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Drinking Water Regulations and Radiological Testing

Drinking Water Regulations and Radiological Testing. Bahman Parsa NJ Department of Health and Senior Services Public Health and Environmental Laboratories Radioanalytical Services. Current Federal Regulations .

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Drinking Water Regulations and Radiological Testing

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  1. Drinking Water Regulations and Radiological Testing Bahman Parsa NJ Department of Health and Senior Services Public Health and Environmental Laboratories Radioanalytical Services

  2. Current Federal Regulations • Current Regulations were Promulgated in 1976. These are known as National Interim Primary Drinking Water Regulations. • These regulations set a maximum contaminant level (MCL) for gross alpha-particle activity, excluding radon and uranium, of 15 pCi/L in public drinking water supplies.

  3. Current Federal Regulations (continued) • Radium-226 measurement is required when gross alpha-particle activity exceeds 5 pCi/L. • Radium-228 measurement is required when 226Ra concentration exceeds 3 pCi/L. • The MCL for combined 226Ra and 228Ra is 5 pCi/L.

  4. Current New Jersey Regulations • Require gross alpha testing within 48 hours from sample collection to include α-particle emissions due to the presence of224Ra, • Recount samples with gross α over 5 pCi/L 24 hours later to eliminate 222Rn and 220Rn progeny contributions to the gross α-particle assay, • Require both 226Ra and228Ra testing when gross Follow the current Federal regulations, plus: • α-particle activity exceeds 5 pCi/L.

  5. Background Proposed Rules • EPA published a “proposed Rule” in 1991. • In April 21, 2000, EPA published a ‘Notice of Data Availability’ (NODA) Document. • The NODA reiterates EPA recommendation to States and utilities that the gross alpha-particle analysis be performed within 48 to 72 hours after sample collection to capture the contribution of α particles from 224Ra.

  6. New Federal Regulations • The Final Rule for radionuclides came out December 7, 2000 (Federal Register Vol. 65, No. 236, pp 76708-76753) and will be effective from December 8, 2003. • Rules apply to Community Water Systems. • Non-Community Systems (Transient and Non-Transient) are not effected by this Rule.

  7. Summary of the Final Rule • Set a maximum contaminant level goal (MCLG) of zero for all radionuclides. • No change to the gross alpha MCL. This limit is retained at 15 pCi/L, excluding radon and uranium. • Combined 226Ra & 228Ra MCL is retained at 5 pCi/L. • Uranium is regulated for the first time. The MCL is set at 30 μg/L.

  8. Summary (continued) • Monitoring Criteria: Point of Entry (POE), not the Point of Distribution any longer • During 2004-2007, Initial Compliance Monitoring cycle, 4 consecutive quarterly testing for gross α, Ra-226, Ra-228 and uranium is required. • In certain cases, gross α results can be substituted for the required Ra-226 and uranium analyses. • Mandatory 228Ra testing • Sample holding time 6 months unchanged • Radium-224 is a local issue and more occurrence data is needed.

  9. Implementation Guidance for Radionuclides • USEPA draft paper, January 2002, EPA 816-D-00-002 • Allows use of gross alpha measurements for Ra-226 and uranium assessments. • If the gross alpha activity result is less than detection limit, one half of detection limit (i.e., 1.5 pCi/L) is used for Ra-226 and is added to Ra-228 activity to determine radium compliance.

  10. Implementation Guidance for Radionuclides (Cont.) • If the gross α activity is above detection limit, compliance and future monitoring frequency is determined using the whole gross alpha results. • A gross α activity measurement may be substituted for the required uranium testing if the gross α activity is less than or equal to 15 pCi/L. States should assume all the gross α activity is due to uranium. Samples must be tested for U if the gross α activity is greater than 15 pCi/L.

  11. 226Ra and 228Ra Measurements • Radium-228 carries a higher health risk. • No correlation with 226Ra as previously thought, and hence... • Measure 228Ra separately. • Combined MCL of 5 pCi/L is still valid.

  12. 224Ra • EPA believes that 224Ra is a health concern and is a greater risk factor than previously thought. • Studies in New Jersey indicate a variable 224Ra/228Ra activity ratio, with a maximum of 3 and an average of 1.6. • 224Ra is 8 times less toxic than 228Ra. (It would take 40 pCi/L of 224Ra to equal the health risk of 5 pCi/L of 228Ra).

  13. 224Ra (Continued) • The same mitigation strategies would remove all Radium isotopes. • EPA plans to collect additional national occurrence information for 224Ra. • Based on national occurrence data, EPA may need to issue a proposed amendment to the Rule. • No EPA-approved 224Ra procedure as yet • New Jersey method for 224Ra testing

  14. URANIUM • Uranium is regulated for the first time. • Uranium MCL: 30 μg/L, based on kidney toxicity/cancer risk studies and cost benefit studies (cost of regulating vs lowered health risks). • To determine compliance, both uranium mass and activity must be quantified.

  15. Uranium (continued) • If 238U activity is measured isotopically, use its specific activity of 0.3365 pCi/µg to determine the uranium mass. Otherwise, • An appropriate conversion factor should be used. • EPA has recommended different numbers during various times. • Suggest using the more conservative 0.67 pCi/µg ratio

  16. 222Rn • Radon is not currently regulated. • EPA has proposed Rule for Radon and published in the Federal Register in 1999. • Proposed 222Rn MCL: 300 pCi/L or alternate MCL of 4,000 pCi/L (Multi-Media Approach). • A separate Radon Rule was anticipated as early as the summer 2001.

  17. Beta Particle & Photon Emitters • CWS designated by States as ‘vulnerable or contaminated’ are only required to comply. • Current MCL of  4 mrem/year, based on the new risk reported in 1991 proposal, is retained. • CWS near nuclear facilities have additional rules to comply.

  18. Required Detection limits

  19. New Testing Procedures in Progress • Concurrent Determination of 224Ra, 226Ra, and 228Ra by Gamma-ray Spectroscopy (NJDHSS & Georgia Institute of Technology, in EPA approval process as an Alternate Test Procedure) • Simultaneous Determination of Gross Alpha, 224Ra, 226Ra, and 228Ra activities in Water Using a Single Sample Preparation Procedure

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