Groundwater that is contaminated with volatile organic chemicals (VOCs) has flowed into the residential areas near the Union Pacific Rail Yard in NW Eugene. State officials have been concerned about the potential for the chemicals' vapors to drift up through the soil, and into the air of homes located closest to the railyard in the Trainsong neighborhood.
The railyard, located in Northwest Eugene, originally began operations in the late 1800's as a small regional railroad. Throughout the decades of rail operations at the site, drips, spills and operating practices have contaminated the soil and groundwater at the railyard. Public health and DEQ are concerned about the groundwater contamination and the potential effect it has on nearby neighborhoods.
EHAP wrote a report in 2007 that evaluated the public health implications of the contamination. The unanswered question at the time of that report's release was whether homes were being affected by "vapor intrusion" from volatile organic chemicals (VOCs) migrating up through the soil and into the indoor air of nearby homes. This Trainsong Neighborhood Indoor Air Assessment (pdf) addresses that question specifically.
EHAP's assessment examining data from DEQ's vapor intrusion study, confirms that vapor intrusion is not occurring. Of the nine homes in the study, seven showed VOC levels below health guidelines. Two homes showed levels above health guidelines, but after careful examination of the data it appears there is a source of VOCs within these homes that is causing the elevated levels. VOC measurements taken from the soil under the homes, as well as their crawlspaces, showed lower levels than those inside the homes themselves. This is the opposite of what normally occurs with vapor intrusion. There are many commonly used household products that can contaminate the indoor air of people's homes. See gingerbread man study (pdf).
Chemical vapor levels in the soil beneath the Trainsong neighborhood have dropped dramatically in the past two years. However, until DEQ can verify that the levels will stay low, UPRR will continue to maintain vapor barriers for 6 residences as an added measure of safety. With DEQ oversight, the railroad will also continue monitoring soil gas levels in the Trainsong neighborhood. DEQ will use this information to determine how long the vapor barriers will need to be maintained.
- EHAP is available to work with individual homeowners, to determine sources of VOCs within their homes. EHAP & DEQ are also available to answer community-wide questions if requested.
- DEQ staff hosted a public meeting on November 1, 2007, at the Red Cross Building in Bethel.