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Drinking Water Requirements for States and Public Water Systems

Drinking Water Arsenic Rule History

On January 22, 2001, EPA adopted a new standard for arsenic in drinking water of 0.01 mg/l or 10 parts per billion (ppb), replacing the old standard of 50 ppb. Water systems had to meet the new standard by January 23, 2006.

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Review of the 10 ppb standard

In response to the national debate surrounding the arsenic rule related to science and costs, the EPA announced on March 20, 2001, that it would reassess the science and costs associated with the rule.

The EPA postponed the effective date of the rule until February 22, 2002, requested public comment on the standard, and began reviewing the new standard, the science, costs and benefits analyses that supported the regulation. EPA engaged three expert panels to reassess these issues.

On October 31, 2001, the EPA announced the 10 ppb standard for arsenic would remain. The EPA Administrator, Christine Todd Whitman, stated that "the 10 ppb protects public health based on the best available science and ensures that the cost of the standard is achievable."

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Three expert panel reviews

Reports and recommendations on the science, cost of compliance, and benefits analyses in support of the 10 ppb final arsenic in drinking water rule were made available for review and public comment.

These reports were prepared by independent, expert panels convened by the:

  •  National Academy of Sciences
  • National Drinking Water Advisory Council
  • EPA Science Advisory Board

Three expert panel review documents.

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Proposed arsenic rule

In the 1996 amendments to the Safe Drinking Water Act (SDWA), Congress directed the EPA to propose a new arsenic regulation by January 1, 2000.  On June 22, 2000, the EPA proposed a 5 ppb standard for arsenic. The EPA requested comment on 3 ppb, 10 ppb, and 20 ppb.

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Report to Congress

In the Fiscal Year 2002 Appropriations Report, Congress directed the EPA to review the EPA’s affordability criteria and how small system variance and exemption programs should be implemented for the new arsenic standard.

The March 2002 report describes three major activities that address an Agency review of national-level affordability criteria for drinking water rules and small systems implementation issues related to the new arsenic in drinking water standard.

Support Documents for the Final Arsenic Rule

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