Water distibution system

[Gilfred]

We have an existing distribution system supplying 700 people on a school campus and village. A bore hole pump supplies a reservoir via high/low probes. This then feeds the system with a static head.
Problems.
1 Regular air locking in system.
2 Reservoir feeds a "ring main" which during low population periods has a reverse flow affect on the main in certain areas resulting in discoloured water.
Question
Do I need a boosted supply to eliminate the air locking?
Do I need to install a "artery" type main to the buildings to eliminate the potential back flow problem resulting in water discolouration.
I already know the pipework is very old (victorian)cast iron and will be replaced.

 

[johnp]

Air in a line is quite a common problem in water lines. Usually this is handled with air traps, or automatic air relief valves, installed at high points where air would normally get trapped.

A booster pump will compress the air in the air pockets, and may cause bubbles to be carried into the water stream. Once the pressure reduces the air will come out of the water as bubbles.

On your water ring-main, what is causing the discolouration? It could be corrosion in part of the line, sedimentation, or buildup of salts and chemicals or bacteria.

With an arterial line you know that what is coming out of the bore is going to the demand point. But what of the other users? I would do some investigation to see which part of the circuit is causing the trouble, and how serious is the problem. Since you're going to upgrade anyway, it may pay do tackle your problem area earlier, with resulting benefits in the whole circuit.