Topsoil is the top 4 to 6 inches of soil and anything below that is subsoil.
The water your well pulls up comes from much deeper in the ground and as it moves around it flows through rock formations and other things that the water dissolves and carries with it, the minerals that make water hard. what is in the soil around your well has very little to do with your waters hardness, although it may indicate what you might expect from your water. Depending on how deep a well is will determine from how far away the water it draws comes from, generally the deeper the well the further away the water source is.
Limestone formations are quite prevalent in Pennsylvania.

Here is a link that might be useful: Limestone formations in Pennsylvania

While it is true that hard water results in lime accumulations in water heaters and causes other problems, it is thought to reduce the chance of getting heart disease, so it is not necessarily considered bad water to have. If you have lime deposits in your teapot, that is a sure sign of limestone underground, where the water accumulates.

Depending on where you are in PA, you could have limestone. There are several limestone quarries at least in SE PA.

We have massive limestone deposits here in MO, and one of them is called the Pennsylvanian. I think you folks INVENTED limestone. :-]

I am in Fayette county, which is to the west side, next to Greene county, which borders Ohio. My area is closer to West Virginia than any other area. I remember reading a post a while ago, which said my area hasn't got limestone in any plenty-ful amount. I guess it doesn't, until you dig or drill down. As for being good for you, my friends water is unswallowable. I do remember us drinking our well water. We only switched to public water because our neighbor moved his septic system close to our well, from a higher area, after my mom said she didn't want to sign on for public water. He was a home builder and knew what would happen to our well water. We had to sign on to get public water or drink their poo water, which my family did and got sick. After the water got tested they figured out why it was contaminated. I was married at the time and didn't live there, but my family had to sign on to public water. They should have sued. Sueing people isn't always the right thing, but that arrogant ass should have had to be accountable for what he did. That's been many years ago,but , I should just drop it I guess, but some people.........

I will just add that limestone in bags is plentiful in stores around here, and my dad used to lime every year or nearly so when I was a kid, so I guess THAT is why my soil tests have all said 6.8 and some 7.0. I have inherited most of that yard he limed like crazy. He also thought that liming killed pathogens in the soil after burying horses and pets and dog poo yards. He's still living but is done with yard maintenance duties now. I guess I should be happy it is neutral and not alkaline. I have done okay with all trees and plants, but Hemlock trees. Even my Rhodies look okay, I have used peat moss, oak leaves, sulfur. The only Rhodies that are a bit too light green are the native Rhodedendron Maximum that I dug from the wild. However they are still living and growing.

So sorry about that neighbor problem! I bet your family would have had a good case for at least making the neighbor pay for the public water hookup. What I can't figure out is why he would want to contaminate your well on purpose. Did he think there was some advantage to him as a builder to having everyone on public water? Sheesh.

As for the lime, it takes a lot of lime over a long period to change soil pH permanently, I think. What is the pH of the soil around you that wasn't limed over many years?

Toxcrusader, not sure why the neighbor is an ass. It may seem like I am being paranoid, but I am not. The mom of this neighbor family asked for a proof of purchase for a refund on something. My mom gave it to her. When my mom asked for a proof of purchase for a different product, this woman said for her to get it out of their trash. I can only hear that as talking down to my mom. She didn't say it was already in the trash, my mom was supposed to look for it eventually after they threw away the bottle. But as for the high PH I was a kid and not a gardener for quite a while. My dad limed the lawn at least every spring with a drag behind drop spreader. Our local Lowes has a plentiful supply of pulverized lime each spring in a prominate location in the garden supply area. Well, anyway, My yard doesn't need any more limestone. I don't have trouble growing many plants as a result of my dad's liming. I can grow Rhodedendron's. Azaleas are not successful as of the last 2 years. I tried a couple Azaleas, but maybe they needed a little more sun. I planted one under a Pin oak. Yes, the Pin oak liked my soil and they like slightly (or more) acidic soil. I thought that maybe the Azalea wanted more sun, because the Azalea croaked. It looked great in spring, but once the Pin oak had a nice full canopy overhead, the Azalea was gone.

"If you have lime deposits in your teapot, that is a sure sign of limestone underground, where the water accumulates."

Nope. My well is sunk into acid igneous and metamorphic rock, closest limestone is about 150 miles to the east. The calcium/magnesium deposits from my hard water are a result of mineral leaching from the soil and regolith because of the 45"+ annual rainfall

For those of us that get out water from wells that water travels many miles, much over 150, to get to our well point, As it travels in that underground river the water accumulates many minerals, just as the soil it travels through filters other junk, and is why some people have water from a well that cannot be used for the household without treatment.
So piedmontnc , even though your well may be " sunk into acid igneous and metamorphic rock, closest limestone is about 150 miles to the east" that water may well have flowed through those deposits 150 miles away and picked up some of those deposits.

We used to use water softening salts when I was still at home. We had white cloudy build-up on all sink and tub fixtures and basins. In the long run we are better off, I guess. We have no cloudy buildup anymore, but, you can smell bleachy chemicals in our water. If you let it sit for a while it is less bleachy smelling.

Thanks for another useless post kimmsr, but I'll stick with having worked in hydrogeology in the region for the past 8 years. Btw, have you figured out the difference between soil structure and soil texture yet?

Well, I think that the areas in Pa with limestone near the surface are not near me. But we do have it many layers down. Which affects well water. The neighbor who was an ass, and wanted us to hook onto public water, has property where they have drilled for oil, Marcellus shale drilling, that is. I just recently found out that he owned some land where they have gas wells, so getting public water solves the possibility of well contamination. It makes sense to me anyway. The wells came a few years after the public water hook-up for us. I don't know if the couple other neighbors resisted the public water hook-up when it was first mentioned. Well, it's all done and over with I suppose.

I have found the answer to this question on the tree forum. I have silty loam, then clay loam, clay, then bedrock, likely of limestone if I remember right.

As a gardener, WHY should you care about the soil way deep in the ground beyond the use and reach of your plants ? Treat your garden as a bottomless big container.
JMO

Way back in Oct, when I started the thread, I was wondering why my PH was neutral instead of acid. I can't keep a Can. Hemlock alive to save my life, they are our state tree. There is weathered limestone in the topsoil also, according to a web soil survey that you can click on from the tree forum. I've been told that Hemlocks can grow in neutral soil, but there's some reason they die within a week in my yard, no adelgid visible to my eyeballs. Plus I was curious anyway.