PFAS in drinking water, explained
PFAS are a group of synthetic chemicals that have been used in manufacturing since the 1940s. They don't break down in the environment or in the body, which is why they've drawn increasing regulatory attention. In 2024, the EPA set the first enforceable federal limits for several PFAS compounds in drinking water.
What you'll learn
- What PFAS are and where they come from in the environment and in homes
- What the EPA's 2024 enforceable limits cover and why they matter
- Why PFAS don't show up on standard test strips or utility water reports in most cases
- Which filtration methods are effective at reducing PFAS and which are not
- How to find out whether PFAS have been detected in your local water supply
Step by step
- Understand that PFAS stands for per- and polyfluoroalkyl substances, a large class of chemicals used in non-stick coatings, food packaging, firefighting foam, and other products.
- Check your utility's most recent water quality report or the EPA's ECHO database to see whether PFAS have been measured in your supply.
- Know that the 2024 EPA rule set maximum contaminant levels for PFOA and PFOS at 4 parts per trillion, among the most stringent limits ever set for drinking water.
- Standard pitcher filters and basic carbon blocks are not rated for PFAS. Look specifically for NSF 58 or NSF 53 certified systems.
- Reverse osmosis is one of the most effective technologies for PFAS reduction. Most quality RO systems are certified for PFOA and PFOS removal.
- Activated carbon with long contact time can reduce some PFAS compounds, but performance varies by compound and system design.
If PFAS reduction is a priority, verify that any system you're considering carries NSF 58 or NSF 53 certification specifically for PFAS. A free in-home water test can confirm what's present before you invest in a specific solution.
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Keep learning.
How to test your tap water at home
San Diego tap water regularly tests at 17 to 20 grains per gallon, which puts it in the very hard category. A five-minute test strip check gives you a directional reading you can act on. It won't replace a professional analysis, but it tells you enough to know whether treatment is worth exploring.
How to spot hard water in your home
Hard water doesn't smell or look different, so most homeowners don't notice it until the damage is already done. At 17 to 20 grains per gallon, San Diego sits well into the very hard range. Knowing the signs early can save you real money on appliances, plumbing, and fixtures.
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A whole-house filter treats every tap in your home at the point where water enters the main line. That means filtered water for drinking, showering, laundry, and appliances, not just the kitchen sink. Understanding how the system is staged helps you know what it's doing and when it needs attention.