Radionuclides Rule Compliance Workshop developed by RCAPAWWA and
Radionuclides Rule Compliance Workshop developed by RCAP/AWWA and funded by the USEPA
Purpose • Radionuclides are a primary drinking water contaminant regulated by the USEPA. • This workshop will provide small systems with the information needed to learn how to achieve compliance.
Learning Objectives As a result of this lesson, you will be able to: 1. Describe the importance of the Radionuclides Rule in protecting public health 2. Determine if a water system is in compliance with the Rule 3. Communicate radionuclide-related information to customers 4. Evaluate options for achieving compliance 5. Locate technical and funding guidance
Agenda • Background and the Radionuclides Rule • Sampling and Compliance – Analytical Method Selection Activity – Compliance Determination Activity • Compliance Options – Non-Treatment – Treatment • Resources for Technical and Funding Guidance • Summary
Radionuclides • Radioactive elements Radioactive Decay of an Atom naturally present in the environment in rocks, soil, air, plants & animals • Product of some industrial activities • Can be present in surface or ground water sources, Source: U. S. Nuclear Regulatory Commission but most prevalent in ground water
Common Radionuclides • Drinking water regulated radionuclides include the following isotopes: – Radium (Ra) – Uranium (U) – Gross alpha particle radioactivity – Beta particle and photon activity • Each isotope has a specific monitoring requirement • The type of radionuclides present can impact treatment effectiveness
Radionuclides Regulations Radioactive substances are regulated under the USEPA Radionuclides Rule resulting from health concerns associated with excess exposure, including cancer.
Radionuclides Rule • Finalized in 2000 – Objective is to improve public health by limiting exposure to radionuclides • Applies to all community water systems (CWSs) – Does not apply to non-community water systems
Radionuclides Rule • Sets MCLs for 4 groupings of radionuclides • Includes components for: – Sampling, monitoring, compliance determination and reporting – Public communication language for Consumer Confidence Report Radionuclide Maximum Contaminant Levels (MCLs) Beta/photon emitters* 4 mrem/year Gross alpha particle (excluding U & radon) 15 p. Ci/L Radium (combined Ra 226 & 228) 5 p. Ci/L Uranium (U) 30 µg/L *A total of 179 individual beta particle and photon emitters may used to calculate compliance with the MCL.
Radionuclides Rule Timeline • • 2000 – Radionuclides Rule promulgated 2003 – Radionuclides Rule effective 2003 -2007 – Initial monitoring completed 2008 – Future monitoring and compliance requirements determined by the state primacy agency • 2016 – End of first Radionuclides Rule compliance cycle
Knowledge Checkpoint • What type of systems must comply with the Radionuclides Rule? • What are the MCLs for the four regulated radionuclides (radium, uranium, gross alpha, and beta/photon emitters)?
Sampling for Radionuclides Gross Alpha; Radium (Ra-226/228); Uranium • Samples collected at each entry point to the distribution system • Reduced monitoring (if initial monitoring <MCL for each contaminant): a) < detection limit = 1 sample every 9 years b) ≥ detection limit, but ≤ ½ the MCL = 1 sample every 6 years c) > ½ the MCL, but ≤ the MCL = 1 sample every 3 years • Increased monitoring (if initial monitoring >MCL): ˗ Quarterly sampling until 4 consecutive quarterly samples ≤ MCL Radionuclide Detection Limits Contaminant Detection Limit Gross alpha particle activity 3 p. Ci/L Radium-226 1 p. Ci/L Radium-228 1 p. Ci/L Uranium TBD
Sampling for Radionuclides (Cont’d) Beta and photon emitters • Samples collected at each entry point to the distribution system – Only vulnerable or contaminated CWSs required, designated by the state • Reduced monitoring (*RAA of gross beta minus potassium 40 is…) – ≤ 50 p. Ci/L for vulnerable systems (≤ 15 p. Ci/L for contaminated systems) • 1 sample every 3 years • Increased monitoring (*RAA of gross beta minus potassium 40 is…) – > 50 p. Ci/L for vulnerable systems (>15 p. Ci/L for contaminated systems) • Speciate for major radioactive constituents • Conduct monthly monitoring until 3 month rolling average < MCL • Utilities should check with their State for sampling requirements *RAA= running annual average (computed quarterly); Potassium Beta Activity = elemental potassium (mg/L) x 0. 82
Knowledge Checkpoint If radionuclides are present at concentrations greater than the MCL, how often must systems sample for radionuclides (including gross alpha, radium, uranium, and beta/photon emitters) at each entry point to the distribution system?
