San Juan Groundwater Basin, Upper Gobernadora Multi-Use (Recharge and Flood Control) Basin and Recharge Wells, Santa Margarita Water District Utility, and Gobernadora Creek Bridge Crossing - Expert Witness, and Litigation Support

Confidential Client | Orange County, CA

Retained as an expert hydrogeologist to provide forensic groundwater and surface-water technical support for issues associated with Gobernadora Multi-Use Basin and Creek, and related utility and infrastructure improvements. Work included reviewing dewatering evaluations, groundwater data and reports, and assessing groundwater recharge and storm-event impacts on groundwater levels (including documented high-intensity rainfall periods), and evaluating diversion/creek-flow management measures used during construction. Reviewed drilled-shaft/CIDH documentation to understand construction sequencing, shaft/borehole stability and mud procedures, slurry performance metrics, and potential water-entry pathways relevant to construction outcomes and claims.

Performed hydrogeologic assessment of wet-season groundwater behavior and groundwater–surface water interaction relevant to construction, dewatering expectations, and water-management controls. Correlated documented storm totals with observed/anticipated groundwater response timing and magnitude near the canyon/creek corridor, including mountain front recharge. Reviewed dewatering evaluation assumptions (e.g., hydraulic conductivity estimates; groundwater measurements in borings/wells) for reasonableness and applicability to construction conditions. Evaluated temporary clear-water diversion design and O&M concepts (pipes/cofferdams/gravel bags/BMPs; equipment access via cover over pipelines) to assess surface-water routing, potential infiltration pathways, and constructability constraints. Reviewed drilled-shaft/CIDH construction documentation (daily reports, CIDH drilling logs, and slurry QC logs including density/viscosity/pH/sand content) to characterize shaft open time, slurry condition, and potential exposure to stormwater/runoff and/or groundwater.-Developed integrated timelines and technical exhibits summarizing sequence/means-and-methods and hydrologic conditions to support counsel and expert opinions.

Ames-Reche Recharge Basin Relocation, Oeste Demonstration Recharge Pilot Test, & Lucerne Valley Pump Station Recharge Basin & Oeste Permanent Aqueduct Turn Out Projects

Mojave Water Agency | Mojave Desert Region, California

Eros supported the Mojave Water Agency (MWA), one of 29 State Water Contractors (SWCs) with an annual entitlement of 89,800 acre-feet (AF) of State Water Project (SWP) Table A water, in advancing multiple managed aquifer recharge (MAR) and infrastructure projects to enhance basin sustainability. His work contributed to planning, design, permitting, and construction management efforts for the Ames-Reche Recharge Basin Relocation, Oeste Demonstration Recharge Pilot Test, Lucerne Valley Pump Station Recharge Basin, and Oeste Permanent Aqueduct Turnout.

The objective of these projects was to increase recharge capacity up to 12,000 AFY through new and relocated facilities capable of optimizing the distribution of imported SWP water for beneficial use and groundwater replenishment. In collaboration with Ardurra Group, Inc., Eros provided hydrogeologic evaluation and technical support for site selection, infiltration testing, and pilot recharge performance analysis. He also assisted with design development, regulatory permitting, and integration of the permanent aqueduct turnout with MWA’s recharge and conveyance infrastructure. His contributions supported the Agency’s long-term groundwater management strategy to ensure basin health, water supply reliability, and compliance with SGMA objectives.

Rock and Sand Creek Flood Mitigation and Recharge Project

Rock Creek Reclamation District

Eros conducted a comprehensive feasibility investigation under the Small Communities Flood Risk Reduction (SCFRR) grant program to evaluate the groundwater recharge potential of the Rock and Sand Creek system. His work integrated flood-routing models with geomorphic, geotechnical, and geophysical analyses to inform the preliminary engineering of flow-control and recharge infrastructure designed to reduce flood hazards while enhancing aquifer storage.

He performed advanced hydrogeologic assessments using high-resolution frequency-domain electromagnetic (FDEM) surveys, Department of Water Resources (DWR) airborne electromagnetic (AEM) datasets, and the UC Davis Groundwater Recharge Banking Index to delineate favorable recharge zones. Eros also analyzed long-term hydrograph trends, potentiometric gradients, and detailed hydrostratigraphic relationships to estimate the magnitude and spatial trajectory of lateral and vertical groundwater migration. His findings established a scientific foundation for future recharge basin design and basin-scale flood mitigation planning.

