Testing your tap water for safety & health
A practical guide to what's worth testing, how to do it, and where the real risk actually lives in a New York City apartment.
- NYC water arrives clean — contamination almost always comes from your building's plumbing, not the city supply.
- Start with the free DEP lead kit (call 311). It covers the single most important NYC concern at zero cost.
- Want the full picture? Add a mail-to-lab city-water kit for bacteria, disinfection byproducts, and chemistry.
- DIY strips are for monitoring, not diagnosis — fine for pH, chlorine, and hardness only.
How NYC water actually works
The city's water arrives essentially lead-free from upstate reservoirs, carried through lead-free aqueducts and mains. DEP also adds orthophosphate, which coats the inside of pipes with a protective barrier, and tests tap water across the five boroughs year-round.
So the contamination risk almost never comes from the source. It comes from the last stretch — your building's service line and interior plumbing. That's the single most important idea here, and it's what shapes everything below.
A smart zeroth step before spending anything: check whether your building has a lead service line on the NYC Service Line Map, and factor in the building's age. Lead service lines were phased out decades ago, and buildings plumbed before 1987 may still carry lead solder or fixtures. Much of LIC is post-2005 high-rise construction — copper or PEX, low risk — but the older pre-war and converted-industrial buildings near Court Square warrant more attention.
Your testing options
Ordered from the cheapest, best first move to the most thorough.
Free NYC DEP lead test kit
Request it by calling 311 or filling out the online form. You'll get a box with two bottles, sampling instructions, and a prepaid return label — mail it back and results arrive within about 30 days. One kit per household. The catch: it tests for lead and copper only, which happens to be exactly the NYC concern that matters most.
Comprehensive mail-to-lab kit
For everything beyond lead — chlorine/chloramine, bacteria, nitrates, hardness, disinfection byproducts, and optionally PFAS. Tap Score (by SimpleLab) is the most commonly recommended for city water and was Wirecutter's pick. These use ISO 17025-certified labs and the same methods utilities use. For LIC city water, the Essential-tier city-water test is plenty unless you have a specific concern.
DIY strip kit
Instant at-home results from kits like the Varify 17-in-1. But strips are only really reliable for pH, chlorine, and hardness — for lead they only say "detected / not detected," and they can't see PFAS at all. Good for confirming a filter is working or tracking change over time, not for a first answer on whether your water is safe.
What types of tests get done
A full safety/health panel breaks into these categories, roughly ordered by how directly each affects health. The EPA splits them into primary standards (enforceable, health-based) and secondary standards (aesthetic). Tap each to expand.
Microbiological — bacteria
Total coliform & E. coli
Primary
The most immediate acute risk. Labs test for total coliform and E. coli, which signal fecal contamination and can cause GI illness.
Heavy metals & inorganics
Lead, copper, arsenic, chromium…
Primary
Lead and copper are the headliners — they leach from pipes, solder, and fixtures rather than the source water. A fuller panel also covers arsenic, mercury, cadmium, chromium (including chromium-6), plus iron and manganese (more nuisance than danger).
Disinfectants & byproducts (DBPs)
Chlorine residual, THMs, HAAs
Primary
Two things: the disinfectant residual itself (chlorine or chloramine), and the byproducts that form when those react with organic matter — mainly trihalomethanes (THMs) and haloacetic acids (HAAs), which carry long-term health limits.
Nitrates & nitrites
Fertilizer runoff
Primary
Primarily an agricultural and well concern. High nitrate is genuinely dangerous for infants ("blue baby syndrome").
PFAS — "forever chemicals"
Measured in parts per trillion
Emerging
A major emerging category requiring specialized lab methods, measured in parts per trillion. The EPA finalized the first federal drinking-water limits for several PFAS in 2024, so it's become a common add-on — usually a separate, pricier test rather than part of a basic panel.
Volatile organic compounds (VOCs)
Benzene, TCE, PCE
Primary
Industrial solvents typically from industrial contamination or fuel.
Physical & aesthetic
pH, hardness, TDS, turbidity
Secondary
pH, hardness (calcium/magnesium), total dissolved solids (TDS), turbidity, and alkalinity. Mostly not health risks — they affect taste, scale buildup, and how plumbing and filters perform.
Radiological & pesticides
Radon, uranium, gross alpha/beta
Primary
Radon, uranium, and gross alpha/beta on the radiological side, plus agricultural pesticides and herbicides.
Sampling the right way
For lead specifically, you want a first-draw sample — water that's sat in the pipes 6+ hours (first thing in the morning) — because that captures what's leaching from your plumbing.
For general-use testing the opposite applies: flush the line first. Your kit's instructions will tell you which, so follow them exactly — a bad sample makes even a great lab test meaningless.
The priority stack for your apartment
On NYC city water, here's the order that gives you the most assurance per dollar:
The radiological, pesticide, and nitrate categories matter far more for well owners than for you on the city supply — safe to skip unless a panel includes them anyway.