þÿ<html> <head> <meta http-equiv="Content-Language" content="en-us"> <meta name="GENERATOR" content="Microsoft FrontPage 6.0"> <meta name="ProgId" content="FrontPage.Editor.Document"> <meta http-equiv="Content-Type" content="text/html; charset=unicodeFFFE"> <title>NC Radon Program</title> <meta name="Microsoft Border" content="b, default"> </head> <body> <div align="center"> <center> <table border="0" cellpadding="2" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" width="98%" height="117"> <tr> <td width="76%" height="7" colspan="9"><a name="topofpage"></a> <font face="Arial"><b> <a name="topofpage0" href="http://www.dhhs.gov" style="text-decoration: none; background-color: #000080"> <font color="#FFFF00">North Carolina Department of Health and Human Services</font></a></b></font></td> <td width="24%" height="7" colspan="2"></td> </tr> <tr> <td width="69%" height="1" colspan="8" background="color84.gif"> <p align="center"><b><font size="5" color="#000080">NC Radon Program</font></b></td> <td width="34%" height="9" colspan="3" background="color84.gif" rowspan="2"> <p align="center"><a title="NC Radon Home Page" href="index.htm"> <img border="0" src="images/ncradonzonesv2.gif" width="218" height="77"></a></td> </tr> <tr> <td width="16%" height="15" bgcolor="#000080" colspan="3"></td> <td width="33%" height="15" bgcolor="#000080" colspan="3"></td> <td width="20%" height="15" bgcolor="#000080" colspan="2"></td> </tr> <tr> <td width="26%" height="6" bgcolor="#000080" colspan="4" nowrap> <p align="left"><b><font size="2" color="#FFFFFF"> <a target="_self" href="http://www.ncradiation.net/"> <font color="#FFFF00">Radiation&nbsp; Protection</font></a></font></b></td> <td width="19%" height="6" bgcolor="#000080" colspan="2"> <p align="center"><b><font size="2" color="#FFFFFF"> <a target="_self" href="list-mitigation.htm"><font color="#FFFF00">Mitigation</font></a></font></b></td> <td width="17%" height="6" bgcolor="#000080"> <p align="center"><b><font size="2" color="#FFFFFF"> <a target="_self" href="list-measurement.htm"><font color="#FFFF00">Measurement</font></a></font></b></td> <td width="18%" height="6" bgcolor="#000080" colspan="2"> <p align="center"><b><font size="2" color="#FFFFFF"> <a target="_self" href="contacts.htm"><font color="#FFFF00">Radon Contacts</font></a></font></b></td> <td width="19%" height="1" bgcolor="#000080" colspan="2"> <p align="center"><b><font color="#FFFFFF" size="2"><a target="_self" href="index.htm"> <font color="#FFFF00">NC Radon Home</font></a></font></b></td> </tr> <tr> <td width="16%" height="1" colspan="3"></td> <td width="15%" height="1" colspan="2"></td> <td width="18%" height="1"></td> <td width="20%" height="1" colspan="2"></td> <td width="15%" height="1"></td> <td width="19%" height="1" colspan="2"></td> </tr> <tr> <td width="8%" height="41" colspan="2"></td> <td width="86%" height="41" colspan="8"> <font color="#000080" size="4"><b>Radon in Water</b></font></td> <td width="9%" height="36">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top">&nbsp;</td> <td width="78%" height="34" colspan="7"> <a target="_self" href="#Recommendations">Recommendations for Radon in Drinking Water</a></td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top">&nbsp;</td> <td width="78%" height="34" colspan="7">Methods for Removing Radon from Water</td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="35">&nbsp;</td> <td width="12%" height="35" colspan="2" valign="top">&nbsp;</td> <td width="78%" height="35" colspan="7"> <p align="center"> <a target="_self" href="#Aeration">Aeration</a></td> <td width="9%" height="35">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top">&nbsp;</td> <td width="78%" height="34" colspan="7"> <p align="center"> <a target="_self" href="#Granular">Granular Activated Carbon Absorption (GAC)</a></td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top">&nbsp;</td> <td width="78%" height="34" colspan="7"> <p align="center"> <a target="_self" href="#Storage">Water Storage</a></td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top">&nbsp;</td> <td width="78%" height="34" colspan="7"> <a target="_self" href="#Other">Other Concerns &amp; More Information</a></td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="8%" height="34" colspan="2">&nbsp;</td> <td width="8%" height="34">&nbsp;</td> <td width="78%" height="34" colspan="7"> <p align="left"><font face="Times New Roman" size="2"><span class="body">Radon in drinking water is a significant health hazard, though a lesser hazard than radon in indoor air. Homes supplied with drinking water from a private well, or community water systems that use wells as water sources have a greater risk of exposure to radon in water. </span></font></p> <p align="left"><font face="Times New Roman" size="2"><span class="body">Radon in water is found in nearly all sources of surface water and groundwater. It is created by the radioactive decay of radium, a naturally occurring radioactive element found in underground rock formations, particularly granite and quartz.&nbsp;Water that flows through or over radium rich rock formations accumulate radium and thus radon from the decay process.