NREP CES Certified Environmental Scientist

Which of the six NAAQS criteria pollutants is measured at both a 24-hour and an annual average standard by the EPA?

• ACarbon monoxide (CO)
• BOzone (O3)
• CFine particulate matter (PM2.5)
• DLead (Pb)

The six NAAQS criteria pollutants regulated under the Clean Air Act include all of the following EXCEPT:

• ASulfur dioxide (SO2)
• BNitrogen dioxide (NO2)
• CBenzene
• DLead (Pb)

A stable atmospheric condition in which a warm air layer overlies cooler air near the surface is called a:

• AAdiabatic lapse
• BTemperature inversion
• CAtmospheric mixing
• DConvective overturning

Ground-level ozone is primarily formed by the reaction of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the presence of:

• AUltraviolet sunlight
• BHigh relative humidity
• CParticulate matter
• DCarbon monoxide

The Gaussian dispersion model for stack emissions assumes that pollutant concentrations downwind follow which distribution in both the horizontal and vertical directions?

• AUniform distribution
• BLog-normal distribution
• CNormal (Gaussian) distribution
• DExponential decay distribution

Stratospheric ozone depletion is primarily caused by the catalytic destruction of ozone by which compound?

• ACarbon dioxide (CO2)
• BChlorofluorocarbons (CFCs)
• CSulfur hexafluoride (SF6)
• DMethane (CH4)

Acid rain is formed primarily when sulfur dioxide (SO2) and nitrogen oxides (NOx) react with water in the atmosphere to produce:

• ACarbonic acid and nitrous acid
• BSulfuric acid and nitric acid
• CHydrochloric acid and sulfurous acid
• DPhosphoric acid and nitric acid

Pasquill-Gifford stability classes range from A through F (or G). Class A represents which atmospheric condition?

• AExtremely stable conditions (nighttime, low wind)
• BExtremely unstable conditions (strong insolation, low wind)
• CNeutral atmospheric stability
• DModerately stable conditions (light winds at night)

Which greenhouse gas has the highest global warming potential (GWP) over a 100-year time horizon among those listed?

• ACarbon dioxide (CO2)
• BMethane (CH4)
• CNitrous oxide (N2O)
• DSulfur hexafluoride (SF6)

The Clean Air Act New Source Review (NSR) program requires major new or modified stationary sources in nonattainment areas to obtain which type of permit?

• ATitle V Operating Permit
• BPrevention of Significant Deterioration (PSD) Permit
• CNonattainment New Source Review (NNSR) Permit
• DGeneral Permit

In the hydrologic cycle, the process by which water vapor is released from plant leaves into the atmosphere is called:

• AEvaporation
• BCondensation
• CTranspiration
• DInfiltration

The boundary between the saturated and unsaturated zones in an unconfined aquifer is called the:

• AAquitard
• BCapillary fringe
• CWater table
• DPotentiometric surface

Biochemical Oxygen Demand (BOD) is used as a water quality parameter to measure:

• AThe total dissolved solids concentration in surface water
• BThe amount of oxygen consumed by microorganisms decomposing organic matter
• CThe concentration of fecal coliform bacteria in a water sample
• DThe rate of photosynthesis in aquatic ecosystems

Which wastewater treatment process uses microorganisms in the presence of oxygen to break down dissolved organic matter before secondary clarification?

• APrimary sedimentation
• BActivated sludge process
• CAnaerobic digestion
• DChlorination

Under the Safe Drinking Water Act (SDWA), which standard represents the level of a contaminant in drinking water below which there is no known or expected risk to health, allowing for a margin of safety?

• AMaximum Contaminant Level (MCL)
• BMaximum Contaminant Level Goal (MCLG)
• CAction Level (AL)
• DSecondary Maximum Contaminant Level (SMCL)

Eutrophication in lakes and reservoirs is most commonly driven by excessive inputs of which two nutrients?

• AIron and manganese
• BNitrogen and phosphorus
• CCalcium and magnesium
• DSodium and potassium

Under RCRA Subtitle C, a solid waste is classified as hazardous if it is listed or exhibits one or more of the four hazardous characteristics. Which of the following is NOT one of the four RCRA characteristics?

• AIgnitability
• BCorrosivity
• CPersistence
• DToxicity

A solid waste generator produces 600 kg of hazardous waste per month. Under RCRA, what generator category does this facility fall under, and what is the maximum on-site accumulation time allowed?

