I know clams certainly can! I've come across clams in several irrigation jobs. I've never seen snails in mainlines though. I wouldn't put it past those pesky rain jet snails though!
I think it has something to with your pipes not your water. Your pipes are must probably rusty and it is coming out in the water.
rusty water
There must be a leak in one of the pipes in you house.
From the pipes and Plumbing coming into your home. :)
It's colder in the basement than the water coming in the pipes. Seal up the vents and drafts in the basement. Wrap the pipes
water snails but not regular snails
It is the water rushing through the pipes creating a pumping sound
It's the water going through the pipes.
Your pipes aren't clean "Dah"
Water pump with pipes coming in and out.
Depending where the noise was coming from, but this question is most likely to be answered in this way. If you switched a valve off and the noise was coming before the valve in the pipes, that would indicate a burst pipe.
There is rust in the steel pipes of your house, possibly the water heater. Have them looked at soon