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.