Covanta has completed a deal to acquire Circon from Kinderhook, the buyer's largest acquisition in two decades, financial advisory firm Brown Gibbons Lang & Company announced Monday.

The deal doubles Covanta's wastewater footprint and dramatically expands its engineered fuels business, according to a release. It also brings more than 600 employees and 2,500 customers from Circon, which is based in La Porte, Texas. 

The deal was first announced on April 3. In addition to acquiring a market leader in waste-derived fuels, Covanta is also entering the hazardous waste sector via Circon. 

Circon serves customers across more than 20 waste facilities in the Midwest, Southeast, and Gulf Coast, allowing Covanta to expand its geographic reach as well.

Covanta has bought several companies since EQT Infrastructure acquired the New Jersey-based company in 2021. Its eight acquisitions have expanded Covanta's environmental services division as the portfolio company looks to meet sustainability targets included in its deal with EQT.

The terms of the Circon deal were not closed. Previous reporting indicated the deal could be worth as much as $600 million.