Treated wastewater from Meridian is now being used at the Kemper County coal plant.
City officials met with Mississippi Power and South Mississippi Electric Power Association Wednesday in Kemper County to celebrate the deal.
The water is being used in the plant's cooling process. Officials say it will provide economic benefits to the city and to the plant.
The water is being pumped by pipeline into a 75-acre reservoir at the lignite coal facility.
"All of our studies that we did have showed that this is a positive thing for South Mississippi Electric and so we are very excited into our partnership with Mississippi Power," said Jeanetta Bennett.
It will take approximately two months to fill the reservoir.