CES Remediation Technologies & Site Cleanup Flashcards
6 cards from real CES practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CES Remediation Technologies & Site Cleanup flashcards as text
What is 'Risk-Based Corrective Action' (RBCA) in contaminated site remediation?
Answer: A tiered approach that sets site-specific cleanup levels based on actual exposure risk rather than uniform generic standards
RBCA establishes cleanup goals based on site-specific exposure pathways, receptor populations, and acceptable risk levels, enabling more targeted and cost-effective remediation than universal cleanup standards.
What is 'phytoremediation' and for which conditions is it best suited?
Answer: Using plants to extract, degrade, or stabilize contaminants; most effective for metals and low-level organics in shallow soils
Phytoremediation uses plants to extract metals into harvestable biomass (phytoextraction), immobilize contaminants in the root zone (phytostabilization), or volatilize them (phytovolatilization), and is most effective for metals and low-level organics in shallow soils.
What is 'Natural Source Zone Depletion' (NSZD) and why is it significant for LNAPL site management?
Answer: Natural biodegradation and depletion of LNAPL source zones through measurable biological and physical processes
NSZD describes naturally occurring processes—including biodegradation, volatilization, and dissolution—that deplete LNAPL source zones at measurable rates, informing passive site management strategies.
What is 'vapor intrusion' in contaminated site management and why does it require assessment?
Answer: Migration of volatile contaminants from subsurface soil or groundwater into overlying buildings, creating inhalation exposure risk
Vapor intrusion occurs when VOCs or other soil gases from subsurface contamination migrate upward through soil and enter building interiors through foundation cracks and utility penetrations, creating inhalation exposure risk for occupants.
What is the purpose of a 'Five-Year Review' at a CERCLA Superfund site?
Answer: To evaluate whether the implemented remedy continues to be protective of human health and the environment
CERCLA requires five-year reviews at sites where hazardous substances remain at levels that do not allow unlimited use and unrestricted exposure, assessing whether the remedy remains protective over time.
What is 'solidification/stabilization' (S/S) as a remediation technology and for which contaminants is it most commonly applied?
Answer: Adding binders to immobilize contaminants and reduce their leachability; most commonly applied to heavy metals
S/S uses Portland cement, lime, or pozzolanic binders to physically encapsulate (solidify) and chemically reduce the leachability (stabilize) of contaminants, and is most effective for heavy metals evaluated using TCLP leachate testing.