| Requirement Level | Who Pays | Result Validity | Authority |
|---|---|---|---|
| Mandatory at sale | Negotiated (seller common) | 90 days from collection | WI DNR Drinking Water program |
Overview: Wisconsin Well Water Rules
Wisconsin requires water quality testing at all property transfers involving a drilled well under Wisconsin Statute 280.21. The test must be conducted by a DNR-accredited laboratory, and results must be provided to the buyer before closing.
What Must Be Tested in Wisconsin
| Parameter | Standard | Requirement |
|---|---|---|
| Total coliform bacteria | Absent | Required |
| Nitrate | ≤10 mg/L | Required |
| Additional parameters | Varies by county | Check local rules |
Finding a State-Certified Lab in Wisconsin
Wisconsin requires testing through a state-certified laboratory. To find a lab:
- Contact your county health department — many maintain a local lab referral list
- Search the WI DNR Drinking Water program website for a list of certified labs
- Use our national certified lab finder guide for resources
Do not use a DIY kit or an uncertified online mail-in service for loan transactions or state-required testing. Results must come from a DNR-accredited laboratory.
Federal Loan Requirements in Wisconsin
Regardless of Wisconsin's state requirements, federal loan programs impose their own standards:
- VA loans: Always require a water quality test, results valid 90 days. VA guide →
- FHA loans: Require testing when proximity triggers are met (well within 100 ft of septic, etc.). FHA guide →
- USDA loans: Always require testing, results valid 180 days. USDA guide →
I’m buying with cash in Wisconsin — do I need a well water test?
For a cash purchase in Wisconsin, there is no legal requirement in most situations. However, conducting your own water quality test is strongly recommended. A basic certified lab test costs $100–$200 and is far less expensive than discovering contamination after closing.
How much does well water testing cost in Wisconsin?
A basic certified lab panel in Wisconsin (coliform + nitrates + pH) typically costs $75–$150. A comprehensive panel meeting loan requirements runs $150–$350. Some county health departments offer subsidized testing programs — call your county health office to check. See our full cost guide for more detail.
← Back to all state requirements
Disclaimer State requirements change. Always verify current rules with your WI DNR Drinking Water program and your transaction’s real estate attorney before relying on this information.