A helicopter flying over some urban areas of King and Pierce counties will gather radiological readings July 11-28, 2011. The U.S. Department of Energy's Remote Sensing Laboratory Aerial Measurement System will collect baseline levels of radioactive materials. The helicopter's equipment can detect the presence of radioactive materials that emit gamma radiation such as cesium and radioactive iodine. The baseline would be used in the event of a radiation emergency to compare radioactive contamination to the normal levels found during this study. The Washington State Department of Health Office of Radiation Protection is overseeing the project, which is funded by the U.S. Department of Homeland Security.

The helicopter will fly a grid pattern spaced about 600 feet apart at an altitude of 300 feet, flying at 70 mph. The results will be provided to local agencies from the surveyed area by year-end. Some of the data may be withheld for national security purposes. The state Department of Health has been planning this project since 2009.