• Wood foundations are simpler, quicker and cheaper to construct than masonry foundations. On average, they will not, however, last as long as masonry foundations and are less durable in the long-term.
• The design of PWFs requires that dry soil is maintained around the foundation. This means that a properly maintained and constructed basement with wood walls will be dry and mildew-free. Basement mildew, leakage and dampness are common in houses with masonry foundations.
• Finishing a basement is easier when walls are made from wood. Insulation is placed between the wall studs to which drywall can be attached.
• The basement will be warmer because wood is a better insulator than masonry, and the foundation wall studs provide large cavities for insulation. However, it must be considered that wood foundation walls are typically much thinner than masonry walls. Also, masonry can be insulated.

Inspectors can check for the following indicators that wood basement walls are experiencing problems:

• dampness. If dampness is present, its source should be identified. Dampness may be due to a rising water table, an inadequate drainage system, or inadequate damp-proofing. Water from an interior source, such as an air conditioner or a high-efficiency furnace, however, does not indicate a compromised PWF.
• exterior wood decay. Inspectors can check for exterior wood decay by probing the wall from the outside with a rod. It is usually adequate to probe once every 8 feet. If decayed wood is detected by probing, it is likely that decay exists elsewhere in the wall.
• interior wood decay. If the interior wall is not covered by drywall, it may be possible to inspect for wood decay below grade from the inside of the house.
• foundation leakage. Evidence of foundation leakage may be discovered at butt joints where sealant may not have been used.
• buckling. Buckling can occur due to constant pressure over the course of years, or by the back-filling process.
• lack of a moisture barrier. Outside, a moisture barrier should be present and it should rise above grade.
• bowing of the foundation walls, especially the wall next to the basement stairs.

Damp-Proofing

Why would a homeowner use a non-conforming room as a bedroom?  Some of the reasons include:

• to earn money from it as a rental. While they run the risk of being discovered by the city, landlords will profit by renting out rooms that are not legally bedrooms;
• to increase the value of the home. All other considerations being equal, a four-bedroom house will usually sell for more than a three-bedroom house; and
• lack of knowledge of code requirements. To the untrained eye, there is little obvious difference between a conforming bedroom and non-conforming bedroom. When an emergency happens, however, the difference will be more apparent. If you have any questions about safety requirements, ask your InterNACHI inspector during your next scheduled inspection.

Homeowners run serious risks when they use a non-conforming room as a bedroom. An embittered tenant, for instance, may bring their landlord to court, especially if the tenant was forced out when the faux bedroom was exposed. The landlord, upon being exposed, might choose to adjust the bedroom to make it code-compliant, but this can cost thousands of dollars. Landlords can also be sued if they sell the home after having advertised it as having more bedrooms than it actually has. And the owner might pay more than they should be paying in property tax if they incorrectly list a non-conforming bedroom as a bedroom. Perhaps the greatest risk posed by rooms that unlawfully serve as bedrooms stems from the reason these laws exist in the first place:  rooms lacking egress can be deadly in case of an emergency. For instance, on January 5, 2002, four family members sleeping in the basement of a Gaithersburg, Maryland, townhome were killed by a blaze when they had no easy escape.

The following requirements are taken from the 2006 International Residential Code (IRC), and they can be used as a general guide, but bear in mind that the local municipality determines the legal definition of a bedroom. Such local regulations can vary widely among municipalities, and what qualifies as a bedroom in one city might be more properly called a den in a nearby city. In some municipalities, the room must be above grade, be equipped with an AFCI or smoke alarm to be considered a conforming bedroom, for instance. Ceiling height and natural lighting might also be factors. The issue can be extremely complex, so it’s best to learn the code requirements for your area. Nevertheless, the IRC can be useful, and it reads as follows:

• EMERGENCY ESCAPE AND RESCUE REQUIRED SECTION: R 310.1 Basements and every sleeping room shall have at least one operable emergency and rescue opening. Such opening shall open directly into a public street, public alley, yard or court. Where basements contain one or more sleeping rooms, emergency egress and rescue openings shall be required in each sleeping room, but shall not be required in adjoining areas of the basement. Where emergency escape and rescue openings are provided, they shall have a sill height of not more than 44 inches (1,118mm) above the floor. Where a door opening having a threshold below the adjacent ground elevation serves as an emergency escape and rescue opening and is provided with a bulkhead enclosure, the bulkhead enclosure shall comply with SECTION R310.3. The net clear opening dimensions required by this section shall be obtained by the normal operation of the emergency escape and rescue opening from the inside. Emergency escape and rescue openings with a finished sill height below the adjacent ground elevation shall be provided with a window well, in accordance with SECTION R310.2.  
  • MINIMUM OPENING AREA: SECTION: R 310.1.1 All emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet (0.530 m²). Exception: Grade floor openings shall have a minimum net clear opening of 5 square feet (0.465 m²).
  • MINIMUM OPENING HEIGHT: R 310.1.2 The minimum net clear opening height shall be 24 inches (610mm).
  • MINIMUM OPENING WIDTH: R 310.1.3 The minimum net clear opening width shall be 20 inches (508mm).
  • OPERATIONAL CONSTRAINTS: R 310.1.4 Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys or tools or special knowledge.

• WINDOW WELLS: SECTION: R310.2 The minimum horizontal area of the window well shall be 9 square feet (0.9 m²), with a minimum horizontal projection and width of 36 inches (914mm). The area of the window well shall allow the emergency escape and rescue opening to be fully opened. Exception: The ladder or steps required by SECTION R 310.2.1 shall be permitted to encroach a maximum of 6 inches (152mm) into the required dimensions of the window well.
• LADDER AND STEPS: SECTION: R 310.2.1 Window wells with a vertical depth greater than 44 inches (1,118mm) shall be equipped with a permanently affixed ladder or steps usable with the window in the fully open position. Ladders or steps required by this section shall not be required to comply with SECTIONS R311.5 and R311.6. Ladders or rungs shall have an inside width of at least 12 inches (305 mm), shall project at least 3 inches (76mm) from the wall, and shall be spaced not more than 18 inches (457mm) on-center vertically for the full height of the window well.

• BARS, GRILLS, COVERS, AND SCREENS: SECTION: R 310.3 Bars, grilles, covers, screens or similar devices are permitted to be placed over emergency escape and rescue openings, bulkhead enclosures, or window wells that serve such openings, provided the minimum net clear opening size complies with SECTIONS R 310.1.1 to R 310.1.3, and such devices shall be releasable or removable from the inside without the use of a key, tool, special knowledge, or force greater than that which is required for normal operation of the escape and rescue opening.

