## Radionuclides in Drinking Water

Disposal Issues

Residual Characteristics • Waste Characterization • Waste Streams • Waste Disposal Options • Transporting Waste • Waste Disposal Contacts • 

# Radionuclides in Drinking Water
ï»¿ 

# Waste Disposal Options
The disposal options for each type of waste stream will de pend not only on the type of waste but also on federal, state, and local regulations; landfill and treatment plant requiremen ts; and location of the plant in relation to disposal options.
In general, landfills are the primary disposal method f or solid wastes, except for lime softening plants that spre ad their sludge as an agriculture soil amendment. The type of landfill requi red will depend on the characteristics of the waste, loca l requirements, and landfill requirements. Systems can refer to a listing of municipal solid waste landfills (for non-hazardous waste)

. There are several options available for disposal of liqui d wastes. These include discharge to a body of water, disch arge to a wastewater treatment plant (WWTP) via a sewer connection or transport of liquid residuals to a WWTP and underg round injection.
Sludge is a mixture of solids and liquids. It can be di sposed of in landfills, although some landfills may not a llow sludge if there is a free liquid content. The Paint Filter Liquids Test is amethod used to determine the presence of free liquids in a representative sample of waste (9095A- 1 Revisions 1 – December 1996). Sludge, because it also has some liquids and can therefore be so mewhat fluid, can be disposed of by diluting it with liquids and dischar ging to an underground injection well or wastewater t reatment plant. Underground injection may not be an ideal choice for sl udge because it may require increased pressures which can fra cture geologic formations used for disposal.
The table below summarizes disposal options for each type o f waste.
Disposal Options

Residuals Possible Disposal Options

Direct Discharge Discharge to

POTW Underground

Injection Landfill Low Level Radioactive Waste Facility

Liquids X X X
Sludge X X X
Aged Resins/Media X

Exhausted Resins/Media X

Spent Membranes X

Direct Discharge
Direct discharge may be an option for liquid residual di sposal if the system has an accessible and appropriate receivi ng body. The Clean Water Act (CWA) requires anybody discharging pollut ants into U.S. waters through a point source to obtain a National Pollutant Discharge Elimination System (NPDES) permit from the state or EPA Region (CWA, Title IV, Section 402). These permits set limits on the amount of certain pollutants that can be discha rged. They also set monitoring and reporting requireme nts, and they may include other provisions that protect water quality and p ublic health.
Federal NPDES regulations do not set specific limits on r adionuclides in discharges. States have the authority to e stablish these limits, and state anti-degradation policies designed to protect the quality of certain water bodies and supportsource water protection efforts might restrict the levels of radionuclides in disch arged waste. It is very unlikely that a state will allow m any discharges from treatment systems removing radionuclides, where the radio nuclides are highly concentrated. Treatment technologies designated for radionuclide removal also remove co-occurring contaminants for which NPDES regulations set limits, further restri cting disposal options.
Discharge to Wastewater Treatment Plant
Liquids and sludge may be discharged to a wastewater tre atment plant generally through a connection to the sewe r. There are no current federal regulations concerning disposal of radio nuclides to the sewer. Liquid wastes that are mixed with domestic sewage and discharged to the sewer are not considered hazardous waste s, although wastes trucked to a wastewater treatment plan t might be. There are strict conditions for disposal if a system should h ave high enough concentrations to be considered source mat erial in the case of uranium. Then the system must ensure the waste is sol uble and there are limits on the average and total am ounts discharged (10 CFR 20). The amount and type of waste that can be discharged are largely determined by local requirements. Discharges to the sewer must meet technically based local limits (TBLL) establ ished by either the state or the wastewater treatment plant to ensure that 

# Page 1 of 3 Waste Disposal Options | Radionuclides Decision Tree| US EPA

1/13/2014 http://cfpub.epa.gov/safewater/radionuclides/radionuclides.cfm?action=Ra d_Disposal%20

...the wastewater treatment plant can meet its NPDES per mit requirements without upsetting the treatment proce ss. The wastewater treatment plant has the right to refuse any waste that will cause violation of its permit conditions, upset the t reatment process, or hamper its ability to recycle or reuse its biosolids. In gen eral, to dispose of liquid waste to a wastewater treat ment plant, the system will need to obtain a permit or enter into a contractspecifying terms of disposal. Some states will have Technolo gically Enhanced Naturally Occurring Radioactive Materials (TENORM) regul ations that must also be followed. EPA has published gui delines based on U.S. Nuclear Regulatory Commission (NRC) requirements t hat discharges with greater than 600 pCi/L of radium-2 26 and radium-228 and 3,000 pCi/L of uranium should not be discharged to the sewer. There is also a requirement that the total be less than unity. In other words, the following equation should be true:

Ra 226 /600 + Ra 228 /600 + U/3000 < 1 For example, for residuals containing 30 pCi/L of radi um-226, 30 pCi/L of radium-228, and 150 pCi/L of ur anium, the fraction contributed by radium-226 is 30/60 pCi/L, or 0.5; the fraction contributed by radium-228 is 30/60 pCi/L, or 0.5; and the fraction contributed by uranium is 150/300 pCi/L, or 0.5. As the sum of these fractions is 1.5, underground injection of the material would be prohibited. Under the Resource Conservation and Recovery Act’s (RCRA’s) “ domestic sewage exclusion” (40 CFR 261.4(a)(1)) liquid wa stes mixed with domestic sewage and discharged to a wastewater treatment plant are not regulated under RCRA, becau se they are subject to the Clean Water Act. Hazardous waste that is acc umulated, managed, or transported (e.g., by truck) prio r to introduction into the sewer system, however, would still be subject to r egulation as a hazardous waste. State regulators and loca l wastewater treatment plants should be contacted to ensure that waste s are properly managed.
In the unlikely event that the treatment technology gene rates enough source material to require a specific license from the NRC, there are strict conditions set for disposal into any sanitary sewer system (10 CFR 20.2003):
The material must be readily soluble (or readily disper sed biological material) in water. • The quantity of licensed or other radioactive material t hat is released into the sewer in one month divided by t he average monthly volume of water released into the sewer, cannotexceed the concentration listed in Table 3 of Appendix B in 10 CFR 20. •

The total quantity of licensed and other radioactive material released into the sanitary sewer in a year cannot exceed 5 curies of hydrogen-3, 1 curie of carbon-14, and 1 curie o f all other radioactive materials combined. • Additional requirements apply if more than one radion uclide is released. • States that have adopted Technologically Enhanced Natural ly Occurring Radioactive Materials (TENORM) regulations that apply to water treatment facilities may also have placed radionucl ide discharge requirements on wastewater treatment plan ts. Injection to Class I or Class V Underground Injecti on Control Wells
Underground injection into geologic formations throug h injection wells may be an option for liquids and slu dge. It may not be a good option for sludge as the higher pressures required may da mage the confining layer of the geologic formation an d allow for migration out of the injection zone which is not allowed under Un derground Injection Control (UIC) regulations. Class I UIC wells may be used for disposal of hazardous, radioactive, or other wastes. R adioactive waste in this instance is defined as more than 60pCi/L for radium and 300 pCi/L for uranium. Other contaminants in the waste may make it hazardous. These would include toxic chemica ls (e.g. arsenic) or a pH less than 2 or greater than 12. Class I wells have strict requirements for monitoring of the we ll and for maintenance of the well to prevent migration of contaminants out o f the injection zone. States may also impose other more strict requirements. As a result, injection to a Class I well can be very expensive. Ve ry few Class I wells accept waste generated off site.
It may be possible for systems to inject through a Class V w ell, which are generally shallower. To inject into a Cl ass V well the system must demonstrate that an underground source of drinking water is not endangered. This generally involves demonstr ating no maximum contaminant levels (MCLs) will be exceeded in the source. This may be a very difficult requirement to meet for systems disposing of radionuclides. Also, if a waste is determined to be radioactive based on the NRC definitions it is strictly prohibited from using Class V wells for disposal.
These requirements do not currently apply to single-famil y residential waste disposal systems (e.g., single-family sept ic systems) and non-residential septic systems that are used solely for sanita ry waste and have the capacity to serve fewer than 20 person s a day. However, the EPA can take action on a residential waste d isposal system if the system introduces contaminants into an underground source of drinking water, the presence or likely presence o f which causes an imminent and substantial endangermentto public health (SDWA Section 1431).
While Class I injection may be an option for disposal o f hazardous and radioactive liquid wastes, there are sever al limitations:
There are very few commercial Class I facilities that accepthazardous or radioactive wastes generated off-site. • Underground injection wells have very stringent protective requirements to ensure safe injection. • Underground injection wells can be expensive to construct, operate, and monitor. • Injection to a Class V well may be an option for a limi ted number of systems. Class V wells are generally shallow w ells (e.g., large capacity septic systems and dry wells) used to place a variety of non-hazardous liquid wastes into or above underground sou rces of drinking water. Injection of hazardous liquid wastes into Class V wells i s prohibited. In addition, use of Class V wells is prohib ited if it will endanger an underground source of drinking water per 40 CFR 144.12 (cause an exceedance of any primary drinking water standard or otherwise adversely affect public health). Therefore, Class V well i njection will most likely not be an option for radioact ive liquid wastes, as demonstration of the non-endangerment standard would be difficult. 

