A System’s Guide to the 

Management of Radioactive 

Residuals from Drinking Water 

Treatment Technologies 

Community water systems (CWSs) that use source water containing radium-226 (Ra-226), radium-228 (Ra-228),

 gross alpha particle activity, beta particle and photon radioactivity, or uranium must comply with the Radionuclides Rule 

(see www.epa.gov/safewater/radionuc.html). This document provides general information to CWSs on: the available 

treatment technologies for the removal of radium, uranium, and gross alpha particle activity; the residuals produced by each 

technology; disposal options; and, the regulations governing these options. These requirements are decribed here in summary 

form only and there may be additional federal or state laws or regulations that apply to you beyond those described in this 

document. You need to consult the statutory and regulatory provisions that apply to the waste you generate or manage in 

order to determine the requirements with which you must comply. This document also provides additional recommendations 

and information on possible options; these are not regulatory requirements and are provided for your information only. This 

document does not cover residuals from treatment of beta particle or photon radioactivity. Information on those 

radionuclides can be obtained from your primacy agency. EPA will continue to review and update this Guide as necessary 

and appropriate. For additional, more detailed information see A Regulators’ Guide to the Management of Radioactive Residuals from 

Drinking Water Treatment Technologies (EPA 816-R-05-004, July 2005). 

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Treatment Technologies 

In the Radionuclides Rule, EPA has listed Best Available 

Technologies (BATs) and Small System Compliance 

Technologies (SSCTs) for radionuclide treatment based on 

their efficiency at removing radionuclides from drinking 

water, taking cost into consideration. You are not required 

to use a listed BAT or a SSCT. Any technology that is 

accepted by your primacy agency and achieves compliance 

with the maximum contaminant level (MCL) is allowed. 

These technologies produce different types of waste with 

varying contaminant concentrations and restrictions on 

disposal options. It is important that systems carefully 

investigate treatment and waste disposal options before 

installing new or upgrading existing treatment. If possible, 

pilot tests are a good way to determine how much waste 

your system will produce and whether your system will be 

able to dispose of the amount, concentration, and type of 

waste. 

Treatment and Disposal 

Considerations 

Treatment Residual Characteristics 

Each treatment technology will produce solid residuals 

(spent resins, spent filter media, spent membranes, and 

sludge) and liquid residuals (brine, backwash water, rinse 

water, acid neutralization streams, and concentrates). The 

characteristics of the residuals can be affected by: 

• The concentration of radionuclides in the source 

water 

• Frequency of resin/media/membrane replacement 

• How efficient the treatment is at removing

radionuclides

• Loading to the treatment unit 

• Frequency of regeneration (for ion exchange and 

activated alumina) 

• Frequency of filter backwash (for treatment

processes using granular media filters)

TENORM 

Treating water containing naturally occurring radionuclides 

increases the radionuclide concentrations in the residual 

streams. These residual streams are called Technologically 

Enhanced Naturally Occurring Radioactive Materials 

(TENORM), or naturally occurring materials whose 

radionuclide concentrations or potential for exposure to 

humans or the environment are enhanced as a result of 

human activities. The concentration of TENORM in the 

waste stream, the type of waste produced (liquid or solid), 

and federal and state regulations will affect what disposal 

options are available to your system.1 

Nuclear Regulatory Commission Licensing 

If your system generates water treatment residuals 

containing uranium or thorium, this uranium or thorium is 

considered “source material” and may be subject to the 

Nuclear Regulatory Commission’s (NRC’s) licensing 

requirements under the Atomic Energy Act (AEA). 

Licenses are issued either directly by the NRC or by 

“Agreement States” that have entered into agreements with 

the NRC to regulate source material. If you think your 

system may require a license, contact your primacy agency. 

Exempt Material: If the uranium or thorium makes up less 

than 0.05 percent by weight of the residuals it is exempt 

from NRC regulations because it is considered an 

“unimportant quantity” (10 CFR 40.13). For perspective, 

for a system with filter media weighing 30,000 pounds, 0.05 

percent by weight would be equal to 15 pounds of uranium. 

General License: If the source material is greater than 0.05 

percent by weight (or about 335 picocuries per gram [pCi/ 

g] for natural uranium), and the total amount in your 

possession at any time is less than 15 pounds or no more 

than 150 pounds in any one calendar year, you have a 

“small quantity” of source material that is subject to a 

general license (10 CFR 40.22). 

Specific License: If your system exceeds this small quantity 

threshold, you must apply for a specific license from the 

NRC or Agreement State. 

Resource Conservation and Recovery Act Requirements 

Also, since many of the treatment technologies that are 

efficient at removing radionuclides are also efficient at 

removing co-occurring contaminants, your TENORM 

residuals may also be classified as hazardous waste if they 

contain high enough levels of certain co-occurring 

contaminants, like arsenic. Under the Resource 

Conservation and Recovery Act (RCRA), a waste is 

considered hazardous if it exhibits a certain characteristic 

(i.e., toxicity, ignitability, corrosivity, or reactivity) or if it is 

included on a specific list of wastes. Water treatment plant 

residuals are most likely to exhibit the toxicity characteristic. 

