10 exam-style questions with answers and explanations, straight from our 1,050-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
The EPI exam has 125 questions and runs 3 hours.
These 10 free EPI questions are organized by exam domain, so you can see how each part of the Environmental Professional In-Training (EPI) blueprint is tested. Reveal the answer and explanation under each question.
A newly characterized organic compound has a high octanol-water partition coefficient (Kow) and a low water solubility. Compared with a compound having the opposite properties, this compound is MOST likely to:
Correct answer: C - Accumulate in sediment organic matter and biomagnify in the food web
During a summer afternoon, ozone concentrations at a monitoring station peak several kilometers DOWNWIND of an urban core rather than within it. This pattern is BEST explained by the fact that ground-level ozone is:
Correct answer: B - A secondary pollutant formed by photochemical reactions requiring transport time
A release of tetrachloroethylene (PCE), a chlorinated solvent with a specific gravity of approximately 1.62, occurs at a site with an unconfined aquifer. In characterizing the extent of contamination, the investigator should anticipate that the free-phase product will:
Correct answer: C - Sink through the saturated zone and pool on lower-permeability units
A wastewater sample is analyzed and reported as BOD = 180 mg/L and COD = 450 mg/L. The MOST accurate interpretation of this relationship is that:
Correct answer: D - COD oxidizes non-biodegradable organics as well, so it is normally higher
An aquifer has a hydraulic conductivity of 15 m/day, a hydraulic gradient of 0.01, and an effective porosity of 0.25. A conservative tracer is introduced. At what velocity will the tracer actually travel through the aquifer?
Correct answer: C - 0.6 m/day
A landfill gas collection system at a well-established municipal solid waste landfill in stable anaerobic decomposition is being designed. The design team should expect the collected gas to consist primarily of:
Correct answer: A - Roughly equal proportions of methane and carbon dioxide
Two adjacent soils have identical texture and pH. Soil A has 6% organic matter; Soil B has 0.5%. A hydrophobic organic contaminant is spilled equally on both. Relative to Soil B, transport of the contaminant through Soil A will be:
Correct answer: B - Slower, because sorption to organic carbon retards contaminant movement
In a deep, temperate lake during late summer, dissolved oxygen in the hypolimnion is measured at 0.4 mg/L while the epilimnion remains near saturation. The PRIMARY reason for the depleted hypolimnetic oxygen is that:
Correct answer: A - Thermal stratification blocks mixing while decomposition consumes oxygen at depth
A facility implementing an environmental management system documents the following: 'Discharge of non-contact cooling water to the adjacent river.' Within the framework of ISO 14001, this entry is BEST classified as:
Correct answer: D - An environmental aspect, because it can interact with the environment
An EPI is completing a site investigation report when the client's project manager asks that a section describing elevated soil concentrations be removed, arguing it is 'preliminary and will only alarm the buyer.' Under the BGC Code of Ethics, the EPI's MOST appropriate action is to:
Correct answer: D - Retain the section, because honest reporting protects public health
The EPI exam also covers these domains. Drill them in the full free practice test:
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