In the face of critical environmental challenges, the expertise of environmental consulting companies is essential. These companies, found within the heart of Connecticut, analyze, manage and offer insightful solutions to a broad range of environmental issues. Providing services from sustainable energy generation to environmental assessment and testing, they set the pace for the evolving landscape in environmental consultancy. With a focus on both private and public sectors, these companies are leading advancements in sustainable practices, helping to shape a more eco-friendly future for Connecticut and beyond.


Top 21 environmental consulting companies in Connecticut

1. AVANGRID, Inc. (formerly UIL Holdings Corporation)

  • Website: avangrid.com
  • Headquarters: Orange, Connecticut, United States
  • Founded: 1852
  • Headcount: 5001-10000
  • LinkedIn

Avangrid is a leading clean energy company that generates and delivers energy from sustainable, renewable sources. They actively work to protect and enhance the natural environment.


2. Fuss & O'Neill

  • Website: fando.com
  • Headquarters: Manchester, Connecticut, United States
  • Founded: 1924
  • Headcount: 201-500
  • Latest funding type: Grant
  • LinkedIn

Fuss & O'Neill is a full-service civil, transportation, and environmental consulting company. They provide a range of services including engineering, planning, design, and environmental assessment. Their expertise helps shape communities and improve their infrastructure.


3. Phoenix Environmental Laboratories, Inc.

Phoenix Labs is an environmental testing laboratory that offers high quality testing of soils, water, sludge, solids, and air. They provide services to a diverse client base including small businesses, large engineering firms, and state and federal agencies. With a standard turnaround time of 7 to 10 business days, they offer competitive prices and also provide priority, same-day, and emergency response services.


4. BantamWesson

BantamWesson is a company that offers various programs and services related to reducing energy consumption and helping the environment. They provide products and services such as automatic delivery, energy audits, windows, insulation, electric services, lighting, plumbing, equipment upgrades, generators, and Wi-Fi thermostats. By becoming a customer, individuals can benefit from their expertise in energy-saving solutions.


5. JKMuir

  • Website: jkmuir.com
  • Headquarters: Rocky Hill, Connecticut, United States
  • Founded: 2008
  • Headcount: 11-50
  • LinkedIn

JKMuir is an engineering firm specializing in the integration of sustainability and clean energy into public infrastructure projects. They provide design, construction, and consulting services to drive renewable energy generation and minimize carbon impacts. Their expertise includes energy management, pump system efficiency, sustainability, and decarbonization.


6. Green Star Energy Solutions

Go Green Star is a company that offers energy assessments, audits, and various energy solutions including heat pump technology, new construction design and build, and commercial and multifamily energy programs.


7. Greenleaf Energy Solutions

Greenleaf Energy Solutions is a commercial energy efficiency company that offers practical solutions to meet your energy, environmental, and social ideals. They provide complimentary energy assessments, interest-free project financing, and expertise in utility rebates. Their services include lighting assessment, retrofitting, renewable energy solutions, and mechanical & HVAC solutions.


8. FrameworkESG

FrameworkESG is a specialty consulting firm that helps clients align their thinking, strategies, and operations with evolving environmental, societal, and economic realities. Since 2003, they have provided analyses, insights, and support to global companies, helping them build trust, reduce risk, and create long-term value.


9. Harringtons Organic Land Care LLC

Harrington's Organic Land Care provides organic lawn, tree, shrub programs and international consulting for a healthy, sustainable landscape.


10. Redevelopment Institute

Redevelopment Institute is a project of Vita Nuova, LLC, providing resources and expertise to empower communities, states, tribes, and organizations to prevent, inventory, assess, clean up, and reuse brownfield sites.


11. Common Ground High School

Common Ground is a high school, urban farm, and environmental education center located in New Haven, CT. They focus on learning, leadership, and community engagement, aiming to connect people of all ages and backgrounds to their urban environment. Common Ground offers programs for children, families, and adults, including school field trips, community programs, and events. They also operate a mobile market and emphasize sustainability through practices like maple sugaring. Their mission is to empower individuals to reach their full potential and contribute to a just and sustainable world.


