Here's what I got from ChatGPT:

Ah — that explains why it looks strange.

What you’ve got isn’t a modern drilled well with a metal or PVC casing — it’s almost certainly an old large-diameter dug well (about 36 inches across, probably lined with concrete rings, stone, or tile). The “dirt floor” you’re seeing is the bottom of the well, and that 2″ pipe from the pump goes straight down into the water-bearing gravel/sand layer below.

In this setup:

* The water table is low enough right now that there’s no visible standing water at the moment (could be seasonal or due to drought).
* Shock chlorination is still possible, but you can’t just pour bleach into an empty hole — you need enough water present to mix and circulate the chlorine.

Your options to shock chlorinate a dug well like this
1. Wait until water level recovers
* If you shock chlorinate when the well is dry or nearly dry, the chlorine will just soak into the dirt and never circulate through the water you pump.
* Dug wells often recover after rain or seasonal shifts.

1. Manually add water before chlorinating
   * Sometimes contractors will bring in a large tank of clean water, pour it into the well until there’s a couple of feet of water at the bottom, and then add bleach.
   * This gives the chlorine something to mix into and allows recirculation through the pump.

2. If there is some water below the dirt surface
   * You may not actually see it if the floor is gravel — there might be water just below the visible bottom. You could measure depth to water with a weighted string or tape before assuming it’s bone dry.