Hexavalent Chromium in Drinking Water

On September 20, 2016 the Environmental Working Group (EWG) released their analysis of more than 60,000 drinking water tests conducted nationwide from 2013-2015 under the Environmental Protection Agency’s (EPA) Third Unregulated Contaminant Monitoring Rule (UCMR3).  EWG’s report contends that hexavalent chromium, or chromium VI, is in the drinking water of more than 200 million Americans at, or above, the level that California state scientists consider safe.  A copy of EWG’s report can be found at the following location: https://static.ewg.org/reports/2016/chromium6/EWG_Chrome6Report_C06.pdf.


Ensuring safe drinking water for all Americans is a top priority for the Environmental Protection Agency (EPA).  The agency has taken many actions to improve information on chromium and its potential health risks in drinking water.  EPA and states are responsible for ensuring that public water systems are in compliance with the current standard for total chromium.  The agency has also collected nationally representative data on the occurrence of both total chromium and hexavalent chromium through the third Unregulated Contaminant Monitoring Rule (UCMR3).  EPA is actively working on the development of the Integrated Risk Information System (IRIS) assessment of hexavalent chromium, which will include a comprehensive evaluation of potential health effects associated with hexavalent chromium, and EPA expects that the draft IRIS assessment will be released for public comment in 2017.   Under the Safe Drinking Water Act, before EPA can decide whether to regulate a contaminant, it must meet three criteria:

  • The contaminant may have an adverse effect on the health of persons;
  • is known to occur or there is a substantial likelihood that the contaminant will occur in public water systems with a frequency and at levels of public health concern; and
  • in the sole judgment of the EPA Administrator,  the regulation of the contaminant presents a meaningful opportunity for health risk reductions for persons served by public water systems.

EPA has a drinking water standard of 0.1 milligrams per liter (mg/l) or 100 parts per billion (ppb) for total chromium. This includes all forms of chromium, including hexavalent chromium. Only one of the almost 5,000 public water systems that monitored total chromium under the UCMR3 reported results that exceeded EPA’s standard.  The State of California has promulgated an enforceable maximum contaminant level of 0.01 mg/l or 10 ppb for hexavalent  chromium.  While this standard only applies to water systems in California, less than 2 percent of the UCMR3 systems nationally reported hexavalent chromium at levels exceeding this standard.

For more information please visit EPA’s IRIS website for hexavalent chromium: https://cfpub.epa.gov/ncea/iris2/chemicalLanding.cfm?substance_nmbr=144&forceAssessmentTab=true

EPA’s UMCR website: https://www.epa.gov/dwucmr


The Virginia Department of Health (VDH), in cooperation with EPA, is responsible for ensuring that all public water systems in Virginia comply with the federal Safe Drinking Water Act (SDWA).  The State Board of Health has adopted regulations governing total chromium levels in drinking water consistent with the SDWA and the National Primary Drinking Water Regulations.  These regulations are implemented and enforced by VDH on a daily basis.  All routine public water system testing has been below the total chromium drinking water standard of 0.1 mg/L or 100 ppb from 2010 to present.  Should EPA adopt regulations governing hexavalent chromium, VDH stands ready to work with EPA and public water system owners to implement any new requirements to further protect the public health of Virginians. VDH is also aware of the discussions regarding the State of California’s non-enforceable public health goal and enforceable standard for hexavalent chromium in drinking water and is actively following those developments.