Over the last few years an increase in the calorific value of the waste has been observed at our waste-to-energy facilities. Wheelabrator Technologies, Inc. in conjunction with Von Roll/Inova decided to install a zone of water-cooled grate blocks at the Millbury Massachusetts waste-to-energy facility as a pilot program. Common in Europe these water-cooled grate blocks address the issue of higher BTU waste and increase the overall life expectancy of the blocks compared to regular air-cooled grate blocks. This technical paper provides an overview on the installation, operation, and maintenance of a zone of water-cooled grate blocks. Discussed are the procedures for evaluating the overall project and some of the challenges we resolved.