Ways to save on Water bill in a quadruplex

[Moncy Samuel]

We have a quadruplex under contract and looking to close this property in two weeks. Currently 4 units rents for $750 and one for $800 as they have washer/dryer. Owner pays the water bill as there is only one water meter for the building. During inspection time, we met the seller and she was owners about the water bill which is potentially a cash flow killer. It varies between 400-700/month and looking for advises from experts here to solve this and keep this manageable and under budget. The property is in Dekalb county, Georgia. Second question is, because this is a cash deal, should we do an appraisal before closing ?. Looking for your valuable suggestions.