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Regulatory Flexibility Act Section 610 Review of the

Radionuclides National Primary Drinking Water Regulations

United States Environmental Protection Agency

Office of Water

October 20, 2010
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Results of Section 610 Review of the Radionuclides Drinking Water Regulations

Background

On December 7, 2000 (65 FR 76708), EPA promulgated the final national primary drinking 

water regulations (NPDWRs) for nonradon radionuclides as authorized by the Safe Drinking 

Water Act (SDWA). In this action, referred to as the Radionuclides Rule, EPA promulgated 

maximum contaminant level goals (MCLGs), maximum contaminant levels (MCLs), monitoring, 

reporting, and public notification requirements for gross alpha particle activity, combined radium226 and 228, beta particle and photon activity, and uranium. The Radionuclides Rule became 

effective on December 8, 2003.

Section 610 of the Regulatory Flexibility Act requires federal agencies to review regulations that 

have significant economic impact on a substantial number of small entities within 10 years of 

their adoption as final rules. Before the Radionuclides Rule was promulgated EPA developed a 

Regulatory Flexibility Analysis and took several steps to lessen the impacts on small entities. 

These steps included: (1) The selection of a less stringent MCL for uranium, (2) a reduction in 

the overall monitoring frequencies for systems with radionuclides levels less than the MCL, (3) 

allowance of grandfathered data and State monitoring discretion for determining the initial 

monitoring baseline, and (4) the exclusion of nontransient, non-community water systems from 

the radionuclides regulations.

Pursuant to section 610 of the Regulatory Flexibility Act, EPA has reviewed this rule to 

determine if it should be continued without change, or should be rescinded or amended to 

minimize adverse economic impacts on small entities. This review was announced in the 

Regulatory Agenda which was published in the Federal Register in April 26, 2010 (75 FR 

21883). As part of this review, EPA considered, and solicited comments on, the following 

factors: (1) The continued need for the rule; (2) the nature of complaints or comments received 

concerning the rule; (3) the complexity of the rule; (4) the extent to which the rule overlaps, 

duplicates, or conflicts with other Federal, State, or local government rules; and (5) the degree 

to which technology, economic conditions, or other factors have changed in the area affected by 

the rule. 

EPA received six comment letters in response to the April 26, 2010 Federal Register notice. 

One of the six letters was related to the proposed rule for radon. Since the December 2000 

Radionuclides Rule did not include rulemaking on radon, any response to this comment letter is 

outside the scope of this Section 610 review. All the letters are available for public inspection in 

the rulemaking docket (docket number EPA-HQ-OW-2010-0166 at www.regulations.gov). The 

results of EPA’s Section 610 review of the Radionuclides Rule are presented in this report.

Discussion of Factors required by Section 610 of the Regulatory Flexibility Act 

1. Continued need for the rule.

There was consensus among the commenters about the continued need for the Radionuclides 

Rule, because it serves as an important tool to protect the health of people who get their 

drinking water from public systems using sources of water with high levels of radionuclides. 

None of the commenters expressed a need to rescind of the rule.
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One commenter suggested expanding the scope of the rule to apply to non-transient noncommunity water systems, because in his State some of these systems have found 

radionuclides levels above the MCLs. When the final rule was promulgated in 2000, EPA 

decided not to regulate NTNCWS because the Agency had insufficient contaminant occurrence 

data on a national level to determine if regulation of these systems would reduce risk and 

provide for greater health protection. Also, EPA believed that regulating NTNCWS, which tend 

to be small systems, would have resulted in increased economic burden for small entities.

Since the aim of the Section 610 review is to determine whether there are ways to reduce any 

burdens of an existing rule that unnecessarily impact small entities, this comment is outside the 

scope of this analysis. If States find that radionuclides are occurring in NTNCWSs, most States 

have the discretion to regulate radionuclides in these systems.

