My husband and I got a quote from an excavator to trench and dig for our frost free hydrant. Our frost line is 36 inches deep. He quoted to dig and trench 36 inches deep. I asked him if we should go deeper considering everything I’ve read says go past the frost line. He said 36” is plenty. Please advise on what to do, he has great reviews but I’m anxious this is not ideal. #home source