  

Why is mold growing in my home?

Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing.  Molds have the potential to cause health problems.  Molds produce allergens (substances that can cause allergic reactions), irritants and, in some cases, potentially toxic substances (mycotoxins).  Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals.  Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis).  Allergic reactions to mold are common.  They can be immediate or delayed.  Molds can also cause asthma attacks in people with asthma who are allergic to mold.  In addition, mold exposure can irritate the eyes, skin, nose, throat and lungs of both mold-allergic and non-allergic people.  Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold.  Research on mold and health effects is ongoing.  This article provides a brief overview; it does not describe all potential health effects related to mold exposure.  For more detailed information, consult a health professional.  You may also wish to consult your state or local health department.

How do I get rid of mold? 

You must have completely fixed the water or moisture problem before the cleanup or remediation can be considered finished, based on the following guidelines:

• You should have completed the mold removal.  Visible mold and moldy odors should not be present.  Please note that mold may cause staining and cosmetic damage.
• You should have revisited the site(s) shortly after cleanup, and it should show no signs of water damage or mold growth.
• People should have been able to occupy or re-occupy the area without health complaints or physical symptoms.
• Ultimately, this is a judgment call; there is no easy answer. If you have concerns or questions, be sure to ask your InterNACHI inspector during your next scheduled inspection.

  

• Moisture control is the key to mold control, so when water leaks or spills occur indoors, ACT QUICKLY.  If wet or damp materials or areas are dried within 24 to 48 hours after a leak or spill happens, in most cases, mold will not grow.
• Clean and repair roof gutters regularly.
• Make sure the ground slopes away from the building’s foundation so that water does not enter or collect around the foundation.
• Keep air-conditioning drip pans clean and the drain lines unobstructed and flowing properly.
• Keep indoor humidity low.  If possible, keep indoor humidity below 60% relative humidity (ideally, between 30% to 50%).  Relative humidity can be measured with a moisture or humidity meter, which is a small, inexpensive instrument (from $10 to $50) that is available at many hardware stores.
• If you see condensation or moisture collecting on windows, walls or pipes, ACT QUICKLY to dry the wet surface and reduce the moisture/water source.  Condensation can be a sign of high humidity.

Actions that will help to reduce humidity:

• Vent appliances that produce moisture, such as clothes dryers, stoves, and kerosene heaters, to the outdoors, where possible.  (Combustion appliances, such as stoves and kerosene heaters, produce water vapor and will increase the humidity unless vented to the outside.)
• Use air conditioners and/or de-humidifiers when needed.
• Run the bathroom fan or open the window when showering.  Use exhaust fans or open windows whenever cooking, running the dishwasher or dishwashing, etc.

Actions that will help prevent condensation:

• Reduce the humidity (see above).
• Increase ventilation and air movement by opening doors and/or windows, when practical.  Use fans as needed.
• Cover cold surfaces, such as cold water pipes, with insulation.
• Increase air temperature.

Note:  People who do not suffer from these ailments may still be harmed by elevated levels of airborne mold spores.

How does moisture get into the house?

Moisture or water vapor moves into a house in the following ways:

Inspectors can check for moisture intrusion in the following areas:

Roofs 

A roof leak may lead to the growth of visible mold colonies in the attic that can grow unnoticed. Roof penetrations increase the likelihood of water leaks due to failed gaskets, sealants and flashing. The number of roof penetrations may be reduced by a variety of technologies and strategies, including:

• consolidation of vent stacks below the roof;
• exhaust fan caps routed through walls instead of the roof;
• high-efficiency combustion appliances, which can be sidewall-vented;
• electrically powered HVAC equipment and hot water heaters that do not require flue; and
• adequate flashing. Oftentimes, inspectors discover missing, incorrectly installed or corroded flashing pipes.

Plumbing

• Distribution pipes and plumbing fixtures can be the source of large amounts of moisture intrusion. If the wall is moist and/or discolored, then moisture damage is already in progress. Most plumbing is hidden in the walls, so serious problems can begin unnoticed.
• One of the most important means of moisture management in the bathroom is the exhaust fan. A non-functioning exhaust fan overloads the bathroom with damp air. If the exhaust fan doesn’t turn on automatically when the bathroom is in use, consider recommending switching the wiring or switch. The lack of an exhaust fan should be called out in the inspection report. The fan should vent into the exterior, not into the attic.
• The bathroom sink, in particular, is a common source of moisture intrusion and damage. Although overflow drains can prevent the spillage of water onto the floor, they can become corroded and allow water to enter the cabinet.
• Use a moisture meter to check for elevated moisture levels in the sub-floor around the toilet and tub.
• Bathroom windows need to perform properly in a wide range of humidity and temperature conditions. Check to see if there are any obvious breaks in the weatherstripping and seals. Are there are stains or flaking on the painted surfaces?
• Check showers and bathtubs. Is the caulking is cracked, stiff or loose in spots? Are there cracked tiles or missing grout that may channel water to vulnerable areas? If some water remains in the bathtub after draining, it may be a warning sign of possible structural weakening and settlement in the floor beneath the tub.

Utility Room

• The water heater tank should be clean and rust-free.
• The area around the water softener tank should be clean and dry.
• Check that all through-the-wall penetrations for fuel lines, ducts, and electrical systems of heating system are well-sealed. All ducts should be clean and dust-free. Inspect the air supply registers in the house for dust accumulation.
• Filters, supply lines, exterior wall penetrations, vents, ductwork and drainage of the cooling system must all be in good working order to avoid moisture problems.

Attic

• Look for stains or discolorations at all roof penetrations. Chimneys, plumbing vents and skylight wells are common places where moisture may pass through the roof. Any such locations must be inspected for wetness, a musty smell and/or visible signs of mold.
• Are there areas of the insulation that appear unusually thin?
• Rust or corrosion around recessed lights are signs of a potential electrical hazard.

Part of responsible homeownership includes, of course, regular home maintenance.  And there are some tasks that, if deferred, can lead to a home system that’s inefficient and overworked, which can result in problems and expenses.  One such task is changing the filter of the home’s HVAC system.  It’s simple and inexpensive, and taking care of it at least every three months can mean the difference between optimum comfort and avoidable repairs.

