Leaky tap change every few years

[MyBlueFinch]

Every few years i have to change a leaky tap. The problem is i have to buy a pair and only one is faulty. Such a waste .
Just wondering if it is possible to change the washer rather than the whole unit. I think this would be better for the environment.
What do you think?

Thank you for your comments.

You certainly used just to be able to change the washer. It was one of the things we were taught how to do in general studies at school 50 years ago! My DH says they now have cartridges... Whatever they are....
So I assume it should be possible to fix them.