The city of Los Angeles will spend about $43 million to convert the Terminal Island waste-water treatment plant into a water recycling facility.

The plant treats sewage from Wilmington and San Pedro and then discharges it into the harbor.

For 10 years, the city has been unable to prove that the quality of discharged water meets state guidelines, said Jerry Gewe, water resources engineer at the city Department of Water and Power. In 1985, the California Regional Water Quality Control Board ordered the city to improve water quality.