Conversation: 'Semper Fi' Director Rachel Lipert

April 19, 2011 -- Marine Corps Master Sgt. Jerry Ensminger lost his daughter to a rare type of leukemia and in his search for understanding found a Marine Corps cover-up. Ensminger discovered that the water at Camp Lejeune Marine Corps Base in North Carolina had been highly contaminated by toxic chemicals for 30 years and that when the Marine Corps shut down the toxic wells they did not make the contamination public.

Approximately one million Marines and their families were exposed to high levels of carcinogens transmitted through their water supply, and to this day few residents are aware of their exposure.

When he heard the announcement about the dangerous chemicals in the Camp Lejuene water supply, Ensminger says, "I dropped my plate, right there." His first thought was, "Is this what happened to Janey?"

In the new film "Semper Fi: Always Faithful," which premieres on Thursday at the Tribeca Film Festival, director and producer Rachel Libert and Tony Hardmon chronicle Ensminger's journey of discovery and activism. Ensminger is currently leading a coalition of former residents of the base, many of them having suffered tragic family losses from diseases that might be linked to chemicals in the water.

Libert told ABC News, "I went into this really believing at the core of this that the government was really protecting us." However, that changed over the course of making the documentary. "I have to say, after making the film, I am less confidant in those agencies that are set to protect us."

Watch our Conversation with director and producer Rachel Libert to find out more about this story of a man's fierce determination to find out what happened, and to set it right.