Environmental Testing Laboratories

Advance capabilities. In-depth understanding. Cutting-edge technology. Providing superior service and quality analysis for inorganic and organic constituents in tissue, aqueous, and solid matrices for engineering firms, municipalities, school districts, government agencies, industrial facilities, and individuals in the Greater Houston area for forty years. 

Many will attempt to follow in our footsteps, but we will always be on the forefront of the industry, leading the way. NWDLS was founded in 1974 when the first need for wastewater analyses was apparent, and we were then incorporated in 1985. We are certified with the State of Texas as a Historically Underutilized Business (HUB), with the City of Houston as a Woman-Owned Business, and have been a National Environmental Laboratory Accreditation Program (NELAP) Accredited Laboratory since 2008. 

The NWDLS Toxicology Laboratory was acquired in May of 2016, but the laboratory has been in operation since 1978. The Toxicology Laboratory was originally designed by ATKINS to conduct dredged material bioassays supporting USACE construction and maintenance dredging projects. While the laboratory has expanded into other environmental toxicity testing areas, it has continued to specialize in sediment bioassays and bioaccumulation studies and maintains a broad scope of accredited sediment toxicity testing services.

Quality, Dedication, and Passion. Three words you probably don’t often hear to describe an environmental laboratory, but we live and work by these words every day. This drives us to deliver the best results possible. NWDLS’ facilities and services have grown with the water and wastewater industry, equipping us with a broad perspective on the associated regulatory developments. 


The entire NWDLS organization; from our field technicians to our chemists to our Board of Directors, demonstrates a level of technological expertise and strategic prowess that meets the highest standards in the environmental laboratory industry.


We demand differentiation; not only between our organization and its competitors, but also within our organization. Academic preparation, professional experience, culture, ethnic roots, national origin, and gender are only a few of the things we consider when seeking to attract and retain employees with diverse backgrounds. This effort fosters the creative and inventive culture essential for technological leadership. We create and maintain an employment environment that provides employees opportunity to grow, excel, and achieve upward mobility.


Communication, trust, accountability, and integrity. These qualities are necessary to establish and maintain the high levels of efficiency and productivity required to achieve the finest results. Developing and fostering a team approach to problem solving and task accomplishment, NWDLS recognizes individual’s initiatives and accomplishments that reinforce this significant value.


Benchmarking, defining industry standards, and reaching new heights with customer service. We’re always striving for new achievements and efficiencies with our services to ensure superior quality in all services provided. NWDLS routinely employs methods from Test Methods for Evaluating Solid Waste, SW-846 (USEPA), Methods for Chemical Analysis of Water and Wastes (USEPA), Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater (USEPA), Methods for the Determination of Metals in Environmental Samples (USEPA), Methods for the Determination of Inorganic Substances in Environmental Samples (USEPA), Standard Methods for the Examination of Water and Wastewater, and Technical Standards – American Society for Testing and Materials (ASTM). We also incorporate methods provided by our clients for specific in-process utilization and quality control.


The ability to make quick, smart decisions and swiftly adjust to industry changes is a critical competitive advantage in our market. Having a sense of urgency toward continuous improvement and accomplishing high priorities is a key component for future success.


Derek McCoy  

Derek McCoy currently serves as Chief Operating Officer, and has been an employee of NWDLS since 1997.  Mr. McCoy is responsible for the daily operations of the laboratory, overseeing every level of service, including organizing the sample collection schedule, and supervising the laboratory management and reporting staff, coordinating all analytical projects from initiation to completion and reporting for special projects, including sludge testing and permit renewals.  Mr. McCoy has a Bachelor’s Degree from Southern Methodist University.

Whitney McCoy 

Whitney McCoy currently serves as Chief Financial Officer, and has been an employee of NWDLS since 1998.  During her time at NWDLS, she’s served as the Treasurer and Office Manager.  She is responsible for all invoicing, accounts payable and receivable, and staff payroll and benefits.  Mrs. McCoy holds a Bachelor’s Degree from Southern Methodist University. 

Monica Martin 

Monica Martin currently serves as Laboratory Director of the Main Laboratory and has been an employee of NWDLS since 2010. During her time at NWDLS, she’s served as an analytical chemist, Deputy Quality Assurance Officer, Quality Assurance Officer, Inorganics Deputy Technical Director, and Inorganics Technical Director.  Mrs. Martin’s responsibilities at NWDLS include the direct supervision of technical employees that generate data for all environmental projects, overseeing the laboratory training program, ensuring that all client technical, quality and delivery requirements are satisfied, review of all client complaints and participation in complaint resolution, and ensuring compliance with NWDLS’ policies for Quality, Health and Safety, Human Resources, and others as necessary in managing the operation.  She holds a Bachelor of Science Degree in Chemistry from the University of Louisiana at Lafayette.

James D. Horne

Mr. Horne currently serves as Laboratory Director of the Toxicology Laboratory and has more than 40+ years of Environmental Toxicology experience, focusing on product testing, whole effluent toxicity identification and reduction evaluation, and contaminated sediment assessment. In addition, he has 38 years of experience with water column, whole sediment toxicity and bioaccumulation studies for the USACE Galveston District following Guidance in the “Green Book” and “Inland Testing Manual.” Currently, he is responsible for all aspects of toxicology laboratory operations, including personnel decisions (hiring/firing/scheduling), procurement, and senior technical oversight and review of the laboratory’s Quality System and Standard Operating Procedures. Additionally, he provides senior technical review of project deliverables. He is responsible for special projects, including environmental fate and effects testing of chemical products, water effect ratio studies, and sediment toxicity testing programs.

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