Anyhow, we live in New England. Its granite, and we are building into the side of the hill. The ledge will end up being our retaining wall. To make a long story short, we had to blast to gain lateral space and then also the gain depth for the deep end. Finished depth will be just under 8 feet of water, which meant that needed to blast about four feet from the excavated deep end. All in, they moved approximately 15 truckloads of granite. Total cost 15.5k Ouch. On the bright side, a retaining wall system might have been three times the cost and not looked as nice. We knew we were going to hit rock. We just didn't know how much. You never know until you know... We are happy with our builder. And all in all it was a minor or maybe major hiccup. Delayed our build by about 3 weeks with the need for pre-blast inspections of the neighbors houses and permitting.