Same story with my builder on my pond renovation, no compaction except with dozer. We have good clay. He did not make a core trench, and the pond leaks down about 30" after every fill. It leaks at the dam-bowl junction. I may have an excavator dig a core trench on the back side of the dam this summer in dry weather if funds permit. If I had it to do over, it would have been very different. The builder would have rented some sort of compaction equipment. In retrospect, I am so frustrated, I should just have had it filled in and made part of the hay field.

Soil floc treatment did not work for me.