Sampling for Radionuclides • Collect sample and send to certified lab for analysis • Samples typically collected in plastic bottles, which may contain nitric or hydrochloric acid preservative – If pre-packaged with preservative do not rinse • Take steps to avoid contamination, and follow any specific instructions provided by the lab Source: EPA’s Quick Guide to Drinking Water Sample Collection
Sampling for Radionuclides • Failure to sample, not sampling every required sampling point, or not reporting results to the state on time may result in a monitoring and reporting violation • Follow up on any results that are submitted automatically to the state • Be aware of units!
Radionuclide Analytical Method Selection • Critical to select appropriate analytical methods and confirm the lab is performing the methods to minimize uncertainty • AWWA’s Radionuclide Rule Compliance: Utility Guidance on Analytical Methods provides recommendations for selecting appropriate methods and sample handling techniques to obtain higher quality results – Guidance limited to radium (Ra-226 & Ra-228) and gross alpha – Highlights common issues associated with analytical methods – Uses flow charts to assist utilities in obtaining the best quality data
Analytical Method Selection for Gross Alpha Flow chart for selection of method and optimal analytical parameters for gross alpha Is Ra-224 a compliance concern (State of NJ)? Any EPA-approved gross alpha method may be used Use State of New Jersey approved lab and methods. (48 hour hold-time for 2 counts) Will samples contain >500 mg/L solids? Use a coprecipitation method (e. g. , SM 7110 C or EPA 0002) Use approved evaporation or coprecipitation method (e. g. , EPA 900. 0, SM 7110 B or 7110 C) Take measures to minimize uncertainty until the true alpha activity of the water is known (i. e. , increase aliquot and count duration, delay preparation until 2 -3 weeks after collection, and specify method that allows count of prepared sample within 24 hours of prep) and require prompt counting after preparation. Past radiological testing results available? Is combined radium >2 p. Ci/L Source: AWWA’s Radionuclide Rule Compliance: Utility Guidance on Analytical Methods Analyze using default method parameters to meet required detection limit Gross alpha > ½ MCL (7. 5 p. Ci/L) Take measures to minimize uncertainty (i. e. , use more reliable/sensitive method, increase aliquot, increase count duration, adjust time of preparation and count to address decay progeny
Activity • A groundwater system is required to select an appropriate method to determine the gross alpha concentration for their compliance samples. • Using the information provided below, what is the appropriate analytical method, and optimal analytical parameters, for determining gross alpha for this system? – Not concerned with radium-224 – Samples contain <500 mg/L solids – Combined radium <2 p. Ci/L
Compliance Determination Gross Alpha; Radium (Ra-226/228); Uranium • Sample results above the MCL will result in quarterly monitoring – Initial confirmation sample may be required • Compliance is based on a running annual average – Radium compliance • Systems monitor separately for Ra-226 & 228, but compliance is based on combined Ra results – Gross alpha compliance • Ensure gross alpha concentration excludes radon and uranium by consulting with the analytical laboratory • May be able to substitute Ra-226 or U measurements based on state requirements
Compliance Determination (Cont’d) Beta and photon emitters • Sample results above the MCL will result in monthly monitoring • Compliance is based on a “sum-of-the-fractions” method – The sum of the beta and photon emitters should not exceed the MCL • Utilities should check with their State for additional detail on compliance determination
Running Annual Average (RAA) Calculation Gross Alpha; Radium (Ra-226/228); Uranium R 1 + R 2 + R 3 + R 4 4 = RAA
RAA Activity • Calculate the RAA for gross alpha • Determine compliance status
RAA Activity • A groundwater utility sampled for gross alpha for the past 4 quarters. The analytical results are provided below: – Gross alpha (p. Ci/L): 17, 15, 14, 17 • Is this system in compliance with the Radionuclides Rule MCL for gross alpha?
