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Ecological Risk Assessments

Review this page for information on TCEQ's Ecological Risk Assessment Program.

What is an ERA?

TCEQ defines an ecological risk assessment (ERA) as a process that evaluates the likelihood that adverse ecological effects are occurring or may occur as a result of exposure to one or more chemicals of concern (COCs) from a remediation site. According to the Texas Risk Reduction Program (TRRP) rule, some form of an ERA is required to be conducted at all remediation sites under this rule.

Use these resources to develop an ERA for your site:

  • Conducting Ecological Risk Assessments at Remediation Sites in Texas (RG-263) Adobe Acrobat PDF Document (August 2018). This is the agency's primary ERA guidance (ERAG) document and has been updated to the most recent accessibility standards. In addition, a few changes have been made to some of the technical information as described in its Introduction section. It is the parent document to the companion documents described below. The ERAG has also been designed to work with a database (see below) by providing subject-matter instructions for its use, which are dispersed throughout the document in relevant locations.
  • Supporting Documentation for the TCEQ’s Ecological Benchmark Tables (RG-263b) Adobe Acrobat PDF Document (August 2018). This document discusses the sources and the derivations of the media-based, screening-level benchmarks. The actual numeric benchmarks for surface water, sediment, and soil are provided as an Excel file . Microsoft Excel
  • Case Study for the TCEQ's Ecological Risk Assessment Process (RG-263c) Adobe Acrobat PDF Document This document is a case study that presents a hypothetical site and affected property, the releases of COCs from the associated facility, and how ecological risk can be evaluated through the Tier 1 Exclusion Criteria Checklist, the Tier 2 screening level ecological risk assessment (SLERA), and the ecological service analysis. The SLERA also demonstrates how the PCL Database (see below) can be used to help evaluate ecological risk and how the information can be presented to the TCEQ for review.
  • Ecological Protective Concentration Level (PCL) Database. TCEQ and its contractor (West Texas A&M University) have developed a database that provides default ecological PCLs for soil and sediment for a variety of wildlife receptors and COCs. Users may adjust the default PCLs based on site-specific inputs (e.g., home range). Additionally, the database can be used as a source for assessment levels, toxicity profiles, toxicity reference values, life history information, and uptake factors (e.g., bioaccumulation factors). Instructions and options for logging in to the database can be found by clicking the Question Mark on the login page.
  • Determining Representative Concentrations of Chemicals of Concern for Ecological Receptors. This guidance (TRRP-15eco) addresses aspects of ecological evaluations currently not discussed in detail in the ERAG and is intended to be used in conjunction with the ERAG. Topics addressed include: ensuring that data used in ERAs are representative and appropriate for each exposure medium, defining representative concentrations and exposure areas for various ecological exposure pathways, and evaluating potential hot spots.
  • Determining PCLs for Surface Water and Sediment. This guidance (TRRP-24) describes processes for developing PCLs for ecological (and human) receptors that may be exposed to surface water and sediment affected by COCs. It also provides information for developing source media PCLs for soil and groundwater that may release COCs to surface water and sediment.

Questions? Contact Us

For answers to your questions about these documents or the ERA Program itself, contact the Remediation Division at 512-239-2200.
Or contact us via e-mail at techsup@tceq.texas.gov.

History of the ERA Program

TCEQ's ERA Program was established in 1995 to evaluate ecological reports submitted under various agency remediation programs (e.g., Superfund). In 1996, an Ecological Workgroup comprised of technical experts from industry, government, consulting firms, and academia was formed to assist in developing guidance that would interface with the ecological aspects of agency rules. The agency first released Guidance for Conducting Ecological Risk Assessments at Remediation Sites in Texas in 2001. This guidance provided a detailed description of how to conduct ERAs using TCEQ's three-tiered approach. It also identified the participation and coordination processes with the Natural Resource Trustee Programs and outlined methods for establishing ecological PCLs for COCs. A January 2006 update revised the ecological screening benchmarks. A draft version was released in January 2014 that incorporated the 2006 update, revised the screening benchmarks, addressed the 2007 revisions to the TRRP rule, and reflected the TCEQ’s commitment to accessibility. It was considered “draft” because the science and references had not been updated since 2001. The 2017 versions of RG-263, RG-263b, RG-263c, and the release of the PCL Database reflect a more current state of the science and provide a significant improvement to the TCEQ’s ERA Program. The 2018 versions of RG-263 and RG-263b, the development of RG-263c, and the ongoing improvements to the PCL Database provide a comprehensive and user-friendly toolbox for evaluating ecological risk in Texas.