Radionuclides in Drinking Water


Treatment Options:Overview

Once you have ruled out non-treatment options, the next step is to begin evaluating treatment technologies. Deciding which treatment option is most appropriate for your system will require evaluation of source water characteristics, system size and location, average demand, waste disposal options, and operator skill level, among other things. 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. Types of treatment to consider include ion exchange, reverse osmosis, activated alumina, coagulation/filtration, lime softening, electrodialysis/electrodialysis reversal, and pre-formed hydrous manganese oxide filtration. In addition, One-Use media systems have become more popular in recent years, especially where local disposal options are limited. Some technologies may be more or less appropriate considering system size, the levels and types of radionuclides in the source water, disposal and residual management options, capital and operation and maintenance costs, and operator expertise. You should work closely with your state primacy agency to evaluate your treatment options, as your state may have restrictions on using certain treatment technologies to comply with a maximum contaminant level (MCL). Your state may also be able to provide assistance in determining the appropriate radiation protection and waste management measures to take. In addition to working with your state drinking water program, you may need to coordinate with other state and local entities (e.g., radiation control program) and a professional engineer. Your state drinking water program will be a good source of contacts. Many states will require that a professional engineer be involved if treatment changes are made or new treatment is installed. A professional engineer may be helpful in selecting treatment and determining disposal options. A table highlighting these technologies and their considerations is found below.

Applicability of Various Treatment Technologies to Radionuclides Removal.


Treatment Technology

Designation Customers Served (SSCTs only) Treatment Capabilities Source Water Considerations Operator Skill Required
BAT and/or SSCT?a Radium (Ra) Uranium (U) Gross Alpha (G) Beta/ photon (B)
Ion Exchange BAT & SSCT 25-10,000 All ground waters Intermediate
Reverse Osmosis (RO) BAT & SSCT 25-10,000 (Ra, G, B) 501-10,000 (U) Surface waters usually requiring pre-filtration Advanced
Point-of-Use (POU) Reverse Osmosis SSCT 25-10,000 Surface waters usually requiring pre-filtration Basic
Lime Softening BAT & SSCT 25-10,000 (Ra) 501-10,000 (U) All waters Advanced
Electrodialysis/Electrodialysis Reversal SSCT 25-10,000   All ground waters Basic to Intermediate
Pre-formed Hydrous  Manganese Oxide Filtration SSCT 25-10,000   All ground waters Intermediate
Activated Alumina SSCT 25-10,000   All ground waters Advanced
Coagulation/Filtration BAT & SSCT 25-10,000   Wide range of water qualities Advanced

a Best Available Technology (BAT); Small System Compliance Technology (SSCT)