Day & Zimmermann Named the Top O&M Contractor in Power by Engineering News-Record for Seventh Consecutive Year

PHILADELPHIA, PA - September 30, 2014 – Day & Zimmermann (D&Z), the century-old, family-owned provider of construction and engineering, staffing and defense solutions for leading corporations and governments around the world, announced today it has been ranked as Engineering News-Record (ENR)’s number one Operations and Maintenance Contractor in Power for the seventh year in a row.

The ranking is part of ENR’s annual Top 400 Contractors Survey featured in its September Sourcebook. The Sourcebook provides market analysis and rankings of the leading U.S.-based architectural and engineering firms in an assortment of industry sectors.

“We are proud to once again be recognized as the top United States maintenance contractor in the power industry,” said Michael McMahon, president of Day & Zimmermann’s Engineering, Construction and Maintenance group. “This recognition reflects our relentless commitment to safety, quality, innovative solutions and doing what we say. With seven straight years at the top of this list, we have the track record to prove that commitment.”

In addition to earning the top O&M contractor status, D&Z also ranked number six on the list of Top Contractors in Power.


Day & Zimmermann is a century-old, family-owned company whose 21,000 employees specialize in construction & engineering, staffing and defense solutions for leading corporations and governments around the world. Operating from more than 150 worldwide locations with 2.2 Billion USD in revenue, Day & Zimmermann is currently ranked as one of the largest private companies in the U.S. by Forbes. Founded in 1901 and headquartered in Philadelphia, PA, our first work was to develop “Betterment Reports” that helped modernize American factories. Today, we are still in the business of betterment—maintaining the nation’s power infrastructure, protecting American freedoms and driving technological advancements around the world. We do what we say. ®