RAA Activity - Explanation • The RAA for the system: – Gross Alpha RAA = (17 p. Ci/L + 15 p. Ci/L + 14 p. Ci/L + 17 p. Ci/L)/4 – Gross Alpha RAA = 16 p. Ci/L • The system is not in compliance with the Radionuclides Rule MCL for gross alpha (15 p. Ci/L) and must sample quarterly until 4 consecutive quarterly samples are below the MCL.
Reporting and Notification • Violations must be reported according to Radionuclides Rule Requirements • There also specific requirements for the language used in the CCR pertaining to radionuclides
Reporting and Notification • Monitoring and Reporting Violation – Report to state within 48 hours – Public notification within one year (may be included in annual CCR) • MCL Violation – Report to state within 48 hours – Public notification within 30 days
CCR Language Requirements Contaminant Source Health Effects Alpha Emitters Erosion of natural deposits Certain minerals are radioactive and may emit a form of radiation known as alpha radiation. Some people who drink water containing alpha emitters in excess of the MCL over many years may have an increased risk of getting cancer Combined radium Erosion of natural deposits Some people who drink water containing radium-226 or 228 in excess of the MCL over many years may have an increased risk of getting cancer Uranium Erosion of natural deposits Some people who drink water containing uranium in excess of the MCL over many years may have an increased risk of getting cancer and kidney toxicity Beta and Photon Emitters* Erosion of natural deposits* Certain minerals are radioactive any may emit forms of radiation known as photons and beta radiation. Some people who drink water containing beta particle and photon radioactivity in excess of the MCL over many years may have an increased risk of getting cancer *EPA recognizes there is an error in the Rule’s language as relates to the beta and photon emitters CCR language, which appears verbatim in the table above. The beta and photon emitters EPA regulates are all manmade, and the sources of these regulated contaminants are their improper use, storage, discharge, and disposal from commercial, industrial, and military activities. The health effects language refers to minerals that are radioactive. The Rule, however, applies only to man-made substances that do not occur in mineral form.
Activity #3 Based on the water system previously discussed (gross alpha RAA of 16 p. Ci/L), what public notification actions must be completed?
Activity #3 - Explanation • The system is out of compliance with the Radionuclides Rule MCL for gross alpha and must: – Report results to state within 48 hours – Public notification within 30 days – Include health effects and likely source statements in the water system’s CCR
Compliance Options • If radionuclides concentrations in a water source are higher than the MCLs, the system will need to take action to achieve compliance – Non-treatment options – Treatment options
Non-Treatment Options • Change in source water • Partner with other water systems – Connect to an existing system – Consolidate with other utilities – Purchase water from another system
Source Water Changes • Change to a source water low in radionuclides or blend with a low radionuclides source • Considerations: – Water availability/water rights – Presence of contaminants in new source that may require treatment – Switch to a surface water source requires filtration
Partnerships with Other Systems • Combining resources or interconnecting with neighboring systems to provide safe water • Considerations: – – Feasibility of location Administration Water quality Operations
Knowledge Checkpoint What are some non-treatment options for Radionuclides Rule compliance?
