At 10 a.m. Tuesday, May 2, Pierce County will test its lahar warning sirens in an effort to educate and prepare citizens for potential volcanic hazards in the Puyallup and Carbon River valleys.

This drill will allow the Department of Emergency Management to test the siren equipment and monitor sound coverage. Sirens will run for approximately five minutes. The Emergency Alert System will conduct a simultaneous test on local broadcast stations. Some area schools may conduct evacuation drills in concert with the lahar warning test.

According to scientists at the U.S. Geological Survey, lahars from Mount Rainier are the primary hazard to developed areas from Orting to Sumner, Puyallup and Fife. Lahars, also called mudflows, are dense mixtures of water-saturated debris that look and behave much like flowing concrete.

“The evacuation sirens in the Puyallup Valley provide a critically important early warning mechanism that can help save lives. Sirens along with evacuation signs remind residents and visitors alike that the valley is potentially at risk because of Mount Rainier’s proximity,” said Emergency Management Director Steve Bailey.

The warning system includes 24 sirens, nine in Fife, six in Orting, four in Puyallup, three in unincorporated areas (Alderton/McMillin and Riverside) and one each in Milton and Sumner.

While Mount Rainier shows no sign of renewed volcanic activity, the timing of lahars is unpredictable. “Much of our planning efforts are based on the knowledge that scientists have learned that some lahars were caused by landslides that may not have been preceded by volcanic unrest,” Bailey said.

Through public education and the Neighborhood Emergency Team program, Pierce County Emergency Managem ent is educating citizens to recognize the warning sirens, to learn evacuation routes and to organize their response to an emergency situation, which includes being able to provide their own food, water and shelter for at least a week following a lahar or other disaster-type event.