PE Civil WRE design standards: what changes in April 2027, and which list applies to you

The PE Civil: Water Resources and Environmental exam is closed book, but it isn't reference-free. On screen you get the NCEES PE Civil Reference Handbook plus a short list of design standards, and that list changes with the April 2027 exam — from two documents to seven. The syllabus doesn't move. The shelf you're allowed to reach for does, and NCEES scores standards questions against the exact editions it lists: "Solutions based on other standards will not receive credit."

So the first thing to settle is which list is yours.

Which list applies to you

It's decided by your appointment date, not by when you started studying.

Your exam appointment	Standards supplied
Before April 2027	The current list — two documents
April 2027 or later	The April 2027 list — seven documents

If you're scheduling close to the boundary, confirm against the specification NCEES links for your date. It publishes both on its PE Civil page.

The two lists, side by side

Standard	Before April 2027	From April 2027
Recommended Standards for Wastewater Facilities (Ten States Standards)	2014	2014
Recommended Standards for Water Works (Ten States Standards)	2018	2022
OSHA 29 CFR Part 1926, Safety and Health Regulations for Construction (2024; selected subparts)	—	✓
USACE EM 1110-2-1902, Slope Stability (2003)	—	✓
FHWA HDS-5, Hydraulic Design of Highway Culverts, 3rd ed. (2012)	—	✓
FHWA HEC-14, Hydraulic Design of Energy Dissipators for Culverts and Channels, 3rd ed. (2006)	—	✓
UFC 3-220-05, Dewatering and Groundwater Control (2004)	—	✓

Two things in that table are easy to miss:

• The water works standard changes edition. It isn't just added documents. If you sit before April 2027, the 2018 edition is the one that's scored. If you sit after, it's 2022. A course binder or solution set updated "for 2027" is citing the edition you won't have if you test in the winter.
• OSHA 1926 comes in selected subparts, not whole. For WRE the useful ones are Subpart P (Excavations, 1926.650–652 with Appendices A–F) and Subpart M (Fall Protection), plus several general subparts.

What does not change

We compared the current specification with the April 2027 one line by line. The 12 knowledge areas and their question ranges are identical: the same 80 questions, the same 9-hour appointment, SI and USCS both. There's no new topic to learn. The change is in what you can look up while you answer.

That matters for how you read the news. "New specifications" sounds like a new syllabus. For WRE, what's new is the evidence you're allowed to cite.

Where the new documents land on the exam

Each federal document lines up with a specific part of the blueprint. This mapping is ours, read from the NCEES subtopic list. NCEES doesn't publish one.

Document	Where it's relevant	That area's share of the 80
OSHA 1926 (Subparts P, M…)	Project Sitework: excavation, safety	Sitework: 9–14
UFC 3-220-05 (dewatering)	Groundwater & Wells; Sitework (excavation, adjacent facilities)	Groundwater: 4–6
USACE EM 1110-2-1902 (slope stability)	Soil Mechanics: slope stability; Sitework: excavation and embankment	Soil Mechanics: 3–5
FHWA HDS-5 (culverts)	Open Channel: stormwater collection and culverts	Open Channel: 7–11
FHWA HEC-14 (energy dissipators)	Open Channel: energy dissipation (plunge pools, drop structures, culvert outlets)	(same area)
TSS Water Works	Drinking Water Distribution and Treatment	6–9
TSS Wastewater Facilities	Wastewater Collection and Treatment	7–11

Don't read the right-hand column as "questions that need a standard." Most questions in those areas are still worked from the Handbook and first principles. The column tells you where a standards question can appear.

Notice where most of the new material points: Sitework, soils and dewatering. Those are the parts of the WRE exam candidates describe as "not really water." Sitework is the largest single area on the blueprint. From April 2027 it also gets its own reference documents.

If you sit before April 2027

• Work from the 2018 water works edition for anything you'd cite. Solutions updated for 2027 are still good problem-solving practice. Just don't absorb a 2022 value as the one you'll be scored on.
• Culverts, energy dissipation, slope stability and excavation safety are still on your exam. They're in the blueprint now. You answer them from the Reference Handbook, which already has slope-stability charts, OSHA soil types for excavations and the culvert inlet- and outlet-control equations. What you don't get is the full source document behind each one. Expect calculations as well as concepts, and learn where each of those Handbook sections is.
• Don't spend prep time learning to navigate documents you won't be given.

If you sit in April 2027 or later

Seven documents is a real navigation load, and the delivery rule makes it heavier. NCEES supplies standards as individual chapters, and only one chapter can be open and searched at a time. Search works inside the chapter you've already chosen. It won't tell you which chapter to choose.

• Build a one-page map before you build speed. For each document, note which chapters answer which kinds of question. OSHA Subpart P and its appendices (soil classification, sloping and benching, shoring) is the obvious first entry. HDS-5 and HEC-14 are long, so know which chapter holds the charts you'd actually use.
• Practice lookups under the constraint. Open one chapter, find the value, close it, then open the next. If you practice with every document open in tabs, you're rehearsing a different exam.
• Get the right editions. HDS-5 (2012), HEC-14 (2006), EM 1110-2-1902 (2003) and UFC 3-220-05 (2004) are older documents. Whatever copy you find online, check the year on the cover: the exam scores the listed edition.

Common mistakes

• Mixing editions across your materials. One source on 2018, another on 2022, and a cheat-sheet copied from a third. Pick your window and make every cited value match it.
• Treating the change as a syllabus change. It isn't. Candidates who sit in April 2027 need the same hydraulics, hydrology and treatment fundamentals as everyone before them.
• Assuming "supplied" means "fast." A document you've never opened is a slow document, however searchable the PDF.

Where CastorPrep fits

We build exam-real practice and a grounded AI tutor for NCEES PE exams. PE Civil: Water Resources & Environmental is live. Problems that rely on a document supplied only from the April 2027 exam are labeled as such, so you can practice against the list your appointment date gets you. Practice is free with an account.

The standards list is short, specific and dated. Find out which one your appointment gets you, study against that edition, and spend the saved hours on the fundamentals, where most of the points are.