A chemical mixing plant manager in metro Atlanta will spend a year on probation after directing his employees to wash thousands of gallons of carburetor cleaning fluid a tributary of the Chattahoochee River.

Smyrna resident Carlos Conde, 37, was sentenced this week by U.S. District Court Judge Thomas W. Thrash Jr. for violating the Clean Water Act. He will serve the first four months of his sentence on house arrest, and will be required to pay a $2,000 fine and a $100 special assessment.

According to federal prosecutors, on Aug. 12, 2016, a batching tank at Apollo Industries, a Smyrna-based chemical mixing plant, began leaking carburetor cleaner containing naphthalene, which smells like mothballs and can be toxic in large doses, the Centers for Disease Control and Prevention states.

Two employees discovered the spill and called Conde, who arrived at the plant and "instructed the employees to wash the chemical away with water from multiple hoses," prosecutors said.

The chemical flowed into Nickajack Creek and the river. The fluid turned the water a milky white and opaque color, killing several hundred fish and frogs.

An investigation revealed 2,300 gallons of the fluid spilled into the creek and river, and crews had to remove 500,000 gallons of contaminated water for treatment.

Prosecutors said Conde on two occasions deniedhis role in the incident during interviews with the U.S. Environmental Protection Agency. He eventually pleaded guilty to the charges in January.

>> Trending: Humpback whales with huge mouths wide open surprise fishermen, bump boat

"We must ensure that citizens can continue to enjoy the beautiful natural resources we have here in Georgia like the Chattahoochee," said U.S. Attorney BJay Pak. "Protecting those resources, and the environment, is part of our mission. We take this responsibility seriously, and we will prosecute those who have no respect for the laws that preserve them for all to use and enjoy."