A lawsuit filed Tuesday alleges negligence by the Los Angeles Department of Sanitation led to a massive sewage spill last July, as crews continue to clean up Southern California beaches closed because of a sewage spill last week.

The class action lawsuit places blame for last summer’s spill on workers at LA’s Hyperion treatment plant as well as the manufacturer of screens designed to filter debris from raw sewage, the Southern California News Group reported.

Debris clogging a filtering screen became clogged, triggering a flood at the plant that prompted workers to intentionally discharge millions of gallons of raw sewage into the ocean on July 11.

Lingering odors permeated residential neighborhoods in nearby El Segundo for months.

Elena Stern, a spokeswoman for the L.A. Department of Public Works, told the news group that the agency does not comment on pending litigation.

Meanwhile, beaches in Long Beach remained closed Tuesday after a sewage spill shut off large segment of the LA-area coastline before New Year’s Day. Officials said Monday that closures were lifted for five of seven beaches in Los Angeles County.

A sewer main line failed Thursday in the city of Carson, discharging roughly 8.5 million gallons (32 million liters) of sewage into the Dominguez Channel, which empties into LA Harbor.