How often should septic pump be run?

[arthurc]

Got a short term problem here with my old septic system: the float valve switch which normally starts and stops my septic pump, is not working. I can't get in to fix it for a week or so. During that period, I want to be sure the tank doesn't overfill and overflow, so I've been running the pump manually.

My question is, how frequently and for how long, should I run the pump? Once a day for 15 minutes or so? Longer or shorter run period? Run it more frequently, or less? Just run it until the liquid flow starts to decline?

Your advice is very welcome. Thank-you

[AllanJ]

Do you remember how far down the liquid level goes when the pump shuts off after a cycle? This is where you want to shut it off manually. Alternatively the pump may be installed in a manner that it stops gathering liquid when the level gets down far enough. The float switch should have shut it off slightly before then.

If you take the water level down too far, the outlet pipe (pump feed) will gulp some grease from the scum layer on the next water rising cycle. If this happens too often, the leach field will fail.

THis is less of a problem for a pump in the second chamber of a dual chamber tank or if you had the entire tank pumped recently. The scum layer there/then is much thinner.

The normal level in a septic tank, after the pump has shut off, is about 80-85% full.

[joed]

Actual run time will depend on much water you use. There is a big difference between a couple living alone and a couple with kids. Showers. laundry dishes etc. Water use all adds up.
Does your tank have an alarm? If it does then wait for the alarm. Run it until the alarm stops and little longer.

[arthurc]

These are helpful answers, and thank-you. The tank has two chambers, and if I understand you correctly, the pump chamber should remain at 80-85% full after pumping.

I have never been in the tank, so don't know where the float switch is positioned. It's a very old system - there is no high water alarm. It was pumped out very recently, so there shouldn't be too much crud on the bottom.

Guess I have to open it up. Whoopee.

[joed]

Is there a vent hole? Can you stick a a stick down the vent to get the water level?

[AllanJ]

If the pump is in a separate chamber from the septic tank, the chamber should be nearly empty when the pump shuts off.

[arthurc]

I started the pump manually and timed it: in ten minutes, it empties the tank. We are selling the house and the new owners intend to install a new tank with a much larger capacity. Because of that, I am not going to bother replacing the float switch -a project that might cost me well over $200 to have a professional do it, and would cost me perhaps $45 if I bought the float switch and installed it myself. The problem with the DIY option for me is that I can picture one, perhaps all, of these things happening:

- me falling in the tank when I'm lifting the pump out to get at the float switch

- me spraining my back bent over in that small space, lifting up the heavy pump

- me taking eight hours to do what the pro would do in two

- me screwing the job up, spending even more, and ultimately having to call the pro in anyway to clean up my mess

So, I'll just turn the pump on for five minutes or a bit more each day, and make sure I can hear water pumping into the distribution box.

Thanks to all of you for the helpful advice.