• AVery Small Quantity Generator (VSQG) — 1 year
• BSmall Quantity Generator (SQG) — 270 days
• CLarge Quantity Generator (LQG) — 90 days
• DSmall Quantity Generator (SQG) — 180 days

Municipal solid waste (MSW) landfills regulated under RCRA Subtitle D must have which of the following as a base liner requirement?

• AA 2-foot compacted clay liner only
• BA composite liner consisting of a geomembrane and at least 2 feet of compacted soil with…
• CA single high-density polyethylene (HDPE) geomembrane with no soil component
• DNo liner is required for non-hazardous MSW landfills

The Toxicity Characteristic Leaching Procedure (TCLP) is used to:

• AMeasure the flash point of a liquid waste to determine ignitability
• BSimulate the leaching of contaminants from waste into groundwater under landfill conditio…
• CDetermine the biological oxygen demand of organic wastes
• DClassify wastes as either listed or characteristic under RCRA

In a waste management hierarchy, which approach to managing solid waste is ranked highest (most preferred)?

• ARecycling
• BLandfilling
• CSource reduction (waste prevention)
• DEnergy recovery (incineration)

Which federal law established a national policy requiring federal agencies to assess the environmental impacts of major federal actions significantly affecting the quality of the human environment?

• AClean Air Act (CAA)
• BNational Environmental Policy Act (NEPA)
• CComprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
• DResource Conservation and Recovery Act (RCRA)

Under NEPA, when is a full Environmental Impact Statement (EIS) required rather than an Environmental Assessment (EA)?

• AWhenever a federal agency proposes any action affecting land
• BWhen an EA concludes that the proposed action will result in significant environmental im…
• COnly for actions on federal land exceeding 1,000 acres
• DWhen a project costs more than $10 million in federal funds

The Clean Water Act (CWA) Section 404 permit program regulates:

• ADischarge of pollutants from point sources into navigable waters
• BDredge and fill activities in waters of the United States, including wetlands
• CStormwater discharges from municipal separate storm sewer systems
• DUnderground injection of hazardous wastes

CERCLA (Superfund) liability is characterized as joint and several, strict, and retroactive. What does 'strict' liability mean in the CERCLA context?

• ALiable parties must have intentionally disposed of hazardous substances
• BLiability applies regardless of fault or negligence — simply being a PRP is sufficient
• CAll PRPs must pay equal shares of cleanup costs
• DLiability is limited to the amount of hazardous substance each party contributed

Which of the following best describes the concept of bioaccumulation in an aquatic ecosystem?

• AThe increase in a chemical's concentration at each successive trophic level in a food web
• BThe uptake and retention of a chemical within the tissues of a single organism over time
• CThe breakdown of a chemical by microorganisms in sediments
• DThe volatilization of a chemical from water to the atmosphere

In toxicology, the dose-response relationship is used to establish which of the following for non-carcinogenic chemicals?

• AThe maximum contaminant level in drinking water
• BThe Reference Dose (RfD) below which adverse health effects are not expected
• CThe LD50 used to set occupational exposure limits
• DThe cancer slope factor for lifetime risk estimates

The octanol-water partition coefficient (Kow) is used to predict a chemical's:

• AVolatility from aqueous solution
• BTendency to bioaccumulate in fatty tissues and bind to soil organic matter
• CRate of photodegradation in surface water
• DAcute toxicity to aquatic organisms

Which statement correctly describes the difference between acute and chronic toxicity?

• AAcute toxicity results from a single high-dose exposure causing rapid health effects; chr…
• BAcute toxicity only affects the liver; chronic toxicity only affects the lungs
• CAcute toxicity occurs from dermal exposure; chronic toxicity occurs from inhalation only
• DAcute and chronic toxicity differ only in the route of exposure, not the duration

Which type of ionizing radiation has the greatest penetrating power but the lowest ionizing ability per unit path length?

• AAlpha (α) radiation
• BBeta (β) radiation
• CGamma (γ) radiation
• DNeutron radiation

The unit 'rem' (or its SI equivalent 'sievert') is used to measure radiation dose in terms of:

• AThe activity (disintegrations per second) of a radioactive source
• BThe absorbed energy per unit mass of tissue (absorbed dose)
• CThe biological effect on human tissue, accounting for radiation type
• DThe half-life of a radioactive isotope

Non-ionizing radiation differs from ionizing radiation primarily because it:

• ATravels at the speed of light
• BDoes not have enough energy to remove electrons from atoms
• CCannot be measured with standard dosimetry equipment
• DOnly affects skin and eyes, never internal organs

Green chemistry's principle of 'atom economy' encourages chemists to design reactions that:

• AUse the least expensive starting materials
• BMaximize the incorporation of starting materials into the final product, minimizing waste
• COperate at room temperature without a catalyst
• DUse water as the only solvent

Which of the 12 Principles of Green Chemistry addresses the design of chemical products to break down into innocuous degradation products after use?

