Looking to install a solar water heater or high-efficiency toilet? Hoping to measure how much water you and your family consume? Want advice on the best water-saving appliances and rebates? There are times when a regular plumber just won’t do. What you need is a green plumber — one schooled in the ways of water efficiency. A good place to locate one is through Green Plumbers USA, which lets you search its extensive list of certified plumbers. Green Plumbers was originally formed by the Master Plumbers and Mechanical Services Association in Australia and has since been exported around the world, which is good news for homeowners who want to cut water waste.