What should private well water be tested for?

At a minimum, private well water is commonly tested for coliform bacteria, nitrate, and pH. Depending on local conditions, additional tests for arsenic, lead, hardness, volatile organic compounds (VOCs), and PFAS may be appropriate. Your state's drinking water program typically publishes priority contaminants for your region.

How is well water testing different from public utility water testing?

Public water utilities are regulated under the federal Safe Drinking Water Act and must meet EPA standards and testing schedules. Private wells are not regulated by the federal SDWA — the household is generally responsible for testing. This is why private well testing decisions are left to the well owner, and testing frequency and scope vary.

Should I test my well after flooding?

Flooding can introduce surface water, bacteria, and other contaminants into a well through the casing or surrounding soil. Many state health departments recommend testing for coliform bacteria and nitrate after significant flooding events. Contact your local health department or state drinking water program for guidance specific to your area.

Can I use my utility's water quality report for a private well?

No. Consumer Confidence Reports and EPA compliance data apply only to the public water system — they do not reflect private well water quality. Well water is not covered by utility monitoring programs.

What should I do if a well test finds a contaminant?

Contact the certifying laboratory for result interpretation. Depending on the contaminant, your state health department may have guidance. For certain contaminants — such as bacteria, nitrate above EPA's 10 mg/L benchmark, or arsenic — reviewing treatment options or using an alternative water source for sensitive uses may be appropriate next steps.

How often should a private well be tested?

Many state programs and health agencies suggest annual testing for coliform bacteria and nitrate as a baseline. Testing frequency for other contaminants depends on local geology, land use, and any changes near the well. There is no single federal requirement — your state health department is the best source for local guidance.

Water Testing Labs

Private Well Testing

Well Water Testing: What To Test For and When

Private well users are generally responsible for testing their own water. Unlike public utilities, private wells are not regulated under the federal Safe Drinking Water Act — testing decisions are the household's responsibility.

Last updated: 2026-05-13 · Source: EPA, CDC, state health programs

Direct Answer

Private wells are not covered by federal water quality regulations that apply to public utilities. The household is typically responsible for testing, interpreting results, and addressing any issues. Many state health departments recommend testing well water at least annually for coliform bacteria and nitrate, with additional tests depending on local geology, land use, and specific concerns.

This page is for private well users

If your home is served by a public water utility, your water is already monitored and tested under EPA requirements. Check your utility's official compliance records first. Look up your utility →

Quick Facts: Well Water Testing

Who it applies to

Private well owners; households not served by a public utility

Minimum recommended tests

Coliform bacteria, nitrate, pH (annually or per state guidance)

Who regulates private wells

State and local health programs — not federal EPA utility rules

Lab type required

State-certified or NELAP-accredited laboratory

Result turnaround

Typically 5–15 business days depending on tests ordered

Utility report applicability

Does not apply — utility compliance records are for public systems only

Common Well Water Tests

The right tests depend on your location, local land use, well age, and any specific concerns. Your state drinking water program or local health department typically publishes priority contaminants for your region.

Contaminant / Indicator	Why It Matters for Wells
Coliform bacteria	Indicates microbial contamination; required baseline test
Nitrate	Agricultural runoff, septic systems; critical for infants
pH	Affects corrosivity and taste; easy baseline indicator
Hardness (calcium/magnesium)	Affects appliances, plumbing, and taste
Arsenic	Naturally occurring in some aquifers; relevant in many states
Lead	Can leach from well components, pump, or household plumbing
PFAS	Relevant near industrial sites, military bases, landfills, or where public utilities have PFAS records
VOCs (volatile organic compounds)	Gasoline, solvents, dry-cleaning chemicals; relevant near industrial or commercial areas

This list is not exhaustive. Consult your state health department or a certified lab for a priority list relevant to your location.

How Well Water Testing Works

Choose a certified lab

Use a state-certified or NELAP-accredited laboratory. The EPA maintains a national directory at epa.gov/dwlabcert. Your state health department also publishes a list of certified labs.

Request a sampling kit

Contact the lab before collecting samples. Labs provide collection containers, chain-of-custody forms, and instructions. Sampling procedures affect accuracy — follow the lab's instructions precisely.

Collect and submit

Most well samples are collected at the tap. Some tests (first-draw lead, bacteria) have specific collection protocols. Send samples to the lab within the required time window.

What To Do After Test Results

Results should be reviewed in context of applicable EPA maximum contaminant levels (MCLs) and health advisories. The laboratory will typically provide reference ranges on the report.

Review results against benchmarks

Compare detected levels to EPA MCLs and health advisories provided by the lab. For contaminants without an MCL, your state may have its own standard.

Contact your lab or health department with questions

If you have questions about what a result means, the certifying laboratory or your state health department can provide context.

Review treatment options

Treatment depends on the specific contaminant. Reverse osmosis addresses many regulated contaminants including nitrate, arsenic, and PFAS. Activated carbon addresses VOCs and some PFAS.

Next Steps

Find a certified water testing lab

EPA-linked directory and state program links

PFAS water testing guidance

Lab methods required and what PFAS results include

Nitrate water testing

Especially relevant for wells and households with infants

Lead water testing

When it matters and what results may show

Water treatment options

Reverse osmosis, activated carbon, and filtration guides

Nitrate contaminant guide

EPA limits, health context, and treatment

Well Water Testing FAQs

Data Sources and Methodology

Well water testing guidance on this page is summarized from EPA private well guidance, CDC recommendations, and state health department resources. No specific lab products are recommended. All content is general educational guidance — not a substitute for site-specific advice from your state health department or a certified laboratory. Full methodology →

EPA Private Wells CDC Private Well Safety EPA Certified Lab Directory

Last updated: 2026-05-13