Helping You Make Confident Groundwater Decisions

Technical expertise and independent insight for complex groundwater challenges.

Our Story

Groundwater Modeling Is Part of Our DNA.

Founded in 1990 by Michael McDonald and Daniel Morrissey following distinguished careers with the U.S. Geological Survey, MMA was built on a foundation of groundwater science and quantitative analysis.

Mike McDonald developed MODFLOW, now the world’s most widely used groundwater modeling code. That commitment to technical rigor continues to guide MMA today.

WHY MMA

A Legacy of Technical Excellence

McDonald Morrissey Associates has been solving complex groundwater problems since 1990. Nationally recognized for the analysis of groundwater flow systems, MMA combines decades of specialized experience with sophisticated quantitative modeling and practical, independent technical guidance.

Since 1990

More than three decades of specialized groundwater consulting.

100+ Years

Combined experience among MMA principals.

MODFLOW Legacy

Mike McDonald, co-founder of MMA, developed MODFLOW, the world’s most widely used groundwater modeling code.

National Expertise

Complex groundwater projects for industrial, legal and government clients throughout the United States and internationally.

Our Expertise

Quantitative Science. Practical Answers.

MMA combines hydrogeologic expertise with quantitative modeling to help clients understand groundwater systems and make technically sound decisions.

Groundwater & Water Resource Evaluation

Modeling and analysis for water supply, resource management, permitting, and groundwater/surface-water interactions.

Fate-and-transport analysis and modeling to understand contaminant movement, impacts, and remediation.

Expert Technical & Litigation Support

Independent technical opinions, model review, expert reports, testimony, and litigation support.

Mining Hydrogeology

Groundwater modeling and analysis for mine dewatering, extraction, impacts, and regulatory considerations.

Wastewater & Waste Management

Groundwater modeling for landfills, wastewater systems, Superfund sites, and other complex applications.

REPRESENTATIVE EXPERIENCE

Expertise Applied to Real-World Groundwater Challenges

MMA has completed complex groundwater projects throughout the United States and internationally.

Republican River Basin | Nebraska

Water-management and interstate water-resource issues.

Barrick Goldstrike Mines | Nevada

Addressing mine pumping and potential surface-water impacts.

Parkview Well Superfund Site | Nebraska

Evaluating contaminant sources and the influence of municipal pumping.

Trusted for Decisions That Demand Technical Confidence