(MARYSVILLE) -- Enbridge Inc. is replacing approximately 210-miles of existing crude oil pipeline in Indiana and Michigan and work in St. Clair County is slated to begin this fall. Company officials say the project reduces the number of future maintenance activities and restores the ultimate capacity of Line 6B to meet increasing demand. Most of the new pipeline segments will be installed adjacent to existing segments. Construction crews will begin the next phase, which includes a 30-inch diameter pipeline replacement from Ortonville to Marysville this fall. Following the completion of the project, Enbridge will have replaced the entire length of pipeline from Griffith, Indiana to the St. Clair River in Marysville. The Michigan portion of the project is estimated to cost $1.3 billion. In 2010, an Enbridge pipeline broke, spilling over 800,000 gallons of petroleum into the Kalamazoo River. Crews replaced 3,600 feet of pipeline in 2011, which ran from Marysville to Sarnia under the St. Clair River.