Our Team


Daniel J. Morrissey, RPG

Co-Founder and Principal Emeritus

B.A., Biochemistry - Southern Connecticut State University

M.S., Hydrology - Univeristy of New Hampshire

Dan has 40 years of experience as a hydrogeologist and in the use of numerical simulation techniques for analysis of groundwater flow and transport problems.  While with MMA, he has worked on numerous hydrogeologic investigations at sites located throughout the United States.  Recent experiences include projects involving interstate water rights litigation, cost allocation evaluations at Superfund sites, and optimization of water supply systems.  Dan has served as an expert witness in a variety of forums regarding groundwater issues and in the application of numerical simulation models to evaluate hydrogeologic problems.

Prior to founding MMA, Dan served as Chief of the New Hampshire/Vermont District of the Water Resources Division of the U. S. Geological Survey (USGS).  As District Chief, he supervised a staff of 30 hydrologists and technicians and was responsible for data collection, hydrogeologic investigations, and quality control for all work completed by the office.  He has conducted training courses in basic hydrology, surface geophysics, and ground-water flow simulation for the USGS, for the National Ground Water Association, state and local water management districts, and private clients in the United States and abroad.


Charles P. Spalding, PG

Managing Partner

B.S., Geology - Virginia Tech

M.S., Hydrology - New Mexico Tech

Chuck has more than 30 years of experience in the conduct of quantitative hydrogeologic investigations.  During this time, he has applied many numerical and analytical models for the characterization of groundwater flow and solute transport, and performed hydrogeologic investigation management.

Prior to joining MMA, Chuck worked for HSI-GeoTrans, Inc. and was project manager for numerous hydrogeologic investigation projects including groundwater flow and solute-transport modeling for groundwater resource, plume delineation, and remedial design, site characterization of hazardous waste sites, and water resource development.  Additional responsibilities included administrative management of the Site Characterization Group in the Sterling, Virginia office of HSI-GeoTrans.

Chuck is experienced in a broad range of field tasks, including well drilling and installation, groundwater sampling, soil sampling, geophysical surveys, and aquifer tests.


Michael A. Mobile, PhD

Managing Partner

B.S., Hydrology - University of New Hampshire

M.S., Environmental Engineering - Virginia Tech

Ph.D., Civil Engineering - Virginia Tech

Mike has more than 15 years of experience in the areas of quantitative hydrogeology and hydrology, contaminant fate-and-transport assessment, and water resources management.  His professional experience has included model development in support of several large-scale, high-profile construction activities, natural resource management projects, and litigation/conflict resolution assignments. The sensitive nature of much of this work has allowed Mike to explore a wide variety of innovative and interdisciplinary approaches to meeting client needs and addressing site-specific challenges.

Prior to joining MMA, Mike worked for GZA GeoEnvironmental, Inc., where he acted as an in-house expert on Per- and Polyfluoroalkyl Substances (PFAS) and the evolving regulatory environment surrounding these compounds. Between 2014 and 2018, he served as project manager of two New Hampshire site investigations primarily focused on PFAS while providing technical support to other PFAS-related projects, including sites in Michigan, Connecticut, and Massachusetts.

DPA July 2019 at Lake George_Resized

David P. Ahlfeld, PhD, PE

Senior Groundwater Hydrologist

B.S., Environmental Resource Engineering - Humboldt State University

M.A., Civil Engineering - Princeton University

Ph.D., Civil Engineering - Princeton University

David has over 35 years of experience in groundwater modeling and analysis.  He holds a Ph.D. from Princeton University where he studied with Prof. George Pinder, one of the developers of the earliest numerical groundwater simulation codes.  He has held faculty positions at the University of Connecticut and at the University of Massachusetts Amherst where he is now Professor Emeritus.  During his 31 years in these faculty positions, David taught and conducted research in groundwater and many other aspects of water resources modeling and engineering.  His primary focus area has been groundwater modeling and the associated use of optimization methods for design of water resource management systems.  In addition to over 50 referred publications and a reference book on groundwater management modeling, David is lead author of GWM, the MODFLOW-coupled groundwater management code distributed by the USGS (click here for more information).

During his career, he has worked on numerous consulting projects including modeling in Woburn, MA, Tom’s River, NJ, the San Fernando Valley of California, the Tucson, AZ region, and the Republican River basin.


Daniel R. Walters

Hydrogeologist / GIS Analyst

B.A., English - Brandeis University

M.S., Hydrology - University of New Hampshire

Graduate Certificate, Geospatial Science - University of New Hampshire

Daniel has been with MMA since 2015, during which time he has performed hydrologic and geospatial analyses to support a variety of groundwater modeling projects relating to resource management and groundwater contamination assessments.  Specific areas of specialization include spatial and statistical investigations of hydrologic, geologic, and climate data, and digital elevation models.  To perform this work, he uses an array of tools for processing data, such as Python scripting, database development, and GIS analysis.


David W. Simon

GIS Analyst

B.S., Biology - Salem State University

M.S., Hydrology - University of New Hampshire

David focuses in the areas of quantitative hydrogeology/hydrology, GIS analysis, and database management.  He completed graduate studies in hydrology at the University of New Hampshire, where he worked as a research assistant and specialized in numerical hydrologic modeling.  As a graduate student, David’s research was a part of the multi-institutional, inter-disciplinary Future of Dams project, where he presented and collaborated on model results with both colleagues and the public.