Meet Our Team

Meet the team of project managers, scientists, and specialists who bring their technical expertise and attention to each project.

Chad Harrison, PE

President, Chief Executive Officer

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Chad Harrison, PE

President, Chief Executive Officer

Chad Harrison is an accomplished leader and engineer with 30 years of experience in driving business growth, managing multidisciplinary teams, and delivering innovative solutions. Chad holds a B.S. in Geo-Environmental Engineering from The Pennsylvania State University and is a licensed Professional Engineer in Pennsylvania, Ohio, Maryland, and West Virginia. Throughout his career, Chad has held senior leadership positions in the engineering and consulting industry, overseeing large teams, managing complex projects, and implementing strategies that deliver consistent growth and operational efficiency. His expertise spans technical oversight, business development, and organizational management, with a focus on creating value for clients and stakeholders. As President and CEO of Material Matters, Inc., Chad leverages his extensive experience and leadership skills to guide the company into its next phase of growth and innovation while maintaining a strong commitment to advancing the company’s mission and fostering excellence across all operations.

Lisa Challenger

Chief Operating Officer

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Lisa Challenger

Chief Operating Officer

Lisa is the Chief Operating Officer with Material Matters, with more than 12 years of wastewater and leadership experience. Her area of technical expertise focuses on evaluating regulatory and market drivers that influence the management of biosolids and other residuals. Lisa uses her applied experience completing permit applications, engaging with regulators, and completing soils and site evaluations to develop realistic residuals management plans for clients across the country. Lisa graduated from Penn State University’s College of Agriculture with a BS degree in Environmental Resource Management.

Santina Huerta

Business Manager

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Santina Huerta

Business Manager

Santina Huerta is a seasoned Business Manager with more than two decades of experience leading comprehensive financial and operational functions across multiple industries, including hospitality, construction, automotive, architecture, and wellness. She brings advanced expertise in bookkeeping, budgeting, payroll administration, financial reporting, and multi-entity account management.

Trudy Johnston

Technical Director, Certified Operator

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Trudy Johnston

Technical Director, Certified Operator

Trudy is a Technical Director with Material Matters, and has over 39 years in the municipal and industrial wastewater processing and solids treatment and management field, with 36 years as a consultant. Her primary interests include developing innovative uses and strategies for residuals, optimizing solids processing, conducting solids master studies, assessing compliance with biosolids regulatory standards, data/sample collection and validation, evaluating and resolving odors from residuals, and water quality nutrient trading. She participated in the WERF study with UMASS to assess biosolids stability standards and authored the protocol for the AVSR testing. Trudy has a BS degree in Earth Science from Penn State and is a certified wastewater treatment operator.

Robin C. Brandt, Ph.D., PE

Technical Director

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Robin C. Brandt, Ph.D., PE

Technical Director

Robin is a Technical Director of Material Matters. He has over 35 years’ experience in agricultural, municipal, industrial, and food processing residuals assignments. He directs the company’s efforts involving water reclamation and composting facility odor emission studies and biosolids-derived-product odor assessments (current-in-practice and research). Robin contributes to field-trial and plot studies and participates in the conceptualization/ development of emerging beneficial use strategies such as Deep Row Hybrid Poplar biosolids recycling programs (and related research). He serves as technical project manager on selected assignments and functions as liaison for projects involving consultation with the Pennsylvania State University (PSU) and other selected technical service providers. Robin is a full-time faculty member with PSU (17 years), at the University Park, PA main campus, in the Department of Agricultural and Biological Engineering, where he serves as Senior Lecturer and Director of the PSU Odor Assessment Laboratory.

Rachel Fogle, Ph.D.

Senior Project Scientist – Land Application

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Rachel Fogle, Ph.D.

Senior Project Scientist – Land Application

Rachel has a PhD in Cell and Molecular Physiology and leads the Land Application group. She has over 20 years of experience driving innovative solutions for environmental programs. Her leadership of the Environmental Science and Sustainability undergraduate program while serving as Associate Professor of Biological Sciences at Harrisburg University, combined with her applied research in circular nutrient recycling, has built a robust foundation in soil science and nutrient cycling.