Wells 83 and 84 Aquifer Storage and Recovery Wells (ASR)

Sacramento Suburban Water District | Citrus Heights, California

Eros was responsible for QA/QC oversight throughout the development of technical specifications, design phases, and construction management for two Aquifer Storage and Recovery (ASR) wells executed under a Progressive‑Design‑Build framework. Professional contributions encompassed detailed review and validation of contractor submittals, continuous coordination through data evaluation and field implementation, and resolution of drilling complications. Localized stratified contaminant zones and severe lost‑circulation conditions were mitigated through the application of 250‑foot‑deep conductor casings in each borehole, representing an innovative adaptation to site hydrostratigraphy. The wells ultimately achieved target storage and production capacities without the need for post‑construction treatment, demonstrating both design efficacy and long‑term operational viability.Eros was responsible for QA/QC oversight throughout the development of technical specifications, design phases, and construction management for two Aquifer Storage and Recovery (ASR) wells executed under a Progressive‑Design‑Build framework. Professional contributions encompassed detailed review and validation of contractor submittals, continuous coordination through data evaluation and field implementation, and resolution of drilling complications. Localized stratified contaminant zones and severe lost‑circulation conditions were mitigated through the application of 250‑foot‑deep conductor casings in each borehole, representing an innovative adaptation to site hydrostratigraphy. The wells ultimately achieved target storage and production capacities without the need for post‑construction treatment, demonstrating both design efficacy and long‑term operational viability.

Mission Valley Groundwater Basin Aquifer Storage and Recovery (ASR) Program Evaluation

San Diego State University | San Diego, California

Eros served as a third-party hydrogeologic expert providing independent technical evaluation and peer review for the City of San Diego’s Mission Valley Groundwater Basin ASR Program and its integration with the City’s Pure Water initiative. The project aimed to assess the feasibility of large-scale managed aquifer recharge and later provide third party expert review for the seasonal storage operations in proximity to the redevelopment of the former Qualcomm Stadium site by San Diego State University.

His role encompassed review of basin-scale hydrogeologic data, aquifer testing methodologies, and modeling assumptions to validate recharge and recovery performance under varying hydrologic and operational scenarios. Eros provided strategic recommendations to optimize wellfield placement, assess potential hydraulic connectivity and boundary conditions, and identify geochemical or operational constraints to recharge sustainability. His technical review helped the City and SDSU refine the conceptual hydrogeologic framework and guide infrastructure planning for one of the region’s most visible integrated water resource projects.

Mission Valley Groundwater Basin Aquifer Storage and Recovery (ASR) Feasibility Study

City of San Diego | San Diego, California

Eros supported the City of San Diego Public Utilities Department in evaluating the feasibility of developing the Mission Valley Groundwater Basin as a future local water supply source. His work included hydrogeologic characterization of the basin, assessment of aquifer yield potential, and evaluation of groundwater–surface water interactions along the San Diego River corridor. He assisted in developing a conceptual framework for potential brackish groundwater extraction and treatment, addressing key technical considerations such as water quality, recharge dynamics, and infrastructure compatibility.

The study provided a foundation for informed decision-making regarding sustainable groundwater development, integration with regional supply planning, and long-term resource management consistent with the City’s Groundwater Asset Protection and Development Program.

ASR Well Field Optimization

Calleguas Municipal Water District | Moorpark, California

Eros served as the lead hydrogeologist and technical developer for the three-dimensional hydrostratigraphic conceptual model (HCM) of the Las Posas Basin in Ventura County, supporting the Fox Canyon Groundwater Management Agency (FCGMA) and Calleguas Municipal Water District in meeting Sustainable Groundwater Management Act (SGMA) requirements. The 66‑square‑mile basin, extending more than 3,500 feet in depth, was digitally modeled to optimize the operation of 18 ASR Wells in the two ASR well fields owned and operated by CMWD. The model was also used refine understanding of groundwater–surface water interactions, aquifer geometry, and resource availability for sustainable yield and water budget estimation.

He integrated oil and gas well records, geophysical and lithologic logs, and field mapping of paleostratigraphic, lithostratigraphic, and mesoscopic structural features to construct a high‑resolution subsurface framework. Eros applied geostatistical and 3D modeling tools, including RockWorks, Leapfrog, Petra, ArcGIS, and gINT—to synthesize disparate datasets into a cohesive geologic model used to inform basin management and numerical flow modeling. His work strengthened the scientific foundation of the Las Posas Groundwater Sustainability Plan and enhanced stakeholder confidence in regional water resource decision‑making.

Groundwater Injection and Tracer Methods Pilot Testing: Heated Water, Fluorescein, & Hydrogel Beads

Santa Susan Field Laboratory | Canoga Park, California

Eros directed technical field operations, personnel, contractual oversight, and regulatory coordination across multiple task orders under a $17 million site-wide investigation at the 2,850-acre Santa Susana Field Laboratory, an aerospace and defense research and testing facility historically operated by Rocketdyne/Boeing, NASA, and the U.S. Department of Defense. The work was performed under a multi-agency regulatory framework to support long-term groundwater and soil remediation.

He conducted high-resolution hydrogeologic characterization of diffuse fractured bedrock networks (DFNs) within the Chatsworth Formation, performing structural and statistical analyses of joints, bedding-plane shears, and multi-scale fault systems in turbidite sequences. Working collaboratively with Dr. John A. Cherry and the University of Guelph 360 team, Eros advanced DFN conceptualization and monitoring well network design, implementing innovative in-situ subsurface fault mapping and downhole geophysical logging techniques for deformation analysis. His leadership contributed to the development of pilot studies that refined DFN modeling methodologies and informed remediation strategies for one of the most technically complex environmental sites in California.