Design real municipal water and wastewater systems — hydrology, hydraulics, stormwater, water/wastewater treatment, groundwater, flood control, and dams. 17 core modules, 5 complete real-project case studies (municipal water treatment plant upgrade, wastewater treatment plant design, stormwater detention/flood control, water distribution network design, dam spillway/water quality study), a 12-template documentation kit, and a certificate of completion. One-time $4.99 purchase, no account required.
Explore the Full Curriculum →For much public-facing work, yes. Treatment plants, stormwater systems, and discharge permits are public infrastructure that a licensed Professional Engineer must stamp, so the PE carries real weight in environmental and water-resources engineering. You earn it by passing the FE Environmental, gaining about four years of qualifying experience, and passing the PE Environmental (or a PE in Civil with a Water Resources & Environmental focus) through your state board.
The FE Environmental is a 110-question, six-hour, computer-based exam covering mathematics and statistics, engineering economics, fluid mechanics and hydraulics, hydrology and water resources, water and wastewater treatment, water-quality chemistry (BOD, dissolved oxygen, disinfection), groundwater and soils, air quality and solid/hazardous waste, environmental regulations, and ethics. It is open-reference using only the NCEES FE Reference Handbook.
The PE Environmental is an 80-question, roughly eight-hour computer-based exam administered by NCEES. It is open-book — you bring your own references and handbooks. Topics span water resources and hydrology, hydraulics, drinking-water and wastewater treatment, water quality, groundwater and contaminant transport, air quality, solid and hazardous waste, and environmental regulations. You qualify by passing the FE, gaining about four years of experience, and applying through your state board.
The people who run drinking-water and wastewater treatment plants must be certified by their state, typically in graded levels (often I through IV) that correspond to plant size and complexity. Most state programs are harmonized through the Association of Boards of Certification (ABC), which publishes need-to-know criteria and standardized exams. It is a distinct credential from the PE — operators run the facilities; engineers design them — though many engineers pursue it to deepen their treatment-process expertise.
Both are open-reference, but differently. The FE Environmental allows only the on-screen, searchable NCEES FE Reference Handbook — no personal materials. The PE Environmental is open-book in the traditional sense: you bring your own references and handbooks. Practicing how to find formulas quickly in the allowed materials — Manning’s equation, the rational method, treatment-process design — is a major part of preparing for either exam.
Re isn't a measurement — it's a ratio of inertial to viscous forces. Illustrated dye-streak comparison showing why the 2,300 pipe-flow transition doesn't transfer to other flow geometries.
Fast-moving water can boil without any heat at all. Illustrated pump impeller cross-section showing where vapor bubbles form under low pressure and violently collapse downstream.
One counts what bacteria digest in 5 days. The other chemically oxidizes almost everything in a few hours. Illustrated comparison showing why the BOD/COD ratio — not either number alone — decides if biological treatment will work.
They look almost identical — a berm, a basin, an outlet structure. Illustrated cross-sections showing why one is normally dry and sized for peak-flow control, while the other keeps a permanent pool that's the actual water-quality treatment mechanism.
One line tracks total energy. The other matches what a piezometer tube would actually show. Illustrated pipe profiles showing why the gap between them is the velocity head — and why only the HGL reveals a pressure problem.
Screening and settling remove solids, not dissolved pollution. Illustrated treatment train showing why biological (secondary) treatment does the real BOD removal, and why tertiary treatment is an additional step for sensitive waters or reuse — not a universal default.
One needs continuous aeration and produces CO2 and water. The other is sealed against oxygen and produces methane-rich biogas. Illustrated tank comparison showing why the choice flips the process's entire energy balance.
One is an optical proxy for light scattering, reported in NTU. The other is a direct gravimetric weight, reported in mg/L. Illustrated vial comparison showing why a clear-looking sample can still carry more suspended solid mass than a cloudy one.
One comes from a single, identifiable pipe outfall that can be measured and permitted. The other is diffuse runoff with no discharge point to monitor at all — and has become the bigger water-quality problem in many watersheds precisely because of that.
One suspends biomass directly in a mechanically aerated basin; the other fixes it to a stationary media bed with mostly passive airflow. Illustrated aeration-basin-plus-RAS vs. media-bed comparison showing why the trickling filter isn't just outdated activated sludge — it's a deliberately lower-energy alternative.
One is a permitted, designed release point in older combined sewer systems during heavy rain. The other is always an unauthorized failure in a separate sanitary sewer. Illustrated piping diagrams showing why regulators treat the two completely differently.
One has a water table exposed directly to surface infiltration. The other is sealed under pressure between impermeable layers with a potentiometric surface that can rise above ground. Illustrated cross-sections showing why a confined aquifer well doesn't always need a pump.
An 18-section interactive reference spanning hydrology, the rational method and detention basin design, open-channel flow with Manning's equation, groundwater and Darcy's law, drinking water treatment and disinfection, wastewater treatment and biosolids, and hydraulic retention time.