If the stump is still in the ground you'll probably have continuing level problems long term as the stump very slowly rots away. Here is the stump in my yard when they removed a tree. I can't guarantee what will happen in your yard, but they removed the entire stump so that the lawn wouldn't sink in that area and cause a drainage problem.

I figured the stump area would sink when it rots, but I wonder about the slight mound around the stump. If the stump rots will the surrounding soil sort of settle towards the hole or will I have a volcano?

I would have loved to totally remove my stumps like you did, but if I did that for 30 stumps I'd need a whole new yard.

Stumps take decades upon decades to rot away. I buried one under a compost pile thinking the compost would rot it away. Ten years later I uncovered it and the stump was like brand new. Stumps need fresh air to rot. As soon as you bury it that cuts off the air and the decomposition proceeds v-e-r-y slowly.

It should be humped up slightly to account for the soil itself to settle. Every hole you fill should be humped up slightly. The bigger the hole the higher the hump should be, but I would never expect to see more than an inch raised in the center - even for a stump like daniel's.

Thanks. This stump had really raised up the ground in the area. This was a huge white pine. I am going to try to bring the area down and see if I can get it closer to a inch. It's a bit higher then that, but the hump is a large diameter so it doesn't seem that bad/noticeable. It's just the stump grinding was a fiasco to get it as deep as they did.

How deep was the stump ground down below grade? I understand what dchall is saying (I've heard reports of people finding orange colored carrots from the 1940's in landfills). However, if the stump is just a few inches below grade it is going to rot. How fast I don't know. I guess you could just add small amounts of soil or sand as needed.

I think they got it about 6 inches maybe a little more in some spots. It's just the stump was so big under ground and the roots and the stump guy was trying to do as little as possible.