Initial Tests Include 26 Properties with More Results Expected
The first residential soil test results from Houston’s Fifth Ward were recently shared at a public meeting and detailed results shared with property owners. Data collected by Union Pacific under the oversight of the U.S. Environmental Protection Agency (EPA) and analyzed by independent laboratories indicate no immediate risk to human health. These results are part of the most extensive soil testing conducted near the former Houston Wood Preserving Works (HWPW) site.
This first round of testing examined soil samples from 26 properties, including residential and church properties, and a City of Houston parcel, near the former HWPW site. Eighteen properties showed no detections above EPA’s protective screening levels, while eight properties had chemical detections above EPA screening levels, but below the threshold requiring immediate action and do not establish immediate health risks. None of the properties tested require immediate soil removal under EPA guidelines.
Understanding the Screening Process
When assessing environmental contamination, the EPA uses Regional Screening Levels (RSLs) to determine potential risks.
RSLs are conservative health-based guidelines used to assess whether a chemical in soil, water, or air might require further evaluation. If a chemical level is below the RSL, it is considered low enough that no additional action is needed.
In this case, while some properties had chemical levels exceeding the RSLs, none reached the RML threshold that would require immediate removal. This means that while certain properties may warrant further evaluation, the data does not indicate an urgent health threat.
How These Results Contribute to a Human Health Risk Assessment
These results mark an important step in the process of gathering data to understand potential long-term health risks related to historical activities at the former HWPW site. All soil test data from this study—including these residential soil samples—and additional environmental testing from other locations, will be used to develop a Human Health Risk Assessment.
A health risk assessment is a scientific evaluation that estimates whether long-term exposure to contaminants in soil, air, or water could pose health risks to people living in the area. This assessment considers:
- The types and amounts of chemicals detected,
- How people might come into contact with them (such as through skin contact, ingestion, or inhalation),
- The length of time someone could be exposed, and
- The potential health effects based on established toxicology studies.
The assessment will help determine whether any additional steps are needed. These steps could include continued monitoring, targeted remediation efforts, or community health advisories.
The testing process is conducted under the direct oversight of the EPA, with independent laboratories analyzing the data for transparency and accuracy. Union Pacific has collected more than 2,000 soil samples from participating properties across five zones as part of this broader testing program. These results, along with air and groundwater data, will be compiled into the HHRA to provide a more complete picture of potential exposure risks. The final report will be shared with the community once all data has been analyzed.
Individual test results are being mailed to property owners, maintaining privacy protections that prevent public disclosure of specific property data. Additional soil sampling results will be released in phases through the end of May 2025 as independent laboratories complete their analysis.
Soil test results for Zones 1A and 1 have been mailed. Results for Zones 2 through 4 are expected to be mailed by March 31, and results for properties sampled between mid-October and December 2024 will be mailed by April 30.
In the meantime, residents with questions about the soil test results are encouraged to reach out to the EPA Community Involvement Coordinator, Tom Ruiz, at [email protected] or 214-665-3153. As additional results become available, residents will have opportunities to ask questions and participate in upcoming community meetings and EPA office hours. Updates will continue to be shared through hwpwinfo.com and the HWPW Forward Facebook, X (formerly Twitter), and YouTube channels.
Union Pacific has been working under EPA and state oversight to investigate and remediate contamination linked to the former HWPW site since acquiring it in a 1997 merger with Southern Pacific. This latest round of testing is part of that ongoing effort.