Using Multiple Irrigation Pumps

Q.  I have a shallow well that was drilled this summer and a centrifugal pump pulling up about 15 gallons/min (HAPPY!).  The problem, it will only produce somewhere around 30psi (sad!).  Am I able to add a booster pump to this setup to produce more psi or should I just forget it and go for a submersible pump?  Obviously the booster pump would save me $…

A. You can add a booster pump but it is tricky.  The flow range of the booster pump needs to match that of the existing well pump.  Using two pumps will probably use considerably more electricity than a single new pump, especially if it is a submersible.  Submersibles are by nature more efficient than a centrifugal pump at the top of the well and now you are adding the friction drag of two pumps rather than one.  I can’t tell you how much the electricity cost difference would be, that’s beyond my knowledge level.  But ongoing electricity cost is certainly something to look at.

Essentially when you couple two pumps together they are going to have to play nice with each other.  You don’t want one to over-power the other and do most all the work while the other just causes drag.  Plus you need to deal with the wiring issues and how you will start the two pumps.  Hopefully they would both stay primed so, in most cases, you could start them both together using the irrigation controller connected to a relay connected to the pumps.  You might need two relays if the pumps exceed the capacity of the relay.

Finally you will need to deal with figuring out if and how you will handle problems such as the malfunction of one of the pumps.  If one burns out the drag created by the burned out pump could very quickly burn out the other.  Hopefully you would quickly notice the problem, since the irrigation system would not work well at all if only one pump was running.  But what if you were on vacation when it happened?

You probably should get a local pump professional who knows his/her stuff and has experience with two pump systems to help you if you use two pumps.

Basically if you want to keep this a simple do-it-yourself project I’m thinking buying a new submersible for your well would be the better way to go.