Groundwater evaluations have been an integral part of GEI services for years, supporting efforts to develop groundwater production and groundwater recharge. The key objective in managing groundwater is to protect and preserve groundwater quantity and quality.
GEI’s approach to assisting our clients with sustainable groundwater management includes:
- development of hydrogeologic conceptual models and defining principal aquifers and aquitards
- development of water budgets which quantify each component of inflow and outflow to the basin
- characterization of the quality, storage, and movement of groundwater in each aquifer
- outreach to the public and stakeholders
This designed approach gives GEI the understanding necessary to develop innovative groundwater projects. Developing sustainable groundwater management programs requires:
- detailed studies of groundwater conditions (water levels and quality)
- clear understanding of basin hydrogeology (Hydrogeological Conceptual Model)
- multi-year surface water and groundwater budgets]
- balancing recharge and extraction over a multi-year time period while understanding municipal and agricultural requirements for quantity, quality, and reliability; and planning design, and construction management of:
- monitoring wells
- surface water measurement facilities
- water recharge facilities
- well fields
- water conveyance facilities
- groundwater extraction allocations, if necessary
- developing adaptive management strategies for recharge and extraction over a multi-year period
We are proud of our track record integrating these complex studies and facilities to achieve multiple goals and provide an equitable balance of costs and benefits for clients.
Permitting and Project Implementation
GEI has an expert team with decades of experience providing thorough project planning and permitting services for major water resource projects, from start-to-finish. GEI staff are industry leaders in understanding the complexities of an ever-changing regulatory landscape to solve complex and multi-faceted project issues regarding:
• water rights allocation
• stream diversion
• water quality
• environmental effects
Technical Studies and Groundwater Modeling
Our staff are experienced in applying:
• analytical tools
• numerical models
• data management systems (DMSs)
• geographic information systems to define hydrogeological conditions, assess surface and groundwater interactions, and evaluate land use patterns, as well as estimate current and future agricultural, urban, and environmental demands
Water table mounding, flooding and spread of contamination are often concerns associated with proposed groundwater discharges. Permitting generally requires that all these concerns be addressed. GEI’s soil scientists, hydrogeologists and engineers work together to define soil stratigraphy, perform aquifer testing as appropriate and model the system to provide a defensible estimate of the predicted effects.
Water table mounding, flooding, and spread of contamination (nitrate, salts, or contaminant plumes) are often concerns associated with proposed groundwater recharge. Permitting generally requires that all these concerns be addressed. GEI’s soil scientists, hydrogeologists, and engineers work together to define soil stratigraphy and recharge characteristics as appropriate and will model the system to provide a defensible estimate of the predicted effects.
Groundwater Sustainability Plan (GSP) Development
The Sustainable Groundwater Management Act (SGMA) requires all California groundwater basins designated as critically over drafted, high-, and medium-priority to prepare a GSP. GSPs provide a roadmap for how groundwater basins will reach long-term sustainability. GSPs require:
• description of groundwater conditions (water levels and quality)
• clear understanding of basin hydrogeology (Hydrogeological Conceptual Model)
• multi-year surface water and groundwater budgets (as a basis for developing the 6 sustainability management criteria)
• implementation plan to achieve sustainability and to manage the basin sustainably
Since 2014, GEI’s team has led the development of 10 GSPs and participated in 7 other GSPs.
An annual report is submitted to DWR each spring to report on the progress of a basin’s sustainable management results in the past year. The report is often generated from the basin’s own data management system and describes groundwater usage and management during the preceding year. GEI has prepared numerous annual reports to help our clients report on progress.
Data Management Systems
Data and information management have always been essential elements of effective groundwater management. The importance of data and information management was further emphasized with the 2014 passage of the SGMA in California, which required DMSs be developed to meet SGMA requirements. GEI’s web-based DMS is a powerful tool that is not only used to collect and store groundwater data, it is designed to improve efficiency and data quality.
The modular design of GEI’s SGMA DMS enables managers and the public to easily evaluate groundwater conditions based on the six sustainability indicators prescribed in SGMA and presents groundwater data to provide transparency and effective communication to stakeholders, support technical analysis and decision-making.
GEI has over 15 years of experience in developing web-based water management-focused DMSs and has produced over 10 DMS SGMA related systems for our clients. These tools are customized to meet the specific needs of a basin or project and are designed to leverage publicly available data and provide an intuitive user experience for the groundwater professional, decision maker, and stakeholder.
