Overview

When you use water, particularly when you aerate or heat it, radon in the water is released into the air.  Any time you use a dishwasher, washing machine, or take a shower or bath the radon in the water raises the level of radon in the air.  For example if a well has 5,000 pCi/L in the water, the radon levels in an unventilated room might go up to 25 pCi/L when a shower is taken or the washing machine is being used.  One's exposure to this level, however, would be for only a short period of time.  As a rule of thumb it takes 10,000 pCi/L of radon in the water to raise the average radon levels in the house 1 pCi/L.  This is a very general rule that will vary depending upon how much water a family uses, how large the house is, the house ventilation rate, and where the radon test is taken.

The health risk from drinking water with radon in it is very small.  The risk is predominately from breathing radon in the air that is released from the water.

Presently the Pennsylvania DEP has not set a level at which they recommend reducing the radon in water.  A few states have defined the action levels to have a radon in water system installed.  These are the radon in water action levels for the different states.

Radon can be removed from household water with charcoal filtration or aeration.  An aeration system will remove about 99% of the radon.  The typical aeration cost is around $4500.  A single charcoal system can remove up to 75% of the radon in water and costs about a $1000.  A double charcoal system can remove up to 90% of the radon and costs about $1650.   Charcoal systems however require the carbon to be replaced every 1 to 2 years depending on the quality of the water.  Charcoal systems should only be used for radon in water up to 10,000 pCi/L because higher levels tend to emanate stronger gamma energy.  The carbon change can cost $450 while an aeration cleaning might cost $175 so there is savings for the aeration system in maintenance costs.    Each approach has pro's and con's.  Contact the PA DER 800 237-2366 or Bill Brodhead at the WPB office ( 610 346-8004 ) for additional information about these approaches.

Download a copy of this information:  Radon in Water Info

Go to: Radon in water system photos

Radon in Water Test Kits are available from this company.

Additional information:  EPA Radon in Water info

Return to Questions

Questions & Answers

If my Radon in Air is elevated will I have radon in my well water?

There is no correlation between radon in air measurements and radon in well water.  In either case you can only know for sure by testing.  The highest radon in water level in our area had low levels of radon in the air from soil gas while the highest indoor radon levels had low levels in the well.

Do deeper wells have higher levels of radon in the water?

There is no correlation between the depth of the well or the flow rate of the well and the radon levels.

How Do I Test for Radon in Water?

Most professional radon testers will come to your house and take a water sample to be analyzed.  A less expensive way is to buy a radon in water test kit.  You can order a test kit on line from this company. Air Chek  The test kit package will contain a vial that needs to be completely filled with cold water.  The water sample is then promptly mailed back to the lab for analysis.  You should receive your results in about a week to ten days.  If the house has been vacant you should run the water for at least twenty minutes to get a new sample from the well.

Return to Questions

Why be concerned with Radon in Water?

Radon in your water will be released in your home every time water is exposed to the air.  The amount of radon added to the air is dependent on how much radon is in the water, how much water you use and how much the water is aerated when you use it.  Radon levels in the air will be raised from radon in the water when you shower, run the washing machine or use a dishwasher.  Drinking water with radon in it is considered a very small risk.

Are there any government Radon in Water action levels?

The EPA has been trying to set guidelines for maximum levels of radon in water for municipal water systems for more than a decade.  In 1999 the EPA proposed a double standard that set a level of 300 pCi/l for sates that had no radon in air program and 4000 pCi/l for states that have an active radon in air program.   There are presently no recommended action levels from the EPA. The following New England states have set their own recommended action levels.

Pennsylvania has not set a recommended action level of radon in the water.

Return to Questions

What are safe levels of Radon in Water?

When you take a shower or use the washer or dishwasher radon in the water is released into the air and the levels will rise.  The radon will then diffuse throughout the house before escaping to the outside.  In order to raise the whole house average radon levels by 1 pCi/l in a house it is estimated that you need 10,000 pCi/l in the water.  This is only a general rule that varies depending on the size of the house, number of occupants and water usage.  Using this ratio would require 40,000 pCi/L in the water to raise the average radon levels by 4.0 pCi/L.  4.0 pCi/L, however, is not a safe level but a readily achievable level.  Reducing radon in water levels of 10,000 pCi/L is likely to reduce the indoor radon levels by about 1 pCi/L which will reduce the lifetime cancer risk of 5 individuals per 1000 persons in the general population. Certainly as the radon in water levels approach or exceed 20,000 pCi/l serious consideration should be given to having a water treat system installed.

Is there a health risk drinking Water with Radon?

Where as radon in the air is estimated to cause as many as 20,000 additional lung cancers, radon in the water is only estimated to cause less than 10 additional stomach cancers per year in the USA.   So the risk from ingestion is very small.

