LegacyGW geoscientists have applied their extensive groundwater expertise in collecting, compiling and managing data, and in providing effective and accurate products and solutions to various types of clients and audiences including city and county municipalities, oil and gas industries, mine and quarry industries, river authorities, water districts, municipal utility districts, water companies, developers, water marketers, bottled water companies, engineering firms, law firms, State and Federal regulatory agencies and in litigation settings.
Regional and Local Groundwater Availability Assessments
Our specialty involves assessments of hydrogeologic and lithologic settings, aquifer hydraulic and use characteristics, mass-balance groundwater accounting, historic and projected groundwater usage and demand, and water quality evaluations of both artificial and natural stimuli to groundwater systems. LegacyGW hydrogeologists have conducted both regional and site-specific large-scale evaluations for portions of the Carrizo, Wilcox, Simsboro, Edwards-Trinity Plateau, Sparta, Hueco Bolson, Trinity, Ogallala, and Gulf Coast (specifically the Evangeline and Jasper) aquifers.
Groundwater Resources Development and Marketing
Legacy Groundwater has provided services for potential buyers and sellers of groundwater. LegacyGW personnel have conducted technical reviews and investigations to assess the availability of resources and feasibility of producing large volumes of groundwater targeted for transactions including sales and/or leases. Additionally, LegacyGW personnel have conducted evaluations of regulatory and economic settings for the development and marketing of groundwater resources.
Well and Well-Field Evaluations
Legacy Groundwater has evaluated the historic, current and probable future capacities of individual large production wells and entire well fields. In addition, assessments have included evaluating well conditions and performance, including evaluating completion methods and zones, determining well efficiencies, evaluating conditions of existing wells, designing and conducting well rehabilitation programs, quantifying long-term production forecasts for current and potential future wells, and providing recommendations as to pumping equipment selections, settings and operations. Additionally, LegacyGW personnel have considerable experience in assessing the integrity of well completion for water wells and injection wells, including evaluating isolation of the producing zone, analyzing cement bond logs, reviewing drilling and construction record, and evaluating production and water-quality characteristics. Water well evaluations have included large-capacity and deep wells in excess of 3,000 feet deep.
Geologic, Hydrogeologic, and Geophysical Field Investigations
Legacy Groundwater has conducted field investigations involving exploration drilling and coring, collecting geologic samples, obtaining and interpreting downhole geophysical logs, and collecting other pertinent geologic, hydrologic and water-quality information. Field investigations have also included surface geophysical exploration including surface resistivity and electromagnetic conductance (EM) surveys, specifically to locate gravel units favorable for large capacity wells, radial collector wells and infiltration galleries. Additionally, LegacyGW personnel have conducted surface geologic and karst assessments atop the recharge zone of the Edwards aquifer to locate and characterize potential recharge features.
Well and Well-Field Planning
Well and well-field planning has entailed Legacy Groundwater overseeing drilling, field-testing, providing project engineers with detailed assistance in designing wells and preparing specifications, and inspecting construction, completion and development of water wells. Wells have ranged from less than 50 feet to more than 2,800 feet deep, with pumping capacities of between about 10 gallons per minute (gpm) to 5,000 gpm.
Oilfield Groundwater Supplies and Brackish Water Sources Development
Legacy Groundwater geoscientists have compiled, evaluated, and mapped available geophysical logs obtained from old oil and gas drill sites and creating a working database of the information derived from the log evaluations. Evaluations include determining the hydrogeologic properties and hydraulic characteristics of the local aquifers, including depths, lateral extents within the study area, total thickness, net saturated thickness, water levels (i.e., artesian pressure), hydraulic conductivity, transmissivity, and storage coefficient. Results provide determination of the number of wells needed for the amount requested, determination of the optimum well spacing, and the availability of groundwater in the study area. In addition, Calculations are performed to estimate the salinity of a fluid in a sand zone at a specific depth using the information from the geophysical log, including the resistivity of the mud filtrate, the temperature of the mud filtrate, the bottom hole temperature, the depth of analysis, and the deflection of the spontaneous potential (SP) curve at the specific depth from the shale base line in millivolts (mV). Using this information, favorable zones, or areas, for production and quality groundwater are mapped and illustrated.
Groundwater Modeling
Legacy Groundwater has extensive experience involving numerical flow modeling (i.e., MODFLOW), contaminant and solute transport modeling, and analytical modeling. LegacyGW personnel have experience developing, evaluating, and utilizing models for various purposes such as determination of production impacts, assessment of groundwater availability, and calculation of aquifer hydraulic parameters.
GIS and Other Computer Applications
Legacy Groundwater personnel have created and managed useful database and interactive GIS systems, generating maps and work products utilizing state-of-the-art GIS methods
Legacy Groundwater expertise involves environmental and hydrologic impacts assessments, water-quality monitoring and evaluations, design and operation consultation for dewatering and depressurization wells, and water supply development for mining operations and facilities. LegacyGW experience includes several lignite mines, gravel operations along the Colorado River, and limestone quarries in Hays, Travis, and Williamson counties locally, as well as other operations across Texas, Oklahoma, and other states. Additionally, investigations have included mechanical integrity and potential contamination, impacts from injections wells in the oil industry and uranium mining industry, and hydrogeologic assessments and monitoring of landfill sites.
Industrial and Mining Investigations
Groundwater Quality and Contamination Assessments
Legacy Groundwater geoscientists have designed and completed monitoring well networks and programs, field investigations including drilling, soil sampling and water sampling, and evaluations of water quality with respect to natural aquifer conditions and water bearing zones impacted by contamination. LegacyGW experience has included working extensively with laboratories, developing and verifying quality assurance and control procedures, and analyzing laboratory results utilizing Piper, Stiff, and pattern diagrams and other diagrammatic and statistical methods. Additionally, LegacyGW has included distinguishing quality between multiple water-bearing zones, and making determinations whether groundwater is directly under the influence of surface water at spring sites and near rivers and lakes.
Spring Water Source Assessments and Development
Legacy Groundwater personnel have incorporated providing technical and consulting services with respect to evaluating potential spring water sources to assess the quantity, quality, and reliability of such sources. Also, services have included providing technical design recommendations, conducting comprehensive field-testing to assess hydrogeologic settings and groundwater conditions, evaluating potential risks to spring water sources, and appraising potential impacts due to development of spring water. Additionally, LegacyGW services have included obtaining regulatory approvals for developing excellent quality spring water sources.