Soil Contamination Assessment Flashcards
7 cards from real CEA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Soil Contamination Assessment flashcards as text
Which EPA method is most commonly used for the extraction of semivolatile organic compounds (SVOCs) from soil samples?
Answer: EPA Method 3550C
EPA Method 3550C (Ultrasonic Extraction) is the standard extraction method for SVOCs from soil prior to analysis by methods like 8270.
A Phase II ESA soil boring reveals petroleum hydrocarbons at 500 mg/kg at 5 feet bgs. The site is in a residential zone. What is the immediate next step?
Answer: Compare results to applicable state residential soil cleanup standards
Detected concentrations must be compared to applicable state residential cleanup standards to determine if further action is required.
Which parameter best describes the tendency of a contaminant to volatilize from soil into the overlying air?
Answer: Henry's Law constant (H)
Henry's Law constant describes the equilibrium partitioning of a compound between the aqueous phase and vapor phase, indicating volatilization potential.
What is the purpose of a 'soil background concentration' study during a contamination assessment?
Answer: To establish baseline levels of naturally occurring substances for comparison with site data
Background concentration studies establish naturally occurring or ambient levels of substances so that site-related contamination can be distinguished from natural conditions.
Soil vapor intrusion risk is GREATEST under which site condition?
Answer: Shallow groundwater contaminated with chlorinated VOCs beneath a building
Shallow groundwater contaminated with chlorinated VOCs directly beneath a building maximizes the vapor intrusion pathway to indoor air.
Which soil property most strongly controls the adsorption of non-polar organic contaminants?
Answer: Total organic carbon (TOC) content
Total organic carbon content is the primary soil property controlling adsorption of non-polar organic compounds, as described by the Koc relationship.
In a human health risk assessment for soil contamination, the 'exposure frequency' variable for a residential receptor is typically assumed to be:
Answer: 350 days per year
EPA default exposure frequency for a residential receptor is 350 days per year, reflecting nearly continuous occupancy at a home.