2016 NGWA Groundwater Summit

Basin Wide Groundwater Model of the Rialto-Colton Basin for the Source Area OU Remedy for the RFF Superfund Site

Wednesday, April 27, 2016: 2:50 p.m.
Confluence Ballroom B (The Westin Denver Downtown)
Steve Luis , ENVIRON International Corporation
Alka Singhal , Ramboll Environ, Emeryville, CA
Truong Mai , ERM, Irvine, CA
George Linkletter, Ph.D. , ENVIRON International Corporation, Little Deer Isle, ME
Catherine Talbot , TBA, Louisville, CO

ERM and ENVIRON developed a basin-wide groundwater flow model (2012 Model) for purposes of designing the hydraulic control remedy of the