Sump Pumps back flow tank?

[Drainpipe]

I
This is the exit pipe for our sump pump, which is in need of replacement, is this an back flow box?
It is cement, 2' x 1' x 1' deep

 

[Reach4]

I suspect that is a cleanout. A check valve would often be in the pit with the pump.

 

[Sponsor]

 

[Drainpipe]

Clean out? So it is a station to clean out the garbage that might get in the way of it draining?

 

[Drainpipe]

Clean out? So it is a station to clean out the garbage that might get in the way of it draining?

the cement box is very large, and cracked!

 

[Reach4]

Cement box? Guess I don't know what is going on.