Well water testing — what to test for and how often

This article is for educational purposes only and is not a substitute for professional advice. Local codes, regulations, and best practices vary by region.

If your home uses a well instead of municipal water, you’re responsible for ensuring water safety. The municipality isn’t testing it. You need to test your well periodically to confirm it’s safe to drink. Testing is inexpensive and straightforward.

Well water quality depends on soil conditions, proximity to septic systems, and whether contaminants are present. Regular testing catches problems before they cause illness.

What to Test For

Bacteria (E. coli and total coliform) are the primary concern. These indicate fecal contamination and require treatment or the well needs repair.

Nitrates from fertilizer or septic systems might be present. High nitrates are dangerous for infants.

Arsenic occurs naturally in some areas and requires mitigation if present.

pH should be between 6.5 and 8.5 for proper water chemistry.

Hardness (calcium and magnesium) affects water quality and can require a softener.

Iron and manganese create staining and taste issues.

Additional testing for pesticides, volatile organic compounds, or other contaminants depends on your location and concerns.

Testing Protocol

Most health departments provide or recommend well testing. Some offer free testing. Others charge $50 to $300.

Private labs also test wells. Cost is similar.

Sample collection is simple: you collect a water sample in a provided sterile bottle and deliver it to the lab.

Results typically come back within a week.

Testing Frequency

Most jurisdictions recommend testing at least annually. Spring is common (after potential winter contamination).

If you’re concerned about specific contaminants or live near a potential source (farm, septic system), test more frequently.

After well repairs or new well installation, test to confirm the system is working.

If you’ve had positive tests for bacteria, test more frequently and after any corrective action.

Interpreting Results

Bacteria present (E. coli or coliform) means the well needs disinfection. Boil water until the contamination is resolved.

High nitrates require investigation. If from fertilizer or septic, source correction helps. If from natural sources, treatment (nitrate removal system) is needed.

Arsenic presence requires treatment system installation if levels exceed safe limits.

pH issues can be corrected with treatment systems.

Other contaminants might require specific treatment or, if levels are extreme, connection to municipal water or well replacement.

Treatments and Solutions

Chlorination: adding chlorine disinfects bacteria. Can be temporary (after contamination is resolved) or ongoing.

Shock treatment: high-dose chlorination to disinfect a contaminated well. Followed by testing to confirm success.

Filtration systems for specific contaminants (arsenic removal, iron removal, etc.).

Water softeners for hardness.

Whole-house treatment systems for comprehensive water conditioning.

Cost of Testing and Treatment

Annual testing: $50 to $300.

Treatment system installation: $500 to $3000+ depending on specific treatment.

Ongoing maintenance: water filter changes, chemical replenishment.

Well Maintenance

Have a professional inspect your well periodically. They can identify issues before they cause contamination.

Ensure the well cap is secure and functioning. A failing cap allows surface contamination.

Keep the area around the wellhead clear of debris and contaminants.

Have the well developed (cleaned) periodically if sediment accumulates.

When to Replace a Well

If contamination is persistent and untreatable, well replacement might be necessary. This is expensive ($3000 to $15,000+) but sometimes unavoidable.

If the well is producing insufficient water or requires constant repairs, replacement is warranted.

Responsibility Reality

Your well is your responsibility. Testing ensures your water is safe. Treatment systems address specific problems. Maintenance keeps the well functioning.

This is an ongoing cost and responsibility, but it’s manageable with simple testing and occasional treatment.

Most well owners test annually, find no problems, and enjoy safe water. Occasional issues are addressed with targeted treatment.

© The Whole Home Guide