</span></font></p> <p align="left"><font face="Times New Roman" size="2"><span class="body"> Typically, groundwater has much higher levels of radon than surface water. This is because radon in groundwater is &quot;trapped&quot; by being submerged underground and cannot easily escape. Because of this fact, water supplies from underground wells have a much higher probability of having significant levels of radon. If you get your drinking water from a surface water source, radon in water probably is <u>not</u> a significant health hazard. Large, pre-treated municipal water supplies typically have negligible levels of radon in water because usually this type of water supply is drawn from surface water sources, and because water treatment tends to reduce radon levels even further.&nbsp;</span></font></p> </td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top"> <b><font size="2"><a name="Recommendations">Recommendations </a>for Radon in Drinking Water</font></b><p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p>&nbsp;</p> <p align="center"><u><i><font size="2"><b><a target="_self" href="#topofpage">Top of Page</a></b></font></i></u></td> <td width="78%" height="34" colspan="7"> <ul> <li> <p align="left"><font face="Times New Roman" size="2"><b>Test your home for radon in air first.</b>&nbsp; Use a <a target="_self" href="DIY.htm">&quot;do-it-yourself&quot;</a> test kit or have a <a target="_self" href="list-Measurement.htm">certified radon testing and measurement service provider conduct the test for you</a>.<br> &nbsp;</font><ul> <li> <p align="left"><font face="Times New Roman" size="2"><b>If your radon in air test result is 4 picoCuries/liter (pCi/l) or higher with two successive tests, consider installing a radon mitigation system to reduce the level of indoor radon.</b>&nbsp; <a target="_self" href="docs/mitigationnew.pdf">More information about radon mitigation systems </a>&quot;<b>Mitigation</b>&quot; means any solution you use to reduce <u>airborne</u> radon levels in your home.&nbsp;It runs the gamut from installing a ventilation fan in your crawlspace to a full sub-slab depressurization system.&nbsp; Using a <a target="_self" href="list-Mitigation.htm">certified radon reduction and mitigation service provider</a> to mitigate radon in indoor air problems is recommended.<br> &nbsp;</font></li> </ul> </li> <li> <p align="left"><font face="Times New Roman" size="2"><b>If installing a radon in air mitigation system fails to reduce the radon in air levels below 4 pCi/l, test your home for radon in water.</b>&nbsp;A radon in water test kit is inexpensive (less than $50) and includes sample processing/analysis and a report of the results.&nbsp;<a target="_self" href="RadonH2OBus.htm">Companies that test for radon in water in North Carolina.</a><br> &nbsp;</font><ul> <li> <p align="left"><font face="Times New Roman" size="2"><b>Based on EPA&#39;s proposed regulations for community water systems, if your radon in water test result is greater than 4000 pCi/l you should consider modifying your water supply.</b>&nbsp;This step is especially important if you have been able to rule out any contribution to the radon levels in your home from other sources.&nbsp;In other words, <i>if you have already installed a radon in air mitigation system, and you have radon in water levels higher than 4000 pCi/l, water supply modification <u>may</u> be necessary.</i>&nbsp;Keep in mind that it takes approximately 10,000 pCi/l in water to produce 1 pCi/l of radon in air.</font></li> </ul> </ul> </td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top"> <p align="center"> <b><font size="2"><a name="Aeration">Aeration</a></font></b></p> <p align="center">&nbsp;</p> <p align="center">&nbsp;</p> <p align="center">&nbsp;</p> <p align="center">&nbsp;</p> <p align="center">&nbsp;</p> <p align="center"><u><i><font size="2"><b><a target="_self" href="#topofpage">Top of Page</a></b></font></i></u><p align="center">&nbsp;</td> <td width="78%" height="34" colspan="7"> <p align="left"><b><font size="2" face="Times New Roman">Methods for Removing Radon from Water</font></b></p> <p align="left"><font face="Times New Roman" size="2"> The two primary methods for removing radon from water are <b>aeration</b><img src="images/wateragitated.jpg" align="right" width="150" height="321"> and <b>granular activated carbon (GAC) absorption</b>.&nbsp; </font></p> <p align="left"><font face="Times New Roman" size="2"> Removing radon from water by <b>aeration</b> takes advantage of the fact that radon is readily given off (volatile) from water to air. Radon in water is removed by passing as much air through water as efficiently as possible.&nbsp; By venting the now radon-rich air to the outdoors, aeration can remove up to 99.9% of radon from water.&nbsp; Aeration is practical for central treatment of radon in water (i.e. at a water treatment plant, etc.) but is expensive for individual households or small public water systems.&nbsp; A household aeration system suitable for high efficiency radon removal typically costs $3000 - $5000.&nbsp; Special maintenance is required to ensure that waterborne minerals like iron and manganese do not accumulate and foul the aeration system.&nbsp; Otherwise, radon removal efficiency may be reduced.