Most people do not know what is in their tap water. They know it has been treated. They assume it is safe. In most developed cities it meets regulatory standards for most contaminants. But meeting regulatory standards and being free of health-relevant contamination are not the same thing. In April 2024, the US EPA set the first ever enforceable limits for PFAS in drinking water. This was necessary because PFAS have been in the water supply for decades without any limit.
What is in tap water
Tap water in the US and Europe typically contains: chlorine or chloramine (disinfectants), fluoride (added in most US systems for dental health), chlorination byproducts (trihalomethanes and haloacetic acids formed when chlorine reacts with organic matter), and depending on infrastructure and location, variable amounts of lead (from service pipes and household plumbing), arsenic (natural geological source), nitrates (agricultural runoff), and now confirmed in many systems, PFAS. The EWG tap water database, built from utilities' own testing data, shows that the majority of US water systems contain at least some PFAS.
PFAS and the EPA ruling
The 2024 EPA ruling set maximum contaminant levels of 4 parts per trillion for PFOA and PFOS individually, and 10 parts per trillion for a combination of four other PFAS compounds. For context, a part per trillion is one drop in 20 Olympic swimming pools. The limit was set at the lowest measurable level because no safe level for PFOA or PFOS could be identified. Water utilities have until 2029 to comply. The EWG estimates that PFAS contamination above the EPA health limit affects water systems serving more than 200 million Americans.
Lead pipes
Lead enters water through lead service lines (the pipes from the water main to the building), through lead solder used in household plumbing until 1986, and through some brass fittings. The EPA estimates that 9.2 million homes in the US still have lead service lines. Lead does not discolour water, taste metallic at relevant concentrations, or produce any sensory signal. The only way to know if your water contains lead is to test it. If you are in a home built before 1986, request a lead test from your water utility or commission an independent test. The CDC states there is no safe level of lead exposure in children.
Filter types compared
Not all filters remove PFAS. Standard Brita pitchers use activated carbon that removes chlorine taste but does not adequately remove PFAS. The Brita Longlast+ filter removes some lead but not PFAS. Reverse osmosis systems push water through a semi-permeable membrane and remove 99%+ of PFAS, lead, arsenic, nitrates, and most other contaminants. Solid block activated carbon filters, if of sufficient quality and thickness (look for NSF Standard 53 certification), can remove PFAS and lead. The Clearly Filtered pitcher uses a proprietary solid block filter that independently tested shows 99.6% PFAS removal. For comprehensive protection, a reverse osmosis under-sink system is the gold standard.
What to buy
Clearly Filtered Pitcher ($90)
The best pitcher for PFAS. Removes 99.6% of PFAS, 99.9% of lead, and a wide range of other contaminants. More expensive than Brita but substantially more effective. This is the minimum we recommend for PFAS protection.
APEC ROES-50 Under-Sink RO ($200)
Best overall value for comprehensive protection. Removes 99%+ of PFAS, lead, arsenic, nitrates and chromium-6. Installs under the kitchen sink with a dedicated tap. Filter replacement every 12 months.
Check the EWG Tap Water Database
Enter your postcode or zip code at ewg.org/tapwater to see what your utility has tested for and found. This tells you which specific contaminants to prioritise filtering.