Water Supply Engineering Questions

• Potable water chemistry — acceptable pH for drinking: Select the pH value that best represents neutral, acceptable drinking water quality within typical guideline ranges.
• Environmental microbiology — bacteria and oxygen requirement: Bacteria that can survive and metabolize with or without free dissolved oxygen are called
• Pipe joining methods — plain-end cast iron pipes: Which joint is commonly used to join plain (unflanged) ends of cast iron pipes in water-supply systems?
• Chlorination basics: At approximately what pressure does chlorine change from its gaseous form to the liquid phase under typical ambient temperatures used for water-treatment storage and dosing?
• Reservoir sediment behavior: Which statements about bed load, suspended sediment deposition zones, and capacity loss due to sedimentation are correct?
• Potassium permanganate (KMnO₄) field check: The disappearance of the pink colour in well water after adding KMnO₄ indicates the presence of what contaminant class?
• Aqueduct hydraulics (grade aqueduct): A grade aqueduct conveying canal flow across a depression at (approximately) the canal grade is generally not permitted to run in which condition?
• Natural water quality evolution: Which statements about precipitation, percolation, groundwater dissolution, and trace minerals for health are correct?
• Pumping power estimate (economic diameter given): Water is to be pumped at 36,00,000 L/h through a 1506 m main from RL 135 m (max source level; reservoir depth 3 m) to RL 175 m. Friction factor f = 0.01. Using Lea’s economic diameter relation D = 1.2 Q (with Q in m³/s), estimate the water horse power (WHP), neglecting minor losses.
• Pump selection preliminaries: A typical overall efficiency to assume for a complete pumping set (pump + drive + minor losses) in preliminary design is
• Reservoir zoning: The storage capacity of a reservoir is divided into three zones. Which is the lowest zone by elevation?
• Fire-demand empiricism: If P is the city population in thousands and Q is the fire demand in litres per minute, the commonly used empirical relation of this type is attributed to which author/agency?
• Surface-water sources: Identify the incorrect option. Which of the following is not considered a surface-water source for municipal supply?
• Estimating demand for a municipal water-supply project Project cost estimates depend on per-capita rate of supply (LPCD) and the probable population at the end of a chosen design period. For typical Indian urban systems, what design-period range is commonly adopted for water-supply components?
• Reservoir storage zoning in hydrology In a reservoir capacity diagram, which zone is termed the “surcharge storage” (i.e., the flood storage above the normal or useful storage)?
• Process sequence for a rapid gravity filter in water treatment Which type of influent is appropriate for a rapid gravity filter in a conventional treatment train?
• Quality concerns with surface water sources Which of the following correctly describes typical issues associated with untreated surface water?
• Standard per-capita water demand categories A per-capita allowance of approximately 135 litres per person per day is typically adopted for which of the following user groups?
• Pipe joints in cast-iron water mains Which joint type is most commonly used for cast-iron (CI) water-supply pipes in distribution systems?
• Design velocity in plain sedimentation tanks What is the typical horizontal flow velocity maintained in a plain sedimentation tank to promote particle settling without resuspension?