Bioretention Wells Filter Lakewood Runoff

Nature is quietly working for a greener Lakewood, filtering runoff along Paramount Boulevard(PDF, 144KB) of pollutants, capturing litter, and even adding to the beauty of the city’s “urban forest.”

Lakewood has enlisted helpful soil organisms and specially engineered filtration material to improve the quality of the runoff that reaches the city’s storm drain system. Improving runoff is an environmental goal of the Lakewood City Council and the state Water Resources Control Board.

A pair of curb openings and two “Majestic Beauty” raphiolepis hawthorns are the only above-ground signs of “bioretention wells” recently installed as part of street improvements on Paramount Boulevard.

Funding for a major part of the project was made possible under a federal grant secured by Congresswoman Linda Sánchez. The two “bioretention wells” also came at the Congresswoman’s suggestion.

“I first learned about tree wells a few years ago, but there were none in operation in California,” said Sánchez. “I am proud that I was able to bring federal funding for local projects like this that make a positive impact on our environment.”

Lakewood is one of the first cities in southeast Los Angeles County to use bioretention technology, developed by Filterra Bioretention Systems.

The County Department of Public Works, through the efforts of Supervisor Don Knabe, provided engineering and design services for the street improvements.

Nearly all of a “bioretention well” is below ground, in the form of a concrete basin that connects the well to the existing storm drain system. Filtration material, organic mulch, and the roots of the tree planted in the well trap litter (removed by periodic cleaning). The well also filters dissolved toxins and harmful solids suspended in runoff.

Metals, oil, and organic pollutants are captured by the filtration media. The filtered runoff reaches the ocean environment without a load of toxins or trash.

In addition, the Paramount Boulevard project overlaid the street with rubberized asphalt (which recycled 25,000 used tires into the new paving).

The project also included six solar-powered bus shelters.