What Can Go Wrong

Most homes have some sort of furnace or heat pump, and many of those homes (especially newer ones) have combined heating, ventilation and air-conditioning or HVAC systems.  Each type uses some type of air filter or screen to prevent larger airborne particles (up to 40 microns) from entering the system and clogging sensitive machinery.  A system that has a dirty filter can suffer from pressure drop, which can lead to reduced air flow, or “blow-out,” resulting in no air infiltration at all.  Any of these conditions can cause the system to work harder to keep the home warm or cool (depending on the season and the setting).  And any mechanical component that has to work harder to run efficiently puts undue stress on the whole system, which can lead to premature failure, resulting in repair or replacement.

Also, a dirty filter that’s exposed to condensation can become damp, which can lead to mold growth that can be spread throughout the home by the HVAC system.  This can lead to serious health consequences, not to mention a compromised unit that will likely require servicing and may require replacement, depending on the severity of the moisture problem.

Types of Filters

Most HVAC and furnace filters are disposable, made of biodegradable paper or similar media, and shaped in cells, screens or fins designed to trap as much airborne debris as possible.  Filters can typically be purchased in economical multi-packs, and there are many types that will fit different models of furnace/HVAC units.  It’s important to use the appropriate filter for your unit; using the wrong filter that doesn’t fit the unit properly can create the same types of problems as having a dirty filter.  Your HVAC installer can show you where the filter goes and how to remove the old one and install a new one.  Your unit may also have an affixed label with directions for easy filter replacement.

How Often?

Your HVAC or furnace technician should service your unit once a year.  Because a furnace/HVAC unit contains moving parts, it’s important that belts are not cracked and dry, ventilation ductwork is not gapped, cracked or rusted, and components, such as coils and fans, are clog-free and adequately lubricated for unimpeded operation.  This sort of evaluation is best left to the professional, unless the homeowner has had the appropriate training.

The filter of the unit, especially if it’s an HVAC unit that will tend to get nearly year-round use, should be changed by the homeowner at least every three months, but possibly more often.

Check your filter’s condition and change it once a month if:

• You run your unit six months a year to year-round.
• You have pets.  Pet dander can become airborne and circulate through the home’s ventilation system just as typical household dust does.
• You have a large family.  More activity means more household dust, dirt and debris.
• You smoke indoors.
• You or someone in your household suffers from allergies or a respiratory condition.
• You live in a particularly windy area or experience high winds for extended periods, especially if there are no nearby shrubs or trees to provide a natural windbreak.
• You live in an area prone to or having recently experienced any wildfires.  Airborne ash outdoors will eventually find its way indoors.
• You have a fireplace that you occasionally use.
• You live on a working farm or ranch.  Dust and dirt that gets kicked up by outdoor work activity and/or large animals can be pulled into the home’s ventilation system, especially through open windows.
• You have a large garden.  Depending on its size and how often you work it, tilling soil, planting, pulling weeds, using herbicides and pesticides, and even watering mean that dirt, chemicals and condensation can be pulled into your home’s ventilation system.
• There is construction taking place around or near the home.  You may be installing a new roof or a pool, or perhaps a neighbor is building a home or addition.  Even if the activity is only temporary, dust and debris from worksites adjacent to or near the home can be sucked into the home’s ventilation system, and this increased activity can tax your HVAC system.

Change the filter immediately if:

• The filter is damaged.  Whether it happened inside the packaging or while being installed, a damaged filter that has bent fins, collapsed cells or holes will not work as well as an undamaged filter, especially if it allows system air to bypass the filter at any point.
• The filter is damp.  A filter affected by moisture intrusion, system condensation, or even high indoor humidity can quickly become moldy and spread airborne mold spores throughout the home via the ventilation system.
• There is evidence of microbial growth or mold on the filter.  Mold spores already infiltrating the home via the HVAC system are not only bad for the unit itself, but they can pose a health hazard for the family, ranging from an irritated respiratory system to a serious allergic reaction.  The musty smell produced by a moldy HVAC filter is also unpleasant and may take a while to completely eradicate from inside the home.  If you discover that you have moldy air filter, it’s important to have the cause investigated further.  An InterNACHI inspector or HVAC technician can help determine the problem so that it doesn’t recur.

Tips on Changing the Filter

• Turn off the unit before replacing the filter.
• Use the right filter for your unit and make sure it’s not damaged out of the package.
• Follow the directions for your unit to make sure you’re installing the filter properly.  For example, many filters use different colors for the front and back (or upstream and downstream flow) so that they’re not installed backwards.
• Make sure there aren’t any gaps around the filter frame.  If this is the case, you may have the wrong size filter, or the filter itself may be defective or damaged.
• Use a rag to clean up any residual dust before and after you replace the filter.
• Securely replace any levers, gaskets and/or seals.
• Turn the unit on and observe it while it’s operating to make sure the filter stays in place.
• Note the date of filter replacement in a convenient location for the next time you inspect it.  A filter that becomes dirty enough to change within a short period of time may indicate a problem with the unit or ventilation system, so monitoring how often the filter requires changing is important information for your technician to have.

Call a technician for servicing if:

• Your unit fails to turn back on.
• The fan is slow or makes excessive noise, or the fins are bent.
• The coils are excessively dusty or clogged.
• You notice moisture intrusion from an unknown source anywhere in the system.

What is a GFCI?

A ground-fault circuit interrupter, or GFCI, is a device used in electrical wiring to disconnect a circuit when unbalanced current is detected between an energized conductor and a neutral return conductor.  Such an imbalance is sometimes caused by current “leaking” through a person who is simultaneously in contact with a ground and an energized part of the circuit, which could result in lethal shock.  GFCIs are designed to provide protection in such a situation, unlike standard circuit breakers, which guard against overloads, short circuits and ground faults.

History

The first high-sensitivity system for detecting current leaking to ground was developed by Henri Rubin in 1955 for use in South African mines.  This cold-cathode system had a tripping sensitivity of 250 mA (milliamperes), and was soon followed by an upgraded design that allowed for adjustable trip-sensitivity from 12.5 to 17.5 mA.  The extremely rapid tripping after earth leakage-detection caused the circuit to de-energize before electric shock could drive a person’s heart into ventricular fibrillation, which is usually the specific cause of death attributed to electric shock.

