United States Environmental
Protection Agency
Office of Air and Radiation, Office of Radiation and Indoor Air (6604J)
402-K92-003
August 1992
Table of Contents
Overview
Introduction
How Radon Enters Your House
Radon is a Cancer-Causing Radioactive Gas
What Do Your Radon Test Results Mean?
Why Hire a Contractor ?
Why Use a State-Certified and/or Privately Certified
Radon Professional?
How to Select a Contractor
-- Get Estimates
-- The Contract
What to Look for in a Radon Reduction System
-- Installation and Operating Costs
-- How a Radon Reduction System May Affect Your Home
Radon Reduction Techniques
-- House Foundation Types
---- Basement and Slab-on-Grade Houses
---- Crawlspace Houses
-- Other Types of Radon Reduction Methods
Does Your Contractor's Work Meet RPP Requirements?
Living in a House with a Radon Reduction System
-- Maintaining Your Radon Reduction System
-- Remodeling Your Home After Radon Levels Have Been Lowered
Buying or Selling a Home?
Do You Have a Well?: Radon in Water
-- What Do the Results of Your Water Test Mean?
-- How is Radon Removed from Water?
Installation and Operating Cost Table
State Radon and IAQ Contacts
How to Order This Guide
Reduce Radon Levels In Your
Home
Radon is the second leading cause of lung
cancer. The Surgeon General and the EPA recommend testing for radon and
reducing radon in homes that have high levels. Fix your home if your radon
level is confirmed to be 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.
If you smoke and your home has high radon levels, your risk of lung cancer is
especially high.
Select A State Certified
And/Or RPP Contractor
Choose a radon contractor to fix
your home who is state certified and/or listed for radon reduction
[mitigation] in EPA's National Radon
Proficiency Program (RPP). RPP-listed mitigation contractors are trained,
must pass a comprehensive exam, and must agree to follow standards developed
to ensure effective radon reduction. Call your state
radon office for a list of qualified contractors in your area.
Radon Reduction Techniques
Work
Radon reduction systems work. Some
radon reduction systems can reduce radon levels in your home by up to 99%. The
cost of fixing a home generally ranges from $500 to $2500. Your costs may vary
depending on the size and design of your home and which radon reduction
methods are needed. Thousands of people have reduced radon levels in their
homes.
Maintain Your Radon Reduction
System
Maintaining your radon reduction
system takes little effort and keeps the system working properly and radon
levels low.
| Consumer
Federation of America strongly urges consumers to have
elevated radon levels in their homes reduced. EPA's "Consumer's
Guide to Radon Reduction" will assist those individuals and
offers very good advice for selecting and working with a qualified
radon contractor. |
Return to the Table
of Contents
Introduction
You have tested your home for
radon, but now what? This booklet is for people who have tested their home for
radon and confirmed that they have elevated radon levels -- 4 picoCuries per
liter (pCi/L) or higher.
This booklet can help you:
- Select a qualified contractor to reduce the
radon levels in your home
- Determine an appropriate radon reduction
method
- Maintain your radon reduction system
If you want information on how to
test your home for radon, call your state radon
office and ask for a copy of A Citizen's Guide to
Radon.
How Radon
Enters Your House
Radon is a naturally occurring gas
produced by the breakdown of uranium in soil, rock, and water. Air pressure
inside your home is usually lower than pressure in the soil around your home's
foundation. Because of this difference in pressure, your house acts like a
vacuum, drawing radon in through foundation cracks and other openings. Radon
may also be present in well water and can be released into the air in your
home when water is used for showering and other household uses. In most cases,
radon entering the home through water is a small risk compared with radon
entering your home from the soil. In a small number of homes, the building
materials can give off radon, although building materials rarely cause radon
problems by themselves.
Radon is a
Cancer-causing, Radioactive Gas
Radon is estimated to cause many
thousands of lung cancer deaths each year. In fact, the Surgeon General has
warned that radon is the second leading cause of lung cancer in the United
States. Only smoking causes more lung cancer deaths. If you smoke and your
home has high radon levels, your risk of lung cancer is especially high.
What Do Your
Radon Test Results Mean?
