Executive Team


McMillan (Mac) Hummel was named Chief Executive Officer of NorthStar Holdco Energy, LLC and subsidiaries in January 2019.  Prior to joining NorthStar as CEO, Mr. Hummel served for over four years with EnLink Midstream as an Executive Vice President and as the President of the Liquids Business Unit.  During that time, Mr. Hummel led EnLink’s crude business, NGL business and Louisiana gas business.  Preceding his employment with Enlink, Mr. Hummel held various positions with The Williams Companies, which he joined in 1985, including Vice President of Commodity Services, Vice President of Natural Gas Liquids and Olefins and Vice President of Western Region Gathering and Processing.  Mr. Hummel began his career with Williams’ Northwest Pipeline, and also served as Williams’ Director of Business Development while living in Calgary, Alberta.

Mr. Hummel has served as a board member for Aux Sable Liquids Partners and has been a member of the American Fuel & Petrochemical Manufacturers Petrochemical Committee and the Association of Oil Pipe Lines Pipeline Subcommittee.

Mr. Hummel earned a Bachelor of Science in accounting and a Masters of Business Administration from the University of Utah. 

Corporate Headquarters
10077 Grogans Mill Road
Suite 530
The Woodlands, TX 77380
(713) 277-7000

Commercial Point Comfort: Steve Ferro

Commercial North Dakota: Gregg Haslinsky
(917) 751-3671

Engineering: Chip Lang
(713) 702-6701

Operations: Tom Sullivan
(732) 710-7226

NST E. Fairview: Operations Manager
Travis Nellermoe
(406) 939-0862

Point Comfort: Steven Svetlik
(361) 935-1185


Tim Casey serves as SVP LNG and previously served as Chief Executive Officer of NorthStar Holdco Energy, LLC and subsidiaries. Prior to NorthStar Midstream, he worked for Kinder Morgan Terminals as Vice President of Business Development from June of 2013 until September of 2015. Previously, Mr. Casey was the Chief Executive Officer and President of K-Sea General Partner GP LLC, General Partner of K-Sea Transportation Partners LP from July 2003 thru June of 2012. Mr. Casey served as the Chief Executive Officer and President of K-Sea Operating Partnership LP. Mr. Casey was President, Chief Executive Officer of K-Sea Transportation LLC since April 1999.

Mr. Casey joined K-Sea Transportation LLC’s predecessor in October 1988 as its Controller and also … served as its Chief Financial Officer from 1996 to April 1999. Prior to joining K-Sea Transportation LLC’s predecessor, Mr. Casey was Controller for New York Towing Corp., a joint venture with Zapata Gulf Marine. From 1982 to 1987, he worked for Zapata Gulf Marine in operations, traffic and finance. He has been Director of K-Sea General Partner GP LLC, General Partner of K-Sea Transportation Partners LP since July 2003. He has been Director of K-Sea Transportation LLC since April 1999. Mr. Casey served as a board member and Chairman of American Waterways Operators and a board member of The Seamen’s Church Institute. Mr. Casey has a Bachelors of Arts in Business Administration/Finance from Texas A&M University and a Master of Science in Transportation from the State University of New York, Maritime College.



Responsible for oversight of NorthStar Midstream’s various business operations, Thomas Sullivan is focused on employee safety, exceptional customer service, quality and efficiency. His unique operational background combines 14 years sailing as a licensed deck officer with 20 years’ senior executive experience, managing companies involved in the transportation and storage of bulk petroleum products. Accomplishments under Mr. Sullivan’s watch include recognition as the first U.S. flag tug and barge operator to achieve ABS HSQE certification, meeting the standards of the ISM Code, ISO 9001, ISO 14001, OHSAS 18001 and the AWO Responsible Carrier Program. He is a graduate of the NY Maritime College, a member of the American Bureau of Shipping and recipient of the Virginia House of Hope Award and the Fort Schuyler Admiral’s Award for Outstanding Service.



Matt McKenzie is the SVP – Finance and Administration at NorthStar Holdco Energy, LLC and subsidiaries. He is responsible for all accounting, finance, human resources, IT and other administrative services. Prior to joining NorthStar, Mr. McKenzie served in various leadership roles, including Chief Financial Officer, of Watco Companies, a large transportation services company. He is a Certified Public Accountant.