Joseph Tetreault

Senior Wastewater Scientist

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Joseph Tetreault

Senior Wastewater Scientist

Joe assists generators in wastewater treatment plant optimization through data management, process improvement, biosolids and residual management, and best management practice development. He earned his BS in Natural Sciences from Vermont’s Lyndon State College in 2017 and Master’s in Agricultural Sciences from the University of New Hampshire in 2020 while working in the University’s Agricultural Engineering Lab. He has extensive experience in waste and water chemistry, data analysis, and treatment for beneficial use spanning municipal, industrial, and agricultural sectors.

Nickolas Hines

Senior Environmental Scientist

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Nickolas Hines

Senior Environmental Scientist

Nick received his B.S. from Chatham University in 2020 ahead of completing his Master of Natural Resources from Virginia Tech in 2021. Nick serves as an Environmental Scientist and Project Manager for Material Matters with expertise in federal/state regulations, permitting, and market research analysis. Nick is also currently the Co-Chair of WEF’s ABBA Committee and Vice Chair of NEBRA’s Residuals Committee.

Timothy Lois

Environmental Scientist II

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Timothy Lois

Environmental Scientist II

Timothy Lois is a Senior Environmental Project Manager with over 20 years of experience in environmental consulting, specializing in site assessment, remediation, emergency response, and regulatory compliance for industrial, commercial, and public sector clients. He brings deep knowledge of environmental regulations, including PADEP Act 2, RCRA, and CERCLA, and has led projects from initial investigation through regulatory closure. Throughout his career, Timothy has successfully managed complex environmental incidents and high-value remediation efforts, overseeing multidisciplinary teams and coordinating closely with clients, regulators, and insurers. His field-to-leadership experience gives him a well-rounded perspective on project execution—from hands-on sampling and system operations to strategic planning and stakeholder communication. His technical expertise includes remedial system design oversight (SVE, air sparge, dual-phase extraction, pump-and-treat, SSDS), underground storage tank compliance, large-scale sampling programs, and rapid spill response. Timothy is recognized for his ability to deliver results on time and within budget while ensuring environmental integrity and regulatory compliance.

Christine McLain, PMP

Assistant Project Manager

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Christine McLain, PMP

Assistant Project Manager

Christine is a Assistant Project Manager with a wealth of project management experience. With a background in not-for-profit, she has successfully developed and managed programs for a variety of organizations. Christine has a BS in Business Communications and a PMP from Penn State.

Natalie Switala

Senior Wastewater Scientist, Certified Operator

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Natalie Switala

Senior Wastewater Scientist, Certified Operator

Natalie is the Senior Wastewater Scientist of Material Matters. She holds Connecticut’s highest Class IV Operator License. With a B.S. in Civil Engineering and nearly a decade in the environmental sector, she specializes in regulatory compliance, sustainability, and air/water permitting. She has led major infrastructure upgrades, managed emissions and NPDES compliance, and bring hands-on experience in construction management, process optimization, and environmental reporting. Passionate about clean water and air, she offers practical insight into protecting community health through responsible operations.

Ethan Keitel

Environmental Scientist I

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Ethan Keitel

Environmental Scientist I

Ethan is an Environmental Scientist with Material Matters. In his role, he supports residuals and biosolids land application projects through completing site and soil assessments, developing permit application packages, and engaging with local farmers and regulators. Ethan has a background in environmental compliance and agronomy from previous internship experiences. He has a B.S. degree in Environmental Resource Management, with minors in Soil Science, Watersheds & Water Resources, and Wildlife & Fisheries Science from The Pennsylvania State University.

Owen Loper

Civil Engineer Technician

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Owen Loper

Civil Engineer Technician

A recent graduate of York College of Pennsylvania with a Bachelor of Science in Civil Engineering and a minor in Mathematics, Owen is a motivated and well-rounded emerging professional with hands-on experience across multiple facets of civil engineering. With a strong foundation in surveying, wastewater management, construction, and land development, he brings both technical skill and field-tested insight to every project. During internships with RGS Associates, Conewago Enterprises, and Gordon L. Brown & Associates, Owen contributed to plan development, site inspections, cost estimating, and topographic surveying. These roles sharpened his proficiency in tools like AutoCAD, Excel, and Total Station, while also reinforcing a deep understanding of civil engineering design principles. Beyond engineering, Owen has worked in metal fabrication at KLK Welding and performed as a bass player in the York College Symphony Orchestra, demonstrating a balance of technical precision and creative discipline. As an active member of the American Society of Civil Engineers (ASCE), he is committed to continuous learning and professional growth.