Over the past several weeks, both the U.S. Environmental Protection Agency ("EPA" or "the Agency") and Congress have ramped up efforts to regulate hexavalent chromium (also known as "Cr-6" or "chromium six") in drinking water. The pressure has been driven in part by California's efforts to set a separate hexavalent chromium drinking water standard as well as a recent and well-publicized analysis by the Environmental Working Group ("EWG") concluding that hexavalent chromium was present in the tap water of 31 cities (out of 35 sampled) across the country. Even Erin Brockovich is in on the act, meeting with members of Congress this week to continue her crusade against the chemical which inspired the 2000 movie.
There is little doubt that regulators and legislators are seizing the moment and moving to capitalize on the growing public concern and perception that current regulations are not sufficient to protect public drinking water. Federal legislation has been introduced in the 112th Congress, and EPA has published guidance for public water agencies to monitor hexavalent chromium content more closely in their systems. As these efforts move forward, it is critical that regulatory decisions are based on the best available science and sound risk assessments. The following client advisory discusses recent events and explores the implications of a hexavalent chromium drinking water standard.
A Hexavalent Chromium Drinking Water Standard - Activities at the Federal Level and in California
EPA currently has in place a drinking water standard for total chromium of 0.1 mg/L-a standard which includes all forms of chromium including hexavalent and trivalent forms, the latter of which is a human nutrient. As part of its regular drinking water standards re-evaluation process, EPA began assessing possible adverse health effects caused by hexavalent chromium in drinking water in 2008 following the issuance of a National Toxicology Program study finding "clear evidence" that hexavalent chromium caused cancer at high dose levels via oral exposure in rodents.
To this end, in September 2010, EPA released for public comment and peer review a draft Toxicological Review of Hexavalent Chromium under the Integrated Risk Information System ("IRIS") program. While the Agency is slated to finalize the review sometime in 2011, the American Chemistry Council ("ACC") and others have urged the EPA to delay finalization until the Agency has had the opportunity to consider nearly completed research. This research addresses acknowledged data gaps in the scientific database used to support the draft assessment of human health risks posed by oral exposure to hexavalent chromium.
Meanwhile, on January 11, 2011, EPA published guidance for enhanced monitoring of hexavalent chromium in drinking water. The guidance, directed to state and local water systems, presages an almost certain move by EPA to establish a separate hexavalent chromium drinking water standard. Under the guidance, public water systems are encouraged to take additional samples from new locations at increased frequencies, assess the fate of and ability for trivalent chromium ("Cr-3") to be transformed into Cr-6 via oxidants introduced into the system, and send these samples to laboratories equipped to test specifically for hexavalent chromium.
The guidance has been met with frustration by representatives of the public water systems. The American Water Works Association argues that EPA essentially imposed new burdensome and expensive testing requirements that demand screening down to the parts per trillion level without any recommended path should an unacceptable risk be detected.
Meanwhile, on January 26, 2011, Sens. Barbara Boxer (D-CA) and Dianne Feinstein (D-CA) introduced legislation entitled "Protecting Pregnant Women and Children From Hexavalent Chromium Act of 2011." The act, which cites the EWG report, assumes that hexavalent chromium in drinking water currently presents unacceptable carcinogenic risks. The bill would require EPA to issue a health advisory for hexavalent chromium within 90 days of passage and to promulgate a national primary drinking water regulation for hexavalent chromium within 180 days.
For its part, the State of California passed legislation in 2001 requiring the responsible agencies to develop a hexavalent drinking water standard by 2004. California has yet to adopt the standard, but proposed a public health goal of 0.06 parts per billion for hexavalent chromium in drinking water in 2009, and increased the stringency of that goal to 0.02 parts per billion in 2010.
Implications and Concerns
As EPA and California race to establish a hexavalent chromium drinking water standard, it will be crucial for interested parties to be engaged in the process. Protecting the public and vulnerable populations from unacceptable levels of hexavalent chromium in drinking water is a laudable and necessary endeavor. Regulatory agencies properly should revisit science that is almost 20 years old and focus on a separate hexavalent chromium standard in place of the total chromium standard. In doing so, regulators also should be willing to revisit the need for and stringency of a standard applicable to non-hexavalent forms of chromium.
It is critical that EPA's (or California's) process use the best available science to achieve an appropriate risk-based standard. Indeed, the law requires that any determination to regulate a contaminant "be based on the best available health information" using "the best available, peer-reviewed science and supporting studies conducted in accordance with sound and objective scientific practices." See 42 U.S.C. §§ 300g-1(b)(1)(B)(ii)(II), 300g-1(b)(3)(A). In this case, the acknowledged data gaps and deficiencies in EPA's draft IRIS assessment must be filled and corrected prior to establishing the standard. A robust, science-based process is particularly critical with a hexavalent chromium drinking water standard given the high level of public attention focused on the regulatory process.
In addition, the Safe Drinking Water Act requires EPA to "publish a determination as to whether the benefits of the maximum contaminant level justify, or do not justify, the costs." 42 U.S.C. § 300g-1(b)(4)(C). The Obama Administration's recently issued Executive Order (No. 13563) also requires, among other things, EPA to adopt regulations only after a reasoned determination that the benefits justify the costs and based on objective scientific and technological information. As representatives from public water systems have noted, a separate hexavalent chromium standard will require these public systems to revamp significantly the way they monitor for chromium throughout the system - likely at a significant cost. In light of these burdens, EPA (and California) must establish a standard that is scientifically and statistically supportable and for which the benefits in terms of risk reduction outweigh the costs.
Finally, companies whose processes use chromium and chromium chemicals also will be impacted by a new national standard at cleanup sites. Both the Resource Conservation and Recovery Act ("RCRA") and the Comprehensive Environmental Response, Compensation and Liability Act ("CERCLA") base cleanup standards on the relevant drinking water standard. The current total chromium standard (0.1 mg/L) is driven by the perceived risks of hexavalent chromium, rather than any alleged concerns with other forms of chromium. Without evidence to support a new total chromium standard, EPA should either eliminate the total chromium standard or revise it to be applicable only to non-hexavalent forms of chromium. The worst outcome for companies involved in cleanup sites where non-hexavalent chromium is an issue would be for EPA to ratchet down the total chromium standard as part of the hexavalent chromium rulemaking. Thus far, there has been nothing to indicate EPA is headed in this direction. However, the Agency's focus in its recent guidance on the potential for "transformation" of Cr-3 into Cr-6 when exposed to oxidants in drinking water systems could implicate the total chromium standard. For this reason, companies whose processes use chromium and chromium chemicals are advised to stay abreast of developments related to a Cr-6 drinking water standard.