Radon in Keuka Lake Homes: Testing, Results, and Fixes

Last reviewed: October 10, 2026. General information only, not medical, engineering, or legal advice. For a home purchase, use a certified radon professional and talk to your attorney about contract terms.

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Radon is the one home hazard around Keuka Lake you can’t see, smell, or spot during a showing. Old stone foundations, dirt-floor crawlspaces, and basements cut into hillsides are common around the lake, and those are just the kinds of places soil gas can get in. The good news is that radon is cheap to test for and, if it’s high, usually fixable.

This guide covers what radon is, what New York State Department of Health (DOH) data shows for the towns around Keuka, how and when to test, what the numbers mean, how a home purchase changes the process, and what fixing a high result involves. It’s part of our Older Homes section and goes deeper than the radon section of our older homes guide.

What radon is and why it matters

DOH describes radon as “a naturally occurring, radioactive gas found in soil and rock that gets into the air you breathe.” It calls radon the leading cause of lung cancer among nonsmokers. It seeps into buildings through openings in the foundation, and DOH lists the usual entry points:

• cracks in a concrete slab
• pores and cracks in concrete blocks
• slab-footing joints
• exposed soil, as in a sump
• cracks between a poured slab and block walls
• loose-fitting pipes
• water

Any kind of building can have it: old or new, drafty or tight, with or without a basement. DOH points out that the greatest exposure is usually at home, because that’s where people spend the most time. That matters more once a summer cottage becomes a year-round house and you’re spending winter nights inside with the windows shut.

What the state data shows around Keuka Lake

DOH has published town-by-town estimates of the percentage of homes above 4 picocuries per liter (pCi/L), the level where DOH recommends fixing a home. The estimates below come from DOH’s county tables dated February 2007. They’re old and based on limited numbers of homes in some towns, so treat them as a sign of how common elevated radon has been, not a prediction for any one house.

Yates County towns on the lake

Steuben County towns on the lake

In these tables, “living area” figures come from long-term measurements (90 days to a year), and “basement” figures from short-term tests, typically 2 to 7 days. DOH also notes each estimate has an uncertainty range, which is wide in towns with few measurements, like Pulteney.

Two things stand out. First, basement results run much higher than living-area results everywhere, which is why where you test matters. Second, even in the lowest-percentage town on the list, a meaningful share of basements tested above the action level. Neighbors’ results don’t tell you about your house. Testing is the only way to know.

For newer data, DOH’s Environmental Public Health Tracker shows county radon test results as five-year rolling averages. DOH notes those numbers include only short-term tests ordered through its own radon program, so they don’t capture every test done in a county.

How to test a Keuka Lake home

Short-term vs. long-term tests

The EPA’s Home Buyer’s and Seller’s Guide to Radon describes two kinds of tests:

• Short-term tests stay in the house from 2 to 90 days. They’re quick and cheap, and they’re the usual first step.
• Long-term tests stay in more than 90 days. EPA says a long-term result “is more likely to tell you your home’s year-round average radon level than a short-term test.”

A sensible approach for a house you already own is a short-term test first. If it comes back near or above the action level, follow up with a second short-term test or a long-term test before you spend money on a fix.

When to test

DOH recommends testing:

• every five years, or every two years if you have a radon mitigation system, to make sure it’s working;
• during the winter months, when windows and doors can stay closed for 24 hours before and during the whole test;
• when buying a home and after major renovations;
• within 30 days of installing a mitigation system.

For Keuka owners, “after major renovations” is worth taking seriously. Converting a cottage, finishing a basement, pouring a new slab, or tightening a house with air-sealing and insulation can all change radon levels. See our cottage conversion guide.

Setting up the test

DOH and EPA instructions line up on the basics:

1. Keep the house closed. DOH says all doors and windows to the outside should be closed for 24 hours before and during the test, though you can come and go normally. EPA calls these “closed-house conditions” and adds: don’t run fans or machines that bring in outside air.
2. Test the right level. EPA recommends testing the lowest level that could be used regularly. A buyer may plan to use a basement the seller never finished.
3. Run it long enough. EPA says a test should last at least 48 hours.
4. Live normally otherwise. EPA says to run the heating and cooling systems normally during the test.
5. Don’t disturb the detector, and send it back to the lab promptly when the test ends.

Seasonal cottages need a little thought. A house that sits closed and unheated all winter isn’t the same as a house people live in. Test when the house is being used the way you plan to use it, with the heat running.

Where to get a test kit

• NYS DOH kit. DOH sells short-term radon detectors to New York homeowners for $12.25 each, a price that includes the kit, lab analysis, and postage to send it back. Order with DOH’s Radon Detector Order Form (pay by check or money order) or call the radon program at 518-402-7556. The form says one detector is enough for 2,000 square feet per floor.
• Hardware stores and online. DOH says you can also buy kits at hardware stores. Whatever you buy, DOH says the analysis should be done by a lab approved through the state’s Environmental Laboratory Approval Program (ELAP).

Understanding your results

DOH’s guidance is simple:

• 4 pCi/L or higher: fix the home.
• Between 2 and 4 pCi/L: consider fixing it.
• The goal: DOH says that with current technology, radon in most homes can be reduced to 2 pCi/L or below.

