Buying or living in a Wilton home with a private well can feel daunting at first. You want clean, safe water and a smooth home sale or purchase. This guide gives you clear steps on what to test, how often, how to read results, and which filtration systems actually work for common Wilton issues. Let’s dive in.
Why well testing matters in Wilton
Private wells are common in Connecticut, and you are responsible for testing and maintenance. The Connecticut Department of Public Health (DPH) outlines a simple testing schedule and the Wilton Health Department serves as your local contact for permits and guidance. Start with the state’s recommendations on the Private Well Testing page, and keep the Wilton Health Department on your contact list.
Local geology matters too. A statewide study found about 3.9% of sampled private bedrock wells in Connecticut had arsenic above the federal standard. If your well is in bedrock, test at least once for arsenic and uranium. You can read the statewide context in this USGS and CT DPH study.
What to test and when
Annual core tests
Test these basic indicators every year and after repairs, flooding, or heavy rain: total coliform bacteria, nitrate, pH, total dissolved solids, hardness, iron, manganese, chloride, sulfate, turbidity, and odor or color. The state’s schedule and details are on the DPH Private Well Testing page.
Periodic one-time and repeat tests
- Lead: test at least once. If your water is corrosive or you have young children or a pregnancy in the household, retest every 3 to 5 years.
- Arsenic, uranium, radon in water: test at least once, then repeat about every 5 years or sooner if conditions change, especially for bedrock wells.
When to add tests
- PFAS: test if you are near likely PFAS sources such as airports, industrial sites, or fire training areas. See state guidance on Private Wells and PFAS and CT PFAS Action Levels.
- VOCs: test if there is a history of oil or chemical spills, a buried heating oil tank, or industrial activity nearby.
- Nitrate: test more often if there are infants, a pregnancy, or nearby agricultural activity.
How to test in Connecticut
Use a CT-certified lab
Choose a lab certified by the state’s Environmental Laboratory Certification Program (ELCP). The ELCP maintains current certified lab lists and PFAS-capable labs. You can find them on the DPH ELCP page.
Smart sampling tips
Ask your lab for chain-of-custody forms and follow their sampling directions closely. Some tests require first-draw samples, flushed samples, chilled bottles, or special handling. For lead, collect both first-draw and flushed samples to check for corrosion in plumbing.
Make sense of results fast
Health benchmarks and actions
Compare results against EPA and CT DPH standards, and use CT Action Levels for PFAS. Example values include an arsenic limit of 10 micrograms per liter and state PFAS Action Levels such as PFOA at 16 parts per trillion and PFOS at 10 parts per trillion. If results exceed health-based levels, retest to confirm, avoid using the water for drinking and cooking, and contact the Wilton Health Department and DPH for guidance. For PFAS, state contacts are listed on the CT PFAS page.
If bacteria show up
Any total coliform or E. coli positive result is actionable. Stop using the water for drinking and cooking, then disinfect the well through shock chlorination and retest after the chlorine dissipates. Your lab and the state’s Private Well Testing guidance can help you time the retest.
Quick action checklist
- Retest to confirm a single exceedance.
- Stop using the water for drinking and cooking if a health risk is present. Use bottled water until the issue is resolved.
- Notify the Wilton Health Department and follow DPH guidance.
- Fix the source and install treatment that matches the contaminant.
Filtration that works
The best treatment depends on what your test shows. Always test first, then match the technology to your water.
Microbes: UV or chlorination
- UV disinfection works well for bacteria and many viruses when water is clear. It requires prefiltration for sediment or iron and routine lamp changes.
- Shock chlorination is standard for acute bacterial events. Some homes use continuous chlorination for ongoing protection, balanced with taste and byproduct considerations.
Inorganics: arsenic, lead, nitrate, iron
- Reverse osmosis (RO) at the tap is effective for many dissolved inorganics like arsenic and lead. RO is best as a point-of-use system for drinking and cooking water. See EPA’s overview of treatment technologies for performance basics at the EPA treatment page.
- Adsorptive media or anion exchange can target arsenic, depending on your water chemistry. These require professional sizing and scheduled media replacement.
- Water softeners reduce hardness but do not remove many toxic contaminants. Use them to address scale, not health contaminants.
- Iron and manganese filters use oxidation or specialty media to address staining and odors.
PFAS and other organics
- Granular activated carbon (GAC) can reduce many longer-chain PFAS for a limited service life.
- Anion exchange resins can be effective for PFAS, sometimes with higher costs.
- High-pressure membranes like RO are highly effective for a broad range of PFAS at the tap.
Certification to look for
Choose equipment with third-party certifications that match your target contaminant. Look for NSF/ANSI 53 for health-related reduction claims, NSF/ANSI 58 for RO, and NSF listings for PFAS-capable filters. Learn how to verify certifications on NSF’s standards page. You can also review technology overviews on the EPA treatment page.
Buying or selling a Wilton home with a well
Buyers should ask for recent water tests and order new tests if results are more than 6 to 12 months old. Start with the core panel and add arsenic, bacteria, nitrate, and lead. Consider PFAS and VOCs if the property is near potential sources or your lender requests it. The state’s recommended schedule and parameters are on the DPH Private Well Testing page.
Sellers must provide buyers with notice that DPH educational materials are available and disclose known well or water issues in the Residential Property Condition Disclosure. You can review the statute in the Connecticut disclosure law. Proactive, recent lab reports help buyers feel confident.
For records and local history, ask the Wilton Health Department about well permits, depth, and protection.
Local contacts and next steps
- Wilton Health Department: primary local contact for private well permits and guidance. Call (203) 563-0174 or visit the department page.
- CT DPH: testing schedules, action levels, and certified labs are on the Private Well Testing page and the ELCP page.
- PFAS resources: review testing and action steps on Private Wells and PFAS and CT PFAS Action Levels.
- Geological context: see the statewide USGS study on arsenic and uranium.
If you want local guidance as you buy or sell, you can count on a neighborly, step-by-step approach. For clear next steps and trusted referrals, connect with Sandra Calise Cenatiempo.
FAQs
What should you test annually for a Wilton private well?
- Test total coliform bacteria, nitrate, pH, total dissolved solids, hardness, iron, manganese, chloride, sulfate, turbidity, and odor or color per CT DPH guidance.
How often should you test for arsenic and uranium in Wilton?
- Test at least once for bedrock wells, then repeat about every 5 years or sooner if conditions change or results warrant.
What are CT PFAS Action Levels and what should you do if you exceed them?
- CT sets action levels for 10 PFAS; if your results exceed these, retest to confirm, use alternate water for drinking and cooking, and follow DPH and DEEP guidance on next steps.
Who can analyze your Wilton well water?
- Use a Connecticut-certified lab listed on the DPH Environmental Laboratory Certification Program page and follow their sampling instructions.
What treatment removes bacteria, arsenic, and PFAS from well water?
- Bacteria often calls for UV or chlorination, arsenic is commonly addressed with RO or adsorptive media, and PFAS can be reduced with GAC, anion exchange, or RO based on your lab results.
