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 in-situ soil remediation technology works by injecting steam or hot water into the subsurface to volatilize and remove contaminants?
Answer: In-situ thermal treatment (ISTT)
In-situ thermal treatment (ISTT) uses steam injection, electrical resistance heating, or conductive heating to raise subsurface temperatures and volatilize contaminants for extraction.
What is the significance of the 'total threshold limit concentration' (TTLC) in California's soil contamination regulations?
Answer: It is the state-specific total concentration threshold above which a soil is classified as hazardous waste
California's TTLC is a total concentration threshold; soils exceeding TTLC for listed constituents are classified as hazardous waste under California law.
A brownfield redevelopment project proposes to convert an industrial site to a daycare facility. How does this change in land use affect soil cleanup standards?
Answer: It requires more stringent cleanup standards due to the sensitive receptor population and residential-equivalent exposure assumptions
Sensitive receptors such as children at a daycare facility trigger more stringent, residential-type cleanup standards due to higher exposure frequencies, lower body weights, and greater susceptibility.
Which document does EPA require to be completed before initiating a time-critical removal action at a contaminated soil site?
Answer: Action Memorandum
An Action Memorandum documents the basis for and scope of a time-critical removal action and must be approved before cleanup activities begin under CERCLA.
What is 'phytoremediation' and for which soil contaminants is it generally MOST effective?
Answer: Use of plants to accumulate, degrade, or stabilize contaminants; most effective for metals and some organic compounds in shallow soils
Phytoremediation uses plants to hyperaccumulate metals or promote rhizosphere biodegradation of organics; it is best suited for shallow, diffuse contamination with metals such as lead, arsenic, or cadmium.
During a soil contamination investigation, a field screening instrument shows a high PID reading in a boring at 8 feet bgs but laboratory confirmation shows low TPH concentrations. What is the MOST likely explanation?
Answer: The PID response was caused by naturally occurring biogenic gases or non-contaminant volatile compounds
PIDs respond to a wide range of volatile organic compounds including naturally occurring biogenic gases (methane, terpenes) that can produce elevated readings not confirmed by targeted laboratory analysis.
What is the primary regulatory purpose of a 'soil management plan' (SMP) during construction at a contaminated brownfield site?
Answer: To establish procedures for identifying, handling, segregating, and disposing of contaminated soil encountered during grading and excavation
A soil management plan establishes worker protection protocols and procedures for identifying, segregating, and properly disposing of contaminated soil encountered during construction activities.