My female cat has been peeing all over the kitchen counter and there's no way to stop her?

My female cat has been peeing on our kitchen counter, specially on out toaster and coffee maker. She's done it a few times already and we just came back from a trip and found the toaster cover completely covered in her urine. This is of course very unsanitary since she's doing it where we keep and make our food, although we never really put it in the counter and we throw away the toaster every time this happens. But still we can't keep throwing away toasters and one day someone could have an accident or get sick. We've thought of leaving her on an animal shelter but she's a really loving and friendly animal so that's been holding us back a bit. How do we deal with this problem?