Sump pump question

[In The Trenches]

I have a heavy duty basement sump pump which is submersed. The basement is equipped with a toilet. The sump pumps vertically about 6' to send the waste water to the city's sewer level. I have two 6" pipes going into the sump vertically. One has a check valve to stop back flow and when the pump turns on I can hear water moving through it but the other one I'm not sure about. Any ideas? I thought maybe it was a vent stack but I have not idea why the sump would need a vent.

[Joseph Meehan]

Radon vent?

[Speedy Jim]

Ah! Not a "sump" pump but rather a sewage pump (I assume). These pumps are sealed to prevent sewer gas escape. As the pump removes the water in the tank, air must be fed in to replace the lost volume. That's the primary reason for the vent connection.

Jim

[In The Trenches]

Ahhh I think you've got it....this pump empties the toilet and the weeping tile....thanks...

[Joseph Meehan]

Yes, then Speedy was right.

I was wondering why you noted there was a toilet in the basement for a question about a sump pump. I should have caught that.