The Defense Department says the military is beginning to check whether chemicals from its firefighting foam may have contaminated groundwater at hundreds of sites nationwide.
The department tells The Associated Press it identified 664 of its fire or crash training sites and the services have just begun the process of evaluating those sites to assess the risk to groundwater.
California has the most, with 85, followed by Texas, with 57, Florida, with 38, and Alaska and South Carolina, each with 26.
The Navy is now giving its personnel at a landing field in Virginia bottled water and testing nearby after the discovery of perfluorinated chemicals in drinking water.
And several congressmen are raising concerns about the safety of drinking water near two former Navy bases in suburban Philadelphia.