Partner Engineering and Science, Inc. (Partner) was named the fifth largest firm on the 2014 LABJ Top Environmental Firms List. Published in November by the Los Angeles Business Journal, the list ranks the top 25 environmental companies in Los Angeles County by number of employees. The top 25 environmental firms represent over 2000 LA-based employees. Partner is widely recognized as the top provider of Phase I Environmental Site Assessments in the commercial real estate industry. Widely acknowledged by industry professionals, Partner delivers best-in-class Phase I Environmental Site Assessments.
This year’s ranking marks Partner’s first appearance in the top 5. The California presence of the Torrance-headquartered firm, which now includes 165 employees and 8 offices, has grown significantly in the last year. Joseph Derhake, President at Partner, explains that the demand for environmental due diligence services in Los Angeles is continuing to grow. “The LA commercial real estate market is performing well, and in this post-recession world, many borrowers and lenders are placing increased emphasis on thorough pre-transactional due diligence to better manage risks and liabilities,” he explains. “We’re hiring and devoting more resources to strong-performing regions like LA County to ensure we’re well equipped to meet these increased demands.”
In addition to being recognized as the fifth largest environmental firm, Partner was included on LABJ’s top 100 fastest growing businesses for 2014. “I’m hopeful that the combination of these two awards means Partner will continue to climb even closer to the top of the list over the next year!” said Derhake.

April 27, 2026
In this article from Propmodo.com, Jerry Ostrander discusses a number of important factors to consider to help prevent environmental contamination concerns from becoming impenetrable roadblocks to development projects. Environmental challenges are a reality in many development projects.

April 23, 2026
An integrated, enterprise-level environmental strategy unifies environmental due diligence, remediation, environmental, health and safety (EHS), and compliance, energy and sustainability, and real estate support under one coordinated framework supported by building sciences expertise.

March 24, 2026
As PFAS continue to reshape the construction risk landscape, lenders that proactively integrate PFAS considerations into underwriting, due diligence, and loan structuring are better positioned to manage uncertainty and protect collateral value.




