Since its founding in 1939, Norwesco has been North America’s leading manufacturer of proprietary, rotationally-molded polyethylene tanks for agricultural, water, closed-top industrial and below ground septic and cistern applications. In 1988, the company, which had been public since the late 1950s, was taken private by management shareholders and private equity investors, including NEP, in a leveraged buyout transaction. In 1992, NEP, as the majority shareholder, sought liquidity for its investment through the sale of the company to Trivest, a private equity firm.

Six years later in 1998, NEP again purchased Norwesco from Trivest in a privately-negotiated, non-auction management buyout. Over the course of its second-round investment, NEP helped to close five additional add-on acquisitions for Norwesco.

Norwesco was sold to Allied Capital Corporation in July 2005.