FE Environmental

Water and wastewater, hydraulics, hydrology, groundwater, air quality, and waste management.

Practice questions: 2,300+
Study topics: 15
Study topics: …
Study concepts: 61
Difficulty levels: 3
Mock exams: Unlimited

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What's inside

15 study topics, weighted to the NCEES blueprint — tap any topic to drill it.

Mathematics

Analytic geometry and trigonometry, algebraic equations and roots, differential and integral calculus, differential equations, and numerical methods including error propagation.Probability and Statistics

Measures of central tendency and dispersion, probability distributions, confidence intervals for a single mean, regression and curve fitting, and hypothesis testing.Ethics and Professional Practice

Codes of ethics, public health, safety, and welfare, professional liability and licensure, compliance with environmental statutes (CWA, CAA, RCRA, CERCLA, SDWA, NEPA, OSHA), and the engineer's role in sustainability.Engineering Economics

Time value of money and equivalence, cost types and breakdowns, benefit-cost, break-even, and life-cycle analyses, and project selection with depreciation and unequal lives.Fundamental Principles

Population projections and water, wastewater, and solid-waste demand calculations, ideal reactor models (CSTR, batch, plug flow), and materials science including properties and corrosion.Environmental Chemistry

Stoichiometry and chemical equilibrium, acid-base and oxidation-reduction reactions, pC-pH diagrams, reaction kinetics, organic chemistry, and multimedia partitioning by Henry's law and the octanol-water coefficient.Health Hazards and Risk Assessment

Dose-response toxicity for carcinogens and noncarcinogens, exposure routes and pathways and chronic daily intake, and occupational health including PPE and noise exposure.Fluid Mechanics and Hydraulics

12%

Fluid statics, closed-conduit flow (Darcy-Weisbach, Hazen-Williams, Moody), open-channel flow (Manning), pumps and blowers, flow measurement with weirs and orifices, and the Bernoulli and continuity equations.Thermodynamics

First and second laws, energy, heat, and work, efficiencies and coefficient of performance, conduction, convection, and radiation heat transfer, and the behavior of ideal gases.Surface Water Resources and Hydrology

Runoff and the rational method, time of concentration and IDF curves, detention and retention storage sizing, channel and reservoir routing, water-quality modeling (Streeter-Phelps, eutrophication), and the water budget.Groundwater, Soils, and Sediments

Aquifer properties and hydrogeology, Darcy's law and seepage velocity, well drawdown (Theis, Jacob, Thiem, Dupuit), and soil, sediment, and groundwater remediation.Water and Wastewater

12%

Water and wastewater characteristics, mass balance and removal-efficiency loading rates, physical, chemical, and biological treatment processes, sludge treatment and handling, and water conservation and reuse.Air Quality and Control

Ambient and indoor air quality, mass and energy balances, emission factors and rates, atmospheric dispersion and stability classes, and gas and particulate control technologies.Solid and Hazardous Waste

Solid waste management, collection, and disposal, landfill leachate and gas, mass and energy balances, hazardous waste compatibility, site characterization, and waste treatment and disposal.Energy and Environment

Conventional and alternative energy source concepts and the environmental impacts of energy production, including greenhouse gas emissions, carbon footprint, and thermal and water demands.

See a real question

Straight from the FE Environmental bank — 2,300+ questions, every one with a full worked solution.

medium

A. Time value of money & equivalence

An engineer borrows $200,000 to be repaid in 15 equal end-of-year payments at 6% per year. The annual payment is most nearly:

$8,593
$13,333
$20,593 (correct answer)
$25,333

Worked solution

The capital recovery factor (FE Reference Handbook 10.6 p. 235) converts a present amount into equal end-of-year payments:

(A/P,\ 6\%,\ 15)=\dfrac{i(1+i)^n}{(1+i)^n-1}=\dfrac{0.06\,(1.06)^{15}}{(1.06)^{15}-1}=0.10296

, printed as 0.1030 in the handbook's 6% factor table. The annual payment is $200,000 × 0.10296 = $20,593. Distractors:

P/n

, spreading the principal evenly and ignoring interest ($13,333); the sinking-fund factor

(A/F)

read in place of

(A/P)

($8,593), which treats the loan as a future sum; and simple interest on the full principal for all 15 years, spread evenly,

P(1+in)/n

($25,333), which charges interest on money already repaid.

Difficulty mix

How this bank splits by our own difficulty rating, from quick wins to multi-step problems.

Easy26%
Medium50%
Hard24%

Study handbook

61 concepts — worked theory, key equations, and common pitfalls for every topic.

Sample concept

Calculus and Differential Equations

Derivatives as rates and integrals as accumulated mass, maxima and minima, the fundamental theorem, and first- and second-order linear ODEs for decay, reactor, and mixing models.

Calculus is the language environmental engineering uses to describe change: a derivative is a rate (a mass flux, a slope, a velocity), and an integral is an accumulation (the total mass that passed an outfall, the volume under a hydrograph). Every reactor model, every decay curve, and every mixing-t…

\dfrac{dy}{dx} = \lim_{\Delta x \to 0}\dfrac{f(x + \Delta x) - f(x)}{\Delta x}

Open the study handbook

The FE Environmental exam at a glance

Sourced from NCEES — the numbers, not the folklore.

