Free practice quizzes
Try a few questions before you take a class. No sign-up.
Activated Sludge practice quiz
Ten questions on activated sludge control: internal recycle, MCRT and sludge age, settleometer practice, clarifier loading, F/M, permit limits and aeration.
Operator math practice quiz
Ten operator math questions of the kind found on certification exams: area, overflow and weir rates, detention time, volume, alkalinity, digester solids, volatile solids reduction, retention time and methane.
Practice quizzes do not give a certificate. Each online class has its own certification quiz, which opens for paid students from the class thank-you page; pass it to get a certificate of completion. See the online classes.