether there are new contaminants that might present a cause for concern. Depending on the results, you should take precautions against potential hazards and notify authorities.
We have a couple of guides that thoroughly cover the tap water quality of cities and states from both the US and other parts of the world:
- Best & Worst Tap Water in the US: State-by-State Analysis
- 10 Countries With the Cleanest Water Ranked (Best and Worst)
How Is Tap Water Treated?
Water treatment varies depending on where you live. The options usually include filtration and disinfection with chlorine or desalination.
Filtration and Disinfection With Chlorine
In a typical filtration process, the water goes through:
- Coagulation: Coagulation is a process in which a coagulant, like ferric chloride, ferric sulfate, or aluminum sulfate, is added to the water held in a big tank. The positive charge in these chemicals neutralizes the negative charge of contaminants and binds them in clumps, a process referred to as flocculation.
- Sedimentation: Before the coagulation process, the contaminants move freely inside the water. After that, due to flocculation, they’re clumped and heavy, which causes them to sink to the bottom of the tank. This process is called sedimentation.
- Filtration: At the end of sedimentation, suspended solids like dirt and sediment and some organic contaminants like algae, clay, and sand stay at the bottom of the tank while the clear water is at the top. Then, that clear water is passed through multiple filters that can remove dissolved contaminants that can’t be clumped together, like chemicals, bacteria, and viruses.
- Disinfection: In the last step, the water is treated with chlorine, chloramines, or both to get rid of any remaining pathogens. Sometimes, fluorine might be added as well to protect tooth health.
Desalination
As we touched on above, desalination plants filter out the salt, bacteria, and other minerals from seawater. Without this process, seawater is undrinkable.
Well Water Treatment
The two previous ways of treating tap water apply if you have city water. If you live in a rural area, it’s most likely that your water source is a well. Well water comes directly from the ground and does not go through government-funded treatment. It’s up to you to filter and treat your water.
Well water treatment usually involves an in-home treatment unit. The most common units are:
- Whole house filtration systems: The groundwater is pushed through filters to remove impurities, similar to how city water is filtered. Although the number and type of these filters might vary depending on the system, they mostly have a reverse osmosis membrane, an activated carbon filter, and an ultraviolet light source.
- Water softeners: In some places, groundwater might be unusually hard, and water softening units are used to eliminate the hard water minerals by employing a process known as ion exchange.
- Distillation systems: In the distillation process, the water is boiled until it all turns to gas so that the contaminants can’t find any particles to hold on to. The steam then gets collected and condensed, while the impurities are left behind.
- Disinfection: Disinfection is when the water from the well is treated with chemicals like chlorine or physical disinfectants. Physical disinfectants include UV light, electronic radiation, and heat.
To recap, water treatment is different depending on where you live. The options usually include filtration and disinfection with chlorine or desalination.
Selecting the Right Water Filtration System
If you want to improve the quality of your water, you’ll need to invest in a water filtration system. When choosing a water filtration system, consider your specific needs and the contaminants most commonly found in your water. Here are some practical tips:
Identify contaminants
Use water testing kits or your local water quality reports to identify the specific contaminants you need to eliminate, then ensure that the filtration system you pick is equipped to filter out those contaminants.
For example, activated carbon filters are great for removing volatile organic compounds (VOCs), while reverse osmosis systems are effective against a wide range of contaminants.
Check certifications
Look for systems certified by organizations like NSF International, a product testing and certification organization. These certifications confirm whether the filter you’re interested in meets specific standards for contaminant reduction.
Evaluate maintenance needs
Think about how much maintenance it may need, such as filter replacement frequency and ease of use. Bear in mind that whole-house systems, for example, often require a certified professional to perform maintenance on them, which could be costly.
What Are the Healthiest Alternatives to Tap Water?
Spring water and purified water are the healthiest types of water to drink, and the best alternatives to drinking tap water.
The EPA and FDA strictly regulate both. Additionally, the International Bottled Water Association is keen on its members following all the necessary regulations.
Spring Water
Bottled spring water is sourced directly from a water spring that sits in an aquifer and is bottled there. If the content of the groundwater isn’t in line with the EPA and FDA standards, it is then subjected to two main treatment methods:
- Filtration: Water is passed through a filter. Depending on the contaminants, the pore size of this filter might change from 0.2 to 5 microns.
- Ozonation: Ozonation is more effective than chlorination for disinfecting water from pathogens and microorganisms like bacteria, viruses, and microbes. Moreover, since ozone might be converted into oxygen after the process, the taste of the water isn’t affected.
Springwater manufacturers aim to protect the taste and benefits of groundwater by keeping treatment to a minimum.
Purified Water
In contrast to spring water, purified water is heavily treated. Like tap water, it goes through coagulation, flocculation, sedimentation, and filtration.
These treatment methods are often followed by:
- Reverse osmosis – to remove contaminants via a membrane that has a minute pore size
- Distillation – to eliminate contaminants by boiling water until it’s all vapor
- Deionization – to remove mineral salts by ion exchange
- Ozonation – to disinfect water from microorganisms
- Absolute 1-micron filtration – to make sure that no contamination remains.
FAQs
Surface water is found in lakes, rivers, and reservoirs, while groundwater is located in underground aquifers. Surface water is more susceptible to contamination from surface runoff, while groundwater is generally protected but can still be affected by pollutants.
The best way to know this is by using a water testing kit or checking your local water quality report. These reports typically provide ample information on the common contaminants in your area.
PFAS, or per- and polyfluoroalkyl substances are a group of man-made chemicals used for various industrial purposes. They’re known as “forever chemicals” because they don’t break down easily and can accumulate in the environment, especially in water and the human body.
Generally, filters should be replaced about every 6-12 months, but it’s important to follow the manufacturer’s recommendations. Do note that replacement frequency could also come down to the type of filter and the amount of water you use.
Final Thoughts
Knowing the origins and treatment of tap water is a key step in ensuring its safety. Although tap water undergoes extensive filtration and disinfection in certain countries, it’s still wise to regularly check water quality reports and consider additional filtration methods if needed.
Alternatively, bottled water offers a regulated and safe option, though it can be more expensive. Stay informed and proactive about water quality by checking out the rest of our blog content, that way you’ll ensure the health and well-being of your household.
