No records can be found indicating that Marine officials at Camp Lejeune, N.C., ever tested the drinking water there for contaminants, authorities say.
Contamination of the drinking water at the base is believed to be the worst in U.S. history, the Tampa Bay Times reported Sunday.
Although the corps began requiring the testing at Marine bases in 1963, a check of more than 8,000 pages of documents have not found evidence the testing was done, said Corps spokeswoman Capt. Kendra Motz.
She added the absence of records 50 years later "is not an indication that an action was or was not taken, only that no records are available."
More than 185,000 people who drank, cooked or bathed in the water from 1953 to 1987 have signed up for a health registry.
Scientists say the base's polluted water came from a number of sources, including a dry cleaner and discarded industrial solvents.