Recently I’ve noticed a drop in pressure and volume in my city-supplied water system. Initially whenever a hot or cold tap is turned on, the pressure and volume appear fine. However, after a few brief seconds, the pressure and volume start to drop off a bit (it takes about 33% longer to fill up a water closet or washing machine now than before). Also, if there is a demand for water from another source while another is being used both sources drop off significantly. These conditions occur throughout the house. One other thing- I’m getting a hammer effect when I turn on the hot water tap in the master bedroom sink although the other sink right next to it doesn’t have the problem. I’ve got a whole-house sediment filter system and water softener installed (both about 4 years old) and would appreciate any info on where to start troubleshooting. TIA.