- 921 views
Last week in this space we briefly outlined the monumental role of Los Angeles County Sanitation Districts (LACSD) in handling the waste of nearly six million citizens in the greater L.A. area. Broadly speaking, these enormous tasks can be divided into two gritty and unpoetic categories--garbage and sewage. But modern waste treatment is much more than that.
So instead of "sewage," we have "wastewater treatment" and "water reclamation." The LACSD network includes eleven wastewater treatment plants that process water from about 9,500 miles of sewers that "are tributary to the Sanitation Districts' wastewater collection system," according to the LACSD website. This water is treated in a three-stage process that emulates nature: first by separating larger light and heavy waste as it floats to the top or sinks to the bottom, second by allowing natural microorganisms in flowing aeration tanks to feed on dissolved organic materials, and third, simulating nature's groundwater, by filtering out anything that's left.
Even this "tertiary treatment," as it is termed, though "free of harmful bacteria and viruses and safe for human contact," is not permitted for use as drinking water, but is either marketed as "reclaimed water" or released back into groundwater for nature to complete the job as only nature can.
Of the eleven sites mentioned above, this writer has visited the San Jose Creek Water Reclamation Plant (SJCWRP), near LACSD's administration office in Whittier, and it's both impressive and reassuring to witness clean limpid water happily churning through rows of outdoor pools on its way back into the ecosystem--to the tune of 100 million gallons per day.
A different process takes place at the Joint Water Pollution Control Plant (JWPCP) in Long Beach, where waste water from trunk sewers that is too high in salt content for reuse is cleaned to a "secondary treatment" level before being released into the ocean. JWPCP, also toured by this writer, presents itself more as a factory than the San Jose Creek WRP, in part because it also processes over a half million tons of biosolids, creating, among other products, biogas that actually powers not only the plant itself, but releases excess electricity back into the grid.
Back to "garbage," four solid waste facilities complete the diverse picture of waste management in the LACSD system.
The first, in collaboration with the City of Long Beach, is the Southeast Resource Recovery Facility (SERRF), a sophisticated incinerator compound, which simultaneously processes over a thousand tons per day of Long Beach municipal solid waste, recycles over 800 tons of ferrous metals per month, destroys over 8 tons of confiscated illegal narcotics monthly, and, finally, produces enough electricity to furnish more than 35,000 homes with electrical power (all this according to SERRF's published fact sheet).
Secondly, the Puente Hills Landfill has been serving our area since 1958. Similar to both JWPCP and SERRF, it also has an energy production facility. A firsthand look at the landfill site and its operation provides clear evidence of a conscientious daily exercise in odor, dust, and litter control. Impermeable underground liners offer groundwater protection. And finally, as with all LACSD facilities, extensive monitoring ensures overall environmental safeguards.
Last among LACSD's facilities, portending the imminent future of waste management, are the Puente Hills Materials Recovery Facility and the Puente Hills Intermodal Facility, nestled close to the Landfill in the Whittier hills. When the Puente Hills Landfill closes, as mandated in November 2013, the future of waste management will be taking shape, as waste from the MRF is transferred to trains and shipped 200 miles to the Mesquite Regional Landfill, purchased by LACSD in 2002, ushering in waste-by-rail as one of the primary solid waste management techniques of the future.
Published: July 19, 2012 - Volume 11 - Issue 14