Anthrax was buried in Area B, according to the U.S. Environmental Protection Agency, though the Army says it wasn't the type that can make people sick. Army records also indicate the spraying and disposal of a small quantity of herbicides or weed-killers, including the active ingredients of Agent Orange, the defoliant that was sprayed extensively by the military in Southeast Asia during the Vietnam War.

But the most widespread chemical threats found around Fort Detrick have been more commonplace: trichloroethylene (TCE) and perchloroethylene (PCE), both solvents used for degreasing metal and in dry cleaning. Both chemical are known carcinogens.

The chemicals showed up in groundwater on the base, and in 1992 state officials found unsafe levels of TCE in the drinking water of four homes just outside Area B. The Army connected three of the homes to public water; the fourth house was torn down, according to the Maryland Department of the Environment.

In the late 1990s, high levels of the two cleaning chemicals were detected in a spring that flows into Carroll Creek, which runs past the base and through downtown Frederick. Those levels, a thousand or more times the amount EPA has said is safe to consume in drinking water, fell a month later to around the safety threshold, state officials say.

Since then, the Army has dug up chemical containers and biological and medical waste from Area B. It has also excavated and removed almost 4,000 tons of contaminated soil, according to the state.

Groundwater contamination in monitoring wells on the base has decreased but remains high. Federal and state officials became impatient several years ago with what they considered foot-dragging by the Army, and the EPA in 2009 put Area B on its list of Superfund priority cleanup sites.

The Army signed a legally enforceable cleanup agreement last year with EPA and the state.

To help reduce the spread of groundwater contamination, the Army has "capped" six old dump sites with several layers of plastic, clay and clean dirt, through which rainfall cannot soak.

Horacio Tablada, waste management director for the Maryland Department of the Environment, said the attention drawn to Fort Detrick by White has led state regulators to step up their own involvement.

"We believe that right now there's no impact on public health outside the base," Tablada says. But he said officials would like the Army to do more testing to be sure. Trace levels of TCE showed up six years ago in two wells west of Area B.

Military officials are working to sink 150 new monitoring wells to get a better idea of where the chemicals might be seeping underground, and they're planning more sampling off the base as well. They plan ultimately to pump and treat the tainted water.

"We have no indication right now of any contamination flowing outside our property," says Robert Sperling, Detrick's chief of public affairs.

Of the dumping and the use of herbicides on the base decades ago, Sperling says the practices were considered safe at the time.

"We're trying to do better now," he says.

In Frederick last week, Clifford Mitchell, with the Maryland Department of Health and Mental Hygiene, told residents that the number of diagnoses among those living within two miles of the base from 1992 through 2008 — the only period for which the state has data – did not differ significantly from those for Frederick County or Maryland as a whole.

Those findings echoed earlier reports. White disputes them.

He says his team — a group of varying size that he says has grown at times to as many as 10 paid professionals and up to 40 volunteers — has counted hundreds of cancer cases not listed in the state registry.

They include one family that has lost 17 members to cancer, and another that has lost 11. White says his team has found 1,200 cancers in two ZIP codes alone and 118 on a single street: Shookstown Road, which runs along the southern edge of Area B.

White was born and raised in Frederick, and returned after high school to raise a family. He and his wife had three children before divorcing in the early 1990s.

He left for Florida, where he helped found and lead a growing church in Tampa. His ex-wife and children stayed in Frederick, where they lived within a mile of the base.