NEC Requirements for GFCIs

The National Electrical Code (NEC) has included recommendations and requirements for GFCIs in some form since 1968, when it first allowed for GFCIs as a method of protection for underwater swimming pool lights.  Throughout the 1970s, GFCI installation requirements were gradually added for 120-volt receptacles in areas prone to possible water contact, including bathrooms, garages, and any receptacles located outdoors.

The 1980s saw additional requirements implemented.  During this period, kitchens and basements were added as areas that were required to have GFCIs, as well as boat houses, commercial garages, and indoor pools and spas.  New requirements during the ’90s included crawlspaces, wet bars and rooftops.  Elevator machine rooms, car tops and pits were also included at this time.  In 1996, GFCIs were mandated for all temporary wiring for construction, remodeling, maintenance, repair, demolition and similar activities and, in 1999, the NEC extended GFCI requirements to carnivals, circuses and fairs.

The 2008 NEC contains additional updates relevant to GFCI use, as well as some exceptions for certain areas.  The 2008 language is presented here for reference.

2008 NEC on GFCIs

100.1 Definition

100.1  Definitions. Ground-Fault Circuit Interrupter. A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device.

FPN: Class A ground-fault circuit interrupters trip when the current to ground has a value in the range of 4 mA to 6 mA.  For further information, see UL 943, standard for Ground-Fault Circuit Interrupters.

210.8(A)&(B)  Protection for Personnel

210.8 Ground-Fault Circuit Interrupter Protection for Personnel.

(A)  Dwelling Units. All 125-volt, single-phase, 15- and 20-ampere receptacles installed in the locations specified in (1) through (8) shall have ground-fault circuit-interrupter protection for personnel.

(1)   bathrooms;

(2)   garages, and also accessory buildings that have a floor located at or below grade level not intended as habitable rooms and limited to storage areas, work areas, and areas of similar use;

Exception No. 1: Receptacles not readily accessible.

Exception No. 2: A single receptacle or a duplex receptacle for two appliances that, in normal use, is not easily moved from one place to another and that is cord-and-plug connected in accordance with 400.7(A)(6), (A)(7), or (A)(8).

Receptacles installed under the exceptions to 210.8(A)(2) shall not be considered as meeting the requirements of 210.52(G)

(3)   outdoors;

Exception: Receptacles that are not readily accessible and are supplied by a dedicated branch circuit for electric snow melting or deicing equipment shall be permitted to be installed in accordance with the applicable provisions of Article 426.

(4)   crawlspaces at or below grade level.

Exception No. 1: Receptacles that are not readily accessible.

Exception No. 2:  A single receptacle or a duplex receptacle for two appliances that, in normal use, is not easily moved from one place to another and that is cord-and-plug connected in accordance with 400.7(A)(6), (A)(7), or (A)(8).

Exception No. 3: A receptacle supplying only a permanently installed fire alarm or burglar alarm system shall not be required to have ground-fault circuit interrupter protection.

Receptacles installed under the exceptions to 210.8(A)(2) shall not be considered as meeting the requirements of 210.52(G)

(6)   kitchens, where the receptacles are installed to serve the countertop surfaces;

(7)   wet bar sinks, where the receptacles are installed to serve the countertop surfaces and are located within 6 feet (1.8 m) of the outside edge of the wet bar sink;

(8)   boathouses;

(B) Other Than Dwelling Units. All 125-volt, single-phase, 15- and 20-ampere receptacles Installed in the locations specified in (1), (2), and (3) shall have ground-fault circuit interrupter protection for personnel:

(1)   bathrooms;

(2)   rooftops;

Exception: Receptacles that are not readily accessible and are supplied by a dedicated branch circuit for electric snow-melting or de-icing equipment shall be permitted to be installed in accordance with the applicable provisions of Article 426.

(3)   kitchens.

Testing Receptacle-Type GFCIs

Receptacle-type GFCIs are currently designed to allow for safe and easy testing that can be performed without any professional or technical knowledge of electricity.  GFCIs should be tested right after installation to make sure they are working properly and protecting the circuit.  They should also be tested once a month to make sure they are working properly and are providing protection from fatal shock.

If the “RESET” button does not pop out, the GFCI is defective and should be replaced.

Geothermal systems are home heating and cooling systems that gather heat from the earth. Geothermal heat pumps (GHPs) use the relatively constant temperature of sub-surface soil as the exchange medium.

• As of 2004, five countries — El Salvador, Kenya, the Philippines, Iceland and Costa Rica — generate more than 15% of their electricity from geothermal sources. In Iceland, geothermal energy is so cheap that some sections of pavement are heated.
• In the United States, roughly 50,000 geothermal heat pumps are installed every year. The U.S. leads the world in geothermal exploitation.
• The combined production of geothermal energy for all uses places third among renewable energy sources, following hydroelectricity and biomass, and ahead of solar and wind.

• energy efficiency. GHPs require 25% to 50% less electricity than conventional heating and cooling systems. According to the EPA, geothermal heat pumps can reduce energy consumption — and corresponding emissions — up to 44%, compared to air-source heat pumps, and up to 72%, compared to electric resistance heating with standard air-conditioning equipment.
• design flexibility. Geothermal heat pump systems can be installed in both new and retrofit construction. Equipment rooms can be scaled down in size because the hardware requires less space than is needed by conventional HVAC systems. GHP systems also provide excellent “zone” space conditioning, which allows different parts of a home to be heated or cooled to different temperatures.
• durability. Since GHP systems have relatively few moving parts and the parts are sheltered inside a building, the systems are durable and reliable. The underground piping often carries warranties of 25 to 50 years, and the heat pumps can last more than 20 years. The components are easily accessible, which helps ensure that the required maintenance is performed on a timely basis.
• noise reduction. As they have no outside condensing units (such as those in air conditioners), there’s no noise outside the home. Geothermal heat pumps are so quiet inside of a house that users may not be aware they are operating.

How do geothermal systems work?
A geothermal heat pump, unlike a furnace, does not create heat by burning fuel. Instead, it collects the earth’s natural heat through a series of pipes, called a loop, installed below the frost line. At that depth, which varies by climate zone, the soil remains at a relatively constant temperature throughout the year. Fluid circulates through the loop and carries heat to the house. There, an electrically driven compressor and a heat exchanger concentrate the heat and release it inside the home at a higher temperature, where ductwork distributes the heat to different rooms. In summer, the underground loop draws excess heat from the house and allows it to be absorbed into the earth. The system cools the home in the same way that a refrigerator keeps food cool — by drawing heat from the interior, rather than by forcing in cold air.

