u/minnesotagyros

It was definitely fun taking the PE for the first time in the new computer version.

I don't think I passed but now I am more familiar with the test... EET here I come!

That's what I am focusing on. Trying to also identify common traps like extra units i don't need or forget to double a value for example because its an industry standard to double the value of a flocculator. I have been keeping notes of all the problems i have solved and just going back to these and understanding better when to use and for what reason.

I have been using chatgpt for help and some of the explanations are better with Ai because they show steps between the steps if i may use this term.

HYDRAULICS

Manning: Q = (1/n) A R^(2/3) S^(1/2) — R = A/P

Bernoulli: P/g + V²/2g + z = constant (+pump -loss)

Darcy-Weisbach: hf = f(L/D)(V²/2g)

Hazen-Williams: Q = 0.442 C D^2.63 S^0.54

HYDROLOGY

Rational: Q = 1.008 C i A (US units)

Use rainfall intensity based on Tc

Hydrograph: area = volume

OPEN CHANNEL

Subcritical: Fr < 1 | Supercritical: Fr > 1

Critical depth = minimum energy

GROUNDWATER

Darcy: Q = k i A, i = Dh/L

Confined includes thickness (b)

WATER / WASTEWATER

Process: Coag Floc Sed Filter Disinfect

Load = Flow × Concentration (convert to lb/day)

PROBABILITY

100-year storm = 1% annual chance

P = 1 - (1 - p)^n

ECONOMICS

P = F(1+i)^-n

A = P[i(1+i)^n]/[(1+i)^n -1]

QUICK CONVERSIONS

1 cfs = 448.8 gpm | 1 acre = 43,560 ft²

1 ft³ = 7.48 gal | 1 mg/L » 8.34 lb/MG

STRATEGY

1. Identify topic 2) Pick equation 3) Check units 4) Estimate answer