I live in a 2 story 5 year old house on a community well. Just recently, we noticed a banging noise when a toilet is filling up or when multiple faucets are running at the same time. The sound is coming from the main valve where the water comes into the home (a closet). I made sure it was all the way open.. Everything seems to be working fine, it is just a very loud annoying sound. We also noticed the water "pulses" during this sound like it's not a steady flow. Any thoughts? Thanks

Loose washer in main shut off valve. Turn off water to house, remove valve stem, tighten washer, reinstall stem.

Go to each of your plumbing fixture in your house and turn off and on angle-stops. ( on and off valves ). Also, go to your pressure regulator with pair of pliers and 1/4 turn the pressure adjustment bolt.

Private message received from Tim.
"Do I shut off the water at the street or in the house where the noise is coming from?"

You would turn it off at the street, but before doing that do as Milo suggest and adjust your pressure regulating valve slightly up or down if you have one.

PRV will look something like this.

What is considered normal water pressure? There really is no such thing as "normal" water pressure. Since water pressure is influenced by the elevation of the reservoir that serves your neighborhood versus the elevation of your water meter, water pressure varies from property to property. Water pressure in the District typically ranges from 45 - 125 psi; however, typical residential systems are designed to function best under a pressure of 40 - 60 psi. If the water pressure entering you home exceed this level, you should install a pressure regulator in the line to reduce the pressure to an acceptable range. This protects your equipment and piping in your home from damage from excess force exerted by the water. Symptoms of high pressure include "clanging" or "rattling" of pipes that occur when a faucet, dishwasher, or washing machine shuts off; water heater pressure relief valve malfunctions, and reoccurring leaks. The symptom of low pressure is typically a noticeable reduction of flow.

If you need to do any adjustment to the pressure regulator please use pressuer test gauge, Thanks.

John