Our Leadership Team

ESE has a multi-disciplined team of world-class environmental professionals

Bryan Gay


Bryan Gay is one of ESE’s Principal Scientist and the CEO of the firm. Mr. Gay has over 30 years of environmental consulting and executive leadership experience. After receiving a degree in Bioenvironmental Science from Texas A&M University, he worked as an environmental consultant providing site assessment and remediation services to the commercial and industrial real estate markets and oil and gas industry. His primary technical experience is in the areas of environmental due diligence, remediation, bioremediation and risk based corrective action. Additionally, he has extensive experience in leading Brownfields reclamation efforts.

Mr. Gay co-founded ESE Partners in 2007 in Houston, Texas. He has led the strategic growth of ESE Partners from a four-person due diligence practice to a multi-million-dollar, multidisciplinary firm with office locations in Houston, Austin and San Antonio, Texas. He has also served on numerous boards including Managing Director for IRC Environmental, President of Texas A&M University’s Bioenvironmental Sciences Professional Board, Director for Harris County MUD 171 and Cinco Southwest and a member of the Quality Planned Development Committee for the West Houston Association.

Jason Binford


Environmental consultant with more than 25 years of experience in the industry. Diverse and wide-ranging experience in program and project management, field operations, regulatory interactions, negotiations, due diligence, and technical reporting in support of soil and groundwater assessments associated with risk-based regulatory closure programs. Experienced and proficient in providing asbestos, mold, and lead consulting services inclusive of material hazard identification, evaluation, management, specification development, abatement/protocol design and oversight, bid solicitation, and fire/flood/disaster related response.

Tim O’Neil, PE

Managing Director of Remediation and Southeast Texas Regional Manager

Tim O’Neil is ESE’s Managing Director of Remediation and Southeast Texas Regional Manager. Mr. O’Neil has over 30 years of environmental consulting and engineering experience. After receiving a BS degree in Civil Engineering and MS degree in Environmental Engineering from Auburn University, he worked as an environmental consultant providing site assessment and remediation engineering services to industrial, commercial, oil and gas, and public sector markets. His primary technical experience is in the areas of environmental due diligence, remediation, risk based corrective action, engineering/demolition design, and technical specifications. Additionally, he has extensive experience in leading Brownfields reclamation efforts. Mr. O’Neil is a licensed Professional Engineer in Texas and Alabama.

Joseph Hoelzen

Principal Business Development

Joseph Hoelzen is ESE’s Principal Sales Consultant and head of business development for the firm. Mr. Hoelzen has over 14 years of business development and sales leadership experience. After receiving a degree in Business Management from the Rawls College of Business at Texas Tech University, he worked for a 4.5-billion-dollar global recruiting and staffing agency focusing on the environmental, civil, construction, and HSE oil and gas industry sectors by placing industry leaders in their next career path. At ESE, Mr. Hoelzen is accountable for identifying, evaluating, developing, negotiating and procuring Master Service Agreements for the upstream, midstream, energy, chemical, manufacturing, industrial, developers, private equity, financial institutions, attorneys, commercial real estate, and government agencies across 5 business units within ESE. In addition, Mr. Hoelzen is responsible for over 30% of the company’s sales goals while overseeing and managing the marketing division and the day-to-day activities for sales and marketing department.

Mr. Hoelzen started in 2012 in Houston, Texas and has helped assist with ESE’s strategic operational, sales, quality, and cultural growth of ESE Partners that has turned ESE from six-person due diligence and corrective action practice to a multi-million-dollar, multidisciplinary firm with office locations in Houston, Austin and San Antonio, Texas.

Kristin Schultz

Human Resources Specialist

Kristin Schultz has over 5 years of experience managing Human Resources and Full-cycle Recruiting. Upon receiving a degree in Human Resource management from the Rawls College of Business at Texas Tech University, she entered the Recruiting industry and worked for a Fortune 100 global staffing firm placing contract and direct hire talent among various industries and companies. At ESE, Ms. Schultz’s mission is to recruit, hire, and retain A Players and align them with ESE’s mission, vision, and values. Ms. Schultz aims to understand the hiring needs of the business and work diligently with leadership and hiring managers to select and place top talent in all areas of ESE. With a 10-step recruiting process, Ms. Schultz supports our 5 business units as well as our corporate resource departments. Since starting with ESE in 2019, she has developed performance management systems, implemented recruiting and onboarding processes, and increased company headcount across each of our 3 major office locations.

