The State Health Department has approved Tesoro's plan to clean up the site of the state's largest oil pipeline leak near Tioga.
That's where a farmer discovered oil seeping out of the ground of a field last September.
About 20-thousand barrels of crude oil leaked from a pipeline buried beneath the field.
The plan approved by the Health Department includes excavating and treating soil contaminated by oil.
The process is expected to take about two years.