The amount of radon in the air is
measured in "picoCuries of radon per liter of air," or
"pCi/L." Sometimes test results are expressed in Working Levels,
"WL," rather than picoCuries per liter of air. A level of 0.02 WL is
usually equal to about 4 pCi/L in a typical home.
Any radon exposure has some risk
of causing lung cancer. The lower the radon level in your home, the lower your
family's risk of lung cancer. The U.S. Congress has set a long-term goal that
indoor radon levels be no more than outdoor levels; about 0.4 pCi/L of radon
is normally found in the outside air. EPA recommends fixing your home if the
results of one long-term test or the average of two short-term tests taken in
the lowest lived in level of the home show radon levels of 4 pCi/L (or 0.02
WL) or higher. A short-term test remains in your home for two days to 90 days,
whereas a long-term test remains in your home for more than 90 days. With
today's technology, radon levels in most homes can be reduced to 2 pCi/L or
below.
Have
You Confirmed Your Radon Test?
If your first short-term test
result is 4 pCi/L or higher (or 0.02 WL or more), EPA recommends that you take
a second test to be sure. For a better understanding of your year-round
average radon level, take a long-term test. If you need results quickly, take
a second short-term test and average it with the first. The higher your
initial short-term test result, the more certain you can be that you should
take a short-term rather than a long-term follow-up test. If your first
short-term test result is several times the action level -- for example, about
10 pCi/L or higher -- you should take a second short-term test immediately.
Why use a
tester or a test kit that meets EPA requirements?
Whether you use a short- or
long-term test, use a device and a testing company that is state certified
and/or is listed in EPA's Radon
Proficiency Program (RPP). If you want to use a do-it-yourself
test kit, use one that displays the phrase "Meets EPA
Requirements." EPA's RPP Program is designed to help assure that
consumers get reliable radon measurement and mitigation services. If you want
to hire a professional to take the measurement contact your state
radon office for a current list of state certified and/or RPP listed
companies and individuals. Listed RMP Program participants must follow quality
assurance and EPA measurement procedures and have demonstrated the ability to
take reliable measurements with specific devices. Your state may also have
additional requirements for professional radon testers.
Return to the Table
of Contents
Why Hire a
Contractor?
EPA recommends that you have a
qualified contractor fix your home because lowering high radon levels requires
specific technical knowledge and special skills. Without the proper equipment
or technical knowledge, you could actually increase your radon level or create
other potential hazards. But, if you decide to do the work yourself, get
information on appropriate training courses and copies of EPA's technical
guidance documents from your state radon office.
Why Use
A State-Certified And/Or RPP Contractor?
EPA recommends that you use a
contractor trained to fix radon problems. The radon mitigation contractor
portion of EPA's National Radon Proficiency Program (RPP) requires contractors
to take training courses and pass an exam before being listed as proficient.
EPA maintains a list of radon contractors who meet RPP requirements. RPP
mitigation contractors carry a current RPP photo identification card and all
RPP contractors are required to follow EPA standards to make sure that their
work meets minimum quality standards. A number of states have their own
contractor certification programs which have additional requirements. Check
with your state radon office to see if the contractor you are considering is
state certified and/or RPP listed.
How
To Select A Contractor
Get Estimates
Choose a contractor to fix a radon
problem just as you would choose someone to do other home repairs. It is wise
to get more than one estimate, to ask for references, and to contact some of
those references to ask if they are satisfied with the contractors' work.
Also, ask your county or state consumer protection office for information
about the contractors.
Use this check-list when
evaluating and comparing contractors and ask the following questions:
| Yes |
No |
| |
|
Will the
contractor provide references or photographs, as well as test results
of 'before' and 'after' radon levels of past radon reduction work?
|
| |
|
Can the
contractor explain what the work will involve, how long it will take
to complete, and exactly how the radon reduction system will work?
|
| |
|
Does the
contractor charge a fee for any diagnostic tests? Although many
contractors give free estimates, they may charge for diagnostic tests
-- these tests help determine what radon reduction system should be
used, but are not always necessary (see "Radon Reduction
Techniques" below for more on diagnostic tests).
|
| |
|
Did the
contractor inspect your home's structure before giving you an
estimate?
|
| |
|
Did the
contractor review the quality of your radon measurement results and
determine if EPA testing procedures were followed? [An RPP
requirement]
|
Compare the contractors' proposed
costs and consider what you will get for your money. Take into account the
following: a system that is less expensive to install may have higher
operating and maintenance costs than a system that is more expensive to
install; the best system for your house may be the more expensive option; and
the quality of the building material will affect how long the system lasts.
