Subsurface gasoline contamination follows a predictable migration path: free product floats on the water table, volatiles partition into soil vapor, and that vapor migrates upward through building foundations. The longer the source goes unreported, the wider each exposure pathway grows. Berger Montague and Locks Law Firm filed a class action complaint on behalf of Aston, Pennsylvania residents alleging that Monroe Energy, LLC and MIPC, LLC knew about a months-long release at the Chelsea Tank Farm and said nothing while approximately 378,000 gallons of gasoline spread through the soil, groundwater, drinking water, and indoor air of a Delaware County neighborhood.
Four contamination pathways, one source
The complaint identifies an exposure footprint spanning four distinct media. Soil contamination is the proximate problem: gasoline saturates the surrounding formation and acts as a persistent source term for everything downstream. Groundwater contamination follows as dissolved-phase hydrocarbons travel with the water table, putting both private wells and supply infrastructure in the plume's path.
From there the pathways diverge into drinking water and indoor air, the two routes where residents come into direct contact with the release's byproducts. Indoor air contamination through vapor intrusion is typically the hardest to remediate because it requires both addressing the subsurface source and sealing building entry points. The complaint's inclusion of all four pathways signals a claim that goes well beyond surface cleanup.
The concealment allegation carries the weight
The phrase "months-long" in the complaint is the legally operative term. In environmental liability, the gap between when a release begins and when it is disclosed determines the plume's size, the remediation cost, and the scope of any medical monitoring a court may order. A contained release produces a very different exposure picture than one left to migrate unchecked across multiple seasons. The complaint frames the community's contamination as a direct consequence of Monroe Energy's and MIPC's concealment, not simply of the initial failure at the Chelsea Tank Farm.
Filing details
Berger Montague and Locks Law Firm announced the filing out of Philadelphia on July 15, 2026, with the suit naming Monroe Energy, LLC and MIPC, LLC as defendants. The case turns on a single quantity: approximately 378,000 gallons of gasoline that the complaint alleges were never disclosed to Delaware County residents during the months the leak ran unaddressed.