62-550.519. Radionuclides Monitoring Requirements

This section contains monitoring frequency and compliance requirements for radionuclides for community and nontransient noncommunity water systems.

(1) Monitoring and Compliance Requirements for Gross Alpha Particle Activity, Radium-226, Radium-228, and Uranium.

(a) Community water systems (CWSs) and nontransient noncommunity water systems (NTNCs) shall conduct monitoring to determine compliance with paragraph 62-550.310(6)(a), F.A.C.

1. All existing CWSs and NTNCs shall sample at every entry point to the distribution system under normal operating conditions.

2. All new CWSs and new NTNCs or existing CWSs or NTNCs that use a new source of water shall begin to conduct initial monitoring for the new source within the first quarter after initiating use of the source.

3. The conversion factor for converting uranium results expressed in pCi/L to ug/L is 1.50 ug/pCi. When converting uranium results expressed in ug/L to pCi/L, use 0.67 pCi/ug.

4. Compliance and reduced monitoring frequencies shall be calculated based on the analytical results. The analytical result is the number that the laboratory reports, not including (i.e., not adding or subtracting) the standard deviation.

(b) Initial monitoring: Systems shall conduct initial monitoring for gross alpha particle activity, radium-226, radium‑228, and uranium as follows:

1. Systems shall collect four consecutive quarterly samples at all sampling points. All CWSs will have completed their initial monitoring by January 1, 2007. CWSs constructed after that time and all new NTNCs will conduct one year of initial monitoring within the first year of operation. Existing CWSs and NTNCs can use historical data to satisfy the initial monitoring requirement as specified in paragraph 62-550.519(1)(c), F.A.C., below.

2. For gross alpha particle activity, uranium, radium-226, and radium-228 monitoring, the Department shall waive the final two quarters of initial monitoring for a sampling point if the results of the samples from the previous two quarters are below the regulatory detection limit.

3. If the average of the initial monitoring results for any sampling point is above the MCL, the system is out of compliance. The system must continue to collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are at or below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the Department.

4. CWSs serving more than 3,300 people that were required to sample prior to January 1, 2012 and had no detections shall sample again during 2014. CWSs serving 3,300 or fewer people that were required to sample prior to January 1, 2013 and had no detections shall sample again during 2015. All existing NTNCs shall begin routine monitoring under paragraph 62-550.519(1)(d), F.A.C., starting January 1, 2016, unless the system has historical data that allows them to go either to reduced monitoring or waives the monitoring requirement entirely.

(c) Use of Historical Data. Under the following conditions, CWS’s data gathered between June 1, 2000 and December 8, 2003 and NTNC’s data gathered between January 1, 1996 and December 31, 2015, may be used to satisfy the requirement to monitor during the initial monitoring period described in paragraph 62-550.519(1)(b), F.A.C., above.

1. The water system shall have at least one sample result from every point of entry for gross alpha and radium-228;

2. The gross alpha result shall not exceed 15 pCi/L;

3. The system must either sample for radium-226 or may substitute the gross alpha value if it is less than 5 pCi/L. If the gross alpha particle activity result is less than the regulatory detection level of 3 pCi/L, half the detection level (1.5 pCi/L), shall be used if substituting for radium-226; and

4. The combined value for radium-226 and radium-228 shall not exceed 5 pCi/L.

5. Systems that use historical data gathered between June 1, 2000, and December 8, 2003, in lieu of testing during the initial monitoring period do not need to monitor again until 2008 for systems serving 3,300 or more people, and 2009 for systems serving fewer than 3,300 people.

(d) Routine monitoring began January 1, 2008 for community water systems serving 3,300 or more people. Community water systems serving fewer than 3,300 people began monitoring January 1, 2009. NTNCs will begin routine monitoring January 1, 2016. Routine monitoring will take place every three years and must meet the following conditions:

1. The water system shall have at least one sample result from every point of entry for gross alpha and radium-228.

2. The system may either sample for uranium or may substitute the gross alpha value if it is less than 15 pCi/L. If the gross alpha value exceeds 15 pCi/L, the system must sample for uranium. The uranium result shall be subtracted from the gross alpha result in order to determine compliance with the gross alpha MCL. In the event the gross alpha result minus the uranium result exceeds 15 pCi/L, the system shall begin quarterly monitoring for gross alpha.

3. In the event the uranium value exceeds 30 ug/L (20 pCi/L), the system shall begin quarterly monitoring for uranium.

4. The system must either sample for radium-226 or may substitute the gross alpha value if it is less than 5 pCi/L. If the gross alpha value result is less than the regulatory detection level of 3 pCi/L, half the detection level (1.5 pCi/L) shall be used if substituting for radium-226.