Do the contractors' proposals
and estimates include:
| Yes |
No |
| |
|
Proof of
liability insurance and being bonded and licensed?
|
| |
|
Proof of state
certification and/or RPP Listing?
|
| |
|
Diagnostic
testing prior to design and installation of a radon reduction system?
|
| |
|
Installation
of a warning device to caution you if the radon reduction system is
not working correctly? [An RPP Requirement]
|
| |
|
Testing after
installation to make sure the radon reduction system works well? [An
RPP requirement]
|
| |
|
A guarantee to
reduce radon levels to 4 pCi/L or below, and if so, for how long?
|
The Contract
Ask the contractor to prepare a
contract before any work starts. Carefully read the contract before you sign
it. Make sure everything in the contract matches the original proposal. The
contract should describe exactly what work will be done prior to and during
the installation of the system, what the system consists of, and how the
system will operate. Carefully consider optional additions to your contract
which may add to the initial cost of the system, but may be worth the extra
expense. Typical options might include a guarantee that the contractor will
adjust or modify the system to reach the promised radon level, or an extended
warranty and/or a service plan.
Important information that should
appear in the contract includes:
- The total cost of the job, including all
taxes and permit fees; how much, if any, is required for a deposit; and
when payment is due in full.
- The time needed to complete the work.
- An agreement by the contractor to obtain
necessary licenses and follow required building codes.
- A statement that the contractor carries
liability insurance and is bonded and insured to protect you in case of
injury to persons, or damage to property, while the work is done.
- A guarantee that the contractor will be
responsible for damage and clean-up after the job.
- Details of warranties, guarantees, or other
optional features, including the acceptable resulting radon level.
- A declaration stating whether any warranties
or guarantees are transferable if you sell your home.
- A description of what the contractor expects
the homeowner to do (e.g., make the work area accessible) before work
begins.
What to
Look for in a Radon Reduction System
In selecting a radon reduction
method for your home, you and your contractor should consider several things,
including: how high your initial radon level is, the costs of installation and
system operation, your house size and your foundation type.
Installation and Operating
Costs
For most homes, radon reduction
measures are no more expensive than having a new hot water heater installed
or having the house painted. The cost of a contractor fixing a home
generally ranges from $500 to $2500, depending on the characteristics of the
house and choice of radon reduction methods.
Most types of radon reduction
systems cause some loss of heated or air conditioned air, which could
increase your utility bills. How much your utility bills will be affected
depends on the climate you live in, what kind of reduction system you
select, and how your house is built. Systems that use fans are more
effective in reducing radon levels; however, they will increase your
electric bill. The table below lists the installation and average operating
costs for different radon reduction systems and describes the best use of
each method.
How a Radon Reduction System
May Affect Your Home
In order to minimize the effect
of installing a radon reduction system in your house, ask your contractor
before any work starts how the system can be made to blend with its
surroundings. For instance: radon vent pipes may be encased with materials
that match the exterior of your house, or the pipes may be routed up through
closets.
Return to the Table
of Contents
Radon
Reduction Techniques
There are several methods that a
contractor can use to lower radon levels in your home. Some techniques prevent
radon from entering your home while others reduce radon levels after it has
entered. EPA generally recommends methods which prevent the entry of radon.
Soil suction, for example, prevents radon from entering your home by drawing
the radon from below the house and venting it through a pipe, or pipes, to the
air above the house where it is quickly diluted.
