I cannot address home systems, but have a bit of experience with automatic water systems for animals. Many systems hyperchlorinate water between 10-15ppm at a central chlorinator before entering a manifold, which distributes the water to various rooms. Another manifold branches off supplying water to each animal rack and is again branched to supply water to each cage. Animals access the water through a “licks it” which allows the water to come through the valve as the animal licks a small internal valve.

If you test the water entering the rack, it will run between 8-10ppm (so it has lost between 2-5ppm) and if you test the water at the cage valve it runs around 0-2ppm. Water pressure at the cage level is very low, so regardless of whether or not you have a check valve, bacteria, viruses and fungi will enter the system (from the animal’s mouth) as the animal licks the valve. Generally the systems are automatically flushed several times per day to ensure enough chlorine is flowing through the system.

So what does this have to do with a home system? For most municipal water systems, chlorine levels will be around 0.5ppm at the tap level. If you have a system that does not flush adequate amounts of chlorinated water through on a daily basis, the chlorine levels will drop, most likely to 0.0ppm. Why? The various organic compounds that are in almost everyone’s water supply will bind forming chlorinated-hydrocarbons so there will be no free chlorine for bacterial-cidal / bacterial-static functions.


I don’t if any of this helps or is just a bunch of useless information, but for what it is worth (2 cents)-

Pete