Removing Rubbish

By Joseph Serna, Staff Writer
Hamilton Bowl
Minimizing water pollution in California is like finding letters in alphabet soup, there is an NPDES, a TMDL, some controlled by the EPA, some mandated by the federal CWA.
In the end, it all spells out to getting trash out of the water.
At the Tuesday, April 24, Signal Hill City Council meeting, city officials and a consultant for the city’s storm water program will give a detailed overview of Signal Hill’s Hamilton Bowl.
Hamilton Bowl, which also doubles as Chittick Field on Walnut Avenue just north of Pacific Coast Highway, is a 2.2-acre flood control detention basin with various trash capturing systems to mitigate pollution into the Los Angeles River.
The bowl serves about half of Signal Hill and portions of Long Beach–2,000 acres in all. While the bowl’s purpose as a reservoir during a storm is rather simple, installing and operating the various trash catchers within it was more involved.
The County of Los Angeles, and cities of Long Beach and Signal Hill all contributed to various mechanisms. Long Beach put about $600,000 into the project, said John Hunter, Signal Hill’s storm water consultant. Signal Hill’s $785,000 came from a state grant.
According to regulations by the California State Water Resources Board, cities must take steps to bring water quality to Environmental Protection Agency standards when they will inevitably be exposed to an unacceptable amount of pollution. These benchmarks set by the EPA are called Total Max Daily Loads, or TMDLs.
In other words, a TMDL is the government’s water-pollution bar that a city like Signal Hill cannot fall below.
Signal Hill and Long Beach are using more than three different techniques to capture the trash that flows through the Hamilton Bowl.
There are the underground Continuous Deflective Separation (CDS) units Long Beach uses, which filters the water in a swirling fashion as the trash is constantly floated to the top and captured. Officials estimate their cost at more than $600,000.
Signal Hill prefers one-quarter-inch wire mesh nets to capture much of the trash, which cost less than $100,000 a piece but do not hold as much as a CDS unit.
Convex GrateThe city also uses linear radials–a dozens-of-feet-long stainless steel convex grate with one-quarter-inch slots.
One of the radials in Hamilton Bowl is about 25 feet long, with about a three-foot circumference and costs about $58,000. The stainless steel prevents water from being contaminated with the device’s metals. Hamilton Bowl also contains a larger, $121,000 linear radial.
Hunter said the catchers are cleaned out about every other rainstorm–defined as more than a quarter-inch of rain.
Even with these and more devices in place, meeting the current TMDL remains to be seen. However, a new TMDL will be introduced in July, said City Manager Ken Farfsing.
Hamilton Bowl is capturing about 90 percent of the trash that passes through it, Farfsing said.
Hamilton Bowl protects about 75 percent of the watershed from Signal Hill and parts of Long Beach, he noted.
A 1996 TMDL called for a 10 percent reduction of trash flowing into the Los Angeles River every year for 10 years, which would leave the river virtually pollution free.
He argued the standard set more than 10 years ago calling for nearly pure water by the 10th year was unattainable. Signal Hill spearheaded litigation that overturned the TMDL, leaving the city with no pollution bar to rise above.
However, the city is anticipating the next TMDL, due out within a year, may call for a 40 percent reduction of trash in the first year. Signal Hill is already above that. Signal Hill is the last line of defense for one of seven flows into the river.
Los Angeles County cities must also meet the Regional Board’s regulations, which are set by the National Pollutant Discharge Elimination System (NPDES). The NPDES aims to regulate point-source polluters, like industrial buildings.
While the average compliance cost is $18 per household in Los Angeles County, Signal Hill dedicated more than $126 per household last year.
Complying with the trash TMDL (the Hamilton Bowl devices) cost Signal Hill residents $34.43 a household. The cost is covered in the city’s NPDES trash fee, a 5.6 percent municipal service fee hike approved about four years ago by residents.