Any information that you may have
about the construction of your house could help your contractor choose the
best system. Your contractor will perform a visual inspection of your house
and design a system that considers specific features of your house. If this
inspection fails to provide enough information, the contractor will need to
perform diagnostic tests to help develop the best radon reduction system for
your home. For instance, your contractor can use a "smoke gun" to
find the source and direction of air movement. A contractor can learn air flow
sources and directions by watching a small amount of smoke that he or she shot
into holes, drains, sumps, or along cracks. The sources of air flow show
possible radon routes.
Another type of diagnostic test is
a "soil communication test." This test uses a vacuum cleaner and a
smoke gun to determine how easily air can move from one point to another under
the foundation. By inserting a vacuum cleaner hose in one small hole and using
a smoke gun in a second small hole, a contractor can see if the smoke is
pulled down into the second hole by the force of the vacuum cleaner's suction.
Watching the smoke during a soil communication test helps a contractor decide
if certain radon reduction systems would work well in your house.
Whether diagnostic tests are
needed is decided by details specific to your house, such as the foundation
design, what kind of material is under your house, and by the contractor's
experience with similar houses and similar radon test results.
House
Foundation Types
Your house type will affect the
kind of radon reduction system that will work best. Houses are generally
categorized according to their foundation design. For example: basement,
slab-on-grade (concrete poured at ground level), or crawlspace (a shallow
unfinished space under the first floor). Some houses have more than one
foundation design feature. For instance, it is common to have a basement under
part of the house and to have a slab-on-grade or crawlspace under the rest of
the house. In these situations a combination of radon reduction techniques may
be needed to reduce radon levels to below 4 pCi/L.
Radon reduction systems can be
grouped by house foundation design. Find your type of foundation design above
and read about which radon reduction systems may be best for your house.
Basement and Slab-on-Grade
Houses
In houses that have a basement
or a slab-on-grade foundation, radon is usually reduced by one of four types
of soil suction: subslab suction, drain tile suction, sump hole suction, or
block wall suction.
Active Subslab suction (also
called subslab depressurization) is the most common and usually the most
reliable radon reduction method. Suction pipes are inserted through the
floor slab into the crushed rock or soil underneath. They also may be
inserted below the concrete slab from outside the house. The number and
location of suction pipes that are needed depends on how easily air can move
in the crushed rock or soil under the slab, and on the strength of the radon
source. A contractor usually gets this information from visual inspection,
from diagnostic tests, and/or from experience. Acting like a vacuum cleaner,
a fan connected to the pipes draws the radon gas from below the house and
then releases it into the outdoor air. Passive subslab suction is the same
as active subslab suction except it relies on air currents instead of a fan
to draw radon up from below the house. Passive subslab suction is generally
not as effective in reducing high radon levels as active subslab suction.
Some houses have drain tiles to
direct water away from the foundation of the house. Suction on these drain
tiles is often effective in reducing radon levels if the drain tiles form a
complete loop around the foundation.
One variation of subslab and
drain tile suction is sump hole suction. Often, when a house with a basement
has a sump pump to remove unwanted water, the sump can be capped so that it
can continue to drain water and serve as the location for a radon suction
pipe.
Block wall suction can be used
in basement houses with hollow block foundation walls. This method removes
radon from the hollow spaces within the basement's concrete block wall. It
is often used together with subslab suction.
Crawlspace Houses
In houses with crawlspaces,
radon levels can sometimes be lowered by ventilating the crawlspace
passively (without the use of a fan) or actively (with the use of a fan).
Crawlspace ventilation lowers indoor radon levels both by reducing the
home's suction on the soil and by diluting the radon beneath the house.
Natural ventilation in a crawlspace is achieved by opening vents, or
installing additional vents. Active ventilation uses a fan to blow air
through the crawlspace instead of relying on natural air circulation. In
colder climates, for either natural or active crawlspace ventilation, water
pipes in the crawlspace need to be insulated against the cold.
Another effective method to
reduce radon levels in crawl space houses involves covering the earth floor
with a heavy plastic sheet. A vent pipe and fan are used to draw the radon
from under the sheet and vent it to the outdoors. This form of soil suction
is called sub membrane depressurization.
Other
Types of Radon Reduction Methods
Other radon reduction techniques
that can be used in any type of house include: sealing, house
pressurization, natural ventilation, and heat recovery ventilation. Most of
these methods are considered to be either temporary measures, or only
partial solutions to be used in combination with other measures.