• ACatalysis
• BDesign for degradation
• CPrevent waste
• DUse renewable feedstocks

Which federal regulation primarily governs the manufacture and use of new industrial chemicals and requires manufacturers to notify EPA before producing a new chemical substance?

• ARCRA
• BCERCLA
• CToxic Substances Control Act (TSCA)
• DEmergency Planning and Community Right-to-Know Act (EPCRA)

In ecology, primary productivity refers to:

• AThe number of animal species in an ecosystem
• BThe rate at which producers (plants, algae) convert light energy into chemical energy (bi…
• CThe decomposition rate of organic matter in soil
• DThe total biomass consumed by herbivores

The nitrogen cycle includes a process by which certain bacteria convert nitrogen gas (N2) from the atmosphere into ammonia (NH3) or ammonium (NH4+), making nitrogen available to plants. This process is called:

• ADenitrification
• BNitrification
• CNitrogen fixation
• DAmmonification

In a food web, which trophic level typically contains the LEAST amount of energy available to the organisms within it?

• AProducers (plants/algae)
• BPrimary consumers (herbivores)
• CSecondary consumers (carnivores eating herbivores)
• DTertiary consumers (apex predators)

Which of the following best describes a keystone species?

• AA species that is present in the largest numbers in an ecosystem
• BA species whose impact on its ecosystem is disproportionately large relative to its abund…
• CA species that is found only in a single geographic region (endemic species)
• DA species introduced from another region that outcompetes native species

The carbon cycle process by which decomposers break down dead organic matter and release CO2 back into the atmosphere is called:

• APhotosynthesis
• BDecomposition (mineralization)
• CCarbon sequestration
• DTranspiration

Under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which document is issued at the end of the Remedial Investigation/Feasibility Study (RI/FS) to select the final cleanup remedy for a Superfund site?

• APreliminary Assessment (PA)
• BRemoval Action Memorandum
• CRecord of Decision (ROD)
• DConsent Decree

Which of the following correctly describes the Toxic Release Inventory (TRI) reporting requirement under EPCRA Section 313?

• AFacilities with any amount of listed toxic chemicals must report annually to EPA
• BFacilities in specific SIC codes that manufacture, process, or otherwise use listed chemi…
• COnly federal facilities are required to submit TRI reports to EPA
• DTRI reporting is voluntary for all industries except petroleum refineries

A facility stores 15,000 pounds of sulfuric acid on-site. Under EPCRA Section 312, this facility is required to submit which report to the State Emergency Response Commission (SERC) and local fire department?

• ATRI Form R
• BTier II Emergency and Hazardous Chemical Inventory Report
• CSPCC Plan
• DRCRA Biennial Report

The half-life of a radioactive isotope is defined as:

• AThe time required for the activity of a radioactive sample to decrease to exactly zero
• BThe time required for exactly half of the atoms in a radioactive sample to decay
• CThe time required for the dose rate 1 meter from a source to decrease by half
• DThe time required for the biological elimination of half of a radioisotope from the body

The As Low As Reasonably Achievable (ALARA) principle in radiation protection means:

• ARadiation doses must always be maintained below 1 mrem per year
• BRadiation doses should be kept below regulatory limits and reduced further when practical…
• CAll radiation workers must wear dosimetry badges and undergo annual medical exams
• DAny radiation exposure above background levels is prohibited

Which of the following pesticide classes works by inhibiting acetylcholinesterase, causing overstimulation of the nervous system in target pests?

• APyrethroids
• BOrganophosphates
• CNeonicotinoids
• DChlorinated organics (e.g., DDT)

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires that pesticides sold or distributed in the United States must be:

• AApproved by the FDA as safe for human food consumption before sale
• BRegistered with EPA, which evaluates efficacy and potential environmental and health risks
• CTested by an independent laboratory selected by the manufacturer
• DReported to OSHA under the Hazard Communication Standard before use in workplaces

In environmental sampling, a field blank is used to:

• ACalibrate laboratory instruments before analysis
• BDetect contamination introduced by sampling equipment, containers, or field procedures
• CMeasure the background concentration of a chemical in uncontaminated reference soil
• DVerify the accuracy of the analytical method by spiking a known amount of analyte