Groundwater Technical Services
Sephira Environmental groundwater experts can assist with a wide variety of water quality and quantity needs. The focus of our expertise is on water quality and contaminant transport issues, but we can also assist with questions around groundwater abstraction such as estimating yield and/or possible water table drawdown. Sephira Environmental has connections with industry experts to assist you with all your environmental, engineer, and mining needs.
GROUNDWATER FLOW AND QUALITY INVESTIGATIONS
Sites with contamination that could seep into groundwater such as at uncontrolled landfills, sheep dips, or treated timber piles may need to be assessed for possible risk to human health or the environment. Sephira Environment uses available data to develop a Conceptual Site Models (CSM) of existing conditions. Data gaps may prompt a field investigation. With seasoned geologists and chemists on our team, our investigations are efficient, thorough and accepted by regional councils with little back and forth at the consent processing stage of a project.
To know the actual permeability of underground soil or bedrock is key to estimated groundwater yield or contaminant transport rate. Sephira Environmental can undertake simple or sophisticated (72-hour) aquifer tests to determine soil or rock permeability, depending on the project needs.
FLOW AND CONTAMINANT TRANSPORT MODELLING
Sometimes predictive modelling is necessary to give confidence to stakeholders that future risks will be acceptable. Sephira Environmental has expertise in building simplified or complex hydrogeologic flow models and contaminant transport models using numerical modelling software such as AnAquSIM, SESOIL, and AT123D. Once we've established a model of existing site conditions, we can add planned features such as pumping wells, low permeability caps, treatment zones, etc. A contaminant transport model could be used to estimate if an engineered structure such as a low permeability cap or an insitu treatment wall is likely to mitigate contaminant migration issues. A contaminant transport model can also assess if simply monitoring, to confirm that natural processes will limit risks, is an adequate solution. Contaminant transport modelling can be for unsaturated soil/bedrock (between the ground surface and the top of the groundwater table) or for saturated soil/bedrock (aquifer systems).
WATER QUALITY TESTING
Sephira Environmental has on-staff chemists who have hands-on experience with surface water, groundwater, and sediment quality sampling. We focus testing to meet project needs and our subcontract laboratories are quick and reliable.
WATER PERMIT AEE - WELL INTERFERENCE ASSESSMENTS
Sephira Environmental can assist with your application for, or renewal of ,a resource consent to abstract water from an irrigation bore.
MONITORING WELL PLACEMENT AND DESIGN
Sephira Environmental can help you decide the best location for water supply or monitoring wells. We can help determine optimum depth, well screen length, and oversee aquifer testing. Call us for assistance with all your well installation needs.
WATER MANAGEMENT PLANNING
Water is getting more and more attention these days. We can help you with high-level planning and detailed solutions for water supply, water discharge, and water quality issues.
MINING, QUARRIES, AND LANDFILLS
Sephira Environmental staff have provided technical advice on water management from project startup to closure. We're familiar with water-related issues for open-cast mines, aggregate quarries, and modern or historic landfills.
CONTAMINANT TRANSPORT ASSESSMENT
We do simple to complex groundwater flow and contaminant transport modelling for small or large projects. Our combined expertise in geology, water flow, and chemistry makes us perfectly suited for this type of assessment. We have engineering knowledge to help design and model groundwater contamination solutions.
DRILLING OVERSIGHT - HYDROGEOLOGIC LOGGING
Our years of geologic logging experience allows us to prepare detailed and useful bore logs for environmental and water management project site characterisation. We have good relationships with drilling contractors and can get bore and well installation projects done without problems.
CONTOUR MAP DEVELOPMENT
Sephira Environmental can create contour maps for easy determination of groundwater flow direction.
GROUNDWATER ASSESSMENT REPORTING
We document our hydrogeologic assessments and conceptual site models in clear and user friendly reports for all project stakeholders.