Well Water Testing: What to Test For, How Often, and What It Costs
Unlike city water, private well water is not monitored by the EPA. That means you're responsible for testing your own water to make sure it's safe. The EPA recommends testing at least once a year for bacteria and nitrates — but a comprehensive panel can catch problems you'd never notice by taste or smell alone.
What Should You Test For?
| Contaminant | Why It Matters | How Often |
|---|---|---|
| Total coliform bacteria | Indicates contamination from surface water or sewage | Annually |
| E. coli | Indicates fecal contamination — serious health risk | Annually |
| Nitrates | Dangerous for infants; indicates agricultural runoff | Annually |
| pH | Low pH corrodes pipes, leaches metals | Every 2–3 years |
| Hardness | Causes scale buildup, soap scum | Every 2–3 years |
| Iron & manganese | Staining, metallic taste, clogged fixtures | Every 2–3 years |
| Arsenic | Naturally occurring carcinogen in many regions | Once, then every 3–5 years |
| Lead | Toxic even at low levels; leaches from old pipes/fittings | Once, then if plumbing changes |
| PFAS | "Forever chemicals" — linked to cancer and immune issues | Once, especially near military bases or industrial sites |
How Much Does Well Water Testing Cost?
| Test Type | What's Included | Cost |
|---|---|---|
| Basic panel | Bacteria + nitrates | $50 – $100 |
| Standard panel | Bacteria, nitrates, pH, hardness, iron, manganese | $150 – $300 |
| Comprehensive panel | Standard + arsenic, lead, VOCs | $250 – $400 |
| Full panel with PFAS | Comprehensive + PFAS testing | $300 – $500 |
State health department labs often offer basic testing at reduced rates ($0–$50 in some states). Private labs like Tap Score or local certified labs handle more comprehensive panels.
How to Collect Water Samples Properly
Proper sample collection is critical — a contaminated sample gives false results. Follow these steps:
- Use the lab's container — don't use your own bottles. Labs provide sterile containers for bacteria tests.
- Use a clean faucet — choose a faucet closest to the well, before any treatment systems. Remove aerators and screens.
- Run the water first — let cold water run for 3–5 minutes to flush the pipes.
- Don't touch the inside — keep the container sterile by not touching the rim or inside of the cap.
- Fill and cap immediately — fill to the line indicated, cap tightly.
- Keep it cold — transport samples on ice and deliver to the lab within 24 hours (6 hours for bacteria).
Reading Your Results: What the Numbers Mean
| Parameter | Safe Level | Action Needed If Exceeded |
|---|---|---|
| Total coliform | 0 (absent) | Shock chlorinate well, retest |
| E. coli | 0 (absent) | Stop drinking immediately, disinfect |
| Nitrates | <10 mg/L | Do not give to infants, find source |
| pH | 6.5 – 8.5 | Install acid neutralizer if low |
| Iron | <0.3 mg/L | Install iron filter |
| Arsenic | <10 µg/L (ppb) | Install treatment system immediately |
| Lead | <15 µg/L (ppb) | Replace plumbing fittings, install RO |
State Requirements for Well Water Testing
Several states require well water testing at the time of home sale:
- New Jersey — required for all private well sales
- Connecticut — required at sale or transfer
- Oregon — arsenic and nitrate testing required at sale
- Virginia — required for FHA/VA loans
Even if your state doesn't require it, annual testing is the only way to know your water is safe.
Frequently Asked Questions
How often should I test my well water?
The EPA recommends testing for bacteria and nitrates at least once a year. Test more frequently if you notice changes in taste, odor, or color, or after flooding, nearby construction, or septic system problems.
Can I use a DIY home water test kit?
DIY kits ($20–$50) can give you a rough idea of water quality, but they're not as accurate as certified lab tests. For health-related contaminants like bacteria, arsenic, and lead, always use a certified laboratory.
Where do I send my water sample?
Contact your state health department for a list of certified testing labs. Many offer mail-in testing kits. Companies like Tap Score and National Testing Laboratories also offer comprehensive mail-in panels.
What do I do if my well water test comes back positive for bacteria?
Stop drinking the water immediately. Shock chlorinate (disinfect) the well, wait 24 hours, flush thoroughly, then retest. If bacteria persists, you may need to install a UV disinfection system or investigate the contamination source.
Does well water testing check for PFAS?
Standard well water tests do NOT include PFAS. You need to specifically request PFAS testing, which costs $200–$400 extra. This is especially important if you live near military bases, airports, or industrial facilities.