ATC Group Services LLC, a leading full-service environmental consulting and industrial hygiene firm, today announced that it has agreed to acquire Environmental Compliance Services, a leading multi-regional provider of environmental consulting, site remediation and regulatory compliance services. Terms of the transaction were not disclosed.

Founded in 1982 with headquarters in Agawam, Mass., ECS has more than 250 employees operating out of 27 offices in 15 states and provides a range of environmental services, with a particular focus on the retail petroleum market and associated underground storage tank inspection, remediation and regulatory compliance.

“Environmental consulting is the heart of ATC’s business, and ECS’s expertise and service offering are a perfect addition to our existing environmental capabilities,” said ATC CEO Bobby Toups. “ECS’s strong customer base is highly complementary to our own, so by joining forces we will be better positioned to drive growth and deliver an even broader portfolio of environmental services to our valued customers. On behalf of everyone at ATC, I want to extend a warm welcome to the ECS team. We are delighted to have their talented employees join the ATC family.”

As a result of the planned acquisition, ATC will grow to more than 1,900 employees across more than 100 locations, further expanding the company’s national footprint. ECS will continue to be led by Mark Hellstein, ECS’s current president and CEO.

“Having worked closely with ATC in the past, I am confident that they are the best partner to accelerate our growth moving forward as we expand into new markets,” said Hellstein. “We look forward to continuing to redefine consulting, with best-in-class field and customer service.”

ATC’s agreement to acquire ECS follows its recent purchase of Dexter Field Services, a leading provider of leak detection and repair (LDAR), monitoring and other specialized technical environmental services, along with Sage Environmental Consulting, a recognized leader in technical consulting services with a particular focus in air quality control and consulting, due diligence and emission-reduction credit services.

ATC is owned by a group of investors led by Bernhard Capital Partners, an operationally focused private equity firm dedicated to investing across the energy services spectrum.