Bristow Group, Inc.
TC Pipelines LP
Ameresco, Inc.
Superior Drilling Products, Inc.
Infrastructure & Energy Alternatives, Inc.
SemGroup Corp.
MasTec, Inc.
MPLX LP
Antero Midstream Corp.
Sharps Compliance Corp.
Estre Ambiental, Inc.
Superior Energy Services, Inc.
Sterling Construction Co., Inc.
Hudson Technologies, Inc.
USA Compression Partners LP
Pioneer Energy Services Corp.
North American Construction Group Ltd.
Exterran Corp.
BlueKnight Energy Partners LP
MYR Group, Inc.
Hornbeck Offshore Services, Inc. (Louisiana)
Core Laboratories NV
Liberty Oilfield Services, Inc.
Mitcham Industries, Inc.
New Fortress Energy LLC
Vertex Energy, Inc.
McDermott International, Inc.
IES Holdings, Inc.
Tallgrass Energy LP
KNOT Offshore Partners LP
EQM Midstream Partners LP
NuStar Logistics LP
TETRA Technologies, Inc.
Tidewater, Inc.
Perma-Fix Environmental Services, Inc.
Clean Harbors, Inc.
Key Energy Services, Inc.
Republic Services, Inc.
Avalon Holdings Corp.
Covanta Holding Corp.