Private Well Water in Delaware
Private domestic wells are not regulated like public water systems. If you own a well, you are responsible for testing, maintaining, and treating your own water.
Short answer: Find your well's permit and record through the DNREC Well Viewer, obtain a test kit or use a certified laboratory through Delaware DPH resources, and test on your own schedule. Delaware does not have a New Jersey-style Private Well Testing Act, so routine and transaction-related testing are generally voluntary.
Who this is for: homeowners on a private well, buyers considering a well-supplied property, and anyone comparing well-water treatment options in Delaware.
Delaware context
Groundwater is central to Delaware drinking water, especially in Kent and Sussex Counties. Regional concerns include coliform bacteria and E. coli, nitrate, iron and manganese, hardness, sulfur odor, sediment, VOCs, PFAS, and, in coastal Sussex County, saltwater intrusion and salinity. Do not imply that all Delaware groundwater has the same quality — every page must distinguish a regional concern from a verified result at a specific well.
Guides in this section
Delaware Private Well Guide
The full overview of homeowner responsibilities for a private well.
Read the guide →DNREC Well Viewer Guide
Step-by-step instructions for using the Well Viewer map tool.
Read the guide →Private Well Testing
How to get tested, what parameters to consider, and how to read results.
Read the guide →Saltwater Intrusion
Salinity and chloride concerns for coastal Sussex County wells.
Read the guide →Common mistakes
- Assuming a neighbor's clean test means your well is fine
- Buying treatment equipment before testing for the specific contaminant it's meant to address
- Skipping retesting after treatment, repair, or disinfection
- Assuming Delaware requires PWTA-style testing before a home sale — it does not
When to contact DNREC, DPH, a laboratory, or a professional
Contact DNREC for well permits, construction, and allocation questions. Contact DPH or a certified laboratory for testing kits and sample analysis. Contact a qualified well professional for construction, repair, or abandonment work. Only pursue treatment after you have a test result in hand.
Official sources
- DNREC Well Permits and Well Viewer
- 7 DE Admin. Code 7301 (Well construction regulations)
- Delaware Public Health Laboratory and certified laboratories
Related
- Public Water guides (if you are on a public system)
- Sussex County Water Quality Guide
Does Delaware require well testing before a home sale?
No. Unlike New Jersey's Private Well Testing Act, Delaware does not have a direct equivalent requiring certified well testing as part of a real-estate transaction. A lender, buyer, or local requirement may still call for testing — confirm with your real-estate professional.
How often should I test my private well?
There is no single statewide mandate for routine testing frequency. See our Private Well Testing guide and confirm current DPH recommendations.
This page provides general educational information and is not medical, legal, or laboratory advice. DelawareWaterQuality.com is an independent resource and is not affiliated with DNREC or DPH.
Last reviewed: 2026-07-11. Report a correction.