Unless you give him permission to use your water, I think he is responsible for the charges associated with his use of the water. One suggestion would be to go the go to the Clerk of Court's office in your county and ask for a copy of the landlord tenant guide - that may be available. You should consider the possibility of asking the landlord for an offset of rent owed - in other words a rent reduction for for a sum that matches the value of the water he used. Good luck.
I agree with the previous attorney. However, how much is the water? Is it really worth fighting over? While I agree that the practice should stop which could be resolved with a simple letter, fighting over the a rent reduction may not be worth the hassle.
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