The Pennsylvania Attorney General's office told Action News its "environmental crimes section" is taking up the case.
The spill involves jet fuel and other petroleum products.
The Sunoco Twin Oak-Newark Pipeline is operated by Energy Transfer and spans more than 100 miles from Philadelphia to Newark, New Jersey.
RELATED: Bucks County residents say important questions remain unanswered following pipeline leak
Energy Transfer confirmed a leak last month, but residents said they've been reporting the issue since 2023.
Earlier this month, the State Department of Environmental Protection ordered the company to supply all residents in the neighborhood with bottled water, as well as install and monitor well filters.