Rural Home Compass

Oregon homeowner guide · Private well water

When should you test a private well in Oregon?

Oregon separates construction, real-estate testing, and routine owner care. A qualifying seller has a defined three-analyte duty and reporting path; an existing owner follows OHA’s annual bacteria and nitrate and three-to-five-year arsenic recommendations; floods, wildfire, septic trouble, regional nitrate programs, or a declared health area can change the panel.

Evidence reviewed 2026-09-22Rural Home Compass editorial desk15 official sources
Homeowner organizing a sealed well-water sample kit, records, and calendar beside a rural window
Use the calendar only after identifying the decision: new-well work, a purchase baseline, routine care, and post-event testing do not have the same purpose.
What this testing guide covers

This plan connects Oregon’s Domestic Well Testing Act to its one-year result window and 90-day reporting route, keeps routine recommendations separate from law, preserves Area of Public Health Concern and Lower Umatilla Basin boundaries, and explains OWRD records coverage before and after 1955.

Four different decisions

Start with why you are testing.

01RHC planning advice

New well

Separate construction compliance from a drinking-water baseline.

OWRD regulates well construction, licensed constructors, start cards, inspections, and well reports. OHA recommends regular laboratory testing but does not present the routine arsenic, nitrate, and bacteria group as one statewide new-well acceptance mandate. Local use, financing, and site conditions can require a different report.

  • Confirm the licensed-constructor or landowner-permit path, well report, well ID, local land-use conditions, and any receiving-party requirements.
  • Use an accredited laboratory to establish a drinking-water baseline selected for the household, geology, land use, and plumbing; retain it separately from the construction report.

Official guidanceRoutine Domestic Well Testing RecommendationsBasic Information About Private WellsWell Construction and Compliance

02State requirement

Buying or selling

Apply the seller duty only to a covered domestic-well transaction.

After accepting an offer to sell or exchange real estate with a domestic well, the seller must test arsenic, nitrate, and total coliform using the prescribed collection and accredited-laboratory route. Springs, irrigation-only wells, and wells on undeveloped land are exempt. Results are valid for one year and must be sent to the buyer and OHA within 90 days of receipt.

  • Verify the well is covered, order the three required analyses from an accredited laboratory, and complete the current Real Estate Transaction form.
  • Review the result and construction report before relying on the water, while recognizing that failure to test does not by itself invalidate or stop the sale under the current rule.

Official guidanceDomestic Well Testing Act and Real Estate Transaction FormDomestic Well Real Estate Transaction RulesAbout Oregon Well Reports and Coverage

03State recommendation

Routine care

Use annual bacteria and nitrate plus a three-to-five-year arsenic date.

OHA recommends annual coliform/E. coli and nitrate testing and arsenic every three to five years. More frequent testing can be appropriate after prior contamination, septic malfunction, household stomach illness, infant use, or equipment failure. Routine results do not need to be reported to OHA.

  • Keep annual microbial and nitrate testing separate from the arsenic cycle and record the sample point, treatment status, and laboratory scope.
  • Use prior results, nearby sources, regional programs, plumbing, and household vulnerability to decide whether lead, pesticides, VOCs, PFAS, or another analyte belongs in the next panel.

Official guidanceRoutine Domestic Well Testing RecommendationsBasic Information About Private Wells

04State recommendation

Flood, wildfire, or repair

Use the event—not the old calendar—to choose the next sample.

OHA warns that flood contamination can persist or appear after an initial result and recommends repeated testing. For wildfire-impacted wells, OHA recommends arsenic, nitrate, bacteria, lead, and BTEX when the damage assessment supports it. A repaired or malfunctioning system also calls for event-specific testing.

  • Use an alternate safe source until the well is inspected, cleared of floodwater or fire damage, disinfected when appropriate, and tested on the responsible agency’s schedule.
  • Tell the accredited laboratory whether the event involved floodwater, septic waste, ash, heat-damaged components, fuel, solvents, or another source before collecting.

Official guidanceRoutine Domestic Well Testing RecommendationsEmergencies, Disasters, and Domestic Wells

New wells and regulated work

Build a purpose-specific starting panel.

Oregon regulates construction through OWRD but the reviewed statewide sources do not define one universal new-domestic-well water-quality acceptance panel. This list is Rural Home Compass planning advice derived from OHA’s routine health guidance; confirm construction, local, lender, and intended-use requirements before sampling.

  • Total coliform and E. coli
  • Nitrate
  • Arsenic
  • Lead when new plumbing, corrosion, or site evidence supports it
  • Site-specific pesticides, VOCs, PFAS, minerals, or other contaminants only when supported by local evidence

The responsible professional and certified laboratory determine the accepted sample and report. Do not assume a retail package satisfies a regulatory purpose.

Official basis for the new-well panelRoutine Domestic Well Testing RecommendationsBasic Information About Private WellsWell Construction and Compliance

Existing wells

Oregon law and routine health guidance use different clocks.

CadenceEvery three to five years
Starting testsArsenic

OHA recommends this interval for routine arsenic monitoring; an initial result above 8 ppb calls for retesting and confirmed elevated results change treatment and follow-up decisions.

Official guidanceRoutine Domestic Well Testing Recommendations

The calendar is not the whole answer

When should the panel change?

A declared Area of Public Health Concern

OHA may declare a defined aquifer or geographic area after confirming contaminants likely to cause adverse health effects and may add transaction tests for the named contaminant. Apply only the declaration’s actual boundary, contaminant, and duration.

Official guidanceDomestic Well Real Estate Transaction Rules

A private well household in the Lower Umatilla Basin Groundwater Management Area

OHA currently offers result-based nitrate testing, water delivery, and treatment support to eligible households in this specific area. Eligibility and retest frequency depend on the highest nitrate result; this is not a statewide benefit.

