The project, which cost more than $3 million, involved installing new pipes and water mains to replace old ones that had become unsafe.
The faulty infrastructure led to a series of water main breaks and water outages over the past several years.
Officials also broke ground on construction of a new water tower in an empty field.
It's all part of a large plan which his said to bring relief to the north end of Dixmoor, reducing water loss and increasing water pressure.
Village President Fitzgerald Roberts became emotional while speaking about the progress.
"You've got to excuse me for feeling this way. This is something that the residents been needing for years," he said.
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"This repaired water main will ensure Dixmoor residents have access to safe water for years to come; a human right that everyone should be entitled to," said Cook County Board Commissioner Monica Gordon.
Local elected officials, including Cook County President Toni Preckwinkle, were joined by the U.S. Army Corp of Engineers for a noon celebration.
"We are deeply grateful to Congresswoman Kelly, the Army Corps of Engineers and all our partners for their commitment to ensuring that Dixmoor residents have access to reliable and safe water," Preckwinkle said. "This project is a testament to what we can accomplish when federal, county and local governments work together to address critical infrastructure needs. However, there is still much work to be done. We will continue to advocate for additional federal resources to improve vital water infrastructure, not only in Dixmoor, but across all under-resourced communities in Cook County."
Village and county leaders said it would take billions of dollars to fix the aging infrastructure not only in Dixmoor but other parts of Cook County's west and south suburbs.