Frozen Water Line

[chocophile]

We opened our camp on Saturday and discovered that the underground line to the lake is frozen. That's the first time it's happened in the 14 years we've owned the house.

Any suggestions about how to thaw it (aside from waiting)?

I tried running very hot water down the line (black plastic), waiting, repeating several times. I ran a cable down the line from both the lake side and the house side, and I know where it's blocked. There must be a dip in the line at that point and the water didn't drain in the fall. I thought about trying to dig, but if the ground is still frozen I won't get very far.

I see from the ice-out history that this isn't the latest ice-out in the past 14 years, but maybe it's the coldest winter, so the ground is still frozen.

Thanks for any ideas.