LONGVIEW, Wash. — Remember the mysterious odor that wafted around Portland starting around Sept. 25? The unknown smell, described as akin to sulfur, natural gas or burning garbage, was widely reported but left fire and law enforcement agencies stumped. There were plenty of theories online, some of which could be quickly debunked, but there was no clear origin at the time.
The Washington Department of Ecology now says it's found the source — or at least, the most likely source that we're probably going to get: the WestRock paper mill in Longview.
In a statement released this week, the department said it found that WestRock "vented a gas stream containing odor-causing chemicals" on Sept. 24, and that this action "likely caused an increase in odors in Longview."
The venting isn't done daily, according to the department, but it's part of the mill's normal operations and is allowed under the terms of the facility's permit. The permit requires WestRock to report each round of venting, and it did so on Sept. 24.
There are two caveats, however. First, the department said it can only show that WestRock likely contributed to the odor; it can't prove that the paper mill venting was responsible for all of the odor complaints received that day. And second, there isn't data available to confirm whether the facility was also responsible for the odor complaints in Vancouver and Portland.
The department did say it reviewed the facility's emissions data and found that release of the odor-causing chemicals was too small to pose a threat to human health or the environment.
The department said its conclusions are based on air quality and meteorological data, emissions data, official odor complaints and in-person visits to assess the operational conditions at WestRock and another nearby paper mill, Nippon Dynawave.
Some of the online speculation about the origin of the smell had focused on the Kelso-Longview area because that's where the first odor complaints were made: on the evening of Sept. 24. The Portland complaints began the following morning. The National Weather Service also projected a likely Kelso-to-Portland path for the smell based on wind patterns at the time.
