The city of Los Angeles, forced by the federal government to stop dumping sewage sludge into Santa Monica Bay more than two years ago, has been quietly seeking permission to spread up to 300 tons a day of the gooey material as a fertilizer over farm fields in the Antelope Valley.
In a disclosure that raised environmental concerns, officials in the Los Angeles City Bureau of Sanitation confirmed Monday that they hope to truck the sludge, more than 20% of that produced by the entire city, to as many as five privately owned Antelope Valley sites totaling about 3,500 acres.
The proposal, which had gotten little public notice, was scheduled to be approved last week by the California Regional Water Quality Control Board, meeting in Death Valley, about 150 miles to the northeast.
But approval was postponed for two months after some board members raised concerns about potential ground-water contamination.
Officials of Palmdale and Lancaster--the closest cities to the proposed dumping grounds, only 10 miles outside their city limits, in some cases--said they were unaware of the proposal until they were asked about it Monday.
And County Supervisor Mike Antonovich, who represents the unincorporated county areas where the farms are located, said he too was unaware of the sludge proposal.
Los Angeles officials insist that the land application of treated sewage sludge as a fertilizer, a relatively new concept locally, is environmentally safe and advantageous. But they also acknowledged that the practice might shock the public and that the sludge can spill and cause odor problems.
"People don't have any problem with using manure or chicken waste as fertilizer. But when you say sewage sludge from a municipality, nobody can understand that," said Kelvin Fossett, an official in the sludge management unit of the city's Bureau of Sanitation.
Sewage sludge, which contains a variety of contaminants including heavy metals, is the mud-like material that remains when waste water is treated. The city's main Hyperion sewage treatment plant in Playa del Rey produces about 1,350 tons of the sludge each day.
For 30 years, the city had dumped all its sludge through a pipeline into Santa Monica Bay. But the federal government, citing environmental concerns, sued the city and forced a halt to that practice in late 1987. Since then, the city has increasingly turned to trying to use the sludge as a fertilizer.
The city now trucks about 600 tons of sludge daily to farms near Blythe in Riverside County and about 350 tons a day to farms near Yuma, Ariz. The Antelope Valley proposal is the first time the city has tried to use sludge as farm fertilizer in Los Angeles County.
The city hopes to shift up to 300 tons a day of the sludge now going to Blythe to the Antelope Valley locations. Because the Antelope Valley is only about 70 miles from Hyperion, compared to about 220 miles for Blythe, the city could save about $1 million a year in trucking costs.
The Antelope Valley sludge operation would be run by Bio Gro Systems Inc., a firm that is already under contract to the city to handle the sludge trucking to Blythe. City officials said it would take about 13 trucks, operating seven days a week, to handle the load.
The five proposed Antelope Valley sludge sites surround the cities of Lancaster and Palmdale. They are Bio Gro's own ranch (640 acres), the Ritter and Goode Ranch (1,280 acres), the Barnes Ranch (941 acres), the Munz Ranch (173 acres) and the Kotchian and Maricich Ranch (480 acres), a Bio Gro spokeswoman said.
Los Angeles officials said the sludge would be used to help grow such products as grass, barley and wheat. The proposed water board permit would not allow any products for human consumption to be grown on that land. But city officials said the sludge could legally be used for that purpose.
The city pays Bio Gro to truck the sludge away. The farmers who agree to accept the sludge get it for free, in return for the use of their land. City officials said that any one field typically receives only about one application of the waste per year.