A July train derailment in McKean County, PA, dumped 48,000 gallons of sodium hydroxide – also known as caustic soda or lye – into Portage Run, a popular fishing stream. The Norfolk Southern train was enroute from Binghamton, N.Y., to Harrisburg when 29 cars derailed. Three of the cars breeched, and for more than a week after the accident, sodium hydroxide continued to seep out of the derailment site and into the creek. The stream flows into the 20-mile-long Driftwood Branch and then eventually into Sinnemahoning Creek below the town of Driftwood in Cameron County.

The spill immediately raised the pH level of the creek to levels lethal to fish. The pH is a measurement for determining levels of acidity and alkalinity, with a higher pH indicating alkalinity. Dead fish were reported up to 35 miles from the original accident site. In the first days after the accident, biological assessments showed essentially no living aquatic insects downstream from the spill site for approximately 7.5 miles.

Biologists used electrofishing gear to study the affected streams. Electrofishing is a common fisheries survey process which passes a mild electric current through water, stunning fish so that they can be captured, evaluated and released. The survey compared site data to historical and reference data to determine the scope and extent of the damage. All types of fish, from top-level predators like bass and trout down through the bottom of the food chain to baitfish, were affected by the spill.

McKean County Emergency Management Agency Deputy Director Bruce Manning explained that since sodium hydroxide is water soluble and heavier than water, some of the chemical in the creek will dissolve, while some will settle to the bottom of the pond. He said the remainder will eventually dissolve. As a temporary measure to neutralize the stream, Norfolk Southern applied a citric acid solution at the spill site to reduce the alkalinity of the sodium hydroxide, which leached into the stream after saturating the soil.

Local environmentalists and sport fishermen are confident that with time and some assistance from biologists, the stream will recover. The accident remains under investigation.

For training on the proper response to incidents involving sodium hydroxide, see Emergency Film Group’s HazChem program Sodium Hydroxide & Potassium Hydroxide.