Water filter type
Lead reduction filters
Point-of-use filters certified for lead under NSF/ANSI 53. In an older building this is usually more effective than any whole-house approach, because most lead enters from the pipe closest to the tap.
Why point of use beats point of entry for lead
Lead is almost never in the water leaving the treatment plant. It dissolves into the water on the way to your tap, from the lead service line connecting the main to the building, from solder at pipe joints in buildings plumbed before 1986, and from brass fittings and older fixtures.
That geography is the whole argument. A filter at the point where water enters the building sits upstream of most of the pipework that contributes lead. A filter at the tap sits downstream of all of it.
For a brownstone or any pre-war building, a certified filter at the kitchen tap will usually reduce your actual exposure more than a far more expensive system at the main line.
Cold water only, and why that matters
These filters are certified for cold water. Hot water dissolves lead more readily and it also degrades the filter media, so a lead filter on a hot line is neither certified nor effective.
The practical consequence is a habit rather than a product. Do not cook with or make baby formula from hot tap water in a building with lead plumbing, even filtered. Draw cold and heat it.
Flushing helps too. Water that has sat in the pipes overnight has had the longest contact with lead surfaces. Running the tap until it turns cold clears that standing volume before you fill anything.
A filter is not a replacement for the line
A certified filter protects the tap it is fitted to. It does nothing for the bathroom tap a child drinks from, nothing for the outside tap, and nothing about the lead pipe still in the ground.
Many municipalities now publish a service line inventory and run replacement programmes, some at no cost to the owner. Check whether your address is listed, because replacement is the permanent fix and filtration is the measure that protects you while you wait.
Immediately after a service line is replaced, disturbed sediment can raise lead temporarily. Keep the filter in place and flush thoroughly for the period your utility recommends.
What it reduces, and under which standard
Each row names the NSF/ANSI standard the category is tested under. A standard describes what the test covers. It does not mean every unit on the market carries that certification, so check the specific model against its listing before you buy.
| Contaminant | Standard | Note |
|---|---|---|
| Lead, particulate and dissolved | NSF/ANSI 53 | |
| Cysts | NSF/ANSI 53 | |
| Chlorine taste and odour | NSF/ANSI 42 |
What it does not do
Every filter has a boundary. These are the things this one will not fix, listed so you can rule it out quickly if your problem is on the list.
- Lead at taps the filter does not feed, including the bathroom taps children drink from.
- The lead service line itself, which stays in the ground until it is replaced.
- Lead in hot water, because these filters are for cold lines only.
- Hardness, nitrates, or bacteria.
When it fits
- The building has a known or suspected lead service line
- A tap sample has returned a detectable lead result
- You want protection in place while waiting for a service line replacement programme
When it does not fit
- The property is new construction with no lead anywhere in the supply
- You expect it to fix lead at every fixture
- You would use it on the hot line, which is not what it is certified for
Space, services, and upkeep
Under-sink housing or a faucet-mount unit.
No drain connection is required. It needs no power. In the right configuration this can work in a rental, because it does not have to permanently alter the property.
Replacement interval. Every 6 months, or at the rated capacity, whichever comes first. Capacity is the binding limit.
Problems this is used for
We recommend this equipment against these confirmed problems. Each page explains how to confirm the problem before spending anything, and when treatment is not warranted.
- Lead in drinking water. Lead does not normally come from the source water.
Property types where this comes up
Common questions
Can I use the filtered water for baby formula?
Use cold filtered water from a tap fitted with a filter certified under NSF/ANSI 53 for lead, then heat it. Never draw hot water from the tap for formula or cooking in a building with lead plumbing, because hot water dissolves lead more readily and these filters are certified for cold lines only. If you have any doubt about the plumbing, have the tap tested rather than relying on assumption.
Does this fix the lead service line?
No. The pipe stays in the ground and the filter protects the one tap it is fitted to. Many municipalities now publish a service line inventory and run replacement programmes, some at no cost to the property owner, so it is worth checking whether your address is listed. Replacement is the permanent fix and filtration is what protects you while you wait for it.
Should I still flush the tap?
It remains a sensible habit, particularly after water has stood in the pipes overnight, because standing water has had the longest contact with lead surfaces. It is also important in the weeks immediately after a service line is replaced, when disturbed sediment can raise lead temporarily. Keep the filter in place during that period and follow the flushing advice your utility gives.
Other filter types to compare
If the notes above rule this out, these are the neighbouring options worth reading before you decide.
Next step