Should I be concerned if I have City or Municipal water?

Any city or municipal water that comes from lakes or rivers would have only minimum amounts of radon in the water.  If city or municipal water comes from ground based source such as a community well there could be significant radon in the water.  The highest radon in water levels is assumed to come from private wells.  Pennsylvania DEP checked the radon levels of Pennsylvania community ground water supplies water and found that about 5.0% had levels greater than 3000 pCi/l.

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What is an Aeration system?

The best method for removing radon from the water is an aeration system.  An aeration system is typically installed next to the well tank where your water supply first enters the house.  The aeration system is installed after other water conditioners such as a water softener or neutralizer.  The aeration system consists of a large plastic tank where the water has air injected into it.  Radon will readily come out of the water if it is exposed to air.  The air is then exhausted from the tank, up to the roof line as required for sub-slab depressurization system venting.  The water with 99% of the radon removed is then re-pressurized.  All house water is treated.  The system takes up about 2’ by 4’ of floor space.

What is an Air Well aerator system?

An alternate method to bubble radon out of the water is to aerate the water in the well. This requires a unique setup that does not cause the well pump to air lock. One company in Canada called Radon Environmental has a system called the "Air Well" that has worked out a successful method. You can contact the manufacturer for details and available dealers.

Does Aeration systems become Radioactive?

Aeration systems do not become radioactive when they work and there is no long term accumulation of radioactive elements.

Will an Aeration systems change my water?

An Aeration system will tend to raise the pH by as much as 1.0 point.  This may reduce the need for a neutralizer.  Dissolved minerals in the water such as iron or magnesium can be activated by the aeration and may need to be treated as part of the installation cost.

Return to Questions

What is a GAC system?

GAC stands for granular activated carbon.  GAC treatment is also typically installed next to the well tank where your water supply first enters the house.  The GAC tank is installed after other water conditioners such as a water softener or neutralizer.  A typical GAC tank is  4 ½ tall and 10” round.  The tank is filled with coconut based activated carbon.  Radon gets trapped in the millions of pores inside the carbon as all the house water passes through the carbon.  Fresh carbon can hold the radon atoms until 90% of them decay.  The carbon will also capture other contaminants which is beneficial but it shortens the life of the carbon bed.  If the water is free of contaminants the carbon bed can last for years.  If the water has lots of contaminants then the carbon bed will need to be replaced after a few months which would be very costly.

Do GAC filters become Radioactive?

GAC tanks capture radon atoms in the water and hold them until most have decayed away.  As they decay they emit gamma radiation.  Walking by a GAC tank would not present any risk.  A GAC tank however should never be located within a few feet of where a person spends hours at a time.   A second consideration is that the carbon in the tank needs to be replaced before it accumulates too much Lead 210, a by-product of radon.  GAC systems should only be used for water that has up to 20,000 pCi/l in the water.  In order to be at the maximum allowable Lead 210, a carbon tank needs to be efficiently filtering radon in water in a four person house for about 5 years.  If there is half as much radon in the water or half as much water usage then it would take twice as long to get to the same level or about 10 years.

Return to Questions

Does GAC treat other contaminants in the water?

GAC can capture numerous contaminants and pollutants.  This is a real benefit of installing a GAC system.  The taste of the water can also be improved.  These contaminants at the same time will shorten the life of the carbon and require more periodic carbon replacement.

Do Aeration or GAC systems need maintenance?

The aeration system should have the solenoid valves checked and serviced once per year.  The system may also need to be cleaned once a year depending on the sediment and hardness of the water.  This cost is typically around $175 per visit.  A GAC tank will need to have the carbon replaced on a regular basis.  This may need to be every year at a cost of $400 to $500.

Will my Water Pressure change if I install a removal system?

GAC systems will reduce water pressure by only a few pounds.  An aeration system will change the water pressure to whatever the capacity of the aeration system produces.  In many cases the aeration system can produce higher water pressure than previously existed with a well system.

Return to Questions

How much do these treatment units cost?

A single tank GAC unit typically costs around $1000 to $1200 installed.  A double GAC tank system costs around $1600 to $1800.  An aeration system costs around $4000 to $5000 depending upon the source of electrical power and venting requirements.

Do I need to Pre-Treat the water?

Any sediment in the water will need to be pre-filtered.  In addition the water should be tested for hardness, iron and pH as well as any other contaminants that are common in the area.

Do kitchen charcoal filters or RO units remove Radon in Water?

The kitchen sink water filters can remove radon from the water which would reduce the small risk attributed to drinking water.  The radon entering the air from use of the dishwasher, washing machine, showering etc. will continue to raise the indoor radon levels which is the primary risk.

