Education: Why Filtering Your Tap Water Matters When You’re Breastfeeding

Here in Australia, we’re lucky to have access to treated tap water that’s considered safe by national standards. But that doesn’t always mean it’s ideal for your healing body — or for your baby’s. Even “safe” water can contain things your body doesn’t need — chlorine, fluoride, trace heavy metals, and chemical by-products from disinfection. These chemicals may seem harmless at first glance, but they can accumulate in your body and potentially be passed into your breast milk, exposing your baby to environmental toxins.

Filtering your water reduces chemical exposure and minimises heavy metal intake — both of which support your natural detox pathways and reduce strain on your liver and hormones. It also lowers your exposure to substances known to disrupt the endocrine system, which is crucial when your hormones are doing delicate work to recover and produce nutrient-rich milk for your baby.

1. One of the most common chemicals found in tap water is chlorine, used to disinfect and kill bacteria. But when chlorine interacts with organic matter, it forms disinfection by-products (DBPs). While these chemicals are typically present in small amounts, studies have shown that even low levels of these DBPs can pass into breast milk. While the research is still growing, early findings suggest that even low levels of DBPs could have health implications for developing infants, including potential impacts on thyroid function, immune system development, and neurodevelopment in infants.

1. Other pollutants, such as perfluorinated alkyl substances (PFAS), also known as “forever chemicals,” have been shown to alter the lipid profile of breast milk and may have long-term implications for both maternal and infant health.

1. Heavy metals like lead, arsenic, cadmium, and mercury are known to contaminate drinking water, especially in areas with older plumbing or industrial pollution. These metals can accumulate in breast milk, and even small amounts can harm your baby’s development. Lead, for example, has been linked to neurological and cognitive issues in children, which is especially concerning when infants' brains are growing rapidly during the first months of life.

From a naturopathic lens, any opportunity to lower unnecessary chemical stress on a tiny, growing body is worth considering. For both your and your baby’s health, filtering out these compounds makes sense.

Practically speaking? Filtered water tastes better. From my experience in clinic, I have found that patients who switch to filtering their water tend to drink more and are generally better hydrated. When water is clean and crisp, you naturally want to drink more of it, and staying well-hydrated is one of the best things you can do to support your milk supply.