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On January 24th, 2007, a US Environmental Protection Agency (EPA) On-Scene Coordinator (OSC), a START-3 contractor, and two Washington State Department of Ecology (Ecology) Spill Responders were dispatched to the Hampton Affiliates Lumber Yard in Darrington, Washington. The Plant Manager, Dave Roane, and the Environmental Manager, Jim Reese, met with the responders and indicated that the release occurred in the water treatment area of the power cogeneration plant building. During normal operations, water from a steam generating boiler is treated and released to an on-site log pond. All storm water, process water, and wastewater generated in the lumber yard and the cogeneration plant is collected and drained to this on-site pond. The managers indicated that all water is treated prior to discharge to the pond and then water is pumped periodically from the pond to nearby property for land application. The managers also indicated that there are no other chemicals stored on-site other than those used in the cogeneration plant.
The managers accompanied the responders to the cogeneration plant building to meet with the foreman of water treatment operations, George Jacobs. Mr. Jacobs indicated that the release of acid in the water treatment area occurred when a sampling valve was inadvertently left in the opened position overnight in the water quality lab. The open valve allowed alkaline water to drain from the 12,600-gallon neutralization tank which in turn acted as a siphon for acid (9 - 35% hydrochloric) to drain from the 6,000-gallon acid tank through the open valve into the water treatment laboratory sink which then feeds back into the treatment system. The responders observed staining and corrosion of the stainless steel lab sink around the area where the open valve entered the sink. According to Mr. Jacobs the system is constructed so as to recycle materials in the closed loop system until the parameters are right for discharge to the log pond.
Reportedly, the open valve was discovered by two night shift employees when they observed acid gas vapors in the water treatment laboratory. The two employees had not returned to work since the day of the incident and thus had not been debriefed but they had made a logbook entry noting that the sampling valve was discovered open, that they closed it, and there were strong acid fumes coming from the laboratory. No details were provided as to how the situation was rectified. The managers were uncertain if the employees entered the room, prior to it being vented, to close the valve, or if they closed an alternative valve outside the room to stop the acid tank flow. The door to the water quality lab was reported to have been propped open to allow the acid gas vapors to dissipate.
In conclusion, while there was an unknown amount of acid released from the acid tank in the cogeneration plant, it appears that the acid was captured within the plant treatment system and treated appropriately. There does not appear to be any evidence of a release to the environment.
The management needs to debrief the two workers who discovered the release about their actions and health status and then submit a report on their findings to the EPA and Ecology. Until the report is received, it will remain unclear what actions were taken to mitigate the release and if the workers were potentially exposed to a hazardous situation.
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