Return to Questions

Overview

When you use water, particularly when you aerate or heat it, radon in the water is released into the air.  Any time you use a dishwasher, washing machine, or take a shower or bath the radon in the water raises the level of radon in the air.  For example if a well has 5,000 pCi/L in the water, the radon levels in an unventilated room might go up to 25 pCi/L when a shower is taken or the washing machine is being used.  One's exposure to this level, however, would be for only a short period of time.  As a rule of thumb it takes 10,000 pCi/L of radon in the water to raise the average radon levels in the house 1 pCi/L.  This is a very general rule that will vary depending upon how much water a family uses, how large the house is, the house ventilation rate, and where the radon test is taken.

The health risk from drinking water with radon in it is very small.  The risk is predominately from breathing radon in the air that is released from the water.

Presently the Pennsylvania DEP has not set a level at which they recommend reducing the radon in water.  A few states have defined the action levels to have a radon in water system installed.  These are the radon in water action levels for the different states.

Radon can be removed from household water with charcoal filtration or aeration.  An aeration system will remove about 99% of the radon.  The typical aeration cost is around $4500.  A single charcoal system can remove up to 75% of the radon in water and costs about a $1000.  A double charcoal system can remove up to 90% of the radon and costs about $1650.   Charcoal systems however require the carbon to be replaced every 1 to 2 years depending on the quality of the water.  Charcoal systems should only be used for radon in water up to 10,000 pCi/L because higher levels tend to emanate stronger gamma energy.  The carbon change can cost $450 while an aeration cleaning might cost $175 so there is savings for the aeration system in maintenance costs.    Each approach has pro's and con's.  Contact the PA DER 800 237-2366 or Bill Brodhead at the WPB office ( 610 346-8004 ) for additional information about these approaches.

Download a copy of this information:  Radon in Water Info

Go to: Radon in water system photos

Radon in Water Test Kits are available from this company.

Additional information:  EPA Radon in Water info

Return to Questions

Questions & Answers

If my Radon in Air is elevated will I have radon in my well water?

There is no correlation between radon in air measurements and radon in well water.  In either case you can only know for sure by testing.  The highest radon in water level in our area had low levels of radon in the air from soil gas while the highest indoor radon levels had low levels in the well.

Do deeper wells have higher levels of radon in the water?

There is no correlation between the depth of the well or the flow rate of the well and the radon levels.

How Do I Test for Radon in Water?

Most professional radon testers will come to your house and take a water sample to be analyzed.  A less expensive way is to buy a radon in water test kit.  You can order a test kit on line from this company. Air Chek  The test kit package will contain a vial that needs to be completely filled with cold water.  The water sample is then promptly mailed back to the lab for analysis.  You should receive your results in about a week to ten days.  If the house has been vacant you should run the water for at least twenty minutes to get a new sample from the well.

Return to Questions

Why be concerned with Radon in Water?

Radon in your water will be released in your home every time water is exposed to the air.  The amount of radon added to the air is dependent on how much radon is in the water, how much water you use and how much the water is aerated when you use it.  Radon levels in the air will be raised from radon in the water when you shower, run the washing machine or use a dishwasher.  Drinking water with radon in it is considered a very small risk.

Are there any government Radon in Water action levels?

The EPA has been trying to set guidelines for maximum levels of radon in water for municipal water systems for more than a decade.  In 1999 the EPA proposed a double standard that set a level of 300 pCi/l for sates that had no radon in air program and 4000 pCi/l for states that have an active radon in air program.   There are presently no recommended action levels from the EPA. The following New England states have set their own recommended action levels.

Pennsylvania has not set a recommended action level of radon in the water.

Return to Questions

What are safe levels of Radon in Water?

When you take a shower or use the washer or dishwasher radon in the water is released into the air and the levels will rise.  The radon will then diffuse throughout the house before escaping to the outside.  In order to raise the whole house average radon levels by 1 pCi/l in a house it is estimated that you need 10,000 pCi/l in the water.  This is only a general rule that varies depending on the size of the house, number of occupants and water usage.  Using this ratio would require 40,000 pCi/L in the water to raise the average radon levels by 4.0 pCi/L.  4.0 pCi/L, however, is not a safe level but a readily achievable level.  Reducing radon in water levels of 10,000 pCi/L is likely to reduce the indoor radon levels by about 1 pCi/L which will reduce the lifetime cancer risk of 5 individuals per 1000 persons in the general population. Certainly as the radon in water levels approach or exceed 20,000 pCi/l serious consideration should be given to having a water treat system installed.

Is there a health risk drinking Water with Radon?

Where as radon in the air is estimated to cause as many as 20,000 additional lung cancers, radon in the water is only estimated to cause less than 10 additional stomach cancers per year in the USA.   So the risk from ingestion is very small.