Types of Systems
According to InterNACHI, there are four basic types of geothermal systems. Selection of the most appropriate system depends on the climate, soil conditions, available land, and local installation costs at the site. All of these systems can be used for residential and commercial building applications. They include:

• horizontal:  This type of installation is generally the most cost-effective for residential installations, particularly for new construction where sufficient land is available. The most common layouts use either two pipes (one buried at 6 feet, and the other at 4 feet), or two pipes placed side-by-side buried 5 feet in the ground in a 2-foot wide trench.
• vertical:  Large commercial buildings and schools often use vertical systems because the land area required for horizontal loops is prohibitive. Vertical loops are also used where the soil is too shallow for trenching, and they minimize the disturbance to existing landscaping. For a vertical system, holes (approximately 4 inches in diameter) are drilled about 20 feet apart and 100 to 400 feet deep. Two pipes are inserted into these holes and connected at the bottom to form a loop. The vertical loops are connected to the heat pump in the building.
• pond/lake:  A supply-line pipe is run underground from the building to a body of water and coiled into circles at least 8 feet under the surface. In order for the body of water to be adequate, it must meet minimum volume, depth and quality criteria.
• open-loop system:  This type of system uses well or surface water as the heat exchange fluid that circulates directly through the GHP system. Once it has circulated through the system, the water returns to the ground through the well, a recharge well, or surface discharge. This option is practical only where there is an adequate supply of relatively clean water, which must comply with local codes and regulations regarding groundwater discharge.

Cost
A geothermal system usually costs about $2,500 per ton of capacity. A typical home uses a 3-ton unit costing roughly $7,500. That initial cost is nearly twice the price of a regular heat pump system that includes air conditioning. The cost of drilling, however, can be considerable; drilling can cost in excess of $30,000, depending on the terrain and other local factors. Systems that require drilling vertically deep into the ground will cost much more than systems where the loops are in a horizontal fashion and closer to the surface. Despite these initial costs, a geothermal system saves enough on utility bills that the investment is often recouped in five to ten years.

Checklist for Inspecting Radon Mitigation Systems in Residential Homes

https://www.nachi.org/comsop.htm#19 

Home Buyer’s and Seller’s Guide to Radon 

The EPA recommends:

• If you are buying a home or selling your home, have it tested for radon.
• For a new home, ask if radon-resistant construction features were used and if the home has been tested.
• Fix the home if the radon level is 4 picoCuries per liter (pCi/L) or higher.
• Radon levels less than 4 pCi/L still pose a risk, and in many cases, may be reduced.
• Take steps to prevent device interference when conducting a radon test.

The EPA estimates that radon causes thousands of cancer deaths in the U.S. each year.

 * Radon is estimated to cause about 21,000 lung cancer deaths per year.

The numbers of deaths from other causes are taken from the Centers for Disease Control and Prevention’s 1999-2001 National Center for Injury Prevention and Control Report and 2002 National Safety Council Reports.

Radon is a cancer-causing, radioactive gas.

You cannot see, smell or taste radon. But it still may be a problem in your home.  When you breathe air containing radon, you increase your risk of getting lung cancer.  In fact, the Surgeon General of the United States has warned that radon is the second leading cause of lung cancer in the United States today.  If you smoke and your home has high radon levels, your risk of lung cancer is especially high.

You should test for radon.

Testing is the only way to find out your home’s radon levels. The EPA and the Surgeon General recommend testing all homes below the third floor for radon.

You can fix a radon problem.

If you find that you have high radon levels, there are ways to fix a radon problem. Even very high levels can be reduced to acceptable levels.

If You Are Selling a Home…

The EPA recommends that you test your home before putting it on the market and, if necessary, lower your radon levels. Save the test results and all information you have about steps that were taken to fix any problems. This could be a positive selling point.

If You Are Buying a Home…

The EPA recommends that you know what the indoor radon level is in any home you are considering buying.  Ask the seller for their radon test results.  If the home has a radon-reduction system, ask the seller for information they have about the system.

If the home has not yet been tested, you should have the house tested.

If you are having a new home built, there are features that can be incorporated into your home during construction to reduce radon levels.

These radon testing guidelines have been developed specifically to deal with the time-sensitive nature of home purchases and sales, and the potential for radon device interference.  These guidelines are slightly different from the guidelines in other EPA publications which provide radon testing and reduction information for non-real estate situations.

This guide recommends three short-term testing options for real estate transactions.  The EPA also recommends testing a home in the lowest level which is currently suitable for occupancy, since a buyer may choose to live in a lower area of the home than that used by the seller.

1. Why do you need to test for radon?

a. Radon has been found in homes all over the U.S.

Radon is a radioactive gas that has been found in homes all over the United States. It comes from the natural breakdown of uranium in soil, rock and water, and gets into the air you breathe. Radon typically moves up through the ground to the air above, and into your home through cracks and other holes in the foundation. Radon can also enter your home through well water. Your home can trap radon inside.

Any home can have a radon problem, including new and old homes, well-sealed and drafty homes, and homes with or without basements. In fact, you and your family are most likely to get your greatest radiation exposure at home. That is where you spend most of your time.

Nearly one out of every 15 homes in the United States is estimated to have an elevated radon level (4 pCi/L or more).  Elevated levels of radon gas have been found in homes in your state.

b. The EPA and the Surgeon General recommend that you test your home.

Testing is the only way to know if you and your family are at risk from radon. The EPA and the Surgeon General recommend testing all homes below the third floor for radon.

You cannot predict radon levels based on state, local, or neighborhood radon measurements.  Do not rely on radon test results taken in other homes in the neighborhood to estimate the radon level in your home.  Homes which are next to each other can have different radon levels.  Testing is the only way to find out what your home’s radon level is.

In some areas, companies may offer different types of radon service agreements.  Some agreements let you pay a one-time fee that covers both testing and radon mitigation, if needed.

U.S. Surgeon General’s
Health Advisory

“Indoor radon gas is the second-leading cause of lung cancer in the United States, and breathing it over prolonged periods can present a significant health risk to families all over the country.  It’s important to know that this threat is completely preventable.  Radon can be detected with a simple test, and fixed through well-established venting techniques.”

January 2005

2. I’m selling a home.  What should I do?

a. If your home has already been tested for radon…

If you are thinking of selling your home and you have already tested your home for radon, review the Radon Testing Checklist to make sure that the test was done correctly.  If so, provide your test results to the buyer.

