Below are the NCEES category specifications for exam coverage.

Effective UNTIL July 1st, 2020, these are the categories and subcategories specified by the NCEES that this discipline will cover. It includes an estimate of the number of questions you will see on the official exam for each category. PrepFE provides hundreds of questions in proportional amounts to the official exam.

For the upcoming categories that are effective as of July 1st, 2020, please see the categories here.

Environmental FE exam categories

110 Total Questions

Analytic geometry

Numerical methods

Roots of equations


Differential equations

Measures of central tendencies and dispersions (e.g., mean, mode, standard deviation)

Probability distributions (e.g., discrete, continuous, normal, binomial)

Estimation (point, confidence intervals) for a single mean

Regression and curve fitting

Expected value (weighted average) in decision making

Hypothesis testing

Codes of ethics (professional and technical societies)

Agreements and contracts

Ethical and legal considerations

Professional liability

Public protection issues (e.g., licensing boards)

Regulations (e.g., water, wastewater, air, solid/hazardous waste, groundwater/soils)

Discounted cash flow (e.g., life cycle, equivalence, PW, equivalent annual worth, FW, rate of return)

Cost (e.g., incremental, average, sunk, estimating)

Analyses (e.g., breakeven, benefit-cost)

Uncertainty (expected value and risk)

Properties (e.g., chemical, electrical, mechanical, physical)

Corrosion mechanisms and controls

Material selection and compatibility

Reactions (e.g., equilibrium, acid base, oxidation-reduction, precipitation)


Kinetics (chemical, microbiological)

Organic chemistry (e.g., nomenclature, functional group reactions)

Ecology (e.g., Streeter-Phelps, fluviology, limnology, eutrophication)

Multimedia equilibrium partitioning (e.g., Henry’s law, octonal partitioning coefficient)

Dose-response toxicity (carcinogen, noncarcinogen)

Exposure routes

Fluid statics

Closed conduits (e.g., Darcy-Weisbach, Hazen-Williams, Moody)

Open channel (Manning)

Pumps (e.g., power, operating point, parallel and series)

Flow measurement (e.g., weirs, orifices, flowmeters)

Blowers (e.g., power, operating point, parallel, and series)

Thermodynamic laws (e.g., 1st law, 2nd law)

Energy, heat, and work

Ideal gases

Mixture of nonreacting gases

Heat transfer

Demand calculations

Population estimations

Runoff calculations (e.g., land use, land cover, time of concentration, duration, intensity, frequency)

Reservoir sizing

Routing (e.g., channel, reservoir)

Water quality and modeling (e.g., erosion, channel stability, stormwater quality management)

Water and wastewater characteristics

Mass and energy balances

Conventional water treatment processes (e.g., clarification, disinfection, filtration, flocculation, softening, rapid mix)

Conventional wastewater treatment processes (e.g., activated sludge, decentralized wastewater systems, fixed-film system, disinfection, flow equalization, headworks, lagoons)

Alternative treatment process (e.g., conservation and reuse, membranes, nutrient removal, ion exchange, activated carbon, air stripping)

Sludge treatment and handling (e.g., land application, sludge digestion, sludge dewatering)

Chemical principles (e.g., ideal gas, mole fractions, stoichiometry, Henry’s law)

Mass balances

Emissions (factors, rates)

Atmospheric sciences (e.g., stability classes, dispersion modeling, lapse rates)

Gas handling and treatment technologies (e.g., hoods, ducts, coolers, biofiltration, scrubbers, adsorbers, incineration)

Particle handling and treatment technologies (e.g., baghouses, cyclones, electrostatic precipitators, settling velocity)


Mass balances


Landfilling (e.g., siting, design, leachate, material and energy recovery)

Site characterization and remediation

Hazardous waste treatment (e.g., physical, chemical, thermal)

Radioactive waste treatment and disposal

Basic hydrogeology (e.g., aquifers, permeability, water table, hydraulicconductivity, saturation, soil characteristics)

Drawdown (e.g., Jacob, Theis, Thiem)

Groundwater flow (e.g., Darcy’s law, specific capacity, velocity, gradient)

Soil and groundwater remediation