Sealing cracks and other
openings in the foundation is a basic part of most approaches to radon
reduction. Sealing does two things, it limits the flow of radon into your
home and it reduces the loss of conditioned air, thereby making other radon
reduction techniques more effective and cost-efficient. EPA does not
recommend the use of sealing alone to reduce radon because, by itself,
sealing has not been shown to lower radon levels significantly or
consistently. It is difficult to identify and permanently seal the places
where radon is entering. Normal settling of your house opens new entry
routes and reopens old ones.
House pressurization uses a fan
to blow air into the basement or living area from either upstairs or
outdoors. It attempts to create enough pressure at the lowest level indoors
(in a basement for example) to prevent radon from entering into the house.
The effectiveness of this technique is limited by house construction,
climate, other appliances in the house, and occupant lifestyle. In order to
maintain enough pressure to keep radon out, the doors and windows at the
lowest level must not be left opened, except for normal entry and exit.
Some natural ventilation occurs
in all houses. By opening windows, doors, and vents on the lower floors you
increase the ventilation in your house. This increase in ventilation mixes
radon with outside air and can result in reduced radon levels. In addition,
ventilating your house can help to lower indoor radon levels by reducing the
vacuum effect. Natural ventilation in any type of house, (aside from
ventilation of a crawlspace), should normally be regarded as a temporary
radon reduction approach because of the following disadvantages: loss of
conditioned air and related discomfort, greatly increased costs of
conditioning additional outside air, and security concerns.
A heat recovery ventilator
(HRV), also called an air-to-air heat exchanger, can be installed to
increase ventilation. An HRV will increase house ventilation while using the
heated or cooled air being exhausted to warm or cool the incoming air. HRVs
can be designed to ventilate all or part of your home, although they are
more effective in reducing radon levels when used to ventilate only the
basement. If properly balanced and maintained, they ensure a constant degree
of ventilation throughout the year. HRVs also can improve air quality in
houses that have other indoor pollutants. There could be significant
increase in the heating and cooling costs with an HRV, but not as great as
ventilation without heat recovery (see "Installation and Operating Cost
Table" below).
Return to the Table
of Contents
Does Your
Contractor's Work Meet RPP Requirements?
There are certain basic
requirements that all radon reduction systems should meet. RPP Mitigation
Service Providers (formerly known as RCP Contractors) must meet the following
performance standards (for a complete list of RPP standards call your state
office). Some states have similar requirements:
- Radon reduction systems must be clearly
labeled. This will avoid accidental changes to the system which could
disrupt its function.
- The exhaust pipes of soil suction systems
must vent 10 feet or more above the ground, and away from windows, doors,
or other openings that could allow the radon to reenter the house.
- The exhaust fan must be located in an
unlivable area. For instance, it should be in an un-occupied attic of the
house or outside - not in a basement!
- If installing an exhaust fan outside, the
contractor must install a fan that meets local building codes for exterior
use.
- All active radon reduction systems require
electrical connections that must be installed according to local
electrical codes.
- A warning device must be installed to alert
you if the system stops working properly. Examples of system failure
warning devices are: a liquid gauge, a sound alarm, a light indicator, and
a dial (needle display) gauge.
- A warning device must be placed where it can
be seen or heard easily. If your monitor shows that the system is not
working properly, call a contractor to have it checked.
- RPP contractors must make sure a follow-up
radon test is done within 30 days of system installation, but no sooner
than 24 hours after your system is in operation with the fan on, if it has
one. To test the system's initial effectiveness, a 2-7 day measurement is
recommended. Test conditions: windows and doors must be closed 12 hours
before and during the test, except for normal entry/exit.
- RPP contractors must recommend that you get
an independent follow-up radon measurement. Having an independent tester
perform the test, or conducting the measurement yourself, will eliminate
any potential conflict of interest.
Your RPP contractor should also
check that your radon reduction system's warning device works. Make sure your
contractor completely explains your radon reduction system, demonstrates how
it operates, and explains how to maintain it. Ask for written operating and
maintenance instructions and copies of any warranties.
