Practical Example
Selecting a Drinking Water Source for a Community of 5,000 Inhabitants
Initial Situation
A growing community of 5,000 inhabitants requires a new drinking water supply system.
The existing water source can no longer meet future demand, and local authorities must identify the most suitable long-term water source.
Several options are available:
- Groundwater
- Spring water
- Surface water from a nearby reservoir
- Desalinated seawater from the coast
The objective is to select a source that provides reliable water quantity, good water quality, and sustainable long-term operation.
Step 1: Assess Water Demand
The future drinking water demand is calculated.
Result:
- Required production capacity: 25 m³/h
- Additional reserve capacity required for future growth
The source must be capable of meeting both current and future demand.
Step 2: Evaluate Groundwater Resources
Hydrogeological investigations are performed.
Result:
- Productive aquifer identified
- Good raw water quality
- Sustainable groundwater yield confirmed
Groundwater is considered a promising option.
Step 3: Evaluate Spring Water Resources
Several springs in the surrounding hills are investigated.
Result:
- Good water quality
- Insufficient flow during dry seasons
- Significant seasonal fluctuations
The springs cannot reliably supply the entire community throughout the year.
Step 4: Evaluate Surface Water Resources
A nearby reservoir is assessed.
Result:
- Sufficient water quantity available
- Water quality varies seasonally
- Comprehensive treatment required
The reservoir could provide a reliable supply but would require higher treatment costs.
Step 5: Evaluate Seawater Desalination
The possibility of constructing a desalination plant is reviewed.
Result:
- Unlimited water resource available
- High investment costs
- High energy consumption
- Long transmission pipeline required
Desalination is technically feasible but economically less attractive than other options.
Step 6: Compare All Options
The project team compares all available water sources using the following criteria:
- Water quantity
- Water quality
- Reliability
- Construction costs
- Operating costs
- Long-term sustainability
Result:
Groundwater achieves the highest overall score.
Step 7: Select the Preferred Water Source
Groundwater is selected as the primary drinking water source.
A well field with two production wells is planned to improve reliability and provide redundancy.
Result:
- Secure long-term water supply
- Good raw water quality
- Moderate treatment requirements
- Lower operating costs compared to other alternatives
Final Outcome
The community successfully selects a groundwater-based drinking water supply system.
The project provides:
- Reliable water availability
- Good drinking water quality
- Sustainable resource use
- Cost-effective operation
- Long-term supply security
By systematically evaluating all available water sources, the community is able to make an informed decision and establish a safe, economical, and sustainable drinking water supply system.