What are the Level 1 soil matrix levels for Gx and Dx?

The correct answer regarding the Level 1 soil matrix levels for Gx and Dx reflects the regulatory standards outlined for soil contamination and remediation. Specifically, the threshold levels are set to guide assessment and clean-up strategies in accordance with Oregon's environmental protection regulations.

For Gx, a level of 40 ppm indicates the upper limit for safe soil concentrations, while 100 ppm for Dx serves a similar purpose, delineating where intervention may be required. These numbers are critical for ensuring that soil contamination does not pose undue risk to human health and the environment.

Understanding these specific levels helps in determining necessary actions, such as monitoring, remediation efforts, and compliance with environmental regulations. Therefore, the option providing these values accurately reflects the guidelines established for safe soil management practices in Oregon.