The Mariner East 2 pipeline, which has drawn fierce opposition from residents of Chester and Delaware Counties, began service Saturday.

The pipeline is part of a $5.1 billion effort by Sunoco Logistics to transport natural gas liquids such as propane and ethane to a refinery at Marcus Hook. For more than two years, Sunoco has been the subject of protests and lawsuits over the pipeline, which has also been delayed by state-mandated shutdowns and cited for safety violations.

Sunoco parent company Energy Transfer LP announced the operational opening of the pipeline Saturday and said the secondary Mariner East 2X pipeline is expected to be completed late next year.