2. Nature of complaints or comments received concerning the rule.

There were three main issues for which the commenters requested that the rule be amended to 

ease burden on small systems. These issues were the uncertainty associated with analytical 

methods for detection of contaminants, the cost of disposal of the treatment waste streams and 

the difficulties associated with understanding contaminant monitoring requirements. We address 

each of these concerns and the actions that EPA has taken to resolve these concerns below: 

 Analytical Methods

EPA is aware that there have been concerns reported related to the variability of analytical 

results for the Radionuclides from different laboratories. EPA initiated an effort to understand 

why the problem was occurring. EPA believes that in some laboratories there is a lack of 

qualified radio-chemists to conduct the radiochemical analyses for Radionuclides. This is in part 

due to retirements of qualified and experienced radio-chemists. In addition some laboratories 

were not following the appropriate quality assurance and quality control procedures associated 

with certain analytical methods and as a result were reporting wrong data values to the water 

systems.

EPA has taken action to address the deficiencies that have been found in some laboratories, 

including offering training courses for laboratory auditors and state laboratory analysts. 

Additionally EPA has promoted radiochemistry training through the supplement to the “Manual 

for the Certification of Laboratories Analyzing Drinking Water.”

While EPA recognizes that there have been some issues identified with the variability of 

analytical results for Radionuclides it does not believe that this is a direct result of deficiencies 

with the Rule, but rather an issue resulting from a decrease in qualified personnel to perform the 

analyses. EPA believes that guidance provided to the states and laboratories will improve the 

reliability of the analyses.

 

 Handling & Disposal of Waste Stream

EPA is aware of the difficulties of handling and disposing of treatment waste streams. As a 

result EPA has issued several guidance documents to help systems comply with the 

Radionuclide Rule while minimizing the economic impact of handling and disposing of the 

treatment waste streams. These guidance documents can be found in the EPA website at 

http://water.epa.gov/lawsregs/rulesregs/sdwa/radionuclides/compliancehelp.cfm.
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In addition EPA has developed the Software Program to Ascertain Radionuclide Residual 

Concentrations (SPARCC), to estimate quantities and concentrations of radionuclides in water 

treatment plant residuals. The software is intended for water systems to model their treatment 

operations for the most efficient configuration. The most efficient configuration of the treatment 

process is one which will allow the system to comply with the radionuclide removal as required 

by the rule, while keeping the generation of treatment waste streams at a minimum.

In addition EPA has worked with other Federal Agencies such as the Nuclear Regulatory 

Commission and the Department of Transportation; to develop a guidance document called: “A 

Regulator’s Guide to the Management of Radioactive Residuals from Drinking Water Treatment 

Technologies”. The guidance document is available at

http://www.epa.gov/ogwdw/radionuclides/pdfs/guide_radionuclides_regulatorsguide.pdf. The 

purpose of the unified guidance is to help States address radionuclide disposal options for 

systems with elevated levels of radionuclides. EPA believes that these resources will help 

systems understand the requirements of the rule, while helping them comply with other 

applicable environmental statues. 

 Monitoring Requirements

EPA received several comments on the monitoring requirements of the Radionuclides Rule. 

Most of the comments had to do with the variability of analytical results obtained as described in 

the first bullet. The monitoring requirements of the Radionuclides Rule are based on the 

Standardized Monitoring Framework, which calls for a performance based approach for future 

monitoring requirements. Under this approach, monitoring requirements are based on past 

contaminant detection performance. 

The Rule states that if monitoring results are below the detection limit, then the system will have 

to conduct its next monitoring within nine years. If the monitoring results are above the detection 

limit but below one-half of the MCL, then the system needs to do the next monitoring within six 

years. If the monitoring results are above one-half the MCL but below the MCL, then the system 

needs to do the next monitoring within three years. Finally, if the monitoring results are above 

the MCL, then the system needs to do quarterly monitoring until there are four consecutive 

quarterly monitoring results below the MCL, at that time the system will be placed in the 

corresponding monitoring scheme as previously indicated.

The main concern of the commenters is that the problems with analytical methods and the 

associated variability in the detection results are causing systems on reduced monitoring to 

obtain results stating that the system is exceeding the MCL. Commenters claim that this causes 

unnecessary increased monitoring for an otherwise consistent water supply which would 

normally be in compliance of the MCL. 

EPA agrees with the commenters that the variability of analytical results obtained from the 

laboratories causes uncertainty whether increased monitoring is required for the affected 

system. EPA believes that these problems are related to poor implementation of the analytical 

methods and to the lack of qualified personnel to perform radiochemical analysis. The problems 

being described by the commenters related to monitoring requirements are not a result of lack 

of clarity of the rule, but rather an effect associated with the variability of results obtained from 

some laboratories.
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3. Complexity of the rule.

Comments regarding the complexity of the rule were focused on the monitoring requirements 

and the technical interpretation of monitoring results. There was also one comment stating that 

the Rule implementation was not complex. After considering the comments EPA believes that 

there are adequate guidance documents available on the EPA website to help systems and 

States understand the correct implementation of the Rule. In addition to providing guidance 

documents EPA also conducts periodic training courses to help the regulated community 

understand the requirements of the Radionuclides Rule. More information on past training 

courses can be found at 

http://water.epa.gov/lawsregs/rulesregs/sdwa/radionuclides/compliancehelp.cfm#four.

4. Extent to which the rule overlaps, duplicates, or conflicts with other federal, state, or 

local government rules.

Some commenters expressed concerns about the burden that results from complying with the 

Rule as it relates to the appropriate disposal of wastes generated after the treatment of water 

sources with elevated levels of radionuclides. The main concern is that some systems might 

have to comply with other environmental statues as a result of the generation of wastes from the 

treatment of water to remove radionuclides. EPA has developed guidance documents to help 

the regulated community comply with the Rule while reducing the amount of wastes generated. 

Given the targeted nature of the Rule towards drinking water, and the guidance provided for 

complying with other rules, EPA does not believes that the Radionuclides Rule overlaps, 

duplicates or conflicts with other rules. 

5. The degree to which technology, economic conditions, or other factors have changed 

in the area affected by the Rule.

No specific issues were identified by the commenters regarding whether technological or 

economic conditions had changed in the area affected by the Rule since it was originally 

promulgated.

EPA will continue to periodically review the effectiveness of the Radionuclides Rule through the 

framework provided by the SDWA. SDWA requires that EPA review all of its drinking water 

regulations every six years and revise them if appropriate. The purpose of the review is to 

identify current health effects assessments, changes in technology, and other factors that could 

support a regulatory revision that will maintain or strengthen public health protection.

EPA completed its first Six Year Review in 2003, and its second Six Year Review in 2010. The 

conclusions of those reviews as they pertain to the Radionuclides Rule were that the Agency did 

not believe that revisions to the Rule were appropriate because there was no new information 

regarding health effects, or analytical and treatment feasibility that would warrant a 

reconsideration of the MCL.

Conclusion

While none of the commenters expressed a need to rescind the Rule, most of the comments 

were aimed at suggesting that the Agency make clarifications in certain areas of the Rule to aid 

small entities in Rule compliance. After reviewing all the comments regarding this Regulatory 

Flexibility Act Section 610 review the Agency has concluded that revisions or amendments to 
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minimize economic impacts on small entities from the Radionuclides Rule are not warranted at 

this time. 

EPA will continue to evaluate the effectiveness of the Radionuclides Rule and the potential to

decrease the Rule’s implementation burden within the framework provided by the SDWA and 

other Agency initiatives. EPA is also evaluating the need to provide additional guidance and 

clarification on those issues raised by the commenters to assist in the Rule implementation.

The Agency also bases its decision to not revise or amend the Rule at this time on the analysis 

conducted during the promulgation of the Rule which were aimed at reducing economic burden 

on small entities. Among the measures that the Agency took, at the time of Rule promulgation, 

to minimize impacts on small entities are: (1) The selection of a less stringent MCL for uranium, 

(2) a reduction in the overall monitoring frequencies for systems with radionuclides levels less 

than the MCL, (3) allowance of grandfathered data and State monitoring discretion for 

determining the initial monitoring baseline, and (4) the exclusion of non-transient, noncommunity water systems from the radionuclides regulations. EPA believes these measures 

remain appropriate.

EPA continues to view the NPDWRs for radionuclides as important to ensure and protect the 

health of consumers served by public drinking water systems and intends to continue to require 

compliance with these NPDWRs.