No matter what kind of test you took, a potential buyer may ask for a new test, especially if:

the Radon Testing Checklist items were not met;

the last test is not recent, (e.g., within two years);

you have renovated or altered your home since you tested; or

the buyer plans to live in a lower level of the house than was tested, such as a basement suitable for occupancy but not currently lived in.

A buyer may also ask for a new test if your state or local government requires disclosure of radon information to buyers.

b. If your home has not yet been tested for radon…

Have a test taken as soon as possible. If you can, test your home before putting it on the market.  You should test in the lowest level of the home which is suitable for occupancy. This means testing in the lowest level that you currently live in or a lower level not currently used, but which a buyer could use for living space without renovations.

The radon test result is important information about your home’s radon level.  Some states require radon measurement testers to follow a specific testing protocol.  If you do the test yourself, you should carefully follow the testing protocol for your area or the EPA’s Radon Testing Checklist.  If you hire a contractor to test your residence, protect yourself by hiring a qualified individual or company.

You can determine a service provider’s qualifications to perform radon measurements or to mitigate your home in several ways.  Many states require radon professionals to be licensed, certified or registered.  Most states can provide you with a list of knowledgeable radon service providers doing business in your state.  In states that don’t regulate radon services, ask the contractor if they hold a professional proficiency or certification credential. Such programs usually provide members with a photo-ID card which indicates their qualification(s) and its expiration date.  If in doubt, you should check with their credentialing organization.  Alternatively, ask the contractor if they’ve successfully completed formal training appropriate for testing or mitigation, e.g., a course in radon measurement or radon mitigation.

3. I’m buying a home.  What should I do?

a. If the home has already been tested for radon…

If you are thinking of buying a home, you may decide to accept an earlier test result from the seller, or ask the seller for a new test to be conducted by a qualified radon tester.  Before you accept the seller’s test, you should determine the results of previous testing by finding out:

who conducted the previous test (the homeowner, a radon professional, or some other person);

where in the home the previous test was taken, especially if you may plan to live in a lower level of the home.  For example, the test may have been taken on the first floor.  However, if you want to use the basement as living space, test there, too;

what, if any, structural changes, alterations, or changes in the heating, ventilation, and air conditioning (HVAC) system have been made to the house since the test was done.  Such changes may affect radon levels.

If you accept the seller’s test, make sure that the test followed the Radon Testing Checklist.

If you decide that a new test is needed, discuss it with the seller as soon as possible.

b. If the home has not yet been tested for radon…

Make sure that a radon test is done as soon as possible. Consider including provisions in the contract specifying:

where the test will be located;

who should conduct the test;

what type of test to do;

when to do the test;

how the seller and the buyer will share the test results and test costs (if necessary); and

when radon mitigation measures will be taken, and who will pay for them.

Make sure that the test is done in the lowest level of the home suitable for occupancy. This means the lowest level that you are going to use as living space which is finished or does not require renovations prior to use. A state or local radon official or qualified radon tester can help you make some of these decisions. If you decide to finish or renovate an unfinished area of the home in the future, a radon test should be taken before starting the project, and after the project is finished. Generally, it is less expensive to install a radon-reduction system before (or during) renovations rather than afterward.

4. I’m buying or building a new home.  How can I protect my family?

a. Why should I buy a radon-resistant home?

Radon-resistant techniques work.  When installed properly and completely, these simple and inexpensive passive techniques can help to reduce radon levels.  In addition, installing them at the time of construction makes it easier to reduce radon levels further if the passive techniques don’t reduce radon levels below 4 pCi/L.  Radon-resistant techniques may also help to lower moisture levels and those of other soil-gases.  Radon-resistant techniques:

In a new home, the cost to install passive radon-resistant features during construction is usually between $350 to $500.  In some areas, the cost may be as low as $100.  A qualified mitigator will charge about $300 to add a vent fan to a passive system, making it an active system and further reducing radon levels.  In an existing home, it usually costs between $800 to $2,500 to install a radon mitigation system.

b. What are radon-resistant features?

Radon-resistant features may vary for different foundations and site requirements.  If you’re having a house built, you can learn about the EPA’s Model Standards (and architectural drawings) and explain the techniques to your builder.  If your new house was built (or will be built) to be radon-resistant, it will include these basic elements:

5. How can I get reliable radon test results?

Radon testing is easy and the only way to find out if you have a radon problem in your home.

a. Types of Radon Devices

Since you cannot see or smell radon, special equipment is needed to detect it.  When you’re ready to test your home, you can order a radon test kit by mail from a qualified radon measurement service provider or laboratory.  You can also hire a qualified radon tester, very often a home inspector, who will use the radon device(s) suitable to your situation. If you hire a home inspector, make sure you hire a qualified InterNACHI member — specifically, an IAC2 certified air-quality professional.  The most common types of radon testing devices are listed below.

Passive Devices

Passive radon-testing devices do not need power to function.  These include charcoal canisters, alpha-track detectors, charcoal liquid scintillation devices, and electret ion chamber detectors, which are available in hardware, drugstores, and other stores; they can also be ordered by mail or phone.  These devices are exposed to the air in the home for a specified period of time, and then sent to a laboratory for analysis.  Both short-term and long-term passive devices are generally inexpensive. Some of these devices may have features that offer more resistance to test interference or disturbance than other passive devices. Qualified radon testers may use any of these devices to measure the home’s radon level.

Active Devices

Active radon-testing devices require power to function. These include continuous radon monitors and continuous working-level monitors.  They continuously measure and record the amount of radon and its decay products in the air.  Many of these devices provide a report of this information, which can reveal any unusual or abnormal swings in the radon level during the test period. A qualified tester can explain this report to you.  In addition, some of these devices are specifically designed to deter and detect test interference. Some technically advanced active devices offer anti-interference features.  Although these tests may cost more, they may ensure a more reliable result.

b. General Information for All Devices

A state or local radon official can explain the differences between devices, and recommend the ones which are most appropriate for your needs and expected testing conditions.

Make sure to use a radon measurement device from a qualified laboratory.  Certain precautions should be followed to avoid interference during the test period.  See the Radon Testing Checklist for more information on how to get a reliable test result.

