The answer to 'why is my supply line rusty water' is that a rusty supply line is often caused by corrosion within the pipes. Over time, the metal in the pipes can start to deteriorate, leading to rust and discolored water. This is a common issue, especially in older homes with galvanized steel or copper pipes.
Some common symptoms of a rusty supply line include reddish-brown or orange-colored water coming from your faucets, a metallic taste to the water, and potential low water pressure. In some cases, the rust can also clog the pipes, further reducing water flow.