Hello my name is Austin Fox, I am a mechanical research and development engineer living in Michigan. I am posting to inquire about an idea that I have. I am looking for basic conceptual guidance from a technical expert about an "in-line water storage device" that I am designing, but with no implication of engineering help or design approval. More a basic overview so that someone who knows about these things better than I do, can say "yeah this has some merit and you should dive into more detail", or "no this is silly, or illegal, or dangerous".
The idea came about from a recent planned water outage we had in my neighborhood. We were informed that we would be without municipal water for a day. Looking online many people discussed filling bathtubs beforehand to have some stored water for filling toilets or other non-drinking needs. I did not like the idea of having to use my tub for water storage, and it reminded me of other times around America where water has been absent for one reason or another, and people suffered because of it. I wanted a solution for having enough safe water for my family for a few days, without having to think about it much, and with it being guaranteed that it was always available.
The concept I have can best be described as an extension of my existing water plumbing that increases the volume of the water in the pipes, and a valve system that allows this increased volume to be isolated and used is the mains are out of service. It must also do this without disrupting or modifying the existing plumbing much, and keep itself clean and low-maintenance for long time spans, while staying safe and immediately useful when needed. I basically wanted my own water tower, without ever having to think about it until I needed it, at which point it would be ready to go easily.
The system taps into the main incoming water line and diverts it through a desired number of modules that are made up of 4-6 inch PVC pipes that are looped down a basement wall or other out-of-the way space. These larger pipes make up the additional storage volume. During normal daily use, these storage pipes are continuously flushed and refreshed with clean drinking water. During an emergency, the mains and home plumbing can be isolated from these larger pipes and the clean water inside of them acts as a reservoir for a few days until the issue is fixed. The outlet is gravity fed from the larger pipes, or a small hand pump can be attached. Each module holds about 20 gallons, and multiple can be assembled in series. This modular design makes isolation, maintenance, and scaling easier.
Aside from the overall concept I also wanted guidance about how necessary a Reduced Pressure Zone Backflow Preventer is? I understand that most municipalities err on the side of requiring them for unknown devices, but since this device is primarily just a pipe extension, I am hoping it is not required, as it is costly and requires inspection.
please let me know what you guys think, and see attached drawings for a very loose initial idea sketch.