&nbsp;</font></p> </td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top"> <p align="center"> <b><font size="2"><a name="Granular">Granular</a> Activated Carbon Absorption (GAC)</font></b></p> <p align="center">&nbsp;</p> <p align="center"><u><i><font size="2"><b><a target="_self" href="#topofpage">Top of Page</a></b></font></i></u><p>&nbsp;</td> <td width="78%" height="34" colspan="7"> <font face="Times New Roman" size="2">A second method for treating radon in water is <b>granular activated carbon, or GAC, absorption</b>.&nbsp; Water is filtered through granulated carbon (usually in the form of activated charcoal) and radon is attracted onto the surface of the carbon.&nbsp; Maximizing the carbon&#39;s surface area and the length of filtration time are crucial to peak radon removal efficiency.&nbsp; GAC absorption can remove up to 99.9% of radon from water if large amounts of carbon and long contact times are used.&nbsp; Typical removal efficiencies for GAC vary from 50-99%.&nbsp; GAC can be used for central treatment schemes for small systems (several hundred users or less), but becomes more expensive for larger systems.&nbsp; GAC is also fairly cost effective for individual residential wells.&nbsp; If high levels of radon are present, disposing of spent carbon filters may be difficult due to the significant amount of radioactive material present in the filter. Small carbon filters attached to kitchen faucets or under sinks are inadequate for removing radon from drinking water.&nbsp;&nbsp;</font></td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top"> <p align="center"> <b><font size="2"><a name="Storage">Storage</a></font></b></td> <td width="78%" height="34" colspan="7"> <font face="Times New Roman" size="2">An alternative to these active mitigation systems is simple <b>storage</b>.&nbsp; Because radon is a radioactive element which decays over time (Radon-222 has a half-life of 3.8 days), radon levels in water storage tanks will decrease over time.&nbsp; This strategy would probably be most effective for small systems with average radon levels just a bit above the EPA's maximum concentration level.</font></td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="4%" height="34">&nbsp;</td> <td width="12%" height="34" colspan="2" valign="top"> <p align="center"> <b><font size="2"><a name="Other">Other</a> Concerns &amp; More Information</font></b></p> <p align="center">&nbsp;</p> <p align="center">&nbsp;</p> <p align="center"><u><i><font size="2"><b><a target="_self" href="#topofpage">Top of Page</a></b></font></i></u></p> <p>&nbsp;</td> <td width="78%" height="34" colspan="7"> <p align="left"><font face="Times New Roman" size="2">For a more in-depth discussion of these technologies and the associated costs of each, you can see the EPA&#39;s <a target="_self" href="http://www.epa.gov/OGWDW/radon/hrrca.html">Health Risk Reduction and Cost Analysis for Radon in Drinking Water</a>.&nbsp; Section 5 of the <i><a target="_self" href="http://www.epa.gov/OGWDW/radon/hrrcafr.html"> Federal Register Notice</a></i><a target="_self" href="http://www.epa.gov/OGWDW/radon/hrrcafr.html">, &quot;Costs of Radon Treatment Measures&quot;</a> is particularly helpful in understanding the different technologies.&nbsp; </font></p> <p align="left"><font face="Times New Roman" size="2">Another alternative for some private well owners is to connect to an existing community water system with low radon levels.&nbsp; Drinking bottled water alone will not completely eliminate exposure to radon in water, since this strategy does not prevent radon gas from escaping from well water into indoor air.</font></p> <p align="left"><font face="Times New Roman" size="2">If you are concerned about radon in your private water supply, <a target="_self" href="Certified.htm">a certified professional radon testing and measurement service provider</a> may be of assistance. </font></p> <p align="left"><font face="Times New Roman" size="2">Contact the <a target="_self" href="mailto:Dale.Dusenbury@ncmail.net">Dale Dusenbury</a>, North Carolina Radiation Protection, Environmental Radiation Specialist for further information on Radon in Water. For further information on radon surveys of NC public water supplies, contact <a target="_self" href="mailto:radon@ncmail.net">Radon Coordinator</a>, Radon Specialist.</font></p> </td> <td width="9%" height="34">&nbsp;</td> </tr> <tr> <td width="8%" height="22" colspan="2"></td> <td width="8%" height="22">&nbsp;</td> <td width="15%" height="22" colspan="2"></td> <td width="18%" height="22"></td> <td width="20%" height="22" colspan="2"></td> <td width="15%" height="17"></td> <td width="10%" height="17"></td> <td width="9%" height="17"></td> </tr> <tr> <td width="16%" height="33" colspan="3"> <img border="0" src="images/rps-logosmall.gif" width="84" height="49"></td> <td width="68%" height="33" colspan="6" align="center"> <font size="1" face="Times New Roman"> <a target="_self" href="http://www.dhhs.gov">NC DHHS</a><a target="_self" href="http://www.enr.state.nc.us"> </a> <a target="_self" href="http://www.ncradiation.net">&nbsp;Radiation Protection Section</a> <font color="#1F3D3D"><br> 1645 Mail Service Center</font><b>.</b><font color="#1F3D3D"> Raleigh, NC 27699-1645</font><b><br> </b><font color="#1F3D3D">Office (919)571-4141</font> <font color="#1F3D3D">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Fax (919)571-4148</font></font></td> <td width="19%" height="28" colspan="2"> <img border="0" src="images/dhhs_logo.JPG" width="103" height="73"></td> </tr> </table> </center> </div> <p></p> </body> </html>