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U.S. Department of Transportation
Federal Highway Administration
Subject: INFORMATION: EPA Toxic Determination
of Compound in Road Salt
Date: October 29, 2003
From: Regina S. McElroy
Director, Office of Transportation Operations

James M. Shrouds
Director, Office of Natural and Human Environment
Reply to: HOTO-1

To: Division Administrators
Resource Center Managers
Federal Lands Highway Division Engineers

To the attention of Environmental and Engineering staff.

The purpose of this message is to alert field offices that the Environmental Protection Agency (EPA) Office of Water announced a Final Administrative Determination on September 24 classifying Ferric Ferrocyanide (FFC), commonly called "Prussian Blue," as one of the "cyanides" on the Toxic Pollutant List under Section 307(a) of the Clean Water Act (CWA). The determination can be found at the following web address: http://water.epa.gov/scitech/methods/cwa/metals/cyanide/fsffcfinal.cfm. Toxic Pollutants listed under CWA Section 307(a) are also "hazardous substances" under the Comprehensive Emergency Response, Compensation and Liability Act (CERCLA). The EPA's determination is based on evidence that FFC under exposure to certain environmental conditions can potentially result in the breakdown and release of free cyanide, a highly toxic chemical.

Occurrence of the precise conditions required for the breakdown of FFC are highly unlikely, and State highway agencies (SHAs) have used road salt containing FFC and a similar cyanide compound, Sodium Ferrocyanide (SFC) for decades without incident. The compounds are used as anti-caking additives.

Prior to EPA's action, the Federal Highway Administration (FHWA) raised concerns with EPA about the potential impacts on highway operations and safety. But EPA indicates that States should not have to change any current practice regarding the use of road salt containing FFC, relative to compliance with the CWA or the CERCLA. However, they should be aware that EPA in the future could establish FFC as a reportable toxic pollutant with revised regulations under the CWA and CERCLA. For this reason, we suggest that the SHAs be advised about this determination and the use of salt containing FFC.

Even though reporting is not currently required, there still could be potential liability under CERCLA for required cleanup costs associated with a cyanide contamination problem, now including FFC. But EPA has advised us that no CERCLA cleanup action due to FFC in road salt has ever been undertaken by EPA, or for that matter, by any other party. Nevertheless, we think the potential for increased litigation, adverse public reaction, and other possible liabilities due to the EPA determination remains a concern to the highway program.

The primary contact for further information on the FFC action is: Ms. Marion Kelly, EPA Office of Water, Engineering and Analysis Division, 202-566-1045. If you need further assistance, contact either: Mr. Paul Pisano in FHWA's Office of Transportation Operations, 202-366-1301; or Mr. Fred Bank in FHWA's Office of Natural and Human Environment, 202-366-5004. We have available on request background information provided by EPA in making their determination. In addition, we will continue to monitor the situation and keep you informed as appropriate.

Questions and feedback should be directed to Susan Jones (Susan.Jones@dot.gov, 202-493-2139) and Marcel Tchaou (Marcel.Tchaou@dot.gov, 202-366-4196)

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