Water from a shallow well can change, when I first moved here it was heavy in iron, you didn't dare put bleach in it it would stain everything, slightly high in nitrates too, but within limits. Over the years the iron problem went away and nitrates came way down.. Had a friend that worked for the county test the water a couple times for free and it always came back good.
Here, we use cesspools, private wells need to be I believe 100' or more from your, or any close neighbors cesspool.
some ag areas here the water is contaminated with ag chemicals. If your private water is contaminated, the county will either provide drinking water or run a public water line to your location.

I grew up drinking water from a spring. That spring provides water to two houses now. It all depends on the water source. Drank enough creek water out running around to fill a swimming pool. if your worried about it get it tested. Great Aunt and uncle had creek water to the house. Uncle dug my aunt a well when a campground was put in on the creek a few miles above their house. It was not very deep. Uncle built a house a few hundred yards above great uncles house on the same creek. Not sure how deep the well is but not very. Its still being used also.

What is considered a shallow well?
I have 2 irrigation wells that are 80 feet.
Don’t use it for drinking, but you sure could.

About 25 feet or less is considered shallow well.

We did have our shallow well tested in the old house once or twice after floods and it was all good bacteria wise. Never tested it for other bad ju ju.

Is your spring exposed for a long run before where you draw from it or do you draw from where it comes out of the ground?

Our well at the cabin is 23 ft deep, hand driven. Dad made the pump jack out of pipe, scrap steel and a couple of 2x6s for aesthetics; of course bought the cylinder. Dad was a well driller in his early years. Water samples were sent to the DNR for tests came back pretty pure, must be filtered by the sand. It's the best tasting and softest water I have had in my lifetime, far better than any municipal water system.

Mine is about 40 feet that I now use on my pond as we had a new well drilled.

very common here in the sand flats near the river
it is what my house was fed with until town water happened which I htink was early 1980s

many people still have one , I have one , but I haven't had the pump hooled up in a while , I keep meaning to do it to water the garden

here water is about 16-18 feet below the surface

My well is 30' deep.

Has a foot valve at the bottom and I run a two line jet pump.

My groundwater starts at 11 feet, I think my well is the point and 3, maybe 4 5' sections of 1 1/4" well pipe..
I can go to the barrier beach and dig a 18" hole and get fresh water....

I bet you if you get all your wells tested they will all come out good and safe to drink. There is big money in deep wells, they will try and talk you and scare you into putting one in. Shallow wells 99.99999% of the time have just as good of water as a deep well in the same area.

I will get it tested sometime. The one I have closest to the river I have a gas motor and pump jack on it. The thing works great!!!!

My well is 33 foot deep. The water is clear, does not stink, but it is not good to drink. I bet you can not make it two hours without going to the pot if you drink a glass of it. It is very hard. It will kill a new washing machine in a year. There is a slough just down the hill from the well and if you drive a T post in the slough it will eat it in a couple years. A minnow in the slough water is dead in a minute. I haul all my drinking water and do wash in town. Whites turn yellow in the well water. If you water the garden with it the soil turn white. They have said I was going to get rural water for 10 years plus. But the only thing I hear is this year or next year.