About Us

Staff Profile

Nubia Casler

President and Co-Owner

Mrs. Casler’s work experience spans over 23 years of environmental consulting for government and corporate accounts. Mrs. Casler controls the business development, growth planning, and financial management aspects and is involved in the day to day operations of the company. Mrs. Casler also manages the strategic planning and benefits for employee partnership that promotes professional, technical, and personal growth for each employee of CRG Texas.

Ms. Casler has graduated CRG Texas Environmental Services from the Goldman Sachs 10K Small Businesses Initiative at Houston Community College, has graduated from the Port of Houston Small Business University program, and has certified CRG Texas Environmental Services as a Small Business Enterprise with the City of Houston, METRO, the Port of Houston, State of Texas Historically Underutilized Business (HUB), and the Federal Government Central Contractor Registry servicing the SBA.

She is an active member of the Central Fort Bend Chamber Alliance, the National Association of Minority Contractors (NAMC), the National Hispanic Professionals Organization (NHPO), and the National Association of Credit Service Organizations and the Women in Business EMPRETEC program sponsored internationally that is dedicated to helping promising entrepreneurs put their ideas into action and fledgling businesses to grow. Mrs. Casler is an active member of River Pointe Community Church and provides charity support for the Friends of North Richmond.

Kevin Casler

Vice President and Co-Owner

Mr. Casler’s work experience spans over 32 years of engineering and environmental consulting practices. Mr. Casler attended the University of Texas at San Antonio in Environmental Science studies. Mr. Casler gained construction materials and geotechnical experience while employed for 6 years by a national engineering testing laboratory, Professional Service Industries (PSI), from 1985 until 1991. Mr. Casler was also employed by Malcolm Pirnie, Inc. (MPI), an international environmental consulting firm, from 1991 until 2007 when he founded CRG Texas Environmental Services with his wife Nubia.

His work responsibilities as Vice President include: employee selection and management, financial building and customer relations, business development, and project management. Additionally, he is responsible for the overall administration of the company utilizing his expertise in the technical, business and human resources aspects of environmental consulting. He also provides technical guidance on project design for assessment, corrective action, and regulatory agency reporting. He has extensive experience in the assessment, investigation and remediation of industrial and commercial sites and has represented numerous companies as an expert witness. He also has a working knowledge of all federal and state regulations pertaining to solid and hazardous waste management, air emissions control and wastewater discharges.

Mr. Casler, holds and maintains his A and B Licenses for PST Installations and Removals with the TCEQ as a “Licensed On-site Supervisor,” He is also a TCEQ licensed Corrective Action Project Manager (CAPM), and is experienced field investigation and assessment, preparation and submittal of TCEQ assessment and remediation reports for TCEQ PST Risk Based Assessment (RBA), Voluntary Cleanup Program (VCP), and Texas Risk Reduction Program (TRRP) projects.

Melinda Frey

Office Administrator

Mrs. Frey manages the office operations day to day and brings extensive administrative and financial experience to her position in which she has been connecting people, products, and solutions for over 20 years. Mrs. Frey joins CRG Texas from a builder and construction companies where she most recently served as the Office Manager and lead many initiatives to grow the company’s workforce and to connect with clients for a better service. Melinda manages our office and field staff health benefits, payroll and expenses, and fleet maintenance. Melinda is an integral part of the employee partnership program, and assists the owners with key management tasks to foster growth of our personnel and our office.


Shelton L. Clerk, Ph.D.

Staff Scientist

Mr. Clerk is a research level environmental scientist with master’s degree in environmental health and over 14 years experience as a chemist. He has approximately 10 years of relevant experience in soil and water assessment, corrective action, remediation monitoring, soil monitoring, laboratory chemical analysis, data interpretation and reporting. He has expertise in Phase I and II Environmental Site Assessments of commercial, manufacturing, industrial, farm, and ranch properties.

Lane Voorhies P.G.

Senior Environmental Geo Scientist

Mr. Voorhies is a professional geoscientist with over 30 plus years of experience in all aspects of due diligence including Phase I and Phase II assessments, EPA, TCEQ, and Railroad Commission of Texas responsible party voluntary and enforcement cleanup programs. Mr. Voorhies has carried out numerous Site Assessments on large and small commercial properties, federal, state, and local government facilities, industrial and manufacturing plants, and oil & gas exploration and production sites. Mr. Voorhies is a State of Texas Board of Professional Geoscientists registered professional geoscientist, and a Texas Department of State Health Services (TDSHS) licensed asbestos and mold inspector and management planner.

Lane is responsible for the planning, supervision and implementation of all field activities, including industrial hygiene sampling, asbestos inspections, environmental sampling, mold assessments, and indoor air quality studies. Remediation was done as a team with our clients who needed additional expertise. Lane is also in charge of emergency response planning and actions for dealing with client emergencies such as spills, releases, fires and explosions and in-house preparedness. Lastly, Lane supervised the hiring, development, ongoing training and performance of staff for health, safety, and environmental (HSE) and industrial hygiene (IH) projects.

Russell Duke

Environmental Manager

Mr. Duke is an environmental scientist with over 24 years of experience in all aspects of due diligence including Phase I and Phase II assessments, TCEQ regulatory, Railroad Commission of Texas, and EPA programs. A Senior Estimator/Project Manager with a history of crafting successful proposals along with managing many of the projects with an emphasis on safety and efficiency. Mr. Duke has served as an environmental division manager, senior estimator, lead proposal development, project manager with multiple projects managed remotely, site manager, project accountant, technical writer for operational procedures and HSE/QC Officer.

Mr. Duke lives in a culture of quality and safety to reduce risks and ensure the well-being of each employee, subcontractor, and client. Mr. Duke has carried out numerous Site Assessments on large and small properties, including Phase I and Phase II ESAs, site investigation, regulatory agency reporting, and corrective action. Mr. Duke has also been instrumental in Railroad Commission and USEPA Superfund assessment and remediation projects providing work plan and cost proposals, assessment, remediation, and project management.

Camilo Cardenas

Junior Staff Scientist

Mr. Cardenas is an environmental scientist with over 3 years of relevant work experience in soil and groundwater assessment, corrective action, and reporting. His expertise lies in Phase I and II environmental site assessments of commercial, manufacturing, industrial, farm & ranch, and oil & gas facility due diligence and petroleum storage tank assessments. Mr. Cardenas is also instrumental in many aspects of field assessment, remediation, and construction associated with our projects here at CRG Texas.

Alexis Swanson

Business Development and Marketing Coordinator

Mrs. Swanson provides marketing and sales business development for the company for the past 5 years. Her extensive experience in desktop publishing, social media, monthly newsletters, and direct mail marketing has brought added value to the team through sustainable growth creativity. Alexis’ skills in Microsoft office with focus on Word, PowerPoint, and Excel has taken CRG Texas to the forefront of our products and services as a professional and reliable environmental services provider. In addition, Alexis is responsible for CRG Texas branding, and she creates the artwork for our tee shirts, caps, cups, pens, and other items that post our logo and tag line “Caring for Our Environment’s Future.”