Official guidanceLower Umatilla Basin Groundwater Management Area Well Assistance

A rental dwelling in a groundwater quality management area from January 1, 2027

HB 3525 creates a future landlord testing duty for arsenic, coliform, lead, and nitrate in the covered areas, but OHA is still developing the schedule and laboratory-reporting rules. Do not apply a draft schedule or treat it as a current statewide rental requirement.

Official guidanceHB 3525 Enrolled Measure and Operative DateDomestic Well Landlord Testing Rulemaking

Infant use, pregnancy concerns, stomach illness, septic malfunction, or prior bacteria or nitrate

OHA identifies infant use, household illness, septic malfunction, and contamination history as reasons to test more frequently. Prioritize microbial indicators and nitrate, then add only evidence-based site or plumbing tests.

Official guidanceRoutine Domestic Well Testing Recommendations

Flooding, wildfire, fuel, pesticides, industrial activity, or a change in taste, odor, color, or clarity

Use the source and damage assessment to select targeted tests. Wildfire can support lead and BTEX in addition to the routine group; flood contamination can require repeated testing even after an earlier result looked acceptable.

Official guidanceEmergencies, Disasters, and Domestic WellsHuman Health and Domestic Well Contaminants

Laboratory and sampling

Confirm the route before collecting water.

  1. Use an accredited drinking-water laboratory and verify its current scope for every requested analyte through ORELAP. A laboratory listed for coliform is not automatically accredited for arsenic, lead, PFAS, or VOCs.

    Official guidanceORELAP Accredited Drinking-Water Laboratory GuidanceORELAP Active Laboratory and Analyte Search

  2. For a real-estate transaction, anyone may collect the sample if the OAR collection instructions are followed. Use the laboratory kit, follow the prescribed collection point and handling, and deliver the sample as soon as possible—within 24 hours.

    Official guidanceDomestic Well Testing Act and Real Estate Transaction FormDomestic Well Real Estate Transaction Rules

  3. Routine owner samples also need the laboratory’s containers, preparation, preservation, holding time, and delivery instructions. Confirm whether the lender, agency, or other receiving party requires a professional collector or chain of custody.

    Official guidanceRoutine Domestic Well Testing RecommendationsORELAP Accredited Drinking-Water Laboratory Guidance

Official records

Use the OWRD Well Report Query, then account for coverage gaps.

Record holder

Oregon Water Resources Department keeps constructor-submitted reports for construction, alteration, conversion, and decommissioning; OHA separately holds submitted real-estate transaction test information.

OWRD began requiring well reports in 1955, so an earlier well may have no report. Reports before 2009 may lack a map, and older reports often omit a street address or tax lot. These are archived construction records, not current water-quality certificates.

Open the official OWRD well-report guide ↗

Records and lookup guidanceDomestic Well Testing Act and Real Estate Transaction FormAbout Oregon Well Reports and Coverage

Look for
  • Well report number and well ID label
  • Constructor, completion date, depth, casing, flow, and water level
  • Township, range, section, tax lot, address, and map when available
  • Alteration, conversion, abandonment, laboratory, treatment, and transaction records

Turn the schedule into questions

Build a starting water-test panel.

The recommender combines your current issue, purchase status, flood or repair history, nearby agriculture, vulnerable occupants, and ZIP-based Oregon context. It does not replace the responsible professional or laboratory.

Open the Well Water Test Recommender →

Official sources

These sources were reviewed for this page on 2026-09-22. A build date does not refresh that review.

  1. Oregon Health Authority: Domestic Well Testing Act and Real Estate Transaction FormReviewed 2026-09-22 · Recheck every 90 days
  2. Oregon Health Authority: Domestic Well Real Estate Transaction RulesReviewed 2026-09-22 · Official source updated 2026-02-01 · Recheck every 90 days
  3. Oregon Health Authority: Routine Domestic Well Testing RecommendationsReviewed 2026-09-22 · Recheck every 90 days
  4. Oregon Health Authority: Basic Information About Private WellsReviewed 2026-09-22 · Recheck every 90 days
  5. Oregon Health Authority: Emergencies, Disasters, and Domestic WellsReviewed 2026-09-22 · Recheck every 30 days
  6. Oregon Health Authority: Human Health and Domestic Well ContaminantsReviewed 2026-09-22 · Recheck every 90 days
  7. Oregon Health Authority: Lower Umatilla Basin Groundwater Management Area Well AssistanceReviewed 2026-09-22 · Recheck every 30 days
  8. Oregon Legislative Assembly: HB 3525 Enrolled Measure and Operative DateReviewed 2026-09-22 · Recheck every 30 days
  9. Oregon Health Authority: Domestic Well Landlord Testing RulemakingReviewed 2026-09-22 · Recheck every 30 days
  10. Oregon Health Authority: Oregon PFAS Drinking-Water Monitoring and Laboratory InformationReviewed 2026-09-22 · Recheck every 90 days
  11. Oregon Department of Environmental Quality: Resources for Private Well OwnersReviewed 2026-09-22 · Recheck every 90 days
  12. Oregon Health Authority: ORELAP Accredited Drinking-Water Laboratory GuidanceReviewed 2026-09-22 · Recheck every 90 days
  13. Oregon Environmental Laboratory Accreditation Program: ORELAP Active Laboratory and Analyte SearchReviewed 2026-09-22 · Recheck every 90 days
  14. Oregon Water Resources Department: Well Construction and ComplianceReviewed 2026-09-22 · Recheck every 90 days
  15. Oregon Water Resources Department: About Oregon Well Reports and CoverageReviewed 2026-09-22 · Recheck every 90 days