400 ppm is the clearance quantity for which soil area?

400 ppm is the clearance quantity for which soil area?

• A. non-contact areas
• B. outside areas
• C. window areas
• D. contact areas

Answer: (D)

The test is about how soil clearance is determined after lead remediation. Clearance means checking that soil lead levels meet a protective threshold so people aren’t exposed. The 400 ppm standard is used for soil areas that people actually touch and could put in their mouths—those are the contact areas. These are the exposure-prone zones where remediation is judged by this specific threshold. Non-contact areas aren’t as likely to contribute to exposure, outdoor areas broad in scope aren’t specifically defined by this contact-focused threshold, and window areas aren’t typically soil surfaces at all. So the 400 ppm clearance applies to contact areas.

The test is about how soil clearance is determined after lead remediation. Clearance means checking that soil lead levels meet a protective threshold so people aren’t exposed. The 400 ppm standard is used for soil areas that people actually touch and could put in their mouths—those are the contact areas. These are the exposure-prone zones where remediation is judged by this specific threshold. Non-contact areas aren’t as likely to contribute to exposure, outdoor areas broad in scope aren’t specifically defined by this contact-focused threshold, and window areas aren’t typically soil surfaces at all. So the 400 ppm clearance applies to contact areas.