The Dorr-Leighton Wastewater Treatment Plant has been awarded a $4.85 million grant from the United States Department of Agriculture to expand its size.

Dorr Township Supervisor Jeff Miling said the plant is nearing capacity, at 80 percent, and the two townships are experiencing population and business growth, which prompted the application for the federal grant.

Local officials indicate the plant serves about 500 customers, including homes, businesses, an apartment complex and mobile home park. The grant has been approved but local officials say they still must complete a number of further steps to finalize the financial transaction.

Cost of the expansion project has been estimated at $5 million, and bidding could begin later this year.

The USDA announced Wednesday that five grant awards were selected for wastewater treatment plant upgrades needed to meet Michigan Department of Environment, Great Lakes and Energy regulations.