GEI provides aquatic and terrestrial ecological services that address a wide variety of regulatory and compliance issues. Our ecological studies range from simple biological monitoring for assess­ing ecosystem health and determining if any limiting factors on aquatic populations exist, to complex ecotoxicological assessments based on biomonitoring, toxicity testing, water quality criteria development, and detailed multivariate statistical analysis. We have a long history in studying the effects of human activities on ecosystems, and are experienced in habitat assessment and enhancement, restoration of fish, and mitigation.



Critical Issues

Federal and state regulations and guidelines for water quality and aquatic life are continuously being updated and revised. We assist our clients in navigating the often complex, regulatory framework and preparing for pending modifications. Through our participation in technical advisory groups, GEI contributes to the process, often commenting on draft regulations.

Climate change and increasing populations in many urban and suburban areas coincide, demands on water resources rise, and impacts to endangered, threatened, or sensitive aquatic species have the potential to increase. GEI helps clients evaluate options and alternatives to use water resources sustainably while continuing to prioritize ecosystem health.

GEI provides clients with unique approaches to common regulatory issues. GEI professionals excel at thinking outside-the-box; our scientists use expertise gained over decades of project work on sites across the US, coupled with the most current technology and data collection methods in order to provide our clients with innovative, site-specific solutions.

GEI is adept at interpreting data on aquatic populations, habitat, water quality, and conducting stressor identification analyses to determine what factors are limiting aquatic populations. Our knowledge of complex interactions is critical in assisting our clients to address an impact in the most efficient manner practical.

GEI defines limiting factors to aquatic habitat, designing restoration projects to reverse or ameliorate them, and providing recommendations for post-construction habitat and biological monitoring. Restoration projects that incorporate this additional level of complexity are more likely to benefit resident aquatic species, and the ability to assess project success allows us to continue improving our methods.


GEI is unique in our ability to combine our expertise in biomonitoring and water quality analysis with our strengths in interpreting these data in a regulatory capacity. Our in-house laboratory provides whole effluent toxicity (WET) testing, taxonomic analysis of benthic macroinvertebrate, and other testing to be completed without utilizing outside sources. Our professionals have a long history of assisting our clients as they navigate complex permitting and compliance issues, and they provide expertise and knowledge of the constantly changing regulatory environment of federal and state agencies.


Key Services

Water Quality Assessment

Assessing the impacts of water quality on aquatic life integrates many aspects of toxicology, stream ecology, laboratory toxicity testing, statistical analyses, and negotiations with state and fed­eral regulators. GEI offers a full complement of services to sup­port these studies, including development of site-specific water quality standards, review of ambient water quality criteria, preparation of use-attainability analysis (UAA) reports, development and review of total maximum daily load (TMDL) studies, evaluation of nutrient loading, and stressor identification analysis. In addition to stream ecology, GEI also conducts limnological studies and can assist with development of lake management plans.

To learn more, contact Senior Water Quality Specialist Senior Water Quality Specialist, Richard Meyerhoff,

Laboratory Services

GEI’s in-house laboratory offers a wide variety of biological, chemical, and toxicological testing services. Our laboratory services include identification of benthic invertebrates, ambient toxicity testing and WET, testing, toxicity reduction/identification evaluations (TIE/TRE), and low-level nutrient chemistry analysis, providing the breadth and quality of data necessary for comprehensive ecological analyses of lakes, streams, estuaries, wetlands, and other environments. GEI’s laboratory has over 30 years of experience in analysis of environmental samples and is audited regularly to maintain WET testing accreditation. Special studies can be developed to incorporate multiple laboratory components to achieve the needs of any discharger.

To learn more, contact Laboratory Director, Natalie Love: 


GEI assesses streams, rivers, lakes, and other aquatic environments by monitoring the fish, invertebrates, zooplankton, and algae. We also conduct terrestrial monitoring that assesses mammals, reptiles, amphibians, birds, and plant communities. Biomonitoring supports our water quality assessment services, either for long-term site monitoring, or for assessment of biological populations before and after site modifications. Often, the biomonitoring that we conduct for our mining and other industrial clients serves as assurance that their activities are not adversely affecting the environment, as the most direct and integrative way to measure ecosystem health in streams is to assess the populations within them. In addition, the data collected through biomonitoring can be utilized during the development of site-specific standards protective of resident aquatic life, as the basis for Use Attainability Analysis (UAA’s), and to support stream and river restoration goals. Many states also determine attainment of the aquatic life use for streams through analysis of macroinvertebrate, and less frequently fish, population data.

To learn more, contact Senior Aquatic Ecologist, Jeniffer Lynch, or Senior Aquatic Ecologist, Don Conklin,

Meet the Team

Richard D. Meyerhoff, Ph.D.

Senior Consultant

Scott Dierks, P.E.

Senior Water Resource Engineer

Jeniffer S. Lynch

Aquatic Biologist

Lee C. Bergstedt

Fisheries Ecologist

Don J. Conklin, Jr.

Senior Project Manager

Ashley A. Ficke, Ph.D.

Fisheries Ecologist

Ryan R. Holem


Stuart N. Kogge, PWS

Senior Wetland/Aquatic Biologist

Sarah B. Skigen-Caird

Ecology Division Manager/Senior Environmental Scientist

Craig F. Wolf

Senior Aquatic Ecologist/Limnologist

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