David S. Lipson, Ph.D., P.G., is President of HRS and a Principal Hydrogeologist with more than 36 years of experience solving complex water problems across Colorado, the United States, and internationally. His work spans nearly every facet of the field—groundwater and surface-water hydrology, groundwater–surface water interactions, water quality, contaminant fate and transport (including PFAS), groundwater remediation, geochemistry, aquifer storage and recovery (ASR), and evaluation of water wells.
Dr. Lipson served as an Adjunct Professor at the Colorado School of Mines from 2002 to 2022 and as a Visiting Professor at the Chinese Academy of Sciences in Nanjing. He is an editor of the journal Groundwater and serves on the Board of Directors of the National Ground Water Association.
In addition to his technical and academic work, Dr. Lipson has extensive experience as an expert witness in water-related litigation, including testimony in jury trials. Clients and colleagues know him as a trusted advisor who brings both deep technical knowledge and clear, practical judgment to the full spectrum of water challenges.
Matt specializes in groundwater supply, Colorado water rights, conceptual model development, and project management. After graduating with a Geology degree from Colorado College, he began his career in the fascinating field of groundwater at HRS Water Consultants in 1998. He has completed numerous groundwater projects throughout Colorado. His clients include municipalities, water districts, private well owners, farmers and ranchers, ditch companies, State and Federal agencies, HOA’s, and private natural resources companies.
Mr. Barrett has over twenty-five years of experience in the water resources field. Prior to working at HRS, he worked for the Colorado Division of Water Resources where he developed a strong understanding of the priority system and how water rights are administered and accounted for in the State of Colorado. Mr. Barrett began working at HRS in 2008 and specializes in Colorado groundwater and surface water rights. He assists clients with a variety of projects ranging from change of use cases and augmentation plan development to client water rights protection, water rights accounting, GIS/DB project development, water rights evaluations and valuations, and water resources planning.
Fern Beetle-Moorcroft joined HRS in 2017 and has spent the last twelve years working as a hydrogeologist in both the public and private sectors. Her work is mainly focused on groundwater and groundwater/surface water interactions, where she specializes in providing project management and technical oversight on groundwater resources, sustainability, water rights, contaminant fate and transport, and litigation support projects. Her work is mainly based in Colorado, but she has worked on hydrogeologic projects throughout the United States. She is passionate about working with clients to collaboratively solve complex groundwater problems.
Fern is a registered Professional Geologist in Wyoming and New York. She holds an MS in Hydrology from Colorado School of Mines (2020) and a BA in Geology from Haverford College (2014). Prior to joining HRS, she spent two years working for the New Jersey Geological and Water Survey as a hydrogeology and geophysics research assistant.
Outside of work, Fern enjoys playing ultimate frisbee and hiking with her partner Oliver and dog Lois.
Katharina Lowe joined HRS in 2021 to support the team in all water-related issues. She has a background in hydrogeology and is licensed as a Professional Geologist (P.G.). She also recently became a Certified Associate in Project Management (CAPM) and has experience managing environmental projects.
Katharina is a well-rounded hydrogeologist with expertise in environmental sampling, groundwater modeling, and groundwater resources. Her experience includes groundwater flow and heat transport modeling using MODFLOW and FEFLOW; design and execution of Aquifer Storage and Recovery (ASR) pilot test programs and groundwater and surface water quality sampling programs; interpretation of water geochemistry; and well drilling and aquifer testing for private, municipal, and oil and gas clients. She also provides support on water rights matters and water-related litigation cases. Katharina is committed to regulatory compliance and the implementation of practical, field-focused safety programs.
She is an active member of the groundwater community, volunteering with the Colorado Ground Water Association (CGWA) and the National Ground Water Association (NGWA), and she regularly participates in Colorado Defense Lawyers Association (CDLA) events.
Katharina is motivated by food and enjoys travelling.
Sophia joined HRS as a full-time employee in November 2020 after completing summer internships in 2018 and 2019. She graduated from the University of Portland in 2019 with a Bachelor of Science in Environmental Science and earned a Master’s degree in Hydrology from the New Mexico Institute of Mining and Technology in 2025. At HRS, Sophia contributes to water supply, environmental groundwater, and surface water projects. Her work includes data collection, review, and analysis; GIS mapping and spatial analysis; well and water quality assessments; and report preparation. Outside of work, Sophia is an avid downhill skier, gardener, and creative cook.
