FAIRCHILD AIR FORCE BASE, Wash. – Air Force Civil Engineer Center began to sample off-base wells for elevated levels of PFOS and PFOA Monday.

Base officials said they will continue sampling approximately 50 residential wells for elevated levels of the two chemicals through next week. The decision to continue this phase of sampling is a result of three out of seven northern border wells on base that were found to be above the EPA health advisory levels.

Once sampling is complete, the preliminary results will take approximately 45 days to return to base officials, at which point, individual residents will be personally notified of their results according to a press release. The validated results will come about a month after that and will be mailed to the impacted residents.

“Our goal from the onset of this has been transparency. Our communities deserve to know what we know because this is a concern to all of us,” said Colonel Ryan Samuelson, 92nd Air Refueling Wing commander.

Phase one of sampling included 23 private wells. 17 were above health advisory levels, one was below and five wells did not have any detectable PFOS or PFOA according to a press release.

Phase two included four municipal wells, two monitoring wells and 28 residential wells. Two Airway Heights municipal wells and three residential wells were above the health advisory level. Five residential wells had detectable levels below the health advisory level and the rest of the wells did not have any detectable levels of either chemical according to AFB officials.

All residents whose water supply had levels above the health advisory level were notified and provided bottled water after preliminary results were received.

For more information on water sampling, contact the Fairchild AFB Public Affairs office at (509)-247-5705.

Editor's note: An earlier version of this article incorrectly reported four of seven wells were found to be above the EPA health advisory level. Fairchild Air Force Base issued a corrected press release Tuesday morning clarifying the correct number as three out of nine wells found to be above the advisory level.