Officials blame heavy rains for more than 40 million gallons (33 million imperial gallons) of sewage spills in the Atlanta area in the last four months.
The Atlanta Journal-Constitution reported Fulton County's system has been overwhelmed a number of times since mid-November, dumping untreated sewage into waterways.
State health officials say more than 1 million gallons (0.8 million imperial gallons) spilled six times. A 14 million gallon (12 million imperial gallon) spill in January was the worst spill in Georgia in at least five years.
Fulton County entered a consent agreement with the Georgia Environmental Protection Division in 2010 to reduce. Annual totals had been running less than 700,000 gallons (583,000 imperial gallons) per year.
Fulton County has paid more than $150,000 in fines already. The county has until the end of March to respond to a violation letter from state environmental officials.