Anatomy of an underground plastic cistern tank installation 

It is a 4” pop-up emitter. We don’t generally use them or recommend them, but in this case the property was flat as a pancake with nowhere to run the drainage to daylight

This particular install uses gutters from a high tunnel to channel rainwater into the tank. If you go to 0:59 in the video, you’ll see the picture of all the drainage running from the high tunnel to the cistern tank. If you were installing a hauled water tank, the process would be exactly the same, except you wouldn’t have the 4” overflow, and your 4” inlet would bend 90 degrees up and extend above grade to serve as your fill port. Generally we recommend also installing a 4” cleanout on that fill pipe for hauled water systems. Hope that clarifies things, and thanks for watching!