CEA Environmental Assessment & Sampling Techniques 3 — Questions and Answers
Question 1: During a wetland delineation, which three-parameter approach is used under the 1987 Corps of Engineers Wetland Delineation Manual?
- Soils, vegetation, and wildlife presence
- Hydrology, hydric soils, and hydrophytic vegetation (Correct answer)
- Water depth, pH, and dissolved oxygen
- Floodplain mapping, rainfall data, and plant surveys
Correct answer: Hydrology, hydric soils, and hydrophytic vegetation
The 1987 Corps of Engineers Wetland Delineation Manual requires the presence of hydrology, hydric soils, and hydrophytic vegetation for a wetland determination.
Question 2: When using a PID (Photoionization Detector) during soil gas screening, a reading of 500 ppm in the headspace of a soil sample most appropriately indicates:
- Confirmed regulatory exceedance requiring no further work
- Elevated VOC presence warranting further laboratory confirmation (Correct answer)
- The soil is safe for unrestricted residential use
- Background levels typical of undisturbed native soils
Correct answer: Elevated VOC presence warranting further laboratory confirmation
PID readings are screening tools that indicate the presence of ionizable compounds; elevated readings warrant confirmatory laboratory analysis to identify and quantify specific compounds.
Question 3: A sediment sample is collected for metals analysis. Which preservation method is required for total metals in sediment per EPA guidance?
- Cool to 4°C, acidify to pH < 2 with HNO3
- Cool to 4°C with no chemical preservative (Correct answer)
- Freeze at -20°C immediately in the field
- Add sodium azide as a biocide preservative
Correct answer: Cool to 4°C with no chemical preservative
Sediment samples for total metals analysis are preserved by cooling to 4°C without chemical acidification, unlike dissolved metals in water which require acidification.
Question 4: Which document formally transfers legal custody and responsibility for environmental samples from field collection through laboratory analysis?
- Sampling and Analysis Plan (SAP)
- Chain-of-Custody (COC) record (Correct answer)
- Field logbook entry
- Laboratory data package cover sheet
Correct answer: Chain-of-Custody (COC) record
The Chain-of-Custody record is a legal document that tracks sample possession, transfer, and integrity from collection through final analysis and is required for defensible data.
Question 5: Under EPA's TSCA regulations, what action is required if asbestos-containing materials (ACM) containing greater than 1% asbestos are identified during a facility audit?
- Immediate removal of all ACM within 30 days
- Implement an Operations & Maintenance (O&M) program if ACM is in good condition (Correct answer)
- Notification to EPA within 24 hours of identification
- Encapsulation of all ACM regardless of condition
Correct answer: Implement an Operations & Maintenance (O&M) program if ACM is in good condition
TSCA and AHERA regulations allow ACM in good condition to remain in place under a written Operations & Maintenance program rather than requiring immediate removal.
Question 6: What is the primary purpose of well development after installing a new groundwater monitoring well?
- To determine the seasonal high water table elevation
- To remove drilling fluids and fine particles to restore natural aquifer conditions (Correct answer)
- To collect the initial baseline groundwater sample
- To test the hydraulic conductivity using a slug test
Correct answer: To remove drilling fluids and fine particles to restore natural aquifer conditions
Well development removes drilling-induced sediment, fine particles, and drilling fluids from the well and surrounding formation to restore natural aquifer permeability and ensure representative samples.
Question 7: A regulatory agency requires TCLP (Toxicity Characteristic Leaching Procedure) testing of a waste material. What is the TCLP designed to evaluate?
- Total concentration of contaminants in the waste matrix
- Potential for contaminants to leach under simulated landfill conditions (Correct answer)
- Bioaccumulation potential in aquatic organisms
- Mobility of contaminants in the vadose zone under rainfall
Correct answer: Potential for contaminants to leach under simulated landfill conditions
TCLP (EPA Method 1311) simulates the leaching that would occur in a co-disposal municipal landfill to determine if a waste exhibits the toxicity characteristic under RCRA.
CEA Environmental Assessment & Sampling Techniques 3
During a wetland delineation, which three-parameter approach is used under the 1987 Corps of Engineers Wetland Delineation Manual?