What’s Really in Your Tap Water? Common Contaminants Explained

Tap water is something most Australians rely on every day—whether it’s for a glass of water, a boiling kettle, or brushing our teeth. While we often assume the water flowing from our taps is perfectly clean and safe, the truth is that it may contain a variety of impurities. Understanding what’s in your tap water can help you make more informed decisions about filtration, health, and overall water quality.

The Journey of Tap Water

Before it reaches your home, water undergoes extensive treatment to remove pathogens and contaminants. This usually includes coagulation, filtration, and disinfection processes. However, even with these precautions, some impurities can still remain, or be introduced after treatment through ageing infrastructure.

Common Tap Water Contaminants

Here are some of the most common substances found in tap water—and what they mean for your health and home.

• Chlorine: Used to disinfect water and eliminate harmful bacteria, chlorine is added to tap water as a public health safeguard. While generally considered safe in small amounts, high levels of chlorine can result in a strong odour and taste, and may cause skin or eye irritation for some individuals.
• Fluoride: Australia adds fluoride to tap water to support dental health, a practice endorsed by many health authorities. While beneficial in the right amounts, excessive fluoride can lead to a condition known as dental fluorosis, especially in children.
• Heavy Metals: Old pipes and plumbing fixtures can leach metals like lead, copper, and aluminium into your water supply. Long-term exposure to heavy metals can be harmful, particularly to young children and pregnant women. Lead, for instance, is toxic even at low levels and has no known safe exposure limit.
• Microorganisms: Although rare in treated municipal water, bacteria, viruses, and parasites can sometimes make their way into the system—often due to pipe breaks or treatment failures. These can lead to gastrointestinal illnesses or more serious health concerns in vulnerable individuals.
• Pesticides and Herbicides: Runoff from agricultural areas can introduce trace amounts of pesticides and herbicides into waterways. While treatment plants remove most of these chemicals, residues may remain. These can disrupt endocrine systems and may have long-term health effects with continued exposure.
• Pharmaceuticals and Hormones: Modern research has detected minute quantities of pharmaceutical drugs and hormonal substances in tap water. These enter the supply through wastewater that isn’t fully filtered before reuse. Although concentrations are extremely low, the long-term effects of continuous exposure are still being studied.

Australia’s Tap Water Standards: Among the Best, But Not Flawless

Australia is fortunate to have some of the most stringent drinking water guidelines in the world. Many cities, including Melbourne and Sydney, regularly feature on lists ranking the best tap water in the world, with high scores for both taste and safety. However, environmental changes, infrastructure age, and contamination incidents mean it’s still essential for consumers to stay informed and proactive.

Should You Use a Water Filter?

While tap water is generally safe, those concerned about taste, chlorine, or potential contaminants may opt for home filtration systems. Options include:

• Activated carbon filters (removes odour and chlorine)
• Reverse osmosis units (removes heavy metals, fluoride, and more)
• Water filter jugs (convenient but less comprehensive)

Each system varies in effectiveness and maintenance needs, so it’s worth evaluating your specific concerns before purchasing.

From naturally occurring minerals to residual chemicals and occasional contaminants, being aware of your water’s composition empowers you to make healthier choices. Whether you’re reassured by the quality or prompted to invest in a filter, one thing is clear—clean, safe drinking water is worth paying attention to.