William and Nancy Liebhart together own three houses on the same block in Watertown, Wisconsin. Besides a few other houses, the rest of the block was previously occupied by an abandoned transformer factory, last owned by SPX Corporation. In 2014, SPX demolished the building with the assistance of TRC Environmental Corporation and Apollo Dismantling Services. The Liebharts allege that dust and debris containing toxic chemicals migrated onto their properties, contaminating their yards and jeopardizing their health and the health of their tenants. Per the recommendation of their physician, the Liebharts vacated the property in August 2015; they later learned in October 2017 that the defendants allegedly buried some of the concrete remains on-site rather than removing them to a toxic waste dump as required by the EPA-approved clean-up plan.

The Liebharts subsequently filed a complaint against SPX, TRC, and Apollo under the Toxic Substances Control Act. The district court ruled in favor of the defendants and the Liebharts appealed. Can the Liebharts raise a claim under the TSCA as private citizens? Who is able to raise claims under the TSCA?