["My landlord has not fixed a leaky tap in my apartment even though I've asked 4 times.", "That's not good.  Can't you withhold if they refuse to fix the leak?  I would be really mad!", "Yeah, my next step might be to call the tenant board. It's costing me a lot to lose so much water, not to mention it's wasteful."]
That is true about the waste.  I would sue for compensation.  I think the law is on your side regarding this issue.
My landlord has not fixed a leaky tap in my apartment even though I've asked 4 times.