Water — Track 1: Know Your Water
The most dangerous water quality problems are invisible and tasteless. Municipal water is tested continuously. Well water is tested only when the owner tests it. This page covers what to test, when to test it, and what to do with the results.
Who needs to test
No one else monitors your water — you do
The EPA has no regulatory authority over private wells. Your county health department may test during a permit inspection, but ongoing monitoring is entirely up to you. A contamination problem that develops gradually — bacteria from a nearby septic system, nitrates from agricultural runoff, arsenic from natural geological sources — will go undetected until it's discovered by testing or by illness.
Test schedule
The utility tests the source — not your tap
Municipal water is continuously tested and regulated. Your water utility publishes an annual Consumer Confidence Report covering all detected contaminants and their levels. For most households on municipal water, reading the CCR is the primary monitoring tool — testing your tap water is less often necessary.
There are three situations where testing your specific tap water is warranted even on municipal service:
Contaminants
Sources: EPA Maximum Contaminant Level (MCL) standards; CDC health effect data. "Concern level" reflects health risk at elevated concentrations, not likelihood of presence in any specific water source.
Lead — the invisible risk
Lead in drinking water comes almost entirely from household plumbing — not from the water source itself. Lead pipes, lead solder at pipe joints, and lead service lines (the pipe connecting the street main to the house) dissolve slowly into standing water, especially water with low pH or high chloramine levels.
A municipal water report showing undetectable lead at the treatment plant tells you nothing about lead at your tap. The water picks up lead on its way from the main through your building's plumbing to the faucet. The only way to know is to test at the tap.
First flush vs. flush sample: A first-draw sample (water collected after 6–8 hours of no use) captures the highest potential lead from standing water. A flushed sample (after running the tap for 30 seconds) captures the water quality closer to the main. Testing protocols vary — follow the instructions of your specific lab for the most meaningful results.
If lead is detected above the EPA action level (15 ppb): Stop drinking tap water for infants and pregnant women immediately. Contact your water utility. Install an NSF/ANSI 53-certified lead reduction filter at drinking and cooking taps. Consult your health department about blood lead testing for children in the home.
Risk by home age
Highest risk
Lead service lines and lead pipe common. Test strongly recommended.
Moderate risk
Lead solder at pipe joints common. Test at purchase or renovation.
Lower risk
Lead banned from new construction 1986 but "lead-free" solder allowed up to 8% until 2014.
Lowest risk
True lead-free standard. Risk mainly from distribution infrastructure, not household plumbing.
How lead enters drinking water, NSF 53 filter certification, and the Flint, Michigan case study.
Contamination guide →
Testing options
Home test strips provide quick screening results — useful for detecting the presence of certain contaminants and giving rough concentration ranges. The main products on the market test for chlorine, pH, hardness, bacteria presence/absence, nitrates, and a few others.
Strengths: Immediate results (minutes), inexpensive ($15–50 for a multi-parameter kit), no sample shipping required, good for routine monitoring between lab tests.
Critical limitation: Not reliable for lead. Lead test strips cannot detect lead at concentrations below 15–25 ppb with accuracy — the same range where health concerns begin. For lead specifically, certified lab testing is required.
Best use: Initial screening, routine checks between annual lab tests, verifying chlorine residual in stored water, quick bacterial presence/absence check before using a water source.
Certified laboratory testing analyzes a water sample using validated analytical methods — the same methods utilities use for regulatory compliance. Labs certified under EPA's drinking water program (or state equivalents) produce results you can act on with confidence.
Strengths: Precise quantification, legally defensible results, required for lead and PFAS testing, covers the full range of health-relevant contaminants, often includes interpretation guidance.
Mail-in lab services: Tap Score (SimpleLab), National Testing Laboratories, and TestAssured all offer certified mail-in testing. You order a kit, collect the sample following their protocol, ship it back, and receive a digital results report with interpretation. No local lab required.
Best use: Annual well testing, any lead or PFAS concern, moving into a new home, after flooding, or whenever health decisions depend on the results.
Choosing a test kit
Current picks for home test strips, mail-in lab services, lead-specific testing, and the TDS meter that's worth having for quick daily checks.
Finding a certified lab
Every state maintains a list of certified laboratories for drinking water testing. Search "[your state] certified drinking water laboratory list" to find the official database. State labs are often the least expensive option and are required for any official compliance testing.
Many county Cooperative Extension offices run subsidized well water testing programs for rural households — particularly in agricultural areas. Testing costs are often $10–30 for a basic bacteria and nitrate panel. Contact your county extension office directly to ask about their water testing program.
National mail-in services provide certified testing with home collection. Tap Score (SimpleLab), National Testing Laboratories, and TestAssured ship a sample collection kit to your door. You collect the sample following their instructions and ship it back. Results arrive as a digital report within 5–10 business days with interpretation guidance.
The EPA maintains a searchable database of certified laboratories at epa.gov/safewaterlabs. Search by state and contaminant type. Every lab in this database holds EPA or state certification for the contaminants they test.
For municipal users
Every public water system publishes an annual water quality report. Most people never read theirs. Here is what to look for in five minutes.
Your utility publishes the CCR on their website by July 1 of each year. It must be mailed to customers without email addresses. For digital access:
Maximum Contaminant Level — the highest level of a contaminant allowed in drinking water. If a detected level exceeds the MCL, the utility is in violation and must notify customers.
MCL Goal — the level at which there would be no known or expected health risk. The MCLG for lead and some other contaminants is zero — meaning no level is considered safe. The MCL (the enforceable level) may be higher.
Not Detected — the contaminant was not found above the lab detection limit. This is the best result for health-critical contaminants like lead and arsenic.
Any detected level above the MCL, or a failure to test as required. Violations must be disclosed; treatment technique violations (a failure of the treatment process) are also reportable.
What the CCR does not tell you
Acting on results
Connected guides
What each contamination type means, which treatment methods handle it, and when no household treatment is adequate.
Contamination guide →
The full well owner guide — annual testing schedule, shock chlorination, backup power, and the annual maintenance checklist.
Well owner guide →
When test results call for a home filter — NSF certification, what each type removes, and how to size a system for your household.
Filter guide →