Raw-water intake siting: Pick the incorrect requirement for locating a water-supply intake on a river, lake, or reservoir.

Introduction / Context:
Proper intake location is critical to raw-water quality and operational reliability. Intakes should minimize contamination risk and sediment/debris intake while ensuring access for operation and maintenance across hydrologic conditions.

Given Data / Assumptions:

• Surface-water source used for municipal supply.
• Typical river hydraulics with upstream–downstream gradients.

Concept / Approach:

To reduce contamination, raw-water intakes are placed upstream of wastewater outfalls and other pollution sources. They should also be close to the plant to limit pipeline cost, located in good-quality water zones, and accessible in flood events. Debris/sediment fields are avoided to reduce wear and clogging.

Step-by-Step Solution:

Verification / Alternative check:

Design manuals and environmental regulations emphasize buffer distances upstream of discharges where feasible, or require additional treatment safeguards if hydraulic constraints exist.

Why Other Options Are Wrong (as answers):

• (a), (b), (d), (e) are correct siting principles; they are not the “incorrect” statement.

Common Pitfalls:

• Confusing “upstream” and “downstream” relative to flow direction.
• Ignoring seasonal changes in water quality zones in stratified reservoirs.

Final Answer:

It should be located downstream of the wastewater disposal (outfall) point.