Treatment Options • • • Ion exchange (BAT, SSCT) Reverse osmosis (BAT, SSCT) Lime softening (BAT, SSCT) Coagulation/filtration (BAT, SSCT) Green sand filtration (SSCT) Co-precipitation with barium sulfate (SSCT) Electrodialysis/electrodialysis reversal (SSCT) Pre-formed hydrous manganese oxide filtration (SCCT) Activated alumina (SCCT) Point of use (POU) devices Best available technologies (BAT); small system compliance technologies (SCCT)
Treatment Considerations • Type of radionuclides (radium, uranium, gross alpha, beta & photon emitters) • Concentration of radionuclides • Water p. H • Raw water quality/competing ions • Pre-existing treatment
Treatment Considerations (Cont’d) • • Operational complexity Costs – capital and operational Waste/residual production/disposal System placement – centralized versus localized treatment
Radionuclides: Small System Compliance Technologies Treatment Technology Operator Skill Level Source Water Customers Served Cost ($) Treatment Capabilities Ra U Gross Alpha Ion Exchange Intermediate GW 25 -10, 000 $$ x x Reverse Osmosis Advanced SW 25 -10, 000 (Ra, G, B) 501 -10, 000 (U) $$$$ x x Lime Softening Advanced All waters 25 -10, 000 (Ra) 501 -10, 000 (U) $$ x x Electrodialysis (ED)/ ED Reversal Basic. Intermediate GW 25 -10, 000 $$$ x Hydrous Manganese Oxide Filtration Intermediate GW 25 -10, 000 $$ x Green Sand Filtration Basic 25 -10, 000 $ x Activated Alumina Advanced GW 25 -10, 000 $$ x Coagulation/ Filtration Advanced Most waters 25 -10, 000 $$ x Beta/ Photon x x x Key: GW = groundwater; SW = source water; Ra = radium; U = uranium; G = gross alpha; and B = beta/photon emitters. Source: EPA’s Radionuclides in Drinking Water
Ion Exchange (BAT, SSCT) • Radium, uranium & beta/photon emitter activity removal – Anion exchange for uranium removal – Cation exchange for radium removal – Mixed bed ion exchange for both uranium and radium removal • Can remove up to 99% of radionuclides depending on the resin, p. H and competing ions • Intermediate operator skill required • Radionuclide ions are removed by exchange with – Chloride or hydroxide ions on a strong base ion exchange resin – Sodium or potassium ions on a strong acid ion exchange resin • Water flows through a packed column of ion exchange resin • Resin is regenerated when its exchange capacity is exhausted
Reverse Osmosis (BAT, SSCT) • Membrane, with small pore size, provides physical barrier against radionuclides RO Filtration Process – Up to 99% effective for radionuclide removal – Removes other particulates and ionic contaminants • • Advanced operator skill required Pre-treatment often required Energy requirements Highly concentrated residuals Source: EPA Mitigation Techniques & Treatment Options for Radionuclides
Lime Softening (BAT, SSCT) • Radium and uranium removed by attaching to particles formed during the lime softening process – Particles are filtered to remove radionuclides – Up to 90% effective • Most suitable for systems already using the process for softening • Advanced operator skill required • Process generates waste, direct discharge not permitted
Coagulation/Filtration (BAT, SSCT) • Uranium removal (50 -90% effective) • A coagulant (iron/aluminum based) enables uranium to form a precipitate that is removed by filtration Filters for Uranium Removal – Coagulant effectiveness is p. H-dependent – Removal efficiency depends on prevailing charge on flocculation & uranium species • Advanced operator skill required • Likely not feasible as a new technology for small systems • Backwash, sludge and media disposal considerations Source: EPA Mitigation Techniques & Treatment Options for Radionuclides
Activated Alumina (SSCT) • • Uranium removal (up to 99% effective) Advanced operator skill required Water is run through a packed column of fine grained, absorptive media to remove uranium Media replaced or regenerated when exhausted Activated Alumina Process for Uranium Removal Source: EPA Mitigation Techniques & Treatment Options for Radionuclides
Green Sand Filtration (SSCT) • Radium removal • Simple and operator friendly • An oxidant (potassium permanganate) enabling radium to form a precipitate and is removed from the water by green sand filtration – Potassium permanganate feed rate is critical • Disposal considerations (media & backwash) • Can also remove iron, manganese and arsenic KMn. O 4 – Effectiveness varies (60 -97%) based on water quality Source: EPA Mitigation Techniques & Treatment Options for Radionuclides
