The Two Tap Test
The city tests at the plant, we test at your tap. A comprehensive water test for 100+ contaminants that affect your health.
*Best for city water. Well water coming Q4 '26Choose your sources
Most homes start with the tap, the primary shower, and one more. There's no cap
Not sure what to test? We’ll scope it out with you – shoot us a note with some info on you and your home.
- 1 PFAS-free sterilized Nalgene bottle
- 1 VOC amber glass vial
- 8oz ice pack, freezer ready
- Auto-inflating insulated return mailer
- Pre-paid Next Day UPS Healthcare return label
- Ships back to the lab via dedicated cold-chain logistics
- Box with custom phone holder. Test hands-free
- ISO/IEC 17025 accredited by the ANAB
- NELAP certifications
- EPA-approved for the Unregulated Contaminant Monitoring Rule (UCMR)
- One lab. 60+ years in operation.
Every sample is run by a single lab that’s been analyzing water for over six decades, not a fragmented network of subcontractors. - We don’t sell the treatment.
We take no commission on the treatments we recommend. We tell you what’s in your water and how to treat it, with no stake in which filter or product you choose. - Our scientific advisory board:
We partner with leaders in exposomics, chemistry, toxicology, and exposure science. Our experts guide us on what to test for, our thresholds, and hazard indexes. - Logistics built for health diagnostics.
Next day UPS Healthcare shipping keeps your sample viable from your tap to the lab. - Lab-grade bottleware.
Lot controlled and pre-sterilized PFAS-free Nalgene and analytical-grade glass, so the container never contaminates the result.
The city tests at the plant. We test at your tap.
Why test your water?
The water you drink and cook with is among the most frequent ways your body takes in contaminants, and one you can actually do something about. Yet most people have never verified what’s in it.
Your utility tests at the plant, not your tap – aging mains, lead service lines, and your own plumbing go unmonitored.
“Compliant” isn’t “safe”: lead’s health goal is zero, but no utility must act until 15 ppb.
PFAS “forever chemicals” don’t break down; federal rules are shifting, so the burden falls to you.
A filter without a test is just a guess – the wrong one leaves in what you meant to remove.
Your Report
Understand what’s in your water. Know what to do next.
For every contaminant found
We tell you the exact levels detected, as measured on advanced instruments.
We evaluate against the strictest health-based standard among EPA, WHO, California, and the EU.
We explain what it means for you, in plain language: what's established, what's emerging, and how to weigh it.
Then we break down where you stand, using neighborhood and national context.
One test covers over 100 contaminants: heavy metals, PFAS, disinfection byproducts, VOCs, petroleum, pesticides, and the minerals that shape taste and hardness.
Your sample is analysed on mass spectrometers at an ISO-accredited lab, so you get exact concentrations instead of a colour on a strip.
Every finding clarified, measured against the strictest health-based standard.
We match a filter to what we actually found in your water, so you remove the contaminants you have rather than the ones on a box.
Once you have made a change, confirm it worked with a retest.
How it works
Test
Fill the bottle at your tap or shower, drop it in the prepaid mailer. Takes 3 minutes.
Treat
Get a full breakdown from a leading ISO-certified lab, plus a treatment personalized to your results.
Track
Confirm your treatment worked. Track emerging contaminants. Retest to confirm the treatment is working.
What we test for
100+ contaminants, including PFAS
Contaminant
Amount
Detail
Linked to brain development, cancer, and organ damage. Often enter in the last mile, between the water main and your tap.
Lead
Arsenic
Copper
Aluminum
Antimony
Cadmium
Chromium (Total)
Iron
Manganese
Mercury
Nickel
Uranium
Zinc
The forever chemicals. They don’t break down in your body. Linked to cancer, immune, and thyroid effects.
PFOA
PFOS
PFNA
PFHxS
PFHxA
PFBS
GenX (HFPO-DA)
Form when the chemicals that keep water safe meet organic matter. Fine in trace amounts, linked to long-term risk at higher ones.
Chloroform
Bromodichloromethane
Dibromochloromethane
Bromoform
Dichloroacetic acid (DCAA)
Trichloroacetic acid (TCAA)
Bromochloromethane
Dibromoacetic acid (DBAA)
Dibromomethane
Monobromoacetic acid (MBAA)
Monochloroacetic acid (MCAA)
Monoiodoacetic acid (MIAA)
Total haloacetic acids (HAA5)
Total THMs
Industrial solvents and fuels that reach groundwater. Several are known carcinogens.
