(WBIR) - Eleven people who worked at the Kingston fossil fuels plant after a disastrous 2008 coal ash spill allege a TVA contractor hired as an independent safety contractor negligently allowed them to be exposed to health hazards.

They seek up to $55 million in compensatory damages and punitive damages equal to a fraction of Jacobs Engineering Group Inc.'s contract revenue for its work at the site for TVA.

Liquid coal ash poured from a failed holding cell at the plant in December 2008 into waterways and surrounding acreage. Cleanup of the disaster cost an estimated $1.2 billion.

Jacobs Engineering, according to the plaintiffs' federal lawsuit filed in Knoxville, was hired to provide safety oversight after the spill.

The plaintiffs allege the firm failed to adequately do its job, thus exposing workers on the site to dangerous conditions that ultimately affected their health. The fly ash was contaminated with toxins, a fact that the company knew or should have known, according to the lawsuit.

The plaintiffs are identified as Craig Wilkinson, Christina Wilkinson, Tim Bandy, Harvey Bass, Chris Jones, Glenn Knight, Frankie Norris, Jeff Townsley, Timothy Turner, James Phillips and Kenneth Shepherd. Most are from Tennessee.