About Us

About Us

Cornerstone Environmental, A Tetra Tech Company, is an engineering consulting and field service firm dedicated to providing services to the solid waste industry and commercial, industrial, and agricultural clients throughout the nation.

The firm was founded in 2006 by  industry leaders who have helped to develop and shape solid waste, energy, and environmental technologies over the past 30 years. The entire Cornerstone organization shares a common vision – to serve its clients with energy, integrity, and innovation.

Cornerstone’s staff is a team of professionals recognized nationally for their environmental expertise. Our mission is to provide the highest quality environmental, solid waste engineering, field service, construction management and professional services, from project conception to completion.

Did You Know?



  • Between 2012 and 2015, Cornerstone provided construction quality assurance (CQA) services in 20 states on 30 landfill cell construction projects.


  • Since 2012, Cornerstone has provided landfill gas engineering, compliance, operation and maintenance services at 110 facilities throughout the U.S.


  • Cornerstone provides routine annual air compliance assistance to more than 130 facilities.


  • Since 2012, Cornerstone provided services from conception to completion at over 100 transfer station and materials recycling facilities.


  • Since its inception, Cornerstone has worked on more than 5,800 projects in 47 states and Canada.



  • The Persigo WWTP (BioCNG) produces up to 500 gallons of gasoline equivalent per day of renewable natural gas from the WWPT digester gas that has previously been flared into the atmosphere.


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All professional engineering work is performed by duly licensed professional engineers under the appropriate state-registered professional entity. Representations made on the website using the names Cornerstone, Cornerstone Environmental or Cornerstone Environmental Group are for marketing purposes only. 


Entity names are as follows:

  • Cornerstone Engineering, Geology and Land Surveying, PLLC (NY)
  • Cornerstone Engineering Group LLC (CT)
  • CEG Engineering, PLLC (NC)