Crews installing berms in the pond.
Berms are small slopes constructed in the pond to slow the drainage of water out of the pond. The berms are covered with a long lasting plastic blanket that will protect the structure from erosion. The plastic is then covered in a crushed aggregate rock. The rock attracts metals that are present in the highway runoff water so as water flows over the top of the berm metals are filtered out.
Hydroseeding at the pond near Weyerhaeuser Way.
Buckley Nursery was contracted to plant on the sides of the pond. Plants slow down the drainage of water out of the pond and help with the water treatment process.
Completed Pond near the Federal Way city limits.
This pond can treat water from 514,879 square feet of impervious roadway surface. The cost to construct this pond was 34 cents a square foot. This pond and the five other ponds at the project site benefit the local environment.