# Page 2 of 3 Waste Disposal Options | Radionuclides Decision Tree| US EPA

1/13/2014 http://cfpub.epa.gov/safewater/radionuclides/radionuclides.cfm?action=Ra d_Disposal%20

...Last updated on Monday, January 13, 2014 http://cfpub.epa.gov/safewater/radionuclides/radionuclide s.cfm?action=Rad_Disposal%20Options Landfill Disposal
Solid waste is generally sent to landfills. Prior to la ndfill disposal, it must be determined whether the wast e is hazardous (through process knowledge and/or analytical testing) and whether t he waste contains any free liquids (using the Paint Filt er Liquids Test). Landfills cannot accept wastes containing free liquids. Ge nerally, wastes with greater than 20 percent solids will not have free liquids. If the waste contains free liquids, an intermediate pr ocessing method (such as dewatering) should be used to re move any liquids. An appropriate method for disposing of the liquid residua ls generated by the intermediate processing must also be determined.
There is no federal requirement to test radionuclide concentrations in solid residuals prior to disposal. Howe ver, there are restrictions on the transport of waste that exceeds certain radioactivi ty thresholds and states and disposal facilities may have requ irements for testing or disposal of TENORM. A determination of whet her waste is exempt from NRC licensing requirements for source material should also be conducted.
There are several types of landfills that may provide pro tective disposal for solid residuals containing radionuclide s. The appropriate landfill can depend on the amount, concentration, an d physical and chemical attributes of the radiologically- contaminated material, the mobility of radionuclides and their decay products, th e consideration of future controls and future land use, and state and local regulations.
Disposal at a municipal or industrial solid waste landfi ll may be an option for systems disposing of non-hazardous w aste. These landfills are regulated under RCRA Subtitle D. Municipal solid waste landfills may have restrictions on the amount of radioactivity they accept. These landfills may accept non-hazardous, solid, and TENORM wastes from all water systems, and hazardous waste f rom Conditionally Exempt Small Quantity Generators (CESQG) (40 CFR 258). Industrial solid waste landfillsmay also accept nonhazardous solid TENORM waste, and may be better equipped to handle such waste as it is more like the waste that i ndustrial landfills typically handle (e.g., sludge and ash). Generally, wastes containing less than 3 pCi/g of radium or 30 pCi/g of uranium can be disposed of in these landfills – treatment residuals will likely exceed these concentrations, however.
As disposal facility owners become more aware of issues surr ounding disposal of radioactive materials, more landfil ls are using monitors to scan incoming trucks for radiation. In some case s, wastes that had previously been accepted were found to co ntain elevated levels of TENORM. If the monitors are trigger ed, the source must be identified and evaluated. Note t hat gamma monitors will not detect uranium residuals that do not contain signi ficant radium.

Hazardous waste landfills (regulated under RCRA Subtitle C) may accept hazardous waste (though not mixed waste) from all generator classes. However, they vary in their ability to a ccept Technologically Enhanced Naturally Occurring Radioacti ve Materials (TENORM) wastes. Some hazardous waste landfills have expli cit permit conditions while others may have to request sta te approval before accepting TENORM wastes. Systems should check with the disposal facility to determine whether their TENORM wast e is eligible for disposal at a particular hazardous waste lan dfill.
Low Level Radioactive Waste (LLRW) or mixed waste landfil ls may be an option for systems generating wastes with radio nuclide concentrations deemed to be unacceptable for disposal at m unicipal, industrial, or hazardous waste landfills.
LLRW landfills are licensed by the U.S. Nuclear Regulat ory Commission (NRC) or by a state under agreement with NRC. Guidelines for disposing of radioactive sludge and solids are more st ringent than in a standard landfill. These facilities are licensed based on projected performance and have packaging and burial r equirements that are progressively stricter as the radionucl ide concentrations increase.
Land Application
Some states allow land spreading or soil mixing as an alt ernative to landfill disposal for water treatment resid uals (for example, as a soil amendment on farm fields). One central concern with land application is the potential for build-up or mo vement of radionuclides to create contaminated sites that would require remediatio n and/or use of institutional and engineering controls. Other factors to take into account include the physical and chemical attributes o f the material, the amount of radiation introduced i nto the soil over time, the mobility of the radionuclides and their decay products alo ng multiple pathways of exposure, and the consideration of future controls and future land use. However, some States have been sprea ding lime sludges on agricultural lands for years and th eir studies have shown that this can be a viable and beneficial disposal me thod. 

# Page 3 of 3 Waste Disposal Options | Radionuclides Decision Tree| US EPA

1/13/2014 http://cfpub.epa.gov/safewater/radionuclides/radionuclides.cfm?action=Ra d_Disposal%20

...