Tandem Environmental

About Tandem

Tandem Environmental, LLC provides specialized environmental consulting services for companies, government agencies, and research groups. With experience in hydrogeology, high-resolution and adaptive site characterization, and PFAS technical consulting, Tandem supports environmental programs and project teams with targeted technical expertise and practical, science-driven solutions for complex environmental challenges.

Founded by Kristen Hasbrouck, PG, CPG, Tandem Environmental emphasizes a multidisciplinary approach, integrating advanced scientific methods and practical field experience to evaluate contaminant fate and transport across multiple media. This holistic perspective supports the design and refinement of robust site investigations and the development of meaningful, multidimensional, data-driven conceptual site models (CSMs) that reflect the complexity of real-word conditions. Tandem provides niche expertise to strengthen technical programs, enhance data interpretation, and support regulatory compliance, risk evaluation, and remedial planning for both federal and private-sector projects. 

Tandem is committed to technical excellence, innovation, and collaboration, providing clients and partners with clear, science-based insights that drive confident and informed decisions.

Work in Tandem with us!

Value to Project Teams

Targeted expertise that strengthens environmental programs and project teams

• Niche technical expertise in PFAS, hydrogeology, and contaminant fate and transport

• Adaptive, data-driven approach to high-resolution and multidisciplinary site characterization

• Support for regulatory compliance and risk evaluation across diverse project settings

• Integration of advanced scientific methods with real-world field experience

• Collaborative partnership model designed to strengthen existing project teams and deliver actionable, defensible results

• Focus on complex environmental challenges requiring specialized technical interpretation and strategic problem-solving

Tandem Environmental provides technical expertise that complements project teams and strengthens environmental programs from planning through implementation. By collaborating with environmental consulting firms, government programs, and research groups, Tandem provides specialized insight and practical support that help projects progress efficiently, defensibly, and with a clear understanding of contaminant behavior. 

Our Services

Expert environmental consulting for hydrogeology and site characterization.

Tandem Environmental supports environmental firms, agencies, and research teams with specialized technical expertise across key disciplines. Each service is designed to enhance project performance, ensure data defensibility, and deliver clear, science-based outcomes.

Data Visualization

Direction and refinement of multi-dimensional conceptual models that communicate hydrostratigraphy, contaminant transport, and liabilities. Tandem collaborates with project teams to translate complex datasets into meaningful visual representations that enhance stakeholder understanding and support strategic decision-making.

Technical Review

Independent technical review and quality assurance of environmental investigation and remediation deliverables. Services include evaluation of work plans, data quality assessments, conceptual site model refinement, and verification of hydrogeologic and contaminant transport interpretations. Reviews focus on technical defensibility, regulatory alignment, and the integration of multidisciplinary data to strengthen project outcomes and support sound environmental decision-making.

Hydrogeology Services

Comprehensive hydrogeologic investigations supporting site characterization, remedial planning, and risk evaluation. Services include aquifer testing, hydraulic profiling, vertical aquifer profiling, slug and pumping tests, and groundwater flow analysis. Expertise in lithologic and hydrostratigraphic interpretation, well design and installation (including multi-port and horizontal wells), and porewater sampling with lysimeters. Integration of hydrogeologic data with geochemistry, contaminant transport, and multi-dimensional conceptual site models provides quality interpretation of subsurface conditions and contaminant migration pathways.

High-Resolution Site Characterization

Design and implementation of adaptive, high-resolution investigation programs for evaluating complex subsurface conditions. Integration of lithology, geochemistry, and hydraulic data enhances the understanding of contaminant behavior and exposure pathways

PFAS Expertise

Specialized technical consulting in PFAS fate and transport, source strength evaluation, and mass flux/discharge analysis. Support includes regulatory guidance, investigation strategy development, and data interpretation to address emerging contaminants with scientific rigor and defensible methodologies.

Interested in collaborating? Let's work in Tandem.

Tandem partners with consulting firms and project teams to provide flexible, project-based technical support - offering the expertise of a senior geologist and PFAS specialist without expanding internal staff capacity.