CEA Environmental Assessment & Sampling Techniques 4

Question 1

During low-flow groundwater sampling, which stabilization criteria must be met before collecting a sample?

Accepted Answer

pH ±0.5, specific conductance ±5%, DO ±10%, ORP ±10 mV across three readings

Answer

Low-flow sampling requires stabilization of field parameters (pH ±0.5 units, SC ±5%, DO ±10%, ORP ±10 mV) across three consecutive readings before sample collection.

Question 2

Which type of environmental sampling error occurs when the sample collected does not represent the true population due to a flaw in sampling design?

Accepted Answer

Sampling bias from non-representative location selection

Answer

Sampling bias occurs when the sampling design systematically favors certain portions of the population, resulting in samples that do not accurately represent site conditions.

Question 3

A site investigation requires characterizing contamination at depths ranging from 15 to 60 feet below ground surface in unconsolidated sediments. Which direct push technology is most commonly used?

Accepted Answer

Cone Penetrometer Testing (CPT) with chemical sensors

Answer

Cone Penetrometer Testing (CPT) with chemical sensors provides continuous subsurface profiling for contaminant characterization at depth in unconsolidated sediments without generating significant cuttings waste.

Question 4

When assessing indoor air quality for vapor intrusion from groundwater contamination, which approach provides the most site-specific exposure assessment?

Accepted Answer

Collecting simultaneous sub-slab soil gas and indoor air samples

Answer

Simultaneous sub-slab soil gas and indoor air sampling provides the most defensible site-specific vapor intrusion assessment by measuring actual conditions rather than relying on default model assumptions.

Question 5

A Phase I ESA report identifies a prior underground storage tank (UST) that was removed in 1989 with no closure documentation. How should this be classified?

Accepted Answer

Recognized Environmental Condition (REC) warranting Phase II investigation

Answer

A UST removal without documented closure confirmation or soil/groundwater sampling represents a REC because there is no evidence the removal was completed without a release.

(CEA) Certified Environmental Auditor Practice Test

(CEA) Certified Environmental Auditor Practice Test

CEA Environmental Assessment & Sampling Techniques 4