Our Team

MEET OUR PROFESSIONALS

Management

Sean Griswold
President
Sean calls Durango, Colorado, home, and he lives with his wife and three kids. He is the first employee of Sierra Chemicals, which started in July 1994. Sean purchased Sierra Chemicals in 2005. He hopes to lead in his position as president with empathy and insight from 27 years of industry experience.
Shedrick Lewis
VP of Operations
Shedrick has over 25 years of service in the industrial cleaning industry and has held many roles within safety, sales and operations). Shedrick enjoys the outdoors and spending time with family and friends. He studied business administration – general business at Lamar University.
David Navarrete
National Sales Manager
David is responsible for the overall sales division and sales team across the country. David lives in Grand Prairie, Texas, with his family. David has been with Sierra since 2017 and is always available for questions or direction on planned projects. When he is not working, he enjoys spending his time with his wife, Shea, and his daughter, Lourdes. Besides his passion for helping customers find solutions, fitness and family are David’s passions.

SALES

Danielle Vanzeebroeck
Field Service Sales Zone 1/6 – Western Rockies
Danielle grew up in Southern California and moved to Colorado to attend college. She obtained a Bachelor of Science in accountancy in 2012 from Fort Lewis College. After graduation, Danielle worked in public accounting on the Front Range but eventually found herself drawn back to Durango. Danielle began working at Sierra Chemicals in 2018. When not at work, Danielle is most likely snowboarding or enjoying the great outdoors.
Brian Veitz
Field Service Sales Zone 2 – North Dakota
Brian is the sales representative for the Williston Basin area and beyond. He holds a Bachelor of Science in physics and has more than eight years of oil and gas experience.
Roger Terry
Business Development Manager Zones 4 and 5 – Permian Basin, South Texas and South Louisiana
Roger has been with Sierra Chemicals almost seven years. His career here has been committed to field service sales and helping find safe and effective solutions to customers’ challenges. He is happily married, and he and his wife have eight children between them who keep them on their toes. He enjoys mountain biking, endurance cycling, trail running, kayaking and all things outdoors. His Lutheran Christian faith is important to him and is the framework in which he aims to conduct all his life.
Matt Miller
Field Service Sales Zone 7 – North Texas, South Oklahoma and North Louisiana
Matt has been with Sierra Chemicals almost three years. He draws on our excellent safety team, operations team and administrative staff to bring clear and comprehensive solutions to customers’ needs. When he’s not working, he enjoys spending time with family and friends and all types of outdoor activities, sports and competition.
Josh McCoy
Field Service Sales Zone 4 – Permian Basin, West Texas, Eastern New Mexico
Josh McCoy graduated from Texas A&M University. He started his career in oil and gas with Sierra Chemicals in 2004 and spent the next 9.5 years chasing gas plants and compressors all over the US. He then worked in many aspects of the oil and gas industry: drilling and solids control, plugging and abandonment, workovers, completions and coil tubing, re-entry projects and whipstocks, fracking and surface equipment, SWDs and water management. He also has had many roles in sales and operations throughout his career before returning to Sierra Chemicals.
Francois Therrien
Field Service Sales Zone 8 – Pennsylvania, West Virginia, Ohio, Kentucky
Francois has been with Sierra Chemicals since January 2022. He received his bachelor's degree in Geophysics from the University of Akron. When Francois is not working, he enjoys spending time with his family, watching movies and Football.
Daniel Waer
Account Manager- Zone 5
Daniel joined Sierra Chemicals in April 2022. He graduated from the University of North Texas with a BBA in Organizational Behavior and Human Resources. Upon graduation, he returned home to Goliad, Texas and started his career as a teacher and coach before he entered the Oil and Gas Industry. Daniel has worked in the Oil and Gas Industry for the past 8 years, specializing in Gas Compression and chemical services. Daniel currently resides in Refugio, Texas. During his free time, he and his family love to travel.

