McDonald Morrissey Associates was founded in 1990 by Michael McDonald and Daniel Morrissey following distinguished careers with the U.S. Geological Survey. From the beginning, MMA was built on a simple premise: complex groundwater problems deserve rigorous science and independent judgment. That founding philosophy still shapes how the firm approaches every project today.
What began as a specialized modeling practice has grown into a nationally recognized consultancy serving industrial, legal, and government clients across the United States and internationally. Along the way, MMA’s principals have contributed to landmark groundwater investigations, water-management disputes, and litigation support engagements — building a reputation for technical credibility that clients and courts alike have come to rely on.
Today, MMA carries forward the same commitment to quantitative rigor and practical, independent guidance that defined its earliest work — helping clients navigate groundwater decisions with confidence, backed by decades of proven experience.