GEI has a strong record of success in helping our clients identify and access state and federal funding for groundwater management plans and projects. Within the past 5 years alone, GEI’s funding assistance exceeds $200M in grants awarded for various projects. Project examples include:
• state and federally recognized groundwater storage banks
• design and construction of:
-aquifer storage and recovery wells (for both drinking water and recycled water storage)
-wellhead and centralized treatment systems (to remove contaminants from groundwater)
-surface recharge basins
• diversion and conveyance facilities required to transport surface water to these facilities for aquifer storage
GEI staff are engaged in a large number of groundwater assessments and feasibility studies in support of:
• design of groundwater remediation systems
• development of groundwater recharge and storage projects
• siting and design and new wells
• rehabilitation and redevelopment of existing wells
• groundwater dewatering for applications such as:
-construction and deep foundations
-environmental impacts and permitting
GEI’s groundwater scientists and engineers have extensive experience in a wide variety of field investigations including:
• exploratory drilling for well siting, design, and aquifer characterization
• well and aquifer testing including
-step-drawdown and constant-rate pumping
-surface and groundwater interaction studies
-groundwater level surveys
-groundwater quality sampling and analysis
-well construction oversite
Managed Aquifer Recharge (MAR)
MAR is a water resource management tool available to agencies looking to augment and stabilize groundwater supplies in their basins. MAR is a voluntary strategy of intentionally infiltrating surface water into an aquifer system and storing it for subsequent recovery while achieving other benefits during the storage period. Most recently driven by the requirements of the SGMA in California, MAR fits into multiple planning processes that already exist for agencies to achieve groundwater sustainability. Variations on MAR include:
• Flood-MAR. Uses seasonal flood waters for recharge
• Aquifer Storage and Recovery (ASR). Injects potable water into an aquifer for later municipal use
GEI staff are involved in a large number of MAR projects, such as:
• Aquifer Storage and Recovery. Using a single well for the injection of drinking water during wet periods for aquifer storage and then extracting this water for use during dry periods.
• Ag MAR. Raw surface water in wet periods is applied to agricultural fields through existing or modified irrigation infrastructure for the purpose of groundwater recharge.
• Recycled Water ASR. Highly treated wastewater used for the purpose of groundwater recharge either through surface spreading basins or injection wells or a combination of each.
• Surface Spreading Basins. A basin constructed on the ground surface to receive surface water from streams, storm drains, wastewater treatment facilities or other sources for the purpose of replenishing groundwater supply.
• In-lieu Recharge. Use of available surface water for irrigation “in-lieu” of pumping groundwater, allowing the aquifer to replenish naturally.
• Subsurface Recharge. Recharge below the root zone using a tile drainage system installed below the root zone.
Groundwater banking in the arid west is being recognized as a climate change adaptation and mitigation strategy. GEI has a distinguished history in assisting clients in the development of groundwater banks to deliver statewide, regional, and local water supply benefits. GEI has expertise in all aspects of groundwater bank development and operation. Groundwater bank development and operation involve:
• detailed technical and economic feasibility studies
• coordination with project stakeholders, banking partners and funding agencies
• design and construction diversion, conveyance, recharge, and extraction facilities
GEI is currently involved in the development of three groundwater banks in California being partially funded by Water Storage Investment Program administered by the California Water Commission.
Multi-year water budgets are foundational to groundwater and surface water management planning. The water budget is the framework for understanding:
• volume of water available and the sources
• where that water is used
• where water that is not used goes
Using the water budget framework, the effects of future changes can be evaluated:
• land use
• climatic conditions
Water budgets are used in:
• water supply planning
• preparing feasibility studies
• facilitating integrated water resources management
• estimating and quantifying water resources
• identifying data gaps
• forecasting optimum water management actions
SGMA requires that groundwater subbasins develop water budgets for historical, current, and future time periods. Consumptive use is defined as that part of water withdrawn that is:
• incorporated into products or crops
• consumed by humans or livestock, or otherwise removed from the immediate water environment (also referred to as, “water consumed”) (ASCE, 2016 )
Water consumed is not available for use by anyone else in the subbasin. GEI staff has experience assisting client with water budgets and other related services, such as:
• Water Allocations. Landowner, district, and basin level water allocations may be defined to limit water use to bring supply and demand (consumptive use) into balance to achieve sustainability in a groundwater basin. GEI has experience supporting Groundwater Sustainability Agencies set up and monitor allocations at the landowner, district, and basin levels.
• Outreach. Efforts to support improved groundwater management provides local users a way to contribute ideas and participate to consensus-based methods to achieve sustainable groundwater management.
• Regulatory Support. SGMA requires all California groundwater basins designated as critically over drafted, high-, and medium-priority to prepare a GSP. GEI also has extensive experience in preparing agricultural water management plans, as required by Assembly Bill 1668, to include “an annual water budget based on the quantification of all inflows and outflows for the service area of the agricultural water supplier.”
Nitrate Program. GEI’s team of water quality experts are leading the way in developing nitrate management plans focused on providing safe drinking water for all consumers within a defined management zone. Our plans:
• identify potentially impacted users
• include a testing program to determine where groundwater nitrate levels exceed the drinking water limit
• short-term mitigation measures to ensure consumers have access to safe drinking water
• long-term solutions start with:
-identifying the source of contamination
-community-wide solutions that result in affordable, sustainable, and safe drinking water supplies
Well Head Treatment. As land uses and water management evolve, our experts have found that groundwater quality issues are often complex with the need to mitigate multiple contaminants at a single wellhead. This is where GEI’s team really shines. Our water treatment team consists of process scientists and civil engineers who work collaboratively to design the most suitable wellhead treatment systems for the end use of the water supply. Our team is experienced in drinking water, industrial process water, and groundwater remediation treatment systems.
Salt Nutrient Management Plans. Essential to sustainable groundwater management, GEI’s salt nutrient management plans evaluate sources of a substance and aim to mitigate contaminant loading in a groundwater basin through various source control measures. We have experience developing individual plans for industrial process facilities as well as basin-wide plans that establish discharge limits and provide collective mitigation and management alternatives.
No matter the groundwater project, water quality plays a pivotal role in its measure of success. GEI staff has expertise in both natural and anthropogenic compounds that could affect a groundwater project.