DeKalb County reports show grease backups are to blame for two more raw sewage spills.

The spills were reported last week in the 5200 block of Panola Industrial Boulevard in Lithonia and on Brandywine Road in Atlanta.

About 1,980 gallons spilled into the Panthers Branch stream and about 2,880 gallons spilled into the north fork of Peachtree Creek, according to county watershed management reports.

In December, the federal Environmental Protection Agency mandated DeKalb upgrade its sewer system after the county reported more than 800 sewage spills in five years. DeKalb has since authorized rate increases to pay for $1.35 billion in upgrades to the water and sewer system.