OPERATIONS

Huber Ortega
Lead Foreman
Huber’s areas of expertise are safety, project management, supervisory skills and quality control. He provides leadership and mentoring to his crews. Huber also likes fishing and riding his motorcycle. When he is not working or doing his personal hobbies, he loves spending time with his family and dogs.
KJ Choi
Lead Foreman
KJ has an associate degree in administration of justice. He is also a welding instructor for classrooms and fields. When not working, he loves traveling with his wife and fishing.
Albino Flores
Foreman
Albino’s areas of expertise include quality control, problem solving and project management. His mission is to provide exceptional customer service. His hobbies include building Lord of the Rings miniatures and landscapes and playing Yu-Gi-Oh. Albino also loves spending time with his four sons and grandchildren.
Jose "Joey" Perez
Foreman
Jose has an Associate of Applied Science in automotive technology. He has an exceptional track record in maximizing profit potential in a highly competitive environment. He has strong management and supervisory skills. When not working, Jose is an avid horseman and loves spending time with his two daughters.
James Ferrell
Client Relationship Manager
James is responsible for ensuring logistics, customer satisfaction and scheduling are all managed day to day. James lives in Yukon, Oklahoma, with his family. James has been with Sierra since 2014 and is always available for questions. When he is not working, he enjoys spending his time with family and friends. His family and his sons’ baseball activities are his true passions.
Calvin Alexander
Foreman
Calvin has been with Sierra Chemicals for over 2 years. He currently resides in Marian, TX. When Calvin is not working, he is spending time with his wife and son. He enjoys reading, watching movies, and deep intellectual conversations.
Ledie Gutierrez
Foreman
Ledie has been with Sierra Chemicals since February 2022. Prior to joining our team, Ledie was a Field Supervisor at Evergreen Chemical. When Ledie is not working, he enjoys playing with his dog, disc golf and mountain biking.
Robert Harrison
Foreman
Robert has been with Sierra Chemicals for a total of 5 years and resides in Lubbock. He received his bachelor's degree in Business from Southern New Hampshire University. When Robert is not working, he enjoys spending time with his wife and kids coaching basketball.
Aquental McCollum
Project Manager
Aquental has 18 years of experience in the industrial services industry with primary focus being management, operations management, chemical engineering, and chemical cleaning services applications. He embraces company ethics, commitment, and discretion with respect for confidentiality and the level of responsibility it demands. Aquental received his undergraduate degree in Business Administration (management and computer information systems) from the University of Houston – Downtown, 2001. During his free time, he enjoys spending time with his family, fraternity activities (Omega Psi Phi Fraternity Incorporated) and golfing.

ADMINISTRATION

Pam Vandervalde
Accountant
Pam has been with Sierra Chemicals for 13.5 years. Pam manages accounts receivable, accounts payable, payroll and accounting functions. Pam has a bachelor’s degree in accounting from New Mexico State University and has been working in accounting for 17 years.
Janet Ruper
Administrative Assistant
Janet recently graduated from Fort Lewis College in Durango, Colorado, with a bachelor’s degree in business administration. She is originally from a small town in New Mexico, Peralta. She and her family moved to Durango, Colorado, about six years ago. She has four children, three of which are young adults. In her spare time she enjoys baking and spending time with her youngest child, who is eight. She loves bike rides, snowboarding, building forts, movie and game nights and just spending time with her family.
LaDonna Cooperwood
HR Administrator
LaDonna has more than 10 years of human resources, recruitment, team building and project management experience. She graduated with an MBA from Grand Canyon University in Phoenix and earned a Bachelor of Science from the University of Mississippi. She is the mother of two daughters and the wife of a sports fanatic. She loves spending time with her family, traveling, exploring new places, and enjoying the simple things in life. She was born and partially raised in Chicago until she moved to Mississippi. LaDonna takes pride in all things human resources and impacting employees’ experiences within the company.
Savannah Mize
Marketing/Sales Coordinator
Savannah graduated from Texas Tech in 2018 with her Bachelor of Arts in Public Relations and is also a Texas Tech Cheer Alum. She has 3 years of marketing experience and started working with Sierra Chemicals in March 2022. When Savannah is not working, she enjoys spending time with her friends, family, and fiancé.

Talk to Our Team

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