Trichloroethylene (TCE)
Tetrachloroethylene (PCE)
Vinyl chloride
Carbon tetrachloride
Styrene
Dichloromethane
1,1-Dichloroethane
1,1-Dichloroethylene
1,1-Dichloropropene
1,1,1-Trichloroethane
1,1,1,2-Tetrachloroethane
1,1,2-Trichloroethane
1,1,2,2-Tetrachloroethane
1,2-Dichlorobenzene
1,2-Dichloroethane
1,2-Dichloropropane
1,2,3-Trichlorobenzene
1,2,3-Trichloropropane
1,2,4-Trichlorobenzene
1,2,4-Trimethylbenzene
1,3-Dichlorobenzene
1,3-Dichloropropane
1,3,5-Trimethylbenzene
1,4-Dichlorobenzene
cis-1,2-Dichloroethylene
trans-1,2-Dichloroethylene
Bromobenzene
Bromomethane
Chlorobenzene
Chloroethane
Chloromethane
2-Chlorotoluene
4-Chlorotoluene
Dibromochloropropane
Dichlorodifluoromethane
Ethylene dibromide (EDB)
Hexachlorobutadiene
Isopropylbenzene
Trichlorofluoromethane
n-Butylbenzene
sec-Butylbenzene
tert-Butylbenzene
n-Propylbenzene
p-Isopropyltoluene
Fuel-related compounds that reach water through spills and runoff.
Benzene
Toluene
Ethylbenzene
m,p-Xylene
o-Xylene
Methyl tertiary butyl ether (MTBE)
Naphthalene
Agricultural runoff. Several disrupt hormones.
Atrazine
Simazine
Metolachlor
2,4-D
cis-1,3-Dichloropropene
trans-1,3-Dichloropropene
Not contaminants. Reported for context: hardness, taste, and overall quality.
Calcium
Magnesium
Potassium
Sodium
Hardness
Hardness (calculated)
Expanded hardness
Grains per gallon
Sodium adsorption ratio
Free chlorine
Total chlorine
We follow science. Not trends.
We're building ROSE with a board of environmental-health scientists from Mount Sinai, Yale, Duke, Georgetown, Princeton, and GWU. Experts include chemists, toxicologists, epidemiologists, and physicians. Together, we identify the most important contaminants to test for, how we weigh each contaminant, and what guidance you get.
Your sample is analyzed at an ISO-certified lab led by Dr. Agustin Pierri, who developed one of the earliest PFAS testing methods years before the EPA and sits on California’s water board.
Questions, answered
A filter tries to remove contaminants, but it can't tell you what's in your water or whether it's working. Most are certified for only a handful of contaminants, and the wrong one can leave in what you're trying to remove. ROSE shows what's actually there and provides your personalized treatment. A retest confirms it worked.
Your city's report covers the treatment plant, averaged across the whole system. It can't see what reaches your tap after aging mains, lead service lines, and your home's plumbing, and it often skips PFAS. ROSE tests your water at your faucet.
Compliant means legal, not necessarily fully protective of your health. With lead, the EPA's health goal is zero, but no utility has to act until 15 ppb. We measure against the strictest health-based standard among the EPA, WHO, California, and the EU.
Your sample is analyzed by our partner lab, an ISO/IEC 17025 accredited lab, using methods modernized to reach lower detection limits. Every run includes the quality-control checks regulated tests require. Following the kit instructions matters, since collection and shipping can affect results.
PFAS are "forever chemicals" that don't break down in the environment or your body, and they're linked to cancer, immune, and thyroid conditions. We test for 7: PFOA, PFOS, PFNA, PFHxS, PFHxA, PFBS, and GenX, including the ones the EPA still regulates and ones it has moved to stop enforcing.
When your results flag a contaminant, you can come back anytime to purchase a new test. You may want to check if the filter you installed is working correctly, and to see how your levels have dropped. Water also changes over time, so many people plan a retest several months out.
Kits ship the next business day. Results arrive about two weeks after the lab receives your sample.
While you can use this test for your well water, we built it for city water systems. A dedicated well water test is coming winter '26, so join our email list to be the first to know.
No. ROSE measures your environment, not your body, and doesn't diagnose or treat any condition. If a result raises a health question, your report explains it and suggests sharing it with your doctor.
The full 100+ contaminant panel, including 7 PFAS, in a single kit, plus your plain-language report, matched fix recommendations, and free shipping both ways. No separate PFAS kit required.
On a private well? The Well Water Test is coming.