5. In the event the combined value for radium-226 and radium-228 exceeds 5 pCi/L, the system shall begin quarterly monitoring for both radium-226 and radium-228.

(e) Reduced monitoring. The Department shall allow community and NTNC water systems to reduce the future frequency of monitoring at each sampling point from once every three years or once every six years to once every six or nine years or waive monitoring for NTNCs altogether, based on the following criteria:

1. If the monitoring result for a contaminant (i.e., gross alpha particle activity, uranium, radium-226, or radium-228) is below the regulatory detection limit specified in paragraph 62-550.310(6)(c), F.A.C., above, the CWS shall collect and analyze for that contaminant at that sampling point every nine years, and a NTNC is waived from any future monitoring for that contaminant.

2. For gross alpha particle activity and uranium, if the monitoring results for each contaminant is at or above the regulatory detection limit but at or below half the MCL, the CWS shall collect and analyze for that contaminant using at least one sample at that sampling point every six years and the NTNC shall collect and analyze for that contaminant using at least one sample at that sampling point every nine years. For radium-226 and radium-228, the analytical results shall be combined. If the combined monitoring result for radium-226 and radium-228 is at or above 1 pCi/L, but at or below half the MCL (2.5 pCi/L), the CWS shall collect and analyze for that contaminant using at least one sample at that sampling point every six years and the NTNC shall collect and analyze for that contaminant using at least one sample at that sampling point every nine years.

3. For gross alpha particle activity and uranium, if the monitoring results for each contaminant is above half the MCL but at or below the MCL, the CWS shall remain on routine monitoring and shall collect and analyze at least one sample at that sampling point every three years and every six years for a NTNC system. If the combined monitoring result for radium-226 and radium-228 is above half the MCL but at or below the MCL, the CWS shall remain on routine monitoring and shall collect and analyze at least one sample at that sampling point every three years, and every six years for the NTNC system.

4. Systems with multiple entry points to the distribution system could have different monitoring schedules for radionuclides at each entry point. In the event such a situation occurs, the system shall be responsible for keeping track of its monitoring schedule.

(f) Systems shall use the samples collected during the initial, routine or reduced monitoring period to determine the monitoring frequency for subsequent monitoring periods (e.g., if a system’s sampling point is on a nine year monitoring period, and the sample result is above half the MCL, then the next monitoring period for that sampling point is three years).

(g) If a system has a monitoring result that exceeds the MCL, the system shall collect and analyze quarterly samples at that sampling point until the system has results from four consecutive quarters that are below the MCL, unless the system enters into another schedule as part of a formal compliance agreement with the Department. When the combined MCL for radium-226 and radium-228 exceeds the MCL of 5 pCi/L, the system shall begin quarterly monitoring for both radium-226 and radium-228. Substitution of a gross alpha particle activity result for radium-226 shall not be allowed when the combined result exceeds the MCL.

(h) Compositing. To fulfill quarterly monitoring requirements for gross alpha particle activity, radium-226, radium‑228, or uranium, a system may composite up to four consecutive quarterly samples from a single entry point if analysis is done within a year of the first sample. The Department shall treat analytical results from the composited sample as the average analytical result to determine compliance with the MCLs and the future monitoring frequency. If the analytical result from the composited sample is greater than half the MCL, the Department shall direct the system to take one year of additional quarterly samples before allowing the system to sample under a reduced monitoring schedule.

(i) A gross alpha particle activity measurement may be substituted for the required radium-226 measurement provided that the measured gross alpha particle activity does not exceed 5 pCi/L. A gross alpha particle activity measurement may be substituted for the required uranium measurement provided that the measured gross alpha particle activity does not exceed 15 pCi/L. When a system uses a gross alpha particle activity measurement in lieu of a radium-226 and/or a uranium measurement, the gross alpha particle activity analytical result shall be used to determine the future monitoring frequency for radium-226 and/or uranium.

(j) If any sample result is less than the regulatory detection limit, zero shall be used. If the gross alpha particle activity result is less than the regulatory detection limit and is used in lieu of actual measurements for either radium-226 or uranium, then half the regulatory detection limit (1.5 pCi/L) shall be used.

(k) Use of Historical Data. Under the following conditions, data gathered between June 1, 2000 and December 8, 2003 for CWSs and between January 1, 1996 and December 31, 2015 for NTNCs, may be used to satisfy the requirement to monitor during the initial monitoring period described in paragraph 62-550.519(1)(b), F.A.C., above or may be used to allow a NTNC to go to reduced monitoring or waive the monitoring requirement altogether.

