Part I of this pair walked one integrated scenario from system demand through storage, pumping, and cost. This second guide goes deeper into one specific advanced skill — quantifying and benchmarking real water loss using the Infrastructure Leakage Index — and then closes the Advanced Distribution Math sequence with a short mock exam set: several additional, fully worked, multi-concept problems in the style you're likely to see combined on a Class 4 exam.
Beyond the Basic Water Audit: Real Loss Benchmarking
The Class 3 guide introduced the AWWA/IWA water audit's Real Losses figure — the physical leakage component of total water losses. A raw real-loss number (gallons per day, or gallons per year) is hard to compare meaningfully between systems of different sizes, pipe ages, and operating pressures. A small rural system and a large urban system will naturally have very different abso