Radon Test Device Placement

The EPA recommends that testing device(s) be placed in the lowest level of the home suitable for occupancy. This means testing in the lowest level (such as a basement) which a buyer could use for living space without renovations. The test should be conducted in a room to be used regularly (such as a family room, living room, play room, den or bedroom); do not test in a kitchen, bathroom, laundry room or hallway.  Usually, the buyer decides where to locate the radon test, based on their expected use of the home.  A buyer and seller should explicitly discuss and agree on the test location to avoid any misunderstanding.  Their decision should be clearly communicated to the person performing the test.

c. Preventing or Detecting Test Interference

There is a potential for test interference in real estate transactions. There are several ways to prevent or detect test interference:

Use a test device that frequently records radon or decay-product levels to detect unusual swings.

Employ a motion detector to determine whether the test device has been moved or if testing conditions have changed.

Use a proximity detector to reveal the presence of people in the room, which may correlate to possible changes in radon levels during the test.

Record the barometric pressure to identify weather conditions which may have affected the test.

Record the temperature to help assess whether doors and windows have been opened during the test.

Apply tamper-proof seals to windows to ensure closed-house conditions.

Have the seller/occupant sign a non-interference agreement.

Home buyers and sellers should consult a qualified radon test provider about the use of these precautions.

d. Length of Time to Test

There are two general ways to test your home for radon:

Because radon levels vary from day to day and from season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level.  However, if you need results quickly, a short-term test may be used to decide whether to fix the home.

The quickest way to test is with short-term tests. Short-term tests remain in your home from two days to 90 days, depending on the device. There are two groups of devices which are more commonly used for short-term testing. The passive-device group includes alpha-track detectors, charcoal canisters, charcoal liquid scintillation detectors, and electret ion chambers. The active device group consists of different types of continuous monitors.

Long-Term Testing

Long-term tests remain in your home for more than 90 days. Alpha-track andelectret ion chamber detectors are commonly used for this type of testing. A long-term test will give you a reading that is more likely to tell you your home’s year-round average radon level than a short-term test. If time permits, long-term tests (more than 90 days) can be used to confirm initial short-term results. When long-term test results are 4 pCi/L or higher, the EPA recommends mitigating the home.

e. Doing a Short-Term Test…

If you are testing in a real estate transaction and you need results quickly, any of the following three options for short-term tests are acceptable in determining whether the home should be fixed. Any real estate test for radon should include steps to prevent or detect interference with the testing device.

f.  Using testing devices properly for reliable results.

If you do the test yourself:

When you are taking a short-term test, close windows and doors and keep them closed, except for normal entry and exit.  If you are taking a short-term test lasting less than four days, be sure to:

Close your windows and outside doors at least 12 hours before beginning the test.

Do not conduct short-term tests lasting less than four days during severe storms or periods of high winds.

Follow the testing instructions and record the start time and date.

Place the test device at least 20 inches above the floor in a location where it will not be disturbed and where it will be away from drafts, high heat, high humidity, and exterior walls.

Leave the test kit in place for as long as the test instructions say.

Once you have finished the test, record the stop time and date, re-seal the package, and return it immediately to the lab specified on the package for analysis.

You should receive your test results within a few weeks. If you need results quickly, you should find out how long results will take and, if necessary, request expedited service.

If you hire a qualified radon tester:

In many cases, home buyers and sellers may decide to have the radon test done by a qualified radon tester who knows the proper conditions, test devices, and guidelines for obtaining a reliable radon test result.  They can also:

• evaluate the home and recommend a testing approach designed to make sure you get reliable results;
• explain how proper conditions can be maintained during the radon test;
• emphasize to occupants of a home that a reliable test result depends on their cooperation.  Interference with, or disturbance of, the test or closed-house conditions will invalidate the test result;
• analyze the data and report measurement results; and
• provide an independent test.

g. Interpreting Radon Test Results

The average indoor radon level is estimated to be about 1.3 pCi/L; roughly 0.4 pCi/L of radon is normally found in the outside air. The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. While this goal is not yet technologically achievable for all homes, radon levels in many homes can be reduced to 2 pCi/L or below.

Radon Test Results Reported in Two Ways

Your radon test results may be reported in either picoCuries per liter of air (pCi/L) or working levels (WL). If your test result is in pCi/L, the EPA recommends you fix your home if your radon level is 4 pCi/L or higher. If the test result is in WL, the EPA recommends you fix the home if the working level is 0.02 WL or higher.  Some states require WL results to be converted to pCi/L to minimize confusion.

Sometimes, short-term tests are less definitive about whether the home is at or above 4 pCi/L, particularly when the results are close to 4 pCi/L. For example, if the average of two short-term tests is 4.1 pCi/L, there is about a 50% chance that the year-round average is somewhat below 4 pCi/L.

However, the EPA believes that any radon exposure carries some risk; no level of radon is safe. Even radon levels below 4 pCi/L pose some risk.  You can reduce your risk of lung cancer by lowering your radon level.

As with  other environmental pollutants, there is some uncertainty about the magnitude of radon health risks. However, we know more about radon risks than risks from most other cancer-causing substances. This is because estimates of radon risks are based on data from human studies on underground miners. Additional studies on more typical populations are underway.

Your radon measurement will give you an idea of your risk of getting lung cancer from radon. Your chances of getting lung cancer from radon depend mostly on:

• your home’s radon level;
• the amount of time you spend in your home; and
• whether you are a smoker or have ever smoked.

Smoking combined with radon is an especially serious health risk. If you smoke or are a former smoker, the presence of radon greatly increases your risk of lung cancer. If you stop smoking now and lower the radon level in your house, you will reduce your lung cancer risk.

Based on information contained in the National Academy of Sciences’ 1998 report, The Health Effects of Exposure to Indoor Radon, your radon risk may be somewhat higher than shown, especially if you have never smoked.  It’s never too late to reduce your risk to lung cancer.  Don’t wait to test and fix a radon problem.  If you are a smoker, stop smoking.

Go to the Radon Risk Comparison Charts

Radon Testing Checklist

For reliable test results, follow this Radon Testing Checklist carefully.  Testing for radon is not complicated.  Improper testing may yield inaccurate results and require another test.  Disturbing or interfering with the test device or with closed-house conditions may invalidate the test results, and is actually illegal in some states.  If the seller or qualified tester cannot confirm that all items have been completed, take another test.

Notify the occupants of the importance of proper testing conditions. Give the occupants written instructions or a copy of this Guide and explain the directions carefully.

Conduct the radon test for a minimum of 48 hours; some test devices have a minimum exposure time greater than 48 hours.

