The Southern California Chapter of the American Public Works Association (APWA) has recognized the city’s cutting-edge Strand Infiltration Trench Project under the beach sand with a 2010 B.E.S.T APWA Project of the Year Award.
“We are pleased and gratified to have this recognition of the hard work and innovative efforts of our public works departments and the team responsible for the Strand Infiltration Trench Project,” Mayor Peter Tucker said. “This project exemplifies the city’s commitment to making Hermosa Beach a greener place to live, work and play.”
The award follows on the heels of the U.S. Environmental Protection Agency presenting a “2010 Environmental Achievement Award” to the city for water-saving and pollution-fighting elements of a large construction project to overhaul of upper Pier Avenue.
The beach trench, completed in April, lies three feet under the sand, and runs from the city pier 1,000 feet south, parallel to the Strand wall, ending at Eighth Street. It is designed to collect urban storm-water runoff – a leading cause of ocean pollution – from a huge storm drain at Pier Avenue and filter down through the beach sand instead of spilling into the blue Pacific.
The storm-water runoff, which begins collecting in inland cities and pours through drainpipes to the beach, is dammed from entering the Pier Avenue drain pipe and diverted into an underground well at the base of the pier.
There, it is filtered for gross contaminants and then pumped into the trench, which is made of interlocking plastic boxes, like milk crates, with fabric wound around them to let the water filter downward into the beach sand, which provides further filtering. Bacteria decompose as the water makes its way farther down to the groundwater table and out to sea.
The trench design is so cutting-edge that officials could find only one similar storm drain project nationwide, a filtration trench in the sand dunes of North Carolina that has not yet yielded enough data to fully gauge its usefulness.
Officials will monitor the effectiveness of the seaside filtration trench for a year, and then hope to seek further grants for their “master plan” to extend the trench the length of the city and link it to the other 11 storm drains. Meanwhile, officials up and down the coast await word on the project’s effectiveness, said Kathleen McGowan, an environmental engineer who helped pull together the project and its funding.
Funding for the project came from a number of sources. California’s Proposition 50 Clean Beaches Initiative paid for planning and pre-construction work. The Los Angeles County Flood Control District funded design of the project. Construction and monitoring was funded by the EPA with federal stimulus money.
The Southern California Chapter of the APWA represents more than 1,400 members throughout Los Angeles, Orange, Riverside and San Bernardino counties. The awards program recognizes public agencies for outstanding projects and programs that can serve as models for other cities. ER
