UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                     GUIDANCE FROM HOTLINE COMPENDIUM

                                                                              WSGH51
                                                                  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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