UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                     GUIDANCE FROM HOTLINE COMPENDIUM
                                                                            WSGH48
                                                                Date Issued:  July 1992
SUBJECT:   Sodium Requirements for Public Water Supplies

SOURCE:    Ken Bailey, OST
             (202)260-5535

On August 27, 1980, EPA published final regulations in the Federal Register for monitoring for
sodium in public water supplies.  These regulations required public water suppliers to monitor
for sodium and to report the results to the State, but no standard or guidance level was
established for this contaminant.  However, in the preamble of this rule, EPA suggests that
"sodium levels of 20 mg/1 or less in drinking water be considered optimal (for people on
sodium-restricted diets)."  According to Dr. Ken Bailey, contact for human risk assessment of
sodium in drinking water, Health Effects Assessment Section of the Office of Science and
Technology, there is currently no EPA standard or health advisory level for sodium in drinking
water.

Has EPA established a safe level of sodium in drinking water?

      Response:

      On January 18, 1988, EPA published a notice of substituted contaminants and the first
      Drinking Water Priority List in the Federal Register (53 FR 1892).  In this notice, EPA
      removed sodium from the List of 83 Contaminants to be regulated.  The notice states
      (page 1894), "To assist those who, for medical reasons, require a restricted sodium diet
      (i.e., 500 mg/day), EPA recommends a sodium limit in drinking water of 20 mg/1."  The
      level of 20 mg/1 in drinking water is based on the current American Heart Association's
      recommendation for people who are on a severely restricted sodium diet.

      Ion exchange softening, either with home units or at the treatment plant, can result in
      elevated  levels of sodium in drinking water.

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