• Environmental Engineering Firms: The number of environmental engineering firms have grown quite substantially over the past decade, and our recent research on the top environmental engineering firms in North America has shown that the majority of them are still hiring including recent college graduates.

• Environmental Consultancy Firms: There is actually a difference between Environmental Engineering and Environmental Consultancy firm, engineering firms where the engineering firms are typically more related to major projects. 

The consultancy firms on the other hand, undertake much broader tasks, such as soil remediation assessments, planning, also urban planning and water usage analysis.

• Investment Firms: I will definitely suggest investment firms such as Managed Funds, Venture Capital firms, they are in need of environmental engineers to assist them in analysing investment opportunities
• Government Agencies: Mainly relating to Government Agencies and Think Tank Agencies for planning and providing environmental impact analysis on new infrastructure projects. 
• Utilities Companies: Another sector that has continuous demand for environmental engineers to support their infrastructure upgrades and new constructions, utilities companies are also expanding their projects as part of stimulus programs announced by governments worldwide, and has created new jobs.

We have published companies guides on major environmental engineering firms and utilities companies, these reports are available from our website http://researchwhitepaper.com