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Wastewater treatment and collection, the way the exam asks it.
Focused review of the wastewater half of Section 1, Water. Section 1C plus the wastewater fundamentals in 1A typically account for 9 to 14 of the 80 questions. Written for the Principles and Practice of Engineering (PE) Environmental exam from the National Council of Examiners for Engineering and Surveying (NCEES), to the April 2026 specification.
A comprehensive prep course runs $1,600 to $2,800. All six guides are $129 as a set.
52 pages · 14 worked examples · 8 Field Notes · prints cleanly
What the guide covers.
Only the most-tested material makes the cut. Derivations, untested background theory, and very low-frequency topics are omitted to keep your study time focused on what matters the most.
- Oxygen demand. first-order biochemical oxygen demand (BOD) kinetics and the dilution test, with removal calculations
- Activated sludge design. solids retention time, the food-to-microorganism (F:M) ratio, hydraulic retention time, aeration basin sizing, sludge volume index, recycle ratio, and secondary clarifiers
- Attached growth and lagoons. trickling filters and mixed lagoons in series
- Nutrient removal. nitrification, denitrification, chemical phosphorus removal, and process configurations
- Sludge handling and biosolids. mass-volume relationships, volatile solids reduction, anaerobic digestion, and solids loading
- Collection system hydraulics. Manning's equation, the Harmon peaking factor, partial flow from the handbook's hydraulic-elements graph, infiltration and inflow (I&I), and pump stations
- Primary treatment and disinfection. primary clarifier design, screening and grit, chlorination and dechlorination, and ultraviolet (UV) disinfection
- Regulatory quick reference. Clean Water Act fundamentals, National Pollutant Discharge Elimination System permits, biosolids (40 CFR 503), overflow policy, industrial pretreatment (40 CFR 403), reuse, and septic systems
Every topic, built the same way.
A consistent layout means you always know where to look, the same way you will move through the handbook on exam day.
01 · Concept
The key idea
What the exam is testing on the topic, stated plainly.
02 · Formula
Equations with units
Every variable defined, with the handbook page where the formula appears, or a note that you have to memorize it.
03 · Example
Worked in exam style
A full worked example in the multiple-choice format the exam uses, with the arithmetic shown.
04 · Mistakes
Where points are lost
The errors that cost candidates points on that topic, named so you can catch them.
Summary sections you will want to use
- Exam strategy for the section. Question count and weight, the calculation-versus-conceptual split, common traps, and what the handbook gives you.
- Regulatory and qualitative quick reference. The rules, limits, and distinctions the section tests, in tables, to support success on the qualitative questions.
- Key formulas summary. Every equation in the guide, grouped by topic, with unit conversions.
- Self-assessment checklist. Check off each subtopic as you master it.
Eight Field Notes from practice.
Short sidebars with the operating context textbooks leave out. They are what make the processes and the regulations stick.
Cover more of the exam for less.
Finish Section 1 · Water and Wastewater Bundle
Add the Drinking Water guide and save $19
Water is 19 to 29 of the 80 questions. Both Water guides together are $39 instead of $58.
The whole exam · Complete Guide Set
All six guides for $129
One guide for every section of the specification. 348 pages and 118 worked examples, $174 if bought separately.
Not sure this is your weak area? · Practice Exam
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80 questions built to the 2026 specification, a separate solutions manual, and a score sheet that points each weak area at the guide that closes it.
Matt Bentley, PhD, PE
Environmental engineer, university instructor, and Technical Director at a water treatment chemical company in Colorado. Passed the Environmental PE in February 2026, on the first try, in under 80 hours. He wrote this guide from the materials he wished had existed when he was preparing.
Section 1 is 19 to 29 of the 80 questions. Walk in ready for it.
52 pages · 14 worked examples · or get all six guides for $129
Common questions
What does this guide cover?
This guide covers Section 1C (wastewater) and the wastewater fundamentals of Section 1A in the April 2026 NCEES specification: biochemical and chemical oxygen demand, activated sludge design, trickling filters and lagoons, nitrogen and phosphorus removal, sludge handling and digestion, collection system hydraulics, effluent disinfection, water reuse, and industrial pretreatment, with a quick reference to the Clean Water Act permit programs.
How many Environmental PE exam questions does this guide cover?
Section 1, Water, carries 19 to 29 of the 80 questions. Wastewater content (Section 1C) plus the wastewater fundamentals in Section 1A typically accounts for 9 to 14 of them. The Drinking Water guide covers the rest of Section 1.
Is it written to the April 2026 NCEES specification?
Yes. It was written to the April 2026 computer-based testing (CBT) specification from the first draft and covers Sections 1A and 1C. See what changed in 2026.
Does it reference the NCEES PE Environmental Reference Handbook?
Yes. Each formula cites the handbook page where it appears, and formulas the handbook does not print are marked as ones to memorize. The guide opens with a section on what the handbook gives you for this part of the exam.
What do I get, and how fast?
A 52-page PDF, downloaded immediately after checkout through Gumroad. It has 14 worked examples, 8 Field Notes, and 3 technical figures, and it prints cleanly.
Can I buy it with the other guides?
Yes. The Water and Wastewater Bundle includes both Section 1 guides for $39 instead of $58. The Complete Guide Set includes all six guides, one for every exam section, for $129 instead of $174.
Can I get a refund?
Because the products are digital downloads delivered immediately, sales are generally final. If something is wrong with a purchase, email matt@confluencepeprep.com and we will work with you to resolve it.