CEI Hazardous Materials & Remediation Flashcards

What is the primary goal of 'institutional controls' used at remediated hazardous waste sites?

Answer: To restrict land use and prevent human exposure to residual contamination

Institutional controls are administrative and legal mechanisms that limit land use or access to prevent exposure to contamination that remains in place after remediation.

Which method is most appropriate for treating volatile organic compounds (VOCs) in soil using thermal techniques?

Answer: Thermal desorption

Thermal desorption uses heat to volatilize VOCs from excavated soil, after which the off-gases are captured and treated before release.

What does 'in-situ chemical oxidation' (ISCO) involve in groundwater remediation?

Answer: Injecting oxidants directly into the subsurface to destroy contaminants in place

ISCO involves injecting oxidizing reagents such as permanganate, persulfate, or hydrogen peroxide directly into the subsurface to chemically destroy contaminants.

Under EPA's Land Disposal Restrictions (LDR), what must a generator do before disposing of hazardous waste in a land disposal facility?

Answer: Ensure the waste meets treatment standards or obtain a no-migration determination

LDR requires that hazardous wastes meet specific treatment standards to reduce toxicity or mobility before land disposal, unless a no-migration petition is granted.

Which document formally records the selected cleanup remedy at a CERCLA Superfund site?

Answer: Record of Decision (ROD)

A Record of Decision is the formal EPA document that presents the selected cleanup remedy for a Superfund site, explaining the rationale and how it meets CERCLA requirements.

What is the main function of a 'slurry wall' in hazardous site remediation?

Answer: To create a vertical barrier that controls groundwater flow and contaminant migration

A slurry wall is a subsurface vertical barrier constructed with bentonite or cement-bentonite slurry to contain or redirect contaminated groundwater migration.