Home maintenance in Minnesota

What's different about Minnesota

• 1

  Radon, and Minnesota's two laws

  The Minnesota Department of Health estimates that about two in five Minnesota homes have radon levels above the EPA action level of 4.0 pCi/L, one of the highest rates in the country. The geology behind it is glacial: the sediment left across most of the state carries uranium, and radon is what uranium decay produces.

  Minnesota has responded with two separate laws, and it's worth knowing what each one does and doesn't do.

  Since 2009, all new Minnesota homes must be built radon-resistant. That means a vent pipe running from below the foundation up through the roof, plus sealing of foundation openings, joints, and penetrations. It does not include a fan. This is a passive system, and passive means it works by convection alone.

  The Minnesota Radon Awareness Act (Minn. Stat. § 144.496), effective 2014, requires a seller to disclose in writing, before the purchase agreement is signed, any knowledge of radon concentrations in the home. That includes whether tests have been done, the most current results, a description of any mitigation or radon-resistant construction, and MDH's signed Radon Warning Statement. What the law does not do is require anyone to test or mitigate. It requires honesty about what's known, and if a seller has never tested, the disclosure just says so.

  Here's the gap those two laws leave, and it's the practical point:

  A new home built to code is not a tested home. Radon-resistant construction reduces levels. It doesn't guarantee them. Test after you move in. A passive system can be upgraded to an active one by adding a fan, a monitoring device, and an outlet near the pipe. The expensive part, the pipe, is already there. MDH puts the operating cost of an active system at roughly $14 a year. Retest every two years, and after anything that changes basement airflow: finishing the basement, replacing the furnace, sealing the foundation. If you have an active system, check the monitor. Those fans fail quietly.

• 2

  When frost outruns the code

  Minnesota's code depths are built for a normal winter. In a hard one, with a long cold stretch and thin snow cover, frost drives deeper than the design assumption and reaches buried pipe that is legally deep enough. This is the Minnesota problem no national checklist mentions, and it's the reason cities here send out advisories telling people to leave a faucet running.

  Know which part of the line is yours. In most Minnesota cities the utility owns the water service from the main to the curb stop, typically 10 to 15 feet from the edge of the street, and everything from the curb stop into the house is the property owner's. If the freeze happens on your side, the thaw is your bill.

  What to do, in order:

  Watch for the advisory. When frost depth gets serious, cities publish a notice asking residents, particularly low-volume water users, to run a small stream continuously through one faucet, day and night. Moving water resists freezing. It costs a little on the bill and far less than a thawing crew. Know your risk profile. Low water use is the biggest single factor. A household that travels, a home with one or two occupants, or a place that sits empty part of the winter is more exposed than a busy family of five on the same block. Insulate the interior runs. Pipes in exterior walls, unheated crawl areas, garages, and rim joists freeze before the buried line does. Open cabinet doors under sinks on exterior walls during a cold snap. Keep snow on the lawn over the service line. Snow is insulation. Bare, plowed, or shoveled ground freezes deeper than ground under a foot of snow, which is why driveways and walks are often where the frost drives deepest. If your water slows to a trickle, that's the warning, not the failure. Call the city before it stops entirely.

• 3

  Your well, and the arsenic problem

  Between 1.1 and 1.2 million Minnesotans get their drinking water from a private well. Nobody tests it but you, and in Minnesota the contaminant that deserves top billing is arsenic, which occurs naturally in the state's glacial sediment and bedrock.

  The numbers from MDH are striking. Arsenic has been detected in roughly 40% of new wells drilled since 2008, and about 10% of Minnesota private wells exceed the federal standard of 10 µg/L. Some wells have come back as high as 350 µg/L. Levels vary between wells even within a small area, so a neighbor's clean result means nothing for yours.

  Here's a Minnesota-specific shortcut most well owners don't know about. Since August 2008, state law has required well contractors to test every newly drilled well for arsenic and report the result to both the owner and MDH. If your well was drilled in 2008 or later, that result already exists and you can look it up in the Minnesota Well Index online. No sample, no lab fee. If your well predates 2008, it was probably never tested, and a one-time arsenic test is the single most useful thing you can do about your water.

  On a schedule:

  Arsenic: at least once, ever. MDH's guidance is that if arsenic isn't detected the first time, it's unlikely to appear later, so further arsenic testing isn't necessary. If it was detected in a new well, retest about six months after construction once the water chemistry has settled. Coliform bacteria and nitrate: every year. Bacteria signal that surface water or waste is getting into the well. Nitrate comes from fertilizer, livestock, and failing septic systems, and it's a genuine risk to infants. The wellhead itself: every year. Cap sealed and intact, casing standing at least a foot above grade, ground sloping away rather than toward it. After any flooding, well work, or change in taste, smell, or clarity — test again regardless of where you are in the cycle.

  One more MDH finding worth sitting with: in a survey of households that had already received a high arsenic result, 34% had taken no action to reduce their exposure, and at least 81% weren't testing at the frequency MDH recommends for other contaminants. Knowing isn't the hard part here. Doing something about it is.

Minnesota home maintenance questions