Kathryn O’Gorman, PG

Managing Director of Due Diligence, North Texas Regional Manager

Kathryn O’Gorman, PG has over a decade of experience with environmental due diligence and environmental compliance assistance. Ms. O’Gorman is responsible for managing the Due Diligence Group and conducting site assessments and due diligence investigations on undeveloped, residential, commercial, industrial, and oil and gas properties through performance of various types of Environmental Assessments including Phase I Environmental Site Assessments (ESAs). Ms. O’Gorman oversees the coordination and delivery of wetland determinations, threatened and endangered species reviews, and cultural resource reviews. Additionally, Ms. O’Gorman’s responsibilities encompass all aspects of remediation of groundwater and soil on contaminated sites.

Vidhi Singhal, PE

Managing Director of Compliance

Vidhi Singhal, PE is the Managing Director of Compliance. She is responsible for coordinating permitting and compliance activities for various clients through the identification of technical resources and program management. Additionally, Ms. Singhal’s responsibilities encompass all aspects of environmental problem-solving through process evaluation, facility and equipment design, and regulatory feasibility studies. Other responsibilities include the interpretation of collected data and its organization into technical reports, interpretation of emerging environmental issues/regulations and impacts to industry, and quality assurance/control of all reports, permits, and documents.

Aaron Brewer, PG

Managing Director of Natural Resources

Environmental consultant experienced in wetlands, NEPA, endangered species, due diligence, ecological risk assessment, site assessment, and remediation. Prior to graduating with a B.S. in Plant Biology in 1998, I was hired to research applications for phytoremediation to stabilize brownfields. In 2000, I joined an environmental/geotechnical consulting company and soon worked my way up to Project Manager.

Over my entire career, I have been deeply involved with Phase I/II ESAs, remediation, and regulatory closure. Putting my interest and background in botany to work, I developed a parallel service line in wetland and natural resource consulting in 2000. In 2017 I led a team of excellent natural resource and cultural resource personnel. As Division Manager for Natural and Cultural Resources at ESE, I am leading an experienced team of biologists and cultural resource staff. Over the years, my clients primarily have been real estate developers, electric transmission, upstream oil & gas, fiber optic utilities, gas utilities, and other industrial companies.

Reign Clark

Managing Director of Cultural Resources

Reign Clark is a cultural resource studies expert with over 24 years of environmental consulting experience. Mr. Clark is skilled in cultural resource management planning; archaeological survey, testing, and data recovery; battle field archaeology; industrial archeology; cemetery recordation; geophysical surveys; patent and deed research; regulatory compliance and permitting; and public outreach. Reign has close working relationships with federal and state regulatory authorities and is authorized to act as Principal Investigator for cultural resources projects in Texas, New Mexico, Oklahoma, Louisiana, North Dakota & Arkansas.

Robert Thornton

Central Texas Regional Manager

Robert (Rob) Thornton is an environmental scientist with over 15 years of experience, the Central Texas Due Diligence Business Unit Leader, and ESE’s Central Texas Regional Manager. Mr. Thornton has worked extensively within the Environmental Due Diligence sector, completing over 2,000 Phase I Environmental Site Assessments, as well as other limited assessments for commercial real estate acquisitions, commercial and residential development, telecommunications, oil and gas, industrial, and renewable energy clients. Mr. Thornton has conducted scientific sampling for soil, groundwater, and open-water media encompassing a wide range of techniques from the surf zone to the high desert. Mr. Thornton has also participated and led teams conducting natural resources reviews including water resources evaluations, endangered species reviews and habitat surveys, nest surveys, biological specimen collection, and Waters of the U.S. consultation and permitting. Additionally, Mr. Thornton has experience in building materials testing for asbestos containing material and lead-based paint. In total, Mr. Thornton’s projects have taken him to work on the ground in 48 states and 253 of 254 Texas counties.

Aaron Munsart, PG

League City Office Manager

Aaron is a Senior Geologist in the firm’s Corrective Action / Remediation Group and also manages ESE’s Houston Bay Area operations. He is a licensed Professional Geoscientist in the state of Texas and has over 8 years of environmental consulting experience related to property transaction due diligence, site assessments, and regulatory closure of properties requiring remediation of soil, groundwater, & vapor through TCEQ & RRC guided cleanup programs. These projects and clientele cover a wide variety of markets including but not limited to single-family & multi-family residential, commercial, industrial, oil & gas, alternative energy, financial institutions, local & state government. Mr. Munsart has also provided testimony and served as an expert witness for projects requiring such services. Aaron is also an active member in the Bay Area Houston Economic Partnership (BAHEP), Bay Area Commercial Real Estate Network (BACREN), and the Bay Area Community Advisory Panel (BAYCAP).