Return to the Table
of Contents
Living
in a House with a Radon Reduction System
Maintaining Your Radon
Reduction System
Similar to a furnace or chimney,
radon reduction systems need some occasional maintenance. You should look at
your warning device on a regular basis to make sure the system is working
correctly. Fans may last for five years or more (although manufacturer
warranties tend not to exceed three years) and may then need to be repaired or
replaced. Replacing a fan will cost around $250 including parts and labor. By
testing at least every two years, you will confirm that your radon level is
staying low and that your fan is still performing well.
Remember, the fan should NEVER be
turned off; it must run continuously for the system to work correctly.
The filter in an HRV requires
periodic cleaning and should be changed twice a year. Replacement filters for
an HRV are easily changed and are priced between $5 and $15. Ask your
contractor where filters can be purchased. Also, the vent that brings fresh
air in from the outside needs to be inspected for leaves and debris. The
ventilator should be checked annually by a heating, ventilating, and
air-conditioning professional to make sure the air flow remains properly
balanced. HRVs used for radon control should run all the time.
Remodeling Your Home After
Radon Levels Have Been Lowered
If you decide to make major
structural changes to your home after you have had a radon reduction system
installed (such as converting an unfinished basement area into living space),
ask your radon contractor whether these changes could void any warranties.
After you remodel, retest in the lowest lived-in area to make sure the
construction did not reduce the effectiveness of the radon reduction system.
If you are adding a new foundation for an addition to your house, address the
radon problem during construction.
Return to the Table
of Contents
Buying
or Selling a Home?
If you are buying or selling a
home and need to make decisions about radon, consult EPA's Home Buyer's and
Seller's Guide to Radon. If you are selling a home that has a radon reduction
system, inform potential buyers and supply them with information about your
system's operation and maintenance.
If you are buying a new house,
consider that it is almost always less expensive to build radon-resistant
features into new construction than it is to fix an existing house that has
high radon levels. Ask your builder if he or she uses radon-resistant
construction features. Your builder can refer to EPA guidance about radon and
new construction, or your builder can work with a state certified and/or RCP
contractor to design and install the proper radon reduction system. To obtain
EPA's technical documents contact your state radon office.
All homes should be tested for
radon and high radon levels should be reduced.
Return to the Table
of Contents
Do You
Have a Well?: Radon in Water
Well owners with elevated indoor
radon levels should test their well water for radon. Radon in your water
supply can increase your indoor radon level, although, in most cases, radon
entering the home through water will be a small source of risk compared with
radon entering from the soil. EPA estimates that indoor radon levels will
increase by about 1 pCi/L for every 10,000 pCi/L of radon in water. You can
find publications and documents developed by EPA's Office of Ground Water and
Drinking Water relating to radon in drinking water and the radon in drinking
water rule at http://www.epa.gov/safewater/radon.html.
What do the results of your
water test mean?
Estimate how much the radon in
your water is elevating your indoor radon level by subtracting 1 pCi/L from
your indoor air radon level for every 10,000 pCi/L of radon that was found
in your water. (For example: if you have 30,000 pCi/L of radon in your
water, then 3 pCi/L of your indoor measurement may have come from radon in
water.) If most of the radon is not coming from your water, fix your house
first and then retest your indoor air to make sure that the source of
elevated radon was not your private well. If a large contribution of the
radon in your house is from your water, you may want to consider installing
a special water treatment system to remove radon. EPA recommends installing
a water treatment system only when there is a proven radon problem in your
water supply.
How is radon removed from
water?
Radon can be removed from water
by using one of two methods: aeration treatment or granular activated carbon
(GAC) treatment. Aeration treatment involves spraying water or mixing it
with air, and then venting the air from the water before use. GAC treatment
filters water through carbon. Radon attaches to the carbon and leaves the
water free of radon. The carbon may need special handling in its disposal if
it is used at a high radon level or if it has been used for a long time. In
either treatment, it is important to treat the water where it enters your
home (point-of-entry device) so that all the water will be treated.
