Ground Water and Surface Water Impact Assessments, Damage Claim Investigations and Contamination Evaluations
Alpha Geoscience personnel apply their technical capabilities in the investigation and monitoring of ground water and surface water to assess potential or actual impacts to quality and quantity and to address claims of damage to the resources. Alpha has experience in a wide range of projects and issues, many of which involve litigation or regulatory action that require the rendering of expert opinion, providing expert testimony or assisting in negotiations. These projects generally include:
- Assessment of potential impacts from proposed or existing mines, housing developments, industrial facilities, subsurface waste water disposal (See below), material storage and handling areas, recreational developments and other significant facilities.
- Investigation of claims of water quality and quantity damages from existing recently completed or recently modified facilities.
- Providing geotechnical support regarding impacts from dewatering, erosion, and soil and slope modifications.
- Projects typically require a unique technical approach that may include one or more of the following tasks.
- Aquifer delineation
- Surface water basin delineation
- Storm water runoff calculations
- Water budget analyses (See below)
- Spring and stream flow measurements and water quality monitoring
- Identification of ground water recharge and discharge areas
- Ground water mounding analyses
- Investigation of subsurface conditions
- Determination of ground water flow rates and directions
- Assessment and monitoring of ground water quality
- Prediction of ground water flow volumes, drawdown impacts, and quality changes
- Ground water computer modeling of complex and evolving aquifer systems
Subsurface Disposal of Waste Water:
Investigations and Evaluations Pertaining to Waste Water Treatment Plants and Absorption Fields
Alpha personnel apply their technical capabilities in subsurface characterization and hydrologic analysis to address issues related to subsurface disposal of waste water. Alpha's project experience has included work associated with existing and proposed subsurface disposal systems. These projects generally include:
- Preliminary site characterization through sources such as soil maps, topographic maps and well logs, and through site reconnaissance, to determine a site's subsurface disposal potential.
- Subsurface investigations to determine soil properties, depth to bedrock, and site stratigraphy, and to evaluate the variability of these characteristics across the site.
- Percolation testing to assess the hydrologic capacity of different soil types.
- Installation of ground water monitoring well networks.
- Determination of depth to ground water, the water table configuration, and seasonal variations in ground water flow directions.
- Evaluation of aquifer properties such as hydraulic conductivity, transmissivity, and specific yield, using pumping tests and slug-tests.
- Ground water mounding analyses to evaluate the response of the water table to hydraulic loading beneath proposed absorption fields.
- Assessment of ground water quality and potential impacts from subsurface wastewater disposal.
Water Budget (Balance) Analysis
The water budget analysis or water balance is a highly effective tool that relates local climatic, geologic and land use conditions to the quantity of water available for ground water recharge and surface water runoff. Alpha personnel have extensive experience and training with the method and have adapted it to assess issues such as:
- Determining the quantity of water that will flow into an excavation or mine.
- Assessing the effects on the water table or aquifer by changing drainage patterns and ground cover during site development.
- Assessing impacts to the water table or aquifer level by sustained withdrawals due to well fields, excavation dewatering or mine dewatering.
- Assessing ground water impacts from subsurface injection of septic waste.
- The following are examples of specific types of projects for which Alpha has applied this technique.
- Predicting changes in the water table from a proposed housing development.
- Assessing the average quarry discharge rates and relative effects on receiving streams at various stages of quarry development for several mines.
- Assessing the potential for an aquifer to meet the requirements of proposed golf course and recreational complex.
- Assessing the effects on local springs and trout streams by converting forest land to a golf course and recreational facility.
- Assessing the yield potential of a drainage basin for a municipal water supply.
- Assessing the effects on the water table by quarrying below the water table and creating a lake.
Mining Hydrology, Impact Assessment and Permitting Services
Alpha Geoscience assists the mining industry in resolving hydrologic issues, assessing potential or existing hydrologic impacts to and from the mining operation, and addressing mining permit issues. Alpha often provides services designed to:
- Provide expert opinion and testimony during the environmental review process for mine permit applications or in litigation involving damage claims.
- Estimate quarry discharge rates.
- Predict potential ground water and surface water drawdowns or water quality effects from proposed mining operations.
- Identify and develop water supplies for processing and other operational requirements.
- Investigate sources of mine water inflow and develop strategies for reducing or eliminating excessive inflows.
- Predict future lake levels for reclamation plans for mines excavated below the water table.
- Determine or estimate the depth to water at proposed mine sites.
- Determine ground water recharge areas, discharge areas and flow directions within proposed mine areas.
- Assess potential changes to the ground water flow system from a proposed mine.
- Determine the potential hydrologic changes to critical habitat such as trout streams and wetlands.
- Assess potential impacts to residential or public water supplies by proposed or existing mines.
- Develop long-term ground water monitoring plans to address regulatory requirements.
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