Advanced Disposal Services Inc. has taken managerial and financial control of sister company Interstate Waste Services Inc.

The Jacksonville, Fla.-based Advanced Disposal said in a news release that as of Sept. 1 the two companies owned by Highstar Capital through Star Atlantic Waste Holdings II LP began working together under the Advanced Disposal name. The two companies have historically operated independently of each other.

“While this milestone moves us on our way to become the largest privately-held solid waste company in North America, we remain committed to our foremost goal of being the best in the business,” said Charlie Appleby, Advanced Disposal chairman and CEO. “We look forward to working with our customers, employees and community partners as we grow Advanced Disposal’s footprint in the Northeast.”

On July 18,Highstar’s Star Atlantic signed a definitive agreement to acquire Veolia ES Solid Waste Inc. July 18 for $1.91 billion. The company expects the deal to close this fall.

Advanced Disposal said the combination of Advanced and Interstate is a key step toward in the process.  After closing, the three companies will operate under the Advanced Disposal name.

The new consolidated Advanced Disposal, following the Veolia closing, will operate in 20 states and the Bahamas, serve more than 1.8 million residential customers and more than 200,000 commercial and industrial customers, and generate an estimated $1.4 billion in annual revenues as will be the largest privately held waste and recycling business in the United States.