How to Test Your Water Quality
Updated February 20, 2026
Test your water with DIY strips, reagent kits, or certified lab analysis -- what to test for, how to collect samples, how to read results, and what treatment actually fixes common contaminants.
Overview
Testing your water is the first step to knowing what is actually in it. Municipal water is treated by your utility, but contaminants can enter after it leaves the plant -- aging pipes, lead service lines, your home's plumbing. Well water? Nobody tests or treats that but you. Common concerns: hardness (scale buildup), lead (older pipes and solder), chlorine (taste and byproducts), nitrates (agricultural runoff), iron (staining), pH, and bacteria. Three levels of testing: DIY test strips (quick screening), reagent kits (better accuracy), and certified lab analysis (the gold standard for real estate and health concerns).
What You'll Need
Safety First
- Suspect bacteria (especially well water)? Do not drink until you get results. Boil for at least 1 minute before drinking or cooking. E. coli and coliform cause serious illness.
- Lead concern (home built before 1986 with copper pipes and lead solder, or known lead service line)? Do not use hot water for drinking, cooking, or baby formula -- hot water dissolves more lead. Run the cold for 30 seconds before using. Test to confirm levels.
Step-by-Step Instructions
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Determine What to Test For
Depends on your source and concerns. Municipal water: request your utility's annual Consumer Confidence Report (CCR) -- lists what they test and the results. CCR looks good? You may only need to test for contaminants that enter after the utility (lead from your plumbing is the most common). Well water: EPA baseline -- coliform bacteria, nitrates, pH, TDS, hardness, iron, manganese, plus anything common in your area (check with your county health department). For any source, consider adding: lead, copper, chlorine, fluoride, arsenic, VOCs.
Tip: Not sure what to test? Start with a comprehensive home kit ($25-40) that covers 10-15 parameters. Broad screening. Anything comes back elevated? Follow up with a certified lab test for that specific contaminant. -
Choose Your Testing Method
DIY strips ($10-20): dip, wait, compare colors. Fast but least accurate. Good for pH, hardness, chlorine, iron. Not reliable for lead, bacteria, or VOCs. Reagent kits ($20-40): liquid reagents added to a sample. Better accuracy, more parameters. Good for hardness, iron, pH, nitrates, chlorine. Some include mail-in for bacteria and lead. Certified lab ($50-200+): you collect samples in sterile containers and mail them. Results in 1-2 weeks. Most accurate, only legally defensible method. Required for real estate, mortgage lenders, and health concerns.
Tip: Well water: certified lab testing at least once a year for bacteria and nitrates. Home kits are not accurate enough for bacteria -- false negatives are common. Lab test for bacteria and nitrates costs $30-50. -
Collect Water Samples Properly
How you collect affects accuracy. Lead: first-draw sample from the cold faucet, first thing in the morning before anyone uses water. Let it sit in the pipes at least 6 hours (overnight). Do not flush first -- the first water out has the highest lead because it sat in contact with the pipes longest. Bacteria: sterile lab containers only. Do not touch the inside. Remove the aerator, run 2-3 minutes, then fill. General chemistry (hardness, pH, TDS, iron): run cold 2 minutes, then fill. Label every sample: date, time, which faucet.
Tip: Test at the kitchen faucet (where you drink) and at the first faucet closest to where water enters the house. Higher levels at the kitchen faucet? The source is your plumbing, not the water supply. -
Interpret Your Results
Compare to EPA maximum contaminant levels (MCLs). Key numbers: lead below 15 ppb (any detectable lead is a concern, especially with kids). Coliform bacteria: absent (0 per 100 mL). Nitrates below 10 mg/L. pH 6.5-8.5. Hardness above 7 grains/gallon (120 mg/L) is hard -- benefits from a softener. Iron above 0.3 mg/L stains. Chlorine typically 0.5-2.0 mg/L in municipal (safe, affects taste). TDS below 500 acceptable, below 300 ideal. Anything over the MCL needs action.
Tip: Elevated lead? Test again to confirm -- one test can be anomalous. If confirmed, common sources: lead solder on copper joints (pre-1986 homes), lead service lines, brass fixtures with lead. An NSF/ANSI 53 certified filter provides immediate protection while you address the source. -
Match Treatment to Results
Match treatment to results. Hard water: water softener. Lead: NSF 53 certified filter (under-sink carbon block or RO). Chlorine taste: carbon filter (whole-house or under-sink). Bacteria in well water: shock chlorinate and retest; persistent means UV disinfection. High iron/manganese: iron filter or oxidizing filter. High TDS: reverse osmosis. Low pH (acidic): acid neutralizer (calcite filter). Multiple contaminants: multi-stage or RO covers the broadest range.
Tip: Do not buy treatment before testing. Systems are designed for specific contaminants -- what is perfect for one problem may be useless for another. Test first, buy second. Saves money and ensures effective treatment.
Pro Tips
- Municipal water? Your utility publishes an annual Consumer Confidence Report (CCR) with test results. Free, on their website. Starting point for understanding your water.
- Well water: test annually for bacteria and nitrates at minimum. Test immediately after flooding, after any well work, if taste/odor/color changes, or if anyone has unexplained GI illness.
- TDS meter ($10-15) for ongoing monitoring. Does not tell you what is in the water, but tracks total dissolved substances. Sudden increase means something changed. Also essential for monitoring RO system performance.
- Buying or selling a home? Certified lab test is often required by the lender (especially well water). Get it done early -- results take 1-2 weeks and treatment adds time to the transaction.
- Free or low-cost testing is often available through your county health department or state cooperative extension. Water treatment companies offer free testing too, but be aware it may be a sales tool. Verify results with an independent lab if they recommend an expensive system.
When to Call a Pro
Basic testing is DIY. Call a water treatment specialist or county health department if results show bacteria in well water, if lead is elevated and you need to identify the source (service line vs plumbing), if you need a treatment plan for multiple contaminants, or if you are selling a home and need certified results.