16-Civ-B5 Water Supply and Wastewater Treatment, December 2015: worked solutions

Paper format. 98-Civ-B5 Water Supply and Wastewater Engineering — National Examination, December 2015. Three hours; closed book, one aid sheet written on both sides; an approved calculator is permitted. Question 1 is compulsory and the candidate attempts any five of the remaining six, so 100 marks are written out of the 115 printed (Q1 = 25 marks, Q2 to Q7 = 15 marks each; Q2 splits 12 + 3). Every one of the seven questions is solved below, because this set is a study resource rather than an exam script.

Reference texts.

Metcalf & Eddy / AECOM, Wastewater Engineering: Treatment and Resource Recovery, 5th ed. — solids fractionation, nitrogen chemistry, sedimentation theory, anaerobic digestion.
Crittenden, Trussell, Hand, Howe & Tchobanoglous, MWH's Water Treatment: Principles and Design, 3rd ed. — coagulation and flocculation theory, softening, filtration, disinfection.
Davis & Cornwell, Introduction to Environmental Engineering, 5th ed. — treatment-train selection, hardness chemistry, residuals management.
Mihelcic & Zimmerman, Environmental Engineering: Fundamentals, Sustainability, Design, 3rd ed. — mass balances, reaction kinetics, water-quality indicators.
CCME, Canadian Environmental Quality Guidelines (ammonia and receiving-water criteria) and Health Canada, Guidelines for Canadian Drinking Water Quality (treated-water objectives).
APHA/AWWA/WEF, Standard Methods for the Examination of Water and Wastewater — Method 2540 D/E for the solids series.

Check: representative design data. Questions 1, 3, 4 and 7 are discussion questions and print no numbers. Where a number appears in those answers it is a representative Canadian municipal value chosen by the solver to make the argument concrete; it is labelled as such at the point of use, and every one of them. The graded content of those questions is the reasoning, not the arithmetic.

16-Civ-B5 Water Supply and Wastewater Treatment: December 2015