About AST Environmental, Inc.

Our History

In 1993, Applied Science and Technology Inc., abbreviated shortly after to AST Environmental, Inc., was founded by Bob Welsh. Since then, like-minded civil and environmental professionals have come together with a common vision: safely provide industry leading solutions and expertise to the environmental consulting community. Our project management team, with a combined 100+ years of experience, looks forward to helping you solve your site-specific project challenges.

AST has always taken pride in providing our clients technically strong solutions to their problems and being more than just a contractor. AST loves a challenge and invites our clients to bring us their toughest problems. As we like to say at AST, “We’re a group of engineers, geologists, and scientists that likes to get dirty”. Contact us today to see how we can help you solve your civil and environmental challenges.

Our Team of Remediation Experts

Duane Guilfoil

Duane has been on the AST team since 2003 as the Vice President and is now the President of AST, bringing his experience, expertise, and leadership to his home-state remediation…
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Gary Simpson

Gary has been with the AST team for 17 years. He is from Campbellsville, Kentucky and got his degree from the University of Kentucky. His favorite part about working for…
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Tom Guilfoil

Tom has been on the AST team since 2002 as a Vice President, and he is currently AST’s CFO and Manager of Civil and Environmental operations. Originally from Lexington, Kentucky,…
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Mike Mazzarese

Mike has been on the AST team since 2014 as a Senior Remediation Engineer and is based in Golden, Colorado. Mike received his BS and MS degrees in Environmental Engineering…
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Nathan Thacker

Nathan joined AST in 2013 as a Senior Geologist and manages most of the company’s injection remediation projects along the East Coast. After earning his BS in Geology from the…
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Bill Brab

Bill has been on the AST team since 2011 as a Senior Remediation Geologist and is based in Midway, Kentucky. He manages most of the projects in Kentucky and Tennessee for the…
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Derek Pizarro

Hailing from Pennsylvania, where his alma mater – Lafayette College – also resides, Derek is a team guy through and through. For him, the most rewarding part of working for AST is…
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Zach Zawila

Zach has been with AST for over 15 years as a Senior Project Manager and Corporate Health & Safety Officer. He’s from Liberty Township, Ohio and went on to attend…
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Austin Moore

Austin has been a member of the AST team since 2002, originally from Point Pleasant, WV he serves as a Site Manager on AST’s Civil side of the company. Austin…
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Tony Hawley

Tony has been with AST since 2014 and is originally from Tampa, FL, he still considers the beach his favorite place to be and could ride motorcycles all day. He…
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Colin Hogg

Colin, a James Madison University graduate, has been with AST for over a year. He is originally from Richmond, Virginia, and he says, “I find the greatest pleasure in working for…
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William Shackelford

William has been with AST for five years and counting. A native of Lexington, Kentucky, he went to school at Stetson University as well as the University of Kentucky. William…
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Ben Borth

AST has taken Ben Borth around the world in his 7 years with the company, performing his favorite project at a site in South Africa. Locally, Ben is from Franklin, Kentucky and…
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Earnest Hannah

Earnest, a Williamson, West Virginia native, has been with AST for 4 years. A graduate of Southern New Hampshire University, his favorite project was a little further south in Chico,…
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Nathan Mau

Nathan has been with AST for 7 years, is a Virginia native, and he says the most rewarding part of his work is that he is constantly learning with AST. The most interesting…
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Troy Baesler

A Lexington, Kentucky native, Troy has been with AST for 10 years. The most interesting project he has worked on is a soil/groundwater remediation project at a rail yard in…
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Katie Marletta

Katie has been with AST for past six and a half years. Hailing from Danville, Kentucky, she attended the University of Kentucky. The most rewarding part of working for AST…
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Derrick Miller

Originally from Falmouth, KY, Derrick joined AST in 2020. An Alumni from Eastern Kentucky University, Derrick enjoys working for a small company with a family-like atmosphere that strives to clean…
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Ray Hukill

Ray, a project engineer, has been with AST since 2021. A Marietta College graduate, he says his favorite part of working for AST is being able to travel to new…
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Boyd Gray

Boyd joined AST in 2021 and received his PG in the Spring of 2022 after multiple years in the oil and gas industry, a graduate of Morehead State University this…
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Collin Murphy

Collin has been on the AST team since 2021 as a Field Geologist and is based out of the Harrisonburg, VA AST office. He received his Geology degree from University…
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Laura Brown

She’s back!! Laura served as an intern for AST approximately 10 years ago while attending Centre College where she earned her bachelor’s degree. She recently joined AST on a full-time…
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Brendan Hardin

Brendan has been with AST since 2022 as a Field Geologist and is based in Midway, Kentucky. Brendan received his dual BS  major in Professional Geology and Geographic Information Systems (GIS)…
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Cooper Pflug

Cooper joined AST in 2023 as a dynamic team player, leveraging his education from James Madison University and his Freehold, NJ roots. Renowned for his role in the challenging Linden,…
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Dillon Brooks

Dillon joined AST in 2023 after earning his degree in Environmental Sciences from the University of Kentucky, a native of Taylorsville, KY; he feels rewarded seeing a job site from…
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Brandon Gray

A native of Hillsboro, Kentucky, Brandon joined AST in 2023. Having worked form many years in the gas and oil industry, Brandon is a passionate advocate of the remediation techniques…
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Lucas Simpson

Lucas Simpson, a Business Development and Project Specialist at AST since 2015, hails from Lexington, Kentucky, and is a University of Kentucky alum. His notable work includes the Gallatin Remediation…
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