A dirty pile forms under the medium underground outlet. Is that a bug or by design?

It's by design. The idea is that you need to dig to install the underground outlet.
I should probably make it optional in the settings. I'll work on it.

The setting to disable the dirt spawning under the underground outlet has been added in the 0.8.1 version of the mod.
(by default this interaction is enabled, so if you don't like it you can disable it now)

wowza! thanks man!

Hello, im loving this mod however im new to this game and im wondering how to disable the dirt? do i go to the mods tab in game? or how do i access this option.

Hello, im loving this mod however im new to this game and im wondering how to disable the dirt? do i go to the mods tab in game? or how do i access this option.

I apologize for assuming that everyone knew where to find the mod settings.

You can find them in the game settings, accessible both from the main menu under "Settings" and then "Mod Settings," or from the in-game menu by pressing "Esc" -> "Settings" -> "Mod Settings."
The config to disable the dirt patch, is located under "map" in the category of this mod "UPL - Underground Power Lines".

Note that if you have several mods installed, you might encounter some difficulties locating this option. Remember that you can search through all settings using the magnifying glass icon in the top-right corner.

Happy Holidays :)