City and state officials are preparing for a Wednesday groundbreaking for a $16 million expansion at Springfield's Southwest Wastewater Treatment Plant, at 3301 S. Highway FF. The stimulus-funded project, expected to be complete by spring 2012, will increase energy efficiency and environmental sustainability at the facility, according to a news release from the U.S. Environmental Protection Agency. Improvements to the plant include a new ozone disinfection system, which is expected to save $4 million in energy costs and $2 million in maintenance costs over the next 20 years. The groundbreaking is one of several EPA events nationwide marking the one-year anniversary of President Obama's signature of the stimulus act, through which EPA is awarding $7 billion nationwide in funds for economic and environmental projects.[[In-content Ad]]