About HydroGeoLogica


HydroGeoLogica, Inc. was formed by Anita Johnson in Golden, Colorado in 2006, to provide consulting services in the hydrogeologic sciences. In 2010, Pam Rohal joined HydroGeoLogica, bringing expertise in geochemistry including geochemical characterization and water quality modeling for mining applications. Brent Johnson joined the HydroGeoLogica team in 2015, bringing his extensive experience in aqueous geochemistry and his innovative approaches to managing water quality issues.  Our most recent addition is Liane George, who joined us in 2017, along with her solid surface water, groundwater, and water balance modeling expertise.

In addition to our core experts, HydroGeoLogica maintains a network of specialized, associate experts so we can build a focused team to address your mine water and waste issues.


Anita Johnson

Anita Johnson pic

Anita Johnson is hydrogeologist with twenty-five years of professional experience in environmental consulting and mine water management.  She is the owner of HydroGeoLogica, Inc, and has worked in Europe, North America, Central and South A merica and Asia. 

Anita develops site-specific water balances for industrial, environmental, and mining applications using both spreadsheet and dynamic systems (GoldSim) approach.  She is experienced in the design and implementation of surface water and groundwater investigations and development of water management systems for a variety of sites, primarily mine related. She has extensive experience of aquifer testing design, implementation and analysis, and provides peer review on these subjects. 

She worked in the UK until 1994, when she moved to Colorado. She currently lives in Golden, CO with her husband (a geochemist) and two children. Click to view resume


Brent Johnson

Brent Johnson pic

Brent Johnson joined HydroGeoLogica in 2015. Brent has twenty-three years of professional experience in hydrology, geochemistry, water quality prediction and management. He conducts hydrologic and geochemistry studies for all phases of projects including feasibility, permitting, baseline studies, water use optimization, reclamation, and source control.  

Brent is familiar with Equator Principals, the International Cyanide Code, and ICMM’s water guidelines.  He has expertise in 

hydrogeologic characterization, saturated and unsaturated groundwater flow modeling, seepage modeling for dams and cover/liner systems and he has extensive experience in aqueous geo-chemistry, ARD and metals chemistry, and developing innovative approaches to managing water quality issues.  

Mr. Johnson has worked extensively at sites around the world including Asia, Africa, North and South America, and Europe, from tropical to northern latitude conditions and he is fluent in English and Spanish. Click to view resume


Pam Rohal

Pamela Rohal picPamela Rohal joined HydroGeoLogica in July 2010. Pam is a geochemist with eighteen years of experience providing geochemical and hydrogeological technical support, primarily to the mining and environmental industry.

Much of her early project work dealt with mine site remediation projects focused on characterization and treatment of acid rock drainage impacts.

Over the last seven years, her focus has been on geochemical characterization/modeling and evaluating water quality impacts in support of mine permitting and operations; specifically, mine waste geochemical characterization, geochemical modeling of pit lake water quality and mine facility water quality seepage analyses.

In the United States, she has completed projects in Alaska, Arizona, Colorado, Idaho, Michigan, Montana, Nevada and Wyoming; she has also worked on international projects in Chile, DRC (Africa), Guatemala, Honduras, Indonesia and Australia.

Pam received her M.S. in Environmental Sciences from the University of Virginia in 1995, and Bachelors Degrees in Geology and Chemistry from Bucknell University in Pennsylvania in 1992. She lives in Evergreen, Colorado, with her husband and two girls. Click to view resume


Liane George

Liane George Picture

Liane George joined HydroGeoLogica in January 2017. She has twelve years of experience in the fields of geology, surface water hydrology, and hydrogeology.  She graduated from the Colorado School of Mines in Golden, CO with her Bachelor’s and Master’s degrees in Geological Engineering.  She is both a registered Professional Engineer (Colorado) and Professional Geologist (Utah).

She is a specialist in hydrologic modeling using a variety of computer modeling programs including HEC-HMS for surface water event flow analysis, FEFLOW for groundwater aquifer pore pressure models and GoldSim for water balance and financial analysis modeling.  She is an expert in developing site-wide water balances and facility-specific water balances for the mining industry, including tailings storage facilities, leach pads, storage ponds, mills, pit lakes, dewatering/pumping wells, and predictive climate and runoff modeling.  She has taught GoldSim short courses both internally and for clients.  She is an expert FEFLOW user with respect to evaluation of dewatering options for large open pit mines, supporting geotechnical and slope stability analyses.

Her field related experience includes well testing, installation, stream water testing, drill rigs supervision, logging core and geological mapping.  She has worked on projects domestic and overseas in Japan, Morocco, and Peru.