Charlotte-based environmental and emergency response provider HEPACO LLC has acquired Norfolk, Virginia-based PetroChem Recovery Services Inc., for an undisclosed amount, the latest in a string of similar acquisitions.

HEPACO, headquartered in Charlotte, is a portfolio company of emergency response service groups and has been majority-owned by San Francisco-based private equity group Gryphon Investors since 201. PetroChem had been owned by Succession Capital Partners.

This acquisition marks the fourth for HEPACO in Gryphon’s tenure as majority owner. In December, HEPACO bought Environmental Management Specialists Inc., and October saw two acquisitions of environmental cleanup companies.

“We are excited to continue our successful acquisition strategy with the PetroChem transaction,” says HEPACO Chairman and Gryphon Operating Partner Phil Petrocelli. “We anticipate continuing HEPACO’s expansion through new geographies and greater coverage density in attractive markets.”

HEPACO provides hazardous material spill response and restoration; marine oil spill response and restoration; transportation incident response; train derailment assistance; and chemical transfers.

PetroChem provides environmental services such as emergency spill response, waste management and tank cleaning for transportation, industrial and government clients.

On its website, PetroChem lists Norfolk and Tidewater, Virginia, as well as northeastern North Carolina, as areas covered in its one-hour response zone.

The transaction’s press release can be found here.