Co-Precipitation with Barium Sulfate (SSCT) • Radium removal – Effectiveness varies (40 -90%) based on water quality • • Advanced operator skill required Adding barium chloride enables radium to form a precipitate and is removed from the water by filtration – Requires high sulfate concentrations in raw water – Used mainly for waste effluent treatment • Co-Precipitation Process with Barium Sulfate Sludge disposal and radon generation are issues of concern Source: EPA Mitigation Techniques & Treatment Options for Radionuclides
Electrodialysis/Electrodialysis Reversal (SSCT) • Radium removal (95% effective) – Can also remove uranium, arsenic, nitrate • Basic-intermediate operator skill required • Ions pass through ion exchange membrane via DC voltage to separate ionic contaminants – DC voltage is reversed to clean membranes • Membrane build-up could complicate disposal
Pre-Formed Hydrous Manganese Oxide Filtration (SSCT) • Radium removal (up to 90% effective) • Intermediate operator skill required • Pre-formed manganese oxide is added to the water to adsorb radium, which is removed by filtration • Most suitable for systems with filtration already in place • May need to oxidize iron first • Limited effect if hydrous manganese oxide under- or overdosed
Point-of-Use (POU) Devices • Treatment devices placed at individual customer taps POU Reverse Osmosis Device • Considerations – Water system is responsible for inspection and maintenance, which may include entering residences Source: EPA Mitigation Techniques & Treatment Options for Radionuclides
Radionuclides: Small System Compliance Technologies Treatment Technology Operator Skill Level Source Water Customers Served Cost ($) Treatment Capabilities Ra U Gross Alpha Ion Exchange Intermediate GW 25 -10, 000 $$ x x Reverse Osmosis Advanced SW 25 -10, 000 (Ra, G, B) 501 -10, 000 (U) $$$$ x x Lime Softening Advanced All waters 25 -10, 000 (Ra) 501 -10, 000 (U) $$ x x Electrodialysis (ED)/ ED Reversal Basic. Intermediate GW 25 -10, 000 $$$ x Hydrous Manganese Oxide Filtration Intermediate GW 25 -10, 000 $$ x Green Sand Filtration Basic 25 -10, 000 $ x Activated Alumina Advanced GW 25 -10, 000 $$ x Coagulation/ Filtration Advanced Most waters 25 -10, 000 $$ x Beta/ Photon x x x Key: GW = groundwater; SW = source water; Ra = radium; U = uranium; G = gross alpha; and B = beta/photon emitters. Source: EPA’s Radionuclides in Drinking Water
Knowledge Checkpoint What are some considerations that must be taken into account when selecting a treatment-based compliance option for radionuclides?
Compliance Strategy Selection • EPA decision trees can help to provide guidance – Treatment or non-treatment – Most applicable treatment process – Basic process design considerations • Decision trees are accessible on the EPA’s Radionuclides in Drinking Water page – http: //cfpub. epa. gov/safewater/radionuclides/radionucl ides. cfm? action=Rad_Decide
Compliance Strategy Selection (Cont’d) • Evaluation of treatment alternatives should include bench and/or pilot scale testing of selected treatment methods – Confirms treatment effectiveness – Helps to estimate full scale design and cost • State or consultant guidance recommended
Summary • The Radionuclides Rule protects public health by reducing exposure to radioactive substances in drinking water • Sampling is required to determine compliance status • Non-treatment and treatment based alternatives can help systems achieve compliance
Radionuclides Rule Resources • EPA Resources – Radionuclides Rule (http: //www. epa. gov/dwreginfo/radionuclides-rule): • Radionuclides Rule: A Quick Reference Guide • Approved Methods for Radionuclides – Radionuclide Rule Compliance Help for Public Water Systems (http: //www. epa. gov/dwreginfo/radionuclide-rule-compliance-help-public-water-systems) • Radionuclides in Drinking Water: A Small Entity Compliance Guide • Steps to Selecting a Compliance Option for the Radionuclides Rule • A System’s Guide to the Management of Radioactive Residuals from Drinking Water Treatment Technologies • Talking to Your Customers about Chronic Contaminants in Drinking Water • Funding Sources – Radionuclides in Drinking Water (http: //cfpub. epa. gov/safewater/radionuclides. cfm) • Radionuclides Decision Trees – Mitigation Techniques & Treatment Options for Radionuclides (http: //www. epa. gov/sites/production/files/201509/documents/mitigation_techniques_and_treatment_options_for_radionuclides. pdf) – Radionuclides Rule Overview (http: //www. epa. gov/sites/production/files/201509/documents/radionuclide_rule_overview. pdf) • AWWA Resources – Radionuclide Rule Compliance: Utility Guidance on Analytical Methods (http: //www. awwa. org/Portals/0/files/legreg/documents/Radionuclide. Analytical. Methods. Guide. pdf)
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