Just had a main water line replaced due to storm damage. The plumpers put in PEX tubing and connected to the old glavinized pipe with a pressure regulator. Before the damage of the old main water line we had good pressure (do not know what the pressure was) now the PEX is connected and a water pressure valve was put on. Now pressure will be good when the faucet or washing machine is on then dies down to a small stream of water. I checked the pressure on the outside faucets and the washer faucets and the pressure is at 110 psi. and when faucet, shower, toilet, washer, etc is turn off or filled with water there is this roaring noise until the pressure is built up again. I've never heard or seen this in a old home or even a new home. So what do we do next? Like to be a little educated when I deal with the plumber again. We also have been without water for over 5 weeks so a quick response would be helpful.

I am building a small 20'x16' cabin in the Colorado Mountains. It will not have electricity, water, or septic. Heat will come from a wood stove. It will only have a waterless composting toilet. However, I would like to put in a small 5 gallon water tank in the loft that I could run to a sink in the kitchen and a sink in the bathroom. These would drain to a small leech field. Normally dishes, hand washing etc would be done outside and dumped on the ground. I feel like this would be more environmental safe. So, I have two questions. 1. Do I need P traps below the sinks? (there would be no sewer gas) 2. If the P traps freeze would they cause damage? It seems like the ice would have plenty of room to expand.