When doing a short-term test ranging from two to four days, it is important to maintain closed-house conditions for at least 12 hours before the beginning of the test and during the entire test period.

When doing a short-term test ranging from four to seven days, the EPA recommends that closed-house conditions be maintained.

If you conduct the test yourself, use a qualified radon measurement device and follow the laboratory’s instructions.  Your state may be able to provide you with a list of do-it-yourself test devices available from qualified laboratories.

If you hire someone to do the test, hire only a qualified individual.  Some states issue photo identification (ID) cards; ask to see it.  The tester’s ID number, if available, should be included or noted in the test report.

The test should include method(s) to prevent or detect interference with testing conditions, or with the testing device itself.

If the house has an active radon-reduction system, make sure the vent fan is operating properly.  If the fan is not operating properly, have it (or ask to have it) repaired and then test it.

“Closed-house conditions” mean keeping all windows closed, keeping doors closed except for normal entry and exit, and not operating fans or other machines which bring in air from outside.  Fans that are part of a radon-reduction system or small exhaust fans operating for only short periods of time may run during the test.

Maintain closed-house conditions during the entire time of a short-term test, especially for tests shorter than one week.

Operate the home’s heating and cooling systems normally during the test. For tests lasting less than one week, operate only air-conditioning units which re-circulate interior air.

Do not disturb the test device at any time during the test.

If a radon-reduction system is in place, make sure the system is working properly and will be in operation during the entire radon test.

If you conduct the test yourself, be sure to promptly return the test device to the laboratory.  Be sure to complete the required information, including start and stop times, test location, etc.

If an elevated level is found, fix the home. Contact a qualified radon-reduction contractor about lowering the radon level.  The EPA recommends that you fix the home when the radon level is 4 pCi/L or more.

Be sure that you or the radon tester can demonstrate or provide information to ensure that the testing conditions were not violated during the testing period.

6. What should I do if the radon level is high?

a. High radon levels can be reduced.

The EPA recommends that you take action to reduce your home’s indoor radon levels if your radon test result is 4 pCi/L or higher. It is better to correct a radon problem before placing your home on the market because then you will have more time to address a radon problem.

If elevated levels are found during the real estate transaction, the buyer and seller should discuss the timing and costs of the radon reduction.  The cost of making repairs to reduce radon levels depends on how your home was built and other factors. Most homes can be fixed for about the same cost as other common home repairs, such as painting or having a new hot water heater installed. The average cost for a contractor to lower radon levels in a home can range from $800 to about $2,500.

b. How to Lower The Radon Level in Your Home

A variety of methods can be used to reduce radon in homes. Sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction. The EPA does not recommend the use of sealing alone to limit radon entry.  Sealing alone has not been shown to lower radon levels significantly or consistently.

In most cases, a system with a vent pipe and fan is used to reduce radon.  These “sub-slab depressurization” systems do not require major changes to your home. Similar systems can also be installed in homes with crawlspaces.  These systems prevent radon gas from entering the home from below the concrete floor and from outside the foundation.  Radon mitigation contractors may use other methods that may also work in your home. The right system depends on the design of your home and other factors.

Radon and Home Renovations

If you are planning any major renovations, such as converting an unfinished basement area into living space, it is especially important to test the area for radon before you begin.

If your test results indicate an elevated radon level, radon-resistant techniques can be inexpensively included as part of the renovation. Major renovations can change the level of radon in any home.  Test again after the work is completed.

You should also test your home again after it is fixed to be sure that radon levels have been reduced. If your living patterns change and you begin occupying a lower level of your home (such as a basement) you should re-test your home on that level. In addition, it is a good idea to re-test your home sometime in the future to be sure radon levels remain low.

c. Selecting a Radon-Reduction (Mitigation) Contractor

Select a qualified radon-reduction contractor to reduce the radon levels in your home.  Any mitigation measures taken or system installed in your home must conform to your state’s regulations.

The EPA recommends that the mitigation contractor review the radon measurement results before beginning any radon-reduction work.  Test again after the radon mitigation work has been completed to confirm that previous elevated levels have been reduced.

d. What can a qualified radon-reduction contractor do for you?

A qualified radon-reduction (mitigation) contractor should be able to:

• review testing guidelines and measurement results, and determine if additional measurements are needed;
• evaluate the radon problem, and provide you with a detailed, written proposal on how radon levels will be lowered;
• design a radon-reduction system;
• install the system according to EPA standards, or state or local codes; and
• make sure the finished system effectively reduces radon levels to acceptable levels.

Choose a radon-mitigation contractor to fix your radon problem just as you would for any other home repair.  You may want to get more than one estimate.  Ask for and check their references.  Make sure the person you hire is qualified to install a mitigation system.  Some states regulate or certify radon-mitigation services providers.

Be aware that a potential conflict of interest exists if the same person or firm performs the testing and installs the mitigation system.  Some states may require the homeowner to sign a waiver, in such cases. Contact your state radon office for more information.

e. Radon in Water

The radon in your home’s indoor air can come from two sources:  the soil and your water supply.  Compared to radon entering your home through water, radon entering your home through soil is a much larger risk.  If you’ve tested for radon in air and have elevated radon levels, and your water comes from a private well, have your water tested.  The devices and procedures for testing your home’s water supply are different from those used for measuring radon in air.

The radon in your water supply poses an inhalation risk and an ingestion risk.  Research has shown that your risk of lung cancer from breathing radon in the air is much larger than your risk of stomach cancer from swallowing water with radon in it.  Most of your risk from radon in water comes from radon released into the air when water is used for showering and other household purposes.

Radon in your home’s water is not usually a problem when its source is surface water.  Radon in water is more likely when its source is ground water, e.g., a private well or a public water supply system that uses ground water.  Some public water systems treat their water to reduce radon levels before it is delivered to your home.  If you are concerned that radon may be entering your home through the water, and your water comes from a public water supply, contact your water supplier.

If you’ve tested your private well and have radon in your water supply, it can be treated in one of two ways.  Point-of-entry treatment can effectively remove radon from the water before it enters your home.  Point-of-entry treatment usually employs either granular activated-carbon (GAC) filters, or aeration devices.  While GAC filters usually cost less than aeration devices, filters can collect radioactivity and may require a special method of disposal.  Point-of-use treatment devices remove radon from your water at the tap, but only treat a small portion of the water you use, e.g., the water you drink.  Point-of-use devices are not effective in reducing the risk of breathing radon released into the air from all water used in the home.