Water storage capacity
- Water storage capacity is sufficient to meet user's demand for safe water at times of peak consumption throughout the day.
- Total water storage capacity and safe water available during peak demand reflect differences in regional- and household water consumption.
Key indicators (India example)
- Untreated and treated water container volumes: 9–12 L.
- Total device capacity: 18–24 L.
Notes and exceptions
- Peak demand volumes and total daily consumption will vary by region and market segment.
- Clean water storage volume is large enough to provide “water on demand,” analogous to having a plumbed water tap in the house.
- Storage and treatment rates are inversely related. If the treatment rate is higher, water can be made available more quickly, and the burden of storage is lower.
Example from India
- 4 L per person per day (pp/d) is typical consumption for drinking and cooking in India.
- Morning and evening meal preparation are periods of peak consumption in India.
- Upper container volume reflects volume of typical regional water transport or storage vessels: 20 L is common for transport but difficult to pour; 12 L is a common storage vessel (“matka”) size and should be considered the upper limit for easy pouring.
- Costs increase with increased device volume—a trade-off that must be explicitly made.
- PATH. Extended User Testing of Household Water Treatment and Storage Products in Andhra Pradesh, India: Final Study Report. Seattle, WA: PATH: 2010. Available at: http://www.path.org/publications/detail.php?i=1841.
- Full list of supporting evidence and additional materials.
A family of five may consume 20 L of drinking water in a day, often making several trips to their water source. Photo: PATH.