LEWIS COUNTY, Wash. - Scientists studying the December floods that ravaged Lewis County say it was much worse than first thought, bursting the theory that it was a 100-year storm event.

Instead, researchers with the U.S. Geologic Survey are calling it a "500-year storm."

Researchers lost their high elevation storm and stream-flow monitoring stations during the big flood, so they had to get creative in their investigation.

But what they found is a rain, snow-melt and flood event that eclipses earlier estimates.

"So we know it was something substantially huge because it exceeded our previous level by almost double," said Mark Mastin, USGS Surface Water Specialist.

The storm left debris spread across the region. Groups like the Washington Conservation Corps keep rolling along, but find no end to the hazardous materials left across Lewis County.

"We're finding anywhere from 55-gallon barrels to small aerosol cans empty and full of fluids both," said Bob Milner, of the Washington Conservation Corps.

Ditches and drainages are still filled with toxic containers and household treasures-turned debris.

"We trying to get to the stuff before another flood or heavy rains come through to make it even more difficult to retrieve," said Ron Holcomb, of the state Dept. of Ecology.