The East County Advanced Water Purification Program broke ground Wednesday, marking an important milestone for the project, which could purify up to 11.5 million gallons of water per day when it’s completed.

Program representatives, elected officials and water industry leaders gathered Wednesday at the future site of the treatment facility in Santee. The project was approved on May 19 by the East County AWP Joint Powers Authority, which owns and operates the program, and is a collaborative partnership between four agencies: Padre Dam, the city of El Cajon, the county of San Diego and the Helix Water District.