One short-term result near the line isn’t the final word. Radon can swing day to day and season to season, which is why EPA describes follow-up testing and long-term tests. If you get a very high first result, though, don’t wait months to act.

Radon when buying or selling around Keuka Lake

What the seller’s disclosure covers

New York’s Property Condition Disclosure Statement asks the seller, “Has a radon test been done? If yes, attach a copy of the report.” That’s the extent of it. The form doesn’t require a seller to test, and its own buyer acknowledgment says it “is not a substitute for any home, pest, radon or other inspections or testing of the property.” See Real Property Law § 462.

Use a professional for a purchase test

For a purchase, DOH recommends hiring a certified radon testing professional and checking that the results will come from an ELAP-approved lab. EPA’s guide adds that any real estate test should include steps to prevent or detect tampering with the test device, and it lists short-term testing options that work on a closing timeline, including two tests run side by side for at least 48 hours.

Build radon into the deal

• Schedule it with your other inspections. Radon testing takes at least two days, plus lab time. Start early in your inspection period. See our buying guide.
• Ask the seller for past results and for any mitigation system’s paperwork: who installed it, when, and the most recent test.
• Talk to your attorney about how a high result will be handled: repair by the seller, a credit, or the right to walk away. That’s a contract question, not a radon question.
• Remember the timing. A test done in the fall before snow, during a mild week, or with windows open isn’t a fair test. The setup instructions matter.

Fixing a radon problem

DOH says a radon reduction system can cut radon levels by up to 99%, and that the average cost is about $2,500. Your house could cost more or less depending on its foundation, crawlspaces, and layout. Older lake homes with fieldstone foundations, additions on different foundations, or dirt-floor crawlspaces can take more work than a simple slab.

Who does the work

DOH keeps a list of certified radon mitigation contractors. DOH explains that New York doesn’t certify or license radon mitigators itself. Firms on its list are certified through national or other state programs: AARST’s National Radon Proficiency Program (NRPP), the National Radon Safety Board (NRSB), New Jersey, or Pennsylvania. Ask any contractor which certification they hold and check it.

DOH also notes that the national radon testing and mitigation standards now in use were developed by AARST and the American National Standards Institute, and that they replace earlier EPA standards. A certified mitigator should be working to them.

After the system goes in

• Retest within 30 days of installation, as DOH recommends.
• Retest every two years to confirm it’s still working.
• Keep the paperwork, including the installer’s name and certification, the system’s details, and every test result. You’ll want them when you sell.

Building or adding on? Plan for radon now

DOH says installing a radon reduction system during construction “is easier and less expensive than installing a system after the house is completed.” Radon-resistant construction seals soil-gas entry points and adds a vent path to the outdoors. If radon is still at or above 4 pCi/L afterward, a certified mitigator can activate the system by adding a fan. DOH adds that every new home should be tested, even if it was built to resist radon.

If you’re rebuilding a cottage, adding a foundation, or pouring a slab, ask your builder about this early. It’s cheap insurance. Our setbacks and zoning guide covers what else to check before building near the lake.

Radon and well water

DOH lists water as one of the ways radon gets into a home. If your house is on a private well, ask your water-testing lab whether a radon-in-water test makes sense alongside the usual bacteria and chemistry tests. Our well water guide and drinking water guide cover the routine tests.

A radon checklist for Keuka Lake homes

1. Test the lowest level that is, or could be, lived in.
2. Test in winter with the house closed and heated, if you can.
3. Use an ELAP-approved lab, or the DOH kit.
4. At 4 pCi/L or higher, confirm and fix. Between 2 and 4, consider it.
5. Hire a certified mitigator (NRPP, NRSB, NJ, or PA) from DOH’s list.
6. Retest within 30 days of a new system, then every two years.
7. Retest after renovations that change the foundation, basement, or air-tightness.
8. Keep every result and the system paperwork with your house records.

What to have on hand

For owners who want to test on their own schedule (links go to Amazon search results):

• A short-term radon test kit. Check that the lab analyzing it is ELAP-approved, or use DOH’s $12.25 kit.
• A long-term radon test kit to confirm a borderline short-term result over 90 days or more.
• A digital radon monitor if you want an ongoing reading between formal tests. It’s a supplement, not a replacement for a lab test or a purchase test.

Frequently asked questions

Official sources

• NYS Department of Health: Radon
• NYS DOH: Radon Detector Order Form (PDF)
• NYS DOH: Certified Radon Mitigation Contractors
• NYS DOH: Yates County indoor radon estimates, February 2007 (PDF)
• NYS DOH: Steuben County indoor radon estimates, February 2007 (PDF)
• NYS DOH: About the radon data in the Environmental Public Health Tracker
• U.S. EPA: Home Buyer’s and Seller’s Guide to Radon (PDF)
• U.S. EPA: Radon resources for the real estate community
• NY Real Property Law § 462 (Property Condition Disclosure)

Related on Living on Keuka: Older homes · Buying a home near Keuka Lake · Well water · Converting a cottage to year-round use · KWIC septic inspections at sale · Lead pipes and water testing · Home inspections: what they miss

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