Overland Park ? Ground has been broken in suburban Kansas City on a $15.6 million project that will use solid waste and restaurant grease to power a sewage treatment plant.

An Environmental Protection Agency official called it the largest “green infrastructure” project in Kansas to be funded with federal stimulus dollars.

The project is expected to take about 18 months to complete and provide all the electrical needs of the Douglas L. Smith Middle Basin Treatment Plant in Overland Park.

Johnson County Wastewater general manager John O’Neil said the project will save the county more than $500,000 a year in power costs.

The methane gas that the solid waste and restaurant grease will produce will be used to run two large electric generators.