Questions: 110; scored and pretest, one sitting
Exam time: 5h 20m; in a 6h appointment · about 2.9 min per question
First-time pass rate: 67%; 37% for repeat takers · NCEES Squared 2025 (FY2024-25)
NCEES fee: $225; per attempt, paid to NCEES; your state board's fees are separate
Retakes: 3 per 12 months; at most one attempt per testing window
Reference on screen: FE Reference Handbook 10.6; closed book: no notes or references of your own

What NCEES says is on it

Every knowledge area in the official FE Environmental specification, with the number of questions NCEES says each one gets. The three heaviest are about 33% of the exam. Share is our arithmetic, not an NCEES figure: each range's midpoint as a percentage of all the midpoints.

Knowledge area	Questions	Share
Fluid Mechanics and Hydraulics	12–18	12%
Water and Wastewater	12–18	12%
Surface Water Resources and Hydrology	9–14	9%
Air Quality and Control	8–12	8%
Groundwater, Soils, and Sediments	8–12	8%
Environmental Chemistry	7–11	7%
Fundamental Principles	7–11	7%
Solid and Hazardous Waste	7–11	7%
Engineering Economics	5–8	5%
Ethics and Professional Practice	5–8	5%
Mathematics	5–8	5%
Energy and Environment	4–6	4%
Health Hazards and Risk Assessment	4–6	4%
Probability and Statistics	4–6	4%
Thermodynamics	3–5	3%

Sources: NCEES FE Environmental exam specification (July 2020) · pass rate: NCEES Squared 2025 (FY2024-25) · fee and retake policy: ncees.org, read 2026-09-15. Your state board sets its own fees and deadlines.

How to prepare for FE Environmental

Four steps, in the order that pays off — each one built from this exam's own blueprint.

1
Study to the blueprint, not the textbook
Fluid Mechanics and Hydraulics, Water and Wastewater, and Surface Water Resources and Hydrology are about 33% of the exam. Give them that share of your hours — Thermodynamics is only 3–5 questions.
See every area's question range
2
Practice one area at a time, then mix
Work a knowledge area until its worked solutions stop surprising you, then switch to mixed sets so recognizing the problem type becomes the skill.
Practice FE Environmental questions
3
Sit timed mock exams at the real pace
The real exam gives you about 2.9 minutes per question. Full-length timed mocks are the only way to find out whether you can hold that pace for 5h 20m.
Take a mock exam (with a pass)
4
Read what the exam actually asks
67% of first-time takers pass, third-highest of the seven FE disciplines. Why that number is more encouraging than it should be, and what the exam actually asks of you.
How hard is the FE Environmental exam?

Questions, answered

How hard is the FE Environmental exam?

NCEES reports a 67% pass rate for first-time takers of FE Environmental and 37% for repeat takers in NCEES Squared 2025 (FY2024-25). It is 110 questions in 5h 20m, about 2.9 minutes per question, so pacing matters as much as knowledge. The heaviest areas are Fluid Mechanics and Hydraulics, Water and Wastewater, and Surface Water Resources and Hydrology.

What topics are on the FE Environmental exam?

NCEES's FE Environmental specification lists 15 knowledge areas with a question range for each. The heaviest are Fluid Mechanics and Hydraulics (12–18 questions), Water and Wastewater (12–18 questions), and Surface Water Resources and Hydrology (9–14 questions) — together about 33% of the exam. The full list is in the exam-at-a-glance table on this page.

How long is the FE Environmental exam?

The FE Environmental exam is 110 questions in 5h 20m of exam time, inside a 6h appointment that also covers the nondisclosure agreement, the tutorial and a scheduled break. It is a closed-book, computer-based test offered year-round at Pearson VUE test centers.

What reference material do you get on FE Environmental exam day?

The FE Environmental exam is closed book. NCEES provides an electronic reference on screen (FE Reference Handbook 10.6). No notes, books or references of your own come into the room; you may bring one NCEES-approved calculator, and an on-screen TI-30XS calculator is also available during the exam. Practicing with that same reference in front of you, so you already know where each method lives, is half the preparation.

How much does the FE Environmental exam cost, and can you retake it?

The NCEES fee for the FE Environmental exam is $225, paid per attempt when you register through your MyNCEES account; some state licensing boards also charge their own application fee. NCEES allows one attempt per testing window and no more than three attempts in a 12-month period.

What do I get with FE Environmental on FE → PE Prep?

2,300+ FE Environmental practice questions, every one with a step-by-step worked solution; unlimited full-length timed mock exams weighted to the NCEES blueprint; a 61-concept study handbook, 550+ flashcards, and an AI tutor. Access is a one-time pass for 1, 3, 6 or 12 months — no subscription, no auto-renew — and the free sample questions need no account. Within 7 days, with little or no paid content used, you can ask for a refund, which we consider under the Refund Policy.

Free reading for FE Environmental

No account needed — pass rates, worked problems, and what the exam actually asks.

Free FE Environmental practice problemsReal questions from the bank, with the figures and full worked solutions.Free FE Environmental formula sheet136 key equations by exam topic, each with what it is for and its handbook reference.Which FE exam should you take? Other Disciplines vs your majorFE Other Disciplines ties for the lowest first-time pass rate of the seven FE exams, not the highest, and half of it is mechanics. All seven compared on the published specifications.How hard is the FE Environmental exam?67% of first-time takers pass, third-highest of the seven FE disciplines. Why that number is more encouraging than it should be, and what the exam actually asks of you.FE Environmental practice problems: it is a water examThree FE Environmental practice problems worked in full (rational method, continuity, Darcy), and why four of the fifteen knowledge areas are water, and up to 46% of the exam.

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