Water filters for brownstones and pre-war buildings

Why the build date matters more than the address

Lead solder was not restricted in US plumbing until 1986. Any building plumbed before that date may have lead at the pipe joints even where the service line and the pipework itself are copper, and a great deal of the Northeast's most desirable housing stock predates it by a century.

Service lines are the larger question. Municipalities are now required to inventory the material of every service line and publish the result, and in older neighbourhoods a substantial share of entries come back as lead or as unknown. Unknown is not reassuring. It means nobody has confirmed it either way.

None of this makes the water leaving the treatment plant unsafe. It means the last hundred feet of the journey is doing something the plant cannot control, which is why the utility's report tells you less about your own tap than people assume.

Working in a building that was not designed for this

Point of entry in a brownstone is usually a cellar with low headroom, a single narrow route in, and a main shutoff that has not been touched in decades. We check that valve before quoting, because a valve that will not close turns a half-day job into a street shutoff and a considerably larger scope.

Interior plumbing is frequently a patchwork. A building can have had its risers replaced in the 1970s, one apartment repiped in the 1990s, and original galvanised runs still feeding a back bathroom. That is why tap sampling in these properties is done per outlet rather than once for the building.

Where the building is divided into units, work on shared risers normally needs owner or board consent even when you own your own apartment outright.

What we usually recommend, and why it is the smaller system

In this housing stock the highest-value intervention is usually the cheapest one: a filter certified under NSF/ANSI 53 for lead at the tap you drink and cook from, with the cartridge changed on its rated capacity.

That is not a compromise. Because lead enters from the pipework between the main and the tap, a point-of-use filter sits downstream of the whole problem while a far more expensive whole-house system sits upstream of most of it.

Alongside that, two habits matter. Run the cold tap until it turns properly cold before drinking, particularly first thing. Never draw hot water for cooking or for infant formula, because hot water dissolves lead more readily and these filters are certified for cold lines only.

The constraints that decide what is possible

These are checked before any equipment is discussed, because in this kind of property they rule options in and out before water quality does.

• Service line material is often listed as unknown rather than confirmed
• Interior plumbing may have been replaced in sections, so risk varies floor to floor
• Limited space at the point of entry, often in a cellar with poor access
• Shutoff valves that have not been closed in decades

Permission and approval

Where the building is a multi-unit property, work on shared risers usually needs owner or board consent even when you own your unit.

Equipment that suits this setting

• Lead reduction filters. Point-of-use filters certified for lead under NSF/ANSI 53. No permanent alteration required in the right configuration.
• Under-sink carbon filters. A carbon block cartridge on the cold line under the sink. No permanent alteration required in the right configuration.
• Reverse osmosis, tank. A membrane system under the sink that produces treated water to a dedicated tap and stores it in a small pressure tank.

What this equipment will not do

• 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.

Problems that come up in these properties

• Chlorine and chloramine taste. Confirm with free and total chlorine test strip, plus the utility report for the disinfectant type.
• Lead in drinking water. Confirm with certified laboratory analysis of a first-draw tap sample.
• PFAS. Confirm with certified laboratory analysis using an epa-approved pfas method.
• Nitrates. Confirm with laboratory nitrate-nitrogen analysis.

How the work is done

• Free water testing. Typically 45 to 60 minutes.
• Under-sink reverse osmosis installation. Typically 2 to 4 hours.
• Maintenance and filter replacement. Typically 30 to 90 minutes per visit.
• Repair, any brand. Typically 1 to 3 hours.

Other property types

• Co-ops and condos
• Rentals
• Single-family homes on city water
• Homes on private wells
• New construction
• Restaurants and cafes

Where we work

We cover New Jersey, Pennsylvania, Connecticut, and New York. Water quality is local, so our service area pages carry the utility, source water, treatment method, and reported contaminants for each town, with the source and the year attached.