12. Great Hollow Nature Preserve &a; Ecological Research Center

  • Website: greathollow.org
  • Headquarters: New Fairfield, Connecticut, United States
  • Headcount: 11-50

Great Hollow Nature Preserve & Ecological Research Center is a non-profit organization dedicated to biodiversity conservation, ecological research, environmental education, and outdoor recreation. The preserve offers 825 acres of land with hiking trails and conducts integrative conservation-driven studies of wildlife and plants within and beyond the preserve.


13. Drew Marine

  • Website: drew-marine.com
  • Headquarters: Naugatuck, Connecticut, United States
  • Founded: 1920
  • Headcount: 201-500
  • Latest funding type: Acquired
  • LinkedIn

Drew Marine is a company that offers comprehensive solutions and services for the maritime industry. With expertise in chemicals, equipment, and technical support, the company ensures efficient and sustainable operations for its customers.


14. van Zelm Heywood & Shadford, Inc.

  • Website: vanzelm.com
  • Headquarters: Farmington, Connecticut, United States
  • Founded: 1930
  • Headcount: 51-200
  • LinkedIn

Van Zelm Heywood & Shadford, Inc. is an engineering company that provides a range of services. They specialize in designing and planning various projects, offering expertise in fields such as electrical, mechanical, and environmental engineering. With a focus on quality and innovation, they work with clients to deliver effective solutions.


15. Loureiro Engineering Associates, Inc.

  • Website: loureiro.com
  • Headquarters: Plainville, Connecticut, United States
  • Founded: 1975
  • Headcount: 51-200
  • LinkedIn

Loureiro is a full-service engineering and construction company offering a complete suite of integrated services and dedicated experts. They provide a wide array of engineering and construction services to local, state, and federal governmental agencies throughout New England.


16. Altieri Sebor Wieber LLC

Altieri Sebor Wieber LLC is a MEPF engineering company that provides sustainable design and engineering solutions for various sectors, including museums, educational institutions, and private residences.


17. Naugatuck Valley Council of Governments

  • Website: nvcogct.gov
  • Headquarters: Waterbury, Connecticut, United States
  • Founded: 1957
  • Headcount: 11-50
  • LinkedIn

This company, nvcogct.gov, is a regional planning organization operating in Connecticut. They provide transportation planning, environmental sustainability, and economic development services to the region. They also offer grants, funding opportunities, and loan programs to support various projects. Their website serves as a resource library for publications, maps, and data related to their initiatives.


18. Sustainable Real Estate Solutions (SRS)

  • Website: srsworx.com
  • Headquarters: Trumbull, Connecticut, United States
  • Founded: 2010
  • Headcount: 11-50
  • LinkedIn

SRSworx.com is a company that offers powerful software for energy efficiency projects. Their EPIC software tool allows building owners to estimate savings and financial metrics of multiple project scenarios, streamlining the virtual energy audit process. With EPIC, customers can confidently make investment decisions by having access to professional business cases and real-time calculations.


19. Constellation Health Services

Constellation Health Services is a comprehensive stay-at-home health solution provider, offering a range of community-based health services. With over 15 years of experience, they provide top-quality care based on customer service rankings and create a supportive environment for their employees. They offer home health, palliative home health, hospice, personal caregiving, in-home ABA therapy, and school-based therapy services.


20. Heavy Weight, Inc.

Heavy Weight, Inc. is a woman-owned business that specializes in industrial asset recovery, providing companies with a way to turn old equipment and materials into working capital. They have over 40 years of experience in the field and one of the largest service vehicle fleets in the region. They are committed to sustainability, with recycling solutions that minimize the environmental impact of the industry.


21. Energy Efficiencies Solutions LLC

EES Go Green is a home energy conservation company that specializes in insulation, energy ratings, and retrofits for residential, commercial, and industrial properties. They offer services to eligible homeowners for energy savings, utility bill reduction, and environmental sustainability.


Want to find more environmental consulting companies?


If you want to find more companies that offer varied solutions, from energy generation to environmental testing you can do so with Inven. This list was built with Inven and there are hundreds of companies like these globally.


With Inven you'll also get to know the company's:


  • Ownership: Which of these are private equity backed? Which are family-owned?
  • Contact data: Who are the owners and CEO's? What are their emails and phone numbers?
  • Financials: How do these companies perform financially? What are their revenues and profit margins?

...and a lot more!