Marlena McConville is a hydrogeologist with more than seven years of experience in groundwater modeling, water resources, and water rights across the mining, municipal, and environmental sectors. She specializes in numerical groundwater modeling with MODFLOW, which she has used to support mine dewatering design and long-term water management.
Her work in Colorado includes water rights evaluations, groundwater monitoring and water quality investigations, and the permitting and design of high-capacity production wells.
Marlena is a licensed Professional Geologist. She holds an M.S. in Geology from the University of Oklahoma and a B.S. in Environmental Science from the University of Alabama. Outside of work, she enjoys neighborhood walks with her husband and traveling to Central America.
Kevin Murphy joined HRS as an intern in summer 2021. He returned to HRS in 2023 as full-time Hydrogeologist and EIT following his graduation from the University of Colorado, Boulder with a B.S. in Environmental Engineering and a minor in Geologic Sciences. Over his three years at the company, Kevin’s role has expanded to focus heavily on data infrastructure, spatial analysis, and visualization. He specializes in project database development, ArcGIS Pro spatial mapping, and building interactive dashboards to present complex hydrogeologic and water quality data to clients. Driven by a desire to optimize workflows, he enjoys building custom tools that simplify data processing, management, and analysis across litigation, water supply, and water quality projects.
Alongside his office-based data work, Kevin regularly leads field investigations, including groundwater and surface water sampling, hydraulic testing, drilling oversight, and well installation. In his free time, he can be found fly fishing, hiking, rock-hounding, and camping around Colorado. He maintains an extensive rock and mineral collection both in the office and at home.
Abbey joined HRS in 2025 as a hydrogeologist. She graduated from University of Dayton with a dual major in geology and sustainability with a focus on sustainable watersheds. Prior to joining, Abbey gained diverse experience in Colorado based hydrogeology and environmental consulting, including aquifer testing, lithologic logging, monitoring well drilling and installation, regulatory compliance and water quality sampling under Colorado regulation 11, UIC, PFAS, and GWUDI programs. She has supported projects from start to finish through fieldwork, data collection and analysis, GIS mapping, and technical report preparation.
Abbey values the problem-solving nature of hydrogeology and opportunities to learn both the field and office environments. She especially enjoys projects where she can connect regulatory frameworks with practical groundwater and surface water applications. Outside of work, Abbey loves cooking meals (with lots of leftovers), exploring vintage and thrift stores (and especially estate sales), practicing Pilates, and spending time with her cat, Keith, who makes his feelings known the second Abbey gets home each day.
Abdullah joined HRS in 2026 as a Staff Hydrogeologist. He is a Ph.D. candidate in Civil Engineering at Colorado State University. His research used in-situ, remote sensing, and geochemical techniques to study urban streamflow in Denver, as well as groundwater storage change and arsenic mobilization in the San Luis Valley, Colorado. He holds an M.S. in Civil Engineering from the University of Texas Rio Grande Valley and a B.S. in Petroleum and Mining Engineering from Shahjalal University of Science and Technology. Before joining HRS, Abdullah interned at Denver Water and at the CSU ROSSyndicate.
At HRS, Abdullah conducts technical research, GIS mapping, spatial analysis, and statistical and data analysis. He also supports projects by preparing figures and reports, performing fieldwork, assisting with the interpretation of model results, and handling other technical tasks as needed. Outside of work, Abdullah enjoys spending time with his family, hiking, cricket, soccer, and exploring nature.
Charlotte joined HRS as a Staff Hydrogeologist in 2026 after graduating from Dartmouth College in 2025 with a B.A. in Environmental Earth Science. During her time as an undergraduate she worked on interdisciplinary teams to complete geologic and ethnographic research to understand the history, impacts of, and recovery from extreme flooding in Vermont and New Hampshire.
At HRS, she supports projects through field work, GIS mapping, and data analysis. In her free time Charlotte enjoys spending time outdoors and working on creative projects, be it painting, knitting, block printing, or other crafts.
Tammi is HRS’ office manager.
