If you have any kind of filters or adapters on your faucets, especially in the kitchen, check the rubber washers once in a while. While replacing the filter unit on my kitchen sink, even though it hadn't been leaking, I discovered the old washer had completely disintegrated, leaving behind nothing but black goo. That's not something I want in my drinking water.
In the past, I've encoutered washers partially disintegrated, but I've never seen one completely gone to goo, like this one was.
In the past, I've encoutered washers partially disintegrated, but I've never seen one completely gone to goo, like this one was.