1. The water system shall have at least one sample result from every point of entry for gross alpha and radium-228;

2. The gross alpha result shall not exceed 15 pCi/L;

3. The system must either sample for radium-226 or may substitute the gross alpha value if it is less than 5 pCi/L. If the gross alpha particle activity result is less than the regulatory detection level of 3 pCi/L, half the detection level, that is 1.5 pCi/L, shall be used if substituting for radium-226; and

4. The combined value for radium-226 and radium-228 shall not exceed 5 pCi/L.

(2) Monitoring and Compliance Requirements for Beta Particle and Photon Radioactivity. These requirements only apply to community water systems. To determine compliance with the maximum contaminant levels in paragraph 62-550.310(6)(b), F.A.C., for beta particle and photon radioactivity, a CWS shall monitor at a frequency as follows:

(a) Community public water systems (both surface water and ground water) notified in writing by the Department as being vulnerable to such contamination shall sample for beta particle and photon radioactivity. Systems must collect quarterly samples for beta emitters and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the Department. Systems already designated by the Department must continue to sample until the Department reviews and either reaffirms or removes the designation.

1. If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 50 pCi/L (screening level), the Department shall reduce the frequency of monitoring at that sampling point to once every 3 years. Systems shall collect all samples required in paragraph (2)(a) above during the reduced monitoring period.

2. For systems in the vicinity of a nuclear facility, the Department may allow the community water system to use environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system’s entry point(s), when the Department determines that such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems that are using surveillance data shall begin monitoring at the community water system’s entry point(s) in accordance with paragraph (2)(a) above.

(b) Community water systems (both surface and ground water) designated by the Department as using waters contaminated by effluents from nuclear facilities shall sample for beta particle and photon radioactivity. Systems shall collect quarterly samples for beta emitters and iodine-131 and annual samples for tritium and strontium-90 at each entry point to the distribution system (hereafter called a sampling point), beginning within one quarter after being notified by the Department. Systems already designated by the Department as systems using waters contaminated by effluents from nuclear facilities shall continue to sample until the Department reviews and either reaffirms or removes the designation.

1. Quarterly monitoring for gross beta particle activity shall be based on the analysis of monthly samples or the analysis of a composite of three monthly samples. The former is recommended.

2. For iodine-131, a composite of five consecutive daily samples shall be analyzed once each quarter. As ordered by the Department, more frequent monitoring shall be conducted when iodine-131 is identified in the finished water.

3. Annual monitoring for strontium-90 and tritium shall be conducted by means of the analysis of a composite of four consecutive quarterly samples or analysis of four quarterly samples. The latter procedure is recommended.

4. If the gross beta particle activity beta minus the naturally occurring potassium-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 15 pCi/L (screening level), the Department shall reduce the frequency of monitoring at that sampling point to every 3 years. Systems shall collect all samples required in paragraph (2)(b) above during the reduced monitoring period.

5. For systems in the vicinity of a nuclear facility, the Department may allow the CWS to use environmental surveillance data collected by the nuclear facility in lieu of monitoring at the system’s entry point(s), when the Department determines that such data is applicable to a particular water system. In the event that there is a release from a nuclear facility, systems that are using surveillance data shall begin monitoring at the entry point(s) in accordance with paragraph (2)(b) above.

(c) Community water systems designated by the Department to monitor for beta particle and photon radioactivity can not apply to the Department for a waiver from the monitoring frequencies specified in paragraph (2)(a) or (2)(b) above.

(d) Community water systems may analyze for naturally occurring potassium-40 beta particle activity from the same or equivalent sample used for the gross beta particle activity analysis. Systems are allowed to subtract the potassium-40 beta particle activity value from the total gross beta particle activity value to determine if the screening level is exceeded. The potassium-40 beta particle activity shall be calculated by multiplying elemental potassium concentrations (in mg/L) by a factor of 0.82.

(e) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity exceeds the appropriate screening level, an analysis of the sample shall be performed to identify the major radioactive constituents present in the sample and the appropriate doses shall be calculated and summed to determine compliance with subparagraphs 62-550.310(6)(b)1. and 2., F.A.C. Doses shall also be calculated and combined for measured levels of tritium and strontium to determine compliance.

(f) Systems shall monitor monthly at the sampling point(s) that exceed the maximum contaminant level in paragraph 62-550.310(6)(b), F.A.C., beginning the month after the exceedance occurs. Systems shall continue monthly monitoring until the system has established, by a running average of 3 monthly samples, that the MCL is being met. Systems that establish that the MCL is being met shall return to quarterly monitoring until they meet the requirements set forth in paragraph (2)(a)1. or (2)(b)4., above.

Rulemaking Authority 403.853(3), 403.861(9) FS. Law Implemented 403.853(1), (3), (7), 403.861(16), (17) FS. History–New 1-1-93, Amended 7-4-93, Formerly 17-550.519, Amended 2-7-95, 11-27-01, 4-14-03, 11-28-04, 6-24-14.