But this was no ordinary case. The employee, Kevin M. Shipp, was a veteran Central Intelligence Agency officer. His home was at Camp Stanley, an Army weapons depot just north of San Antonio, in an area where the drinking water was polluted with toxic chemicals. The post includes a secret C.I.A. facility.
Declaring that its need to protect state secrets outweighed the Shipps' right to a day in court, the government persuaded a judge to seal the case and order the family and their lawyers not to discuss it, and to later dismiss the lawsuit without any hearing on the merits, Mr. Shipp said.
More than half a decade later, Mr. Shipp is going public with his story. He contends that the events broke up his marriage and destroyed his career, and that C.I.A. officials abused the State Secrets Privilege doctrine in an effort to cover up their own negligence.
Jennifer Youngblood, a C.I.A. spokeswoman, denied any wrongdoing by the agency. "The C.I.A. takes great care to help protect the health and welfare of its employees," she said.
Mr. Shipp recently completed a memoir filled with unclassified documents that he said backed up his assertions. He says that he submitted the manuscript to the agency for the required prepublication review but that it blacked out swaths of information, like accounts of his children's nosebleeds, strange rashes, vomiting, severe asthma and memory loss.
Citing a confidentiality agreement he signed with the government, Mr. Shipp would not discuss where the secret facility was located, what its purpose was, which agency he worked for or what his duties were.
Still, he said, he was free to say that he worked at C.I.A. headquarters in Langley, Va., both before and after his stint at the facility. And public documents from a separate lawsuit, which he filed against his insurance carrier over a claim for his family's destroyed belongings, make clear that he was stationed at Camp Stanley.
Mr. Shipp's ex-wife, Lorena Shipp, and one of his sons, Joel Shipp, now 28, said in interviews that the C.I.A. had assigned Mr. Shipp to a high-ranking job at the facility to uncover suspected security breaches. The family moved to an Army-owned house at Camp Stanley in June 1999 and left in May 2001.
It is not clear what took place at the C.I.A. facility. But the camp had been used as a weapons depot for generations. Joel and Lorena Shipp described bunkers and many old weapons, including Soviet weaponry. They also said that they occasionally saw officials performing tactical drills, and that sometimes items were burned or buried there.
"The house that our family was moved into was planted on top of a lot of buried ammunition," Joel Shipp said. "One time me and my little brother dug up a mustard gas shell."
The Shipps soon began to get sick. First they got nosebleeds, then they developed symptoms that doctors said resembled H.I.V. infection or exposure to radiation, according to family members. Eventually, Kevin Shipp said, he discovered that the house was full of a spreading black substance.
Camp Stanley has a troubled environmental record. In August 2001, according to local news reports, military officials began distributing bottled water to residents nearby after it was discovered that toxins from the camp had polluted an aquifer in the area, contaminating the drinking water.
The Shipps said they were twice evacuated from the house after expressing concern about their sudden health troubles. But, Kevin Shipp said, his supervisor played down the problems, declaring that the house was fine after its air was tested -- although the windows and doors were open at the time, Mr. Shipp said.
Suspicious of a cover-up, Mr. Shipp said he sent samples from the house to a scientist at Texas Tech University. His manuscript includes a Texas Tech report showing that the samples tested positive for toxic mold.
Eventually, the Shipps sued the C.I.A. using pseudonyms. Meanwhile, Mr. Shipp was transferred to the agency's headquarters, where he became a polygraph operator. But his relationship with the agency was deteriorating, and the family began to suspect that they had been placed under surveillance.
Mr. Shipp said he quit in 2002 after he was accused of using a government credit card to pay for personal expenses; he says he paid the money back, but had been told by a supervisor to use the card for clothes and lodging after his family had to leave the house and their old clothes were destroyed.
A federal judge overseeing the case ordered the family and the C.I.A. into mediation. Mr. Shipp's memoir includes a December 2003 settlement agreement -- signed by a government counsel -- under which the family would be paid $400,000 and would have to stay silent about the matter.
But two days later, he said, one of his attorneys, Clint Blackman, called him to say that the government had withdrawn the settlement. The case would be fought out in court.
The case was already sealed, and the Justice Department invoked the State Secrets Privilege -- a judicially created doctrine that the government has increasingly used to win the dismissal of lawsuits related to national security, shielding its actions from judicial review.
A federal judge dismissed the case, and an appeals court in New Orleans, in a secret ruling, later upheld that dismissal, Mr. Shipp said. Mr. Shipp's manuscript mentions several other lawyers who helped him in the case, including Mark Zaid of Washington, who has represented many intelligence officials in lawsuits against the government, and Jonathan Turley, a George Washington University law professor who has filed several lawsuits challenging claims of executive secrecy.
Mr. Blackman and Mr. Zaid confirmed that Mr. Shipp had been a client, but they declined to discuss any sealed lawsuit. Mr. Turley confirmed that he had been asked to consult on the case, but said he was never given details about it.
Mr. Shipp has moved to Florida and tried to rebuild his life. But angry at what had happened to his family, he says he has decided to go public, no matter the risk of talking about a sealed case.
"I decided to just sacrifice myself for the public to know what they did, how illegal it was, how flawed the State Secrets Privilege is, and how they used it to cover up the destruction of my family," he said. "It's just abominable what they did."