Sorry if this isn't the best sub for this. I can take my ball elsewhere if I get a recommendation.

My question is regarding making holes in your foundation below grade. I am burying the drainage for my sump pump. Currently the sump discharge passes through the exterior 18 inches or whatever above the ground. I am evaluating the idea of dropping directly downward below the grade, but I am weary of disturbing the integrity of the foundation by making a below grade hole.

Am I right to question this, or is a properly sealed hole for 1.5-inch PVC nothing to worry about? Part of my motivation for dropping it is aesthetics and noise isolation for when it runs (which is once every hour or two spring through fall unless it's been ages since rain). However, I am in a NA climate with freezing winters. My functional intention is because I'm worried about the sump discharge freezing and clogging. Our first 2 winters here I noticed that the sump is running a substantial amount during the winter, and at one point last winter the existing sump discharge froze. If I drop the discharge down, I will use the existing/old discharge as an overflow (if it is connected like a standpipe, any backup created by a frozen discharge line will overflow out the old discharge, which will just be a short stub and a 45-degree elbow pointing down).

The follow-up to this is; if I am going to drop this discharge below grade, can I drop it a few feet below grade so it's not in the way of the topsoil, or should I play it safe and drop the discharge to a point that is just a few inches below grade, and then immediately lower it further with a 90-degree elbow?

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I hadn't hit "post" yet, but I may have answered part of my question. Dropping it several feet, regardless of the concern about penetrating the foundation below grade, I think raises the serious concern about what happens when things shift (the house was completed in late 2020 but shifting of course is inevitable). The integrity of the PVC can be compromised and cause a leak or a total failure right next to the foundation.

I think if I go below grade, I need to limit it to just the first few inches and then send it deeper right away with a 90-degree elbow. That will give enough flexibility so that shifting does not pull joints apart. But this still raises the question about penetrating the foundation below grade.

If it makes a difference, the sump discharge is right next to the electrical service riser which comes up from the ground and enters the house at a typical point above ground, so that gives me a landmark if I ever need to access the sump discharge just below the ground.

Thoughts?