SJE (Audax Portfolio) Acquires L.W. Allen from Gen Cap America

Audax Private Equity Acquires Majority Stake in S.J. Electro Systems

June 28, 2021

Manufacturing

Audax Private Equity acquired a majority stake in S.J. Electro Systems (SJE), a Detroit Lakes, Minnesota-based manufacturer of control solutions for the water and wastewater industry. Financial terms were not disclosed; Audax said it will provide strategic capital and operational support to help SJE scale organically and through add-on acquisitions.

Water Engineering Acquires LDW Water Technologies

July 1, 2025

Environmental Services

Water Engineering, a portfolio company of Nolan Capital, has acquired LDW Water Technologies, a Sicklerville, New Jersey-based provider of industrial water and wastewater treatment solutions. The deal expands Water Engineering's Northeast footprint and wastewater capabilities; LDW's former owner John Drimak will remain with the business as it integrates into the WEI platform.

Water Engineering (Nolan Capital Portfolio) Acquires American Water Treatment, Inc.

July 13, 2022

Environmental Services

Water Engineering, a portfolio company of Nolan Capital, has acquired American Water Treatment, a family-owned water treatment services provider headquartered in St. Louis, Missouri. The acquisition adds American Water’s ~900-customer, multi-state footprint to the WEI platform as an add-on to expand geographic coverage and service capabilities while retaining the existing team and legacy brand.

SJE Inc. Acquires Revere Control Systems

September 16, 2024

Industrial Services

SJE Inc., a portfolio company of Audax Private Equity, acquired Revere Control Systems on September 16, 2024. The add-on expands SJE's engineered control solutions capabilities and geographic footprint in water/wastewater and industrial control systems, integrating Revere's engineering, design, installation and commissioning services into SJE's ECS division.

SJE, Inc. Acquires LangeTech Inc.

October 8, 2025

Engineering Services

SJE, Inc. has acquired LangeTech Inc., a system integrator and engineering services provider for the automation industry, to grow its Engineered Control Solutions (ECS) business. LangeTech, founded in 2002 and headquartered in Chesterfield, Missouri, brings system integration, SCADA, control systems and aftermarket services—strengthening SJE's capabilities and U.S. footprint. Terms were not disclosed.

WSB LLC Acquires AE Engineering, Inc.

February 20, 2024

Engineering Services

WSB LLC, a Minneapolis-based design and consulting firm and portfolio company of GHK Capital Partners, has acquired AE Engineering, Inc., a transportation infrastructure engineering firm headquartered in Jacksonville, Florida. The acquisition adds 13 offices and more than 170 employees to WSB, strengthening its presence and service offerings across the southeastern United States.