Protecting the sea from underground
Mayor Michael DiVirgilio lauds a cutting-edge project to keep the ocean clean. Photo
City officials have cut the ribbon on an innovative construction project longer than three football fields, which is invisible to Hermosans, but is being watched by officials up and down the coast for its potential to keep the ocean clean.
The just-completed project, a special storm-water filtration trench, lies three feet under the beach sand, and runs from the city pier 1,000 feet south, parallel to the Strand wall, ending at Eighth Street. The trench 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 down through drainpipes to the beach, will be dammed from entering the Pier Avenue drain pipe and diverted into an underground well at the base of the pier.
There, it will be 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 will provide further filtering. Any bacteria is expected to 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.
The project was funded mainly by a $951,000 grant from the federal economic stimulus act, through the EPA and the state Water Resources Control Board. Other funding included state money set aside for water protection through Prop. 50. The project’s design was funded by the Los Angeles County Flood Control District.
“The whole project was funded by grants. That’s what made it possible,” said the city’s public works director, Rick Morgan, during a seaside ribbon-cutting ceremony Thursday, on the nation’s 40th annual Earth Day. Looking on were City Council members, public works commissioners and officials of the U.S. Environmental Protection Agency, the environmental group Heal the Bay, the California Water Board and Los Angeles County public works.
Morgan hailed a handful of lifeguards stationed at the pier building who were watching the proceedings, and one of them called to him, “You’re cleaning up our water, thank you.”
Mayor Michael DiVirgilio told the gathering that he mentions the trench project as much as any other when he’s touting Hermosa, which he described as a town whose achievements outstrip its size.
“We like to push for these things that are bigger than we are,” he said.
Mark Gold, president of the prominent environmental group Heal the Bay, spent Earth Day morning in Hermosa, where he praised the “great leadership” of Hermosa officials.
Hermosa’s ocean waters are relatively clean because the slope of the land carries most inland storm water to the north or the south. But areas of the beach, and sometimes the ocean, can get nasty near the mouths of the storm drains. During the dry season the drains clog, leaving standing water and oily debris that rots and stinks after being washed into the pipes during previous rains. Then the first rain of a rainy season pushes that debris out into the open.
In addition, during the dry months, winds off the ocean blow inland through the drains and stink up areas around street-side storm grates. In desperation, some residents have poured bleach into the drainpipes – a bad move ecologically – to stem the smell, Morgan said. The Pier Avenue drain pipe stinks up a grated area on the Pier Plaza and along Beach Drive, he said.
But this summer the Pier Avenue pipe will be “bone dry” and there will be no pipe stink, he said.
Because of low-lying land, linking the Pier Avenue storm drain to the filtration trench presented more difficulties than will be expected from the city’s other storm drains, said Zahid Atashzay, a county civil engineer who was the lead designer for the project.
After the ceremony Councilman Jeff Duclos praised the project, but added that more is needed to address urban runoff long before it reaches the seaside.
“It’s an end-point solution to a source-point problem,” he said. “…We need to look at diverting flows, recapturing water, re-treating water and reusing water.”
Other environmental initiatives by the city include an annual beach clean-up effort, sponsoring a yearly toxic waste disposal site, establishing a citywide green task force, and becoming the first city in Los Angeles County to pledge to work toward carbon neutrality. ER