Point-of-use devices, such as those installed on a tap or under the sink,
will only treat a small portion of your water and are not effective in
reducing radon in your water. It is important to maintain home water
treatment units properly because failure to do so can lead to other water
contamination problems. Some homeowners opt for a service contract from the
installer to provide for carbon replacement and general system maintenance.
Return to the Table
of Contents
Refer to the Installation and
Operating Cost Table for more information on water treatment systems.
| INSTALLATION
AND OPERATING COST TABLE |
| Technique |
Typical
Radon Reduction |
Typical
Range of Insulation Costs
(Contractor) |
Typical
Operating
Cost Range for Fan
Electricity & Heated/
Cooled Air Loss
(Annual) |
Comments |
Subslab
Suction
(Subslab Depressurization) |
80-99% |
$800-$2,500 |
$75-$175 |
Works best if
air can move easily in material under slab. |
| Passive
Subslab Suction |
30-70% |
$550-$2,250 |
There may be
some energy penalties |
May be more
effective in cold climates; not as effective as active subslab
suction. |
| Draintile
Suction |
90-99% |
$800-$1,700 |
$75-$175 |
Works best if
draintiles form complete loop around house. |
| Blockwall
Suction |
50-99% |
$1,500-$3,000 |
$150-$300 |
Only in houses
with hollow blockwalls; requires sealing of major openings. |
| Sump Hole
Suction |
90-99% |
$800-$2,500 |
$100-$225 |
Works best
if air moves easily to sump under slab; or if draintiles form complete
loop. |
| Submembrane
Depressurization in a crawl space |
80-99% |
$1,000-$2,500 |
$70-$175 |
Less heat loss
than natural ventilation in cold winter climates. |
| Natural
Ventilation in a crawl space |
0-50% |
none
($200-$500 if additional vents installed) |
There may
be some energy penalties. |
Costs variable |
| Sealing of
Radon Entry Routes |
0-50% |
$100-$2,000 |
None |
Normally used
with other techniques; proper materials & installation required |
| House
(Basement) Pressurization |
50-99% |
$500-$1,500 |
$150-$500 |
Works best
with tight basement isolated from outdoors & upper floors. |
| Natural
Ventilation |
Variable |
None
($200-$500 if additional vents installed) |
$100-$700 |
Significant
heated/cooled air loss; operating costs depend on utility rates &
amount of ventilation. |
| Heat
Recovery Ventilation |
25-50% if
used for full house;
25-75% if used for basement |
$1,200-$2,500 |
$75-$500
for continuous operation |
Limited use;
best in tight house; for full house, use with levels no higher than 8
pCi/L; no higher than 16 pCi/L for use in basement; less conditioned
air loss than natural ventilation. |
| Water
Systems: Aeration |
95-99% |
$3,000-$4,500 |
$40-$90 |
More efficient
than GAC; requires annual cleaning to maintain effectiveness & to
prevent contamination; carefully vent system. |
| Water
Systems: Activated Carbon (GAC) |
85-99% |
$1,000-$2,000 |
None |
Less efficient
for higher levels than aeration; use for moderate levels (around 5,000
pCi/L or less); radon by-products can build on carbon may need
radiation shield around tank & care in disposal. |
| * NOTE: The fan
electricity and house heating/cooling loss cost range is based on
certain assumptions regarding climate, your house size, and the cost
of electricity and fuel. Your costs may vary. Numbers based upon 1991
data. |
Return to the Table of Contents
National Service Center for Environmental
Publications (NSCEP)
http://www.epa.gov/ncepihom/ (to
order EPA documents online)
Or call 1-800-490-9198/(513) 489-8695 (fax)
U.S. Environmental Protection Agency
National Center for Environmental Publications (NSCEP)
P.O. Box 42419
Cincinnati, OH 45242
You can also purchase this document from the
U.S. Government Printing Office:
Superintendent of Documents, Mail Stop: SSOP
Washington, DC 20402-9328
When Ordering, refer to ISBN 0-16-036255-5
Return to the Table of Contents
Created: March 17, 1997, Last Modified: July
18, 2000
http://www.epa.gov/iaq/radon/pubs/consguid.html
