Environmental Assessment & Sampling Techniques 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 Environmental Assessment & Sampling Techniques flashcards as text
When conducting a Phase II Environmental Site Assessment, which QA/QC measure ensures laboratory results are representative of field conditions?
Answer: Using field duplicates and trip blanks
Field duplicates verify sampling reproducibility while trip blanks detect cross-contamination during transport, both are essential QA/QC measures in Phase II ESAs.
Which soil sampling method is most appropriate for collecting a representative composite sample across a large, uniformly contaminated area?
Answer: Systematic grid sampling with equal-spaced intervals
Systematic grid sampling provides equal spatial coverage across a site, making it the most appropriate method for characterizing uniform contamination in large areas.
A NAPL (Non-Aqueous Phase Liquid) is identified in a monitoring well. What does the presence of LNAPL indicate?
Answer: Product is floating on the water table surface
LNAPL (Light Non-Aqueous Phase Liquid) is less dense than water and floats at or near the water table surface, indicating a surface or shallow subsurface release.
During air sampling for volatile organic compounds (VOCs) using Summa canisters, what is the critical parameter to verify before field deployment?
Answer: Pre-evacuated canister vacuum pressure
Pre-evacuated Summa canisters must have the correct vacuum pressure verified before deployment to ensure they can draw the required air sample volume.
Under ASTM E1527-21, which of the following is classified as a 'Recognized Environmental Condition' (REC)?
Answer: A historical dry cleaner operation on the subject property
A historical dry cleaner operation is a classic REC because dry cleaners commonly used chlorinated solvents (PCE/TCE) that create significant contamination risk.
What is the purpose of a 'blank' sample in groundwater sampling protocols?
Answer: To identify contamination introduced during sampling and analysis
Blank samples (equipment, field, or trip blanks) are used to detect and quantify contamination introduced by sampling equipment, field conditions, or laboratory handling.
Which parameter is most critical to measure immediately upon groundwater sample collection to assess sample integrity for dissolved metals analysis?
Answer: Field pH, specific conductance, and dissolved oxygen
Field parameters including pH, specific conductance, temperature, dissolved oxygen, and ORP must be measured immediately upon collection as they change rapidly upon exposure to atmosphere.