Should I be concerned if I have City or Municipal water?

Any city or municipal water that comes from lakes or rivers would have only minimum amounts of radon in the water.  If city or municipal water comes from ground based source such as a community well there could be significant radon in the water.  The highest radon in water levels is assumed to come from private wells.  Pennsylvania DEP checked the radon levels of Pennsylvania community ground water supplies water and found that about 5.0% had levels greater than 3000 pCi/l.

Return to Questions

What is an Aeration system?

The best method for removing radon from the water is an aeration system.  An aeration system is typically installed next to the well tank where your water supply first enters the house.  The aeration system is installed after other water conditioners such as a water softener or neutralizer.  The aeration system consists of a large plastic tank where the water has air injected into it.  Radon will readily come out of the water if it is exposed to air.  The air is then exhausted from the tank, up to the roof line as required for sub-slab depressurization system venting.  The water with 99% of the radon removed is then re-pressurized.  All house water is treated.  The system takes up about 2’ by 4’ of floor space.

What is an Air Well aerator system?

An alternate method to bubble radon out of the water is to aerate the water in the well. This requires a unique setup that does not cause the well pump to air lock. One company in Canada called Radon Environmental has a system called the "Air Well" that has worked out a successful method. You can contact the manufacturer for details and available dealers.

Does Aeration systems become Radioactive?

Aeration systems do not become radioactive when they work and there is no long term accumulation of radioactive elements.

Will an Aeration systems change my water?

An Aeration system will tend to raise the pH by as much as 1.0 point.  This may reduce the need for a neutralizer.  Dissolved minerals in the water such as iron or magnesium can be activated by the aeration and may need to be treated as part of the installation cost.

Return to Questions

What is a GAC system?

GAC stands for granular activated carbon.  GAC treatment is also typically installed next to the well tank where your water supply first enters the house.  The GAC tank is installed after other water conditioners such as a water softener or neutralizer.  A typical GAC tank is  4 ½ tall and 10” round.  The tank is filled with coconut based activated carbon.  Radon gets trapped in the millions of pores inside the carbon as all the house water passes through the carbon.  Fresh carbon can hold the radon atoms until 90% of them decay.  The carbon will also capture other contaminants which is beneficial but it shortens the life of the carbon bed.  If the water is free of contaminants the carbon bed can last for years.  If the water has lots of contaminants then the carbon bed will need to be replaced after a few months which would be very costly.

Do GAC filters become Radioactive?

GAC tanks capture radon atoms in the water and hold them until most have decayed away.  As they decay they emit gamma radiation.  Walking by a GAC tank would not present any risk.  A GAC tank however should never be located within a few feet of where a person spends hours at a time.   A second consideration is that the carbon in the tank needs to be replaced before it accumulates too much Lead 210, a by-product of radon.  GAC systems should only be used for water that has up to 20,000 pCi/l in the water.  In order to be at the maximum allowable Lead 210, a carbon tank needs to be efficiently filtering radon in water in a four person house for about 5 years.  If there is half as much radon in the water or half as much water usage then it would take twice as long to get to the same level or about 10 years.

Return to Questions

Does GAC treat other contaminants in the water?

GAC can capture numerous contaminants and pollutants.  This is a real benefit of installing a GAC system.  The taste of the water can also be improved.  These contaminants at the same time will shorten the life of the carbon and require more periodic carbon replacement.

Do Aeration or GAC systems need maintenance?

The aeration system should have the solenoid valves checked and serviced once per year.  The system may also need to be cleaned once a year depending on the sediment and hardness of the water.  This cost is typically around $175 per visit.  A GAC tank will need to have the carbon replaced on a regular basis.  This may need to be every year at a cost of $400 to $500.

Will my Water Pressure change if I install a removal system?

GAC systems will reduce water pressure by only a few pounds.  An aeration system will change the water pressure to whatever the capacity of the aeration system produces.  In many cases the aeration system can produce higher water pressure than previously existed with a well system.

Return to Questions

How much do these treatment units cost?

A single tank GAC unit typically costs around $1000 to $1200 installed.  A double GAC tank system costs around $1600 to $1800.  An aeration system costs around $4000 to $5000 depending upon the source of electrical power and venting requirements.

Do I need to Pre-Treat the water?

Any sediment in the water will need to be pre-filtered.  In addition the water should be tested for hardness, iron and pH as well as any other contaminants that are common in the area.

Do kitchen charcoal filters or RO units remove Radon in Water?

The kitchen sink water filters can remove radon from the water which would reduce the small risk attributed to drinking water.  The radon entering the air from use of the dishwasher, washing machine, showering etc. will continue to raise the indoor radon levels which is the primary risk.

Return to Questions