LOS ANGELES — A massive homeless camp cleanup at Echo Park Lake has yielded 35 tons of trash, 723 pounds of biological waste, and thousands of hypodermic needles as the California city attempts to return the area to family use.

Recently released Los Angeles Sanitation Department reports show the magnitude of the environmental hazard that the Echo Park tent city had created before city officials stepped in to remove approximately 200 homeless people in March. The collected biological waste included 544 pounds of urine and 180 pounds of feces. Also found were 30 pounds of drug paraphernalia (including hypodermic needles), 45 pounds of corrosive material, 125 pounds of ignitable objects, 80 pounds of paint, and 15 pounds of hazardous oil.