For more information, see A System’s Guide to the Identification 

and Disposal of Hazardous and Non-Hazardous Water Treatment 

Plant Residuals (EPA 816-F-06-011). 

1 The pH and total dissolved solids (TDS), total suspended solids (TSS), and concentrations of other contaminants in the waste stream can also limit 

disposal options. 

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Mixed Waste 

If your treatment residuals contain hazardous waste and a 

“small quantity” of uranium or thorium, you have a mixed 

waste and you must comply with both RCRA hazardous 

waste regulations and NRC’s licensing requirements. These 

requirements also apply to the recipient of the material (i.e., 

a hazardous waste landfill). You do not have a mixed waste 

if the uranium or thorium is of an “unimportant quantity” 

(uranium or thorium makes up less than 0.05 percent by 

weight of the material), or if the waste contains only radium. 

Radium is not considered source or by-product material 

when present in water treatment residuals unless it cooccurs with licensable source material such as uranium or 

thorium. 

Table 1 lists the BATs and SSCTs listed in the 

Radionuclides Rule and includes information on the 

operator skill required to effectively operate each 

technology, the residuals produced, and intermediate 

processing options. Intermediate processing can increase 

the disposal options available to your system and in some 

cases, can reduce the volume of waste produced. Systems 

can also consider several alternative compliance options 

including: developing a new source, blending source waters, 

connecting with a nearby system, or optimizing existing 

treatment. 

Disposal Options 

Your disposal options will vary according to: primacy 

agency regulations; your system’s location; and the type, 

volume, and concentration of residuals your system 

produces. There are numerous state and local regulations 

that govern the disposal of waste streams containing 

radionuclides (although there are no federal waste disposal 

regulations specifically for TENORM wastes), and their 

interaction is complex. Primacy agencies and disposal 

facilities can impose additional restrictions on your system’s 

disposal options. Check with your primacy agency to 

verify which disposal options are available to your 

system. 

Table 2 provides additional general information on disposal 

options for water treatment plant wastes containing 

radionuclides. 

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Transporting Waste 

The U.S. Department of Transportation (DOT) regulates the safe transport of all hazardous materials, 

including radioactive material. DOT has set radionuclide-specific thresholds to determine when a material 

containing radionuclides is subject to requirements for transporting radioactive material. The exemption 

values (listed in 49 CFR 173.436) consist of activity concentrations and total consignment activities; a material 

containing a single radionuclide has to be above both exemption values for that nuclide to be subject to 

DOT requirements. If the activity concentration or total consignment activity is below the exemption value, 

that material is exempt from the DOT requirements for transporting radioactive material. If more than one 

radionuclide is present, the exemption values must be determined as described in 49 CFR 173.433. 

DOT also exempts “natural material and ores containing naturally occurring radionuclides which are not 

intended to be processed for use of these radionuclides” if their activity concentrations and consignment 

activities do not exceed 10 times the levels in 49 CFR 173.436 or calculated using 49 CFR 173.433. For 

example, the exempt activity concentration for uranium is listed as 27 pCi/g, and those for radium-226 and 

radium-228 are 270 pCi/g. Therefore, if your system transports more than 270 pCi/g of uranium or 2,700 

pCi/g of radium, you must comply with DOT’s requirements for radioactive material transport (unless 

consignment activities are below the consignment activity exemption). For more information, see http:// 

hazmat.dot.gov. 

Additional Resources 

Documents and Web Sites 

EPA Office of Ground Water and Drinking Water: 

Q Radionuclides in Drinking Water: www.epa.gov/safewater/radionuc.html 

• Radionuclides Rule (Final), Federal Register, Vol. 65, No. 236, December 7, 2000 

Q Radionuclides Rule Implementation and Guidance: www.epa.gov/safewater/rads/implement.html 

• Implementation Guidance for Radionuclides, EPA 816-F-00-002, March 2002 

• Radionuclides in Drinking Water: A Small Entity Compliance Guide, EPA 815-R-02-001, February 2002 

• Radionuclides Rule: A Quick Reference Guide, EPA 816-F-01-003, June 2001 

• A Regulators’ Guide to the Management of Radioactive Residuals from Drinking Water Treatment Technologies, 

EPA 816-R-05-004, July 2005 

Q Underground Injection Control: www.epa.gov/safewater/uic.html 

EPA Office of Air and Radiation: 

Q Radiation Protection Division: www.epa.gov/radiation/index.html 

Q TENORM: www.epa.gov/radiation/tenorm/index.html 

EPA Office of Solid Waste: www.epa.gov/osw

EPA Office of Wastewater Management, NPDES: cfpub.epa.gov/npdes

RCRA Online: www.epa.gov/rcraonline

The TENORM Page: www.tenorm.com

U.S. Nuclear Regulatory Commission: www.nrc.gov 

Safe Drinking Water Hotline 1-800-426-4791 

Office of Water (4606M)

EPA 816-F-06-012

www.epa.gov

August 2006

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