Quick Answer
Yes, you can use a pressure tank for both drinking and irrigation water, but it's essential to ensure proper separation and protection of the potable water supply.
System Design Considerations
When designing a system that uses a pressure tank for both drinking and irrigation water, it’s crucial to implement a clear separation between the two systems. This can be achieved by installing a separate pressure tank for irrigation water and another for drinking water. For example, if you’re using a single pressure tank, you can install a dedicated check valve between the tank and the irrigation piping to prevent backflow from the irrigation system into the potable water supply.
Backflow Prevention Requirements
The American Society of Plumbing Engineers (ASPE) and the NSF International have established strict guidelines for backflow prevention in irrigation systems that share a pressure tank with a potable water supply. According to these guidelines, a reduced pressure zone (RPZ) backflow preventer or a double-check valve assembly (DCVA) should be installed to prevent contamination of the drinking water supply.
Tank Material and Maintenance
When selecting a pressure tank for a dual-purpose system, choose a tank made from materials that meet the standards for potable water contact, such as stainless steel or fiberglass. Regular maintenance of the tank, including inspection, cleaning, and testing, is also essential to ensure the quality and safety of the water supply. This may involve draining and flushing the tank at least once a year, as well as checking for any signs of corrosion or contamination.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.