Testing your private well is the only way to know what's actually in your water. County-level data tells you what's been found in your area — your own lab test tells you what's coming out of your tap. Here's how to do it right.
1. Start with your county report
Before ordering a test, look up your county to see which contaminants are most commonly detected in local groundwater. This tells you which analytes to include in your test panel — rather than paying for a generic panel that may miss the most relevant contaminants for your area.
2. Choose a test panel
At minimum, test annually for:
- Total coliform bacteria — the most basic indicator of contamination
- Nitrate — especially important in agricultural areas and for households with infants
- pH — affects corrosion and the leaching of metals from pipes
Based on your county's data, you may also want to test for arsenic, lead, iron, manganese, uranium, hardness, or other locally relevant contaminants. Your county page lists a recommended panel.
3. Find a certified lab
Use only a state-certified laboratory. Your state's environmental or health department maintains a list of certified labs. Certification ensures the lab follows standardized analytical methods and participates in quality assurance programs.
Use our Lab Finder to locate certified labs in your area.
4. Collect your sample correctly
Sample collection instructions vary by analyte. The lab will provide containers and specific instructions with your kit. General guidelines:
- Do not run the water before collecting for bacteria samples
- For metals (lead, arsenic), some labs require a first-draw sample; others want a flushed sample — follow the lab's instructions
- Use the lab's containers — don't substitute your own
- Return samples to the lab within the required holding time (usually 6–48 hours depending on analyte)
5. Read your results
Lab reports list each analyte tested, the measured concentration, the method detection limit, and often the EPA MCL (Maximum Contaminant Level). See our Understanding Results guide for help interpreting what the numbers mean for your family's health.
6. Act on the findings
If results show a contaminant above health limits, don't panic — but don't ignore it either. See our Water Treatment guide for an overview of treatment options by contaminant. For bacteria, shock chlorination of the well is often the first step. For chemical contaminants, the right treatment depends on the specific analyte and concentration.