Unspecified future renovations to Savannah’s Wilshire and President Street Water Pollution Control Plants will cost millions of dollars, according to Public Works and Water Resources Director John Sawyer. Sawyer spoke to reporters Thursday after briefing city council on upcoming changes to pollution requirements. On an average day, Sawyer says Savannah’s plants fall well below the pollution limits set by their state permits. But those limits are set to change to bring plants into compliance with Environmental Protection Agency standards revised in 2010. At the time, the new regulations represented a 76 percent reduction in daily pollution along the length of the Savannah river.