The named plaintiffs in the action, Terri Crandall and JoAnn Hubbard, are long-time employees of United Airlines. They allege that physical observation and preliminary testing at the airport--particularly Concourse B where the majority of United's gates are located--have revealed the presence of mold, E. coli, raw sewage from leaks, sewer gases, and other substances.

Drains in a lounge in the B concourse are allegedly so contaminated that airport personnel are required to pour acid down them once a week. Allegedly, an unknown bluish-colored sediment has also been seen oozing through the tarmac near gates B38 and B42.

Ms. Crandall and Ms. Hubbard allege they have developed various recurring respiratory difficulties and other ailments that are consistent with toxic exposure from having spent considerable time at the airport. The action alleges that other employees and patrons at the airport have experienced similar health problems.

The action alleges that the environmental problems at the airport have been further exacerbated by recurring raw sewage leaks and the resulting emissions of toxic gases as well as various other contaminants of concern, including solvents and de-icing chemicals used in aircraft maintenance. As a result of the poor environmental conditions, the airport allegedly poses a health hazard to all who pass through its doors, not just workers. The action alleges that, despite having known of these air-quality problems, Denver has failed to take adequate remedial action and, as a result, recklessly exposed tens of thousands of unwitting victims to the conditions.

Among other specific conditions, the action alleges that massive amounts of mold in a men's locker room on Concourse B have been found--one test revealed more than one million "colony forming units" in a two-inch area. Experts say numbers in the low thousands are generally a cause for concern. Additionally, mold contamination covering an entire wall in Concourse B was allegedly found--an area of growth at least 20 feet high by 80 feet long. Allegedly, another area of contamination made an airport training room unusable. To make things worse, there allegedly are pools of leaking raw sewage in tunnels under Concourse B up to 6 inches deep and 10 feet long by 4 feet wide. Sewer gases allegedly emanate through the east and west Red Carpet rooms, special service rooms and elevator shafts on Concourse B as well.

The action seeks a one-time health checkup for all affected persons to administer blood and other tests to measure existing exposure, diagnose current health problems, and educate individuals regarding toxic exposure and the "warning signs" of potential future problems. It also seeks the establishment of a court-supervised fund to provide ongoing medical monitoring to ensure early detection of any future health problems. Finally, the action seeks to force Denver to abate all existing contamination and to take reasonable steps to protect the public's health in the interim, including closing portions of the airport if necessary during remediation.