US EPA FR Notice on Radon in Drinking Water

[Mike Grissom <mikeg@SLAC.Stanford.EDU>]

radsafers,

The following was published in today's US Federal
Register (Federal Register: October 2, 1998 [Volume 63,
Number 191]) with regards to an "Announcement of
Stakeholders Meeting on the National Primary Drinking
Water Regulation for Radon-222" and may be of
especial interest to state health physicists:

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...
SUPPLEMENTARY INFORMATION:

A. Background

    On July 18, 1991 (56 FR 33050), EPA proposed a
Maximum Contaminant Level Goal (MCLG) and National
Primary Drinking Water Regulation (NPDWR) for radon and
other radionuclides in public water supplies. EPA
proposed to regulate radon at 300 pCi/L. Commenters on
the 1991 proposed NPDWR for radon raised several
concerns, including cost of implementation, especially
for small systems, and the larger risk to public health
from radon in indoor air from soil under buildings.

    On August 6, 1996, amendments to the Safe Drinking
Water Act (SDWA) were enacted, which established a new
charter for the nation's public water systems, States,
and EPA in protecting the safety of drinking water. The
amendments [Sec. 1412(b)(13)] direct EPA to develop MCLG
and NPDWR for radon. EPA is required to (1) withdraw the
1991 proposed MCLG and NPDWR for radon-222 (the proposed
rule for radon was withdrawn on August 6, 1997; 62 FR
42221); (2) arrange for the National Academy of
Sciences (NAS) to conduct an independent risk assessment
for radon in drinking water and an independent
assessment of risk reduction benefits from various
mitigation measures to reduce radon in indoor air (the
NAS report was released to the public on September 15,
1998); (3) publish a radon health risk reduction and
cost analysis for possible radon Maximum Contaminant
Levels (MCLs) for public comment by February, 1999;
(4) propose an MCLG and NPDWR for radon by August,
1999; and (5) publish a final MCLG and NPDWR for radon
by August, 2000.

    If the MCL is "more stringent than necessary to
reduce the contribution to radon in indoor air from
drinking water to a concentration that is equivalent to
the national average concentration of radon in outdoor
air," EPA is also required to promulgate an alternative
MCL and publish guidelines for state multimedia
mitigation programs to mitigate radon levels in indoor
air. The alternative MCL would "result in a contribution
of radon from drinking water to radon levels in indoor
air equivalent to the national average concentration
of radon in outdoor air." States may develop and submit
to EPA for approval a multimedia program to mitigate
radon levels in indoor air. EPA shall approve State
multimedia mitigation programs if they are expected to
achieve equivalent or greater health risk reduction
benefits than compliance with the MCL. If EPA approves
a State multimedia mitigation program, public water
supply systems within the State may comply with the
alternative MCL. If EPA does not approve a State
program, or the State does not propose a program, public
water supply systems may propose multimedia mitigation
programs to EPA, under the same procedures outlined for
States.

B. Request for Stakeholder Involvement

    EPA intends for the proposed NPDWR for radon to
incorporate the best available science, treatment
technologies, occurrence data, cost/benefit analyses,
and stakeholder input on technical and implementation
issues. EPA has evaluated comments on the 1991 proposed
NPDWR for radon and will be considering those comments
in developing the regulation.

    The meeting will cover a broad range of issues
including: (1) Technical updates on radon in drinking
water rule development (treatment technologies,
occurrence, analytical methods); (2) summary of the NAS
report findings on radon in drinking water and
implications of these findings for the overall radon
rule development; (3) implications of the NAS findings
for the multimedia mitigation program component of the
rule; (4) update on the development of the multimedia
mitigation program; and (5) stakeholder involvement
processes.

    EPA has announced this public meeting to present
information to stakeholders and to hear their views on
EPA's activities for developing a NPDWR for radon. The
public is invited to provide comments on the issues
listed above and other issues related to the radon in
drinking water regulation during the October 19-20,
1998 meeting.

Dated: September 28, 1998.

Cynthia Dougherty,
Director, Office of Ground Water and Drinking Water,
Environmental Protection Agency.

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Note that documents printed in the US Federal
Register may be accessed via the GPO Web site at
the following URL:

  http://www.access.gpo.gov/su_docs/aces/aces140.html


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