May. 21, 2011 Puyallup parking lot doubles as rain filter

One of the parking lots at the Washington State University Research and Extension Center in Puyallup isn’t just a place for people to leave their cars while they work or visit.

It’s also a stormwater filtration system. So are the “rain gardens” several feet away.

The asphalt is porous, allowing rain to sink into the ground. And the 36 beds and tanks of soil and plants are designed to catch and filter rainwater before it carries oil, grease and other pollutants to waterways.

Read the full article on the Tacoma News Tribune website.