Wash. Metro Fined $200K for Rail Car Washing Accident

The Washington Metropolitan Area Transit Authority (Metro) agreed to pay a $200,000 fine Nov. 25 for violating the Clean Water Act six years ago when it discharged wastewater containing hydrofluoric acid into the local sewer system. The incident occurred Oct. 2-7, 2003, when wastewater in the collection tanks at Metro’s hand washing facility reached the overflow valve and discharged into the sewer system.

Metro operates automatic rail car washing systems at five of its nine rail yards. The offending facility is the only hand washing location Metro operates. The transit authority reconfigured its rail car washing operations after the incident to ensure compliance with the Clean Water Act, according to a statement released by Metro. The agency no longer uses hydrofluoric acid to wash its fleet of 1,100 rail cars, according to a report by The Washington Post.

In addition to the fine, the U.S. District Court ordered quarterly environmental monitoring of the Branch Avenue Rail Yard by the Environmental Protection Agency and the Washington Suburban Sanitary Commission (WSSC), and placed Metro on an 18-month probation.

Hydrofluoric acid was blamed for collapsing a sewer pipe at Metro’s New Carrollton Rail Yard in May 2003, prompting Metro to move its hand washing operation to the Branch Avenue Rail Yard. Rail car washing at New Carrollton was shut down permanently after the incident, according to Metro.

A pH reading of 2.8 was taken at a sewer location immediately outside the Branch Avenue Rail Yard by the WSSC on Oct. 2, 2003. Similar readings were registered through Oct. 7, 2003. Discharging corrosive material into the sanitary sewer system with a pH lower than 5.0 is a violation of the Clean Water Act.

Hydrofluoric acid is extremely corrosive and commonly used to dissolve metal oxides, including aluminum oxide. The contractor hired by Metro to hand wash the rail cars used hydrofluoric acid, among other chemicals, in removing the heavy soil and oxides that accumulated on the aluminum exterior of the rail cars, according to a WSSC press release.

Hydrofluoric acid has been a source of controversy in the carwash industry for many years. It is used in some tire cleaners, and many operators have used a hydrofluoric acid solution to clean wash bay walls because of its effectiveness. Industry trade press coverage of the acid, along with ammonium bifluoride and caustic sodas, prompted the International Carwash Association to issue an alert in 2001 urging the proper handling and use of such materials.

Although the ICA in general does not take a formal position on the use of particular chemicals, the association adopted an official chemical safety position statement in 2008 and specifically addressed hydrofluoric acid and ammonium bifluoride, urging carwash operators to “educate themselves thoroughly and carefully consider and understand the risks before making a decision to use products containing these ingredients.”

The ICA includes third-party safety literature and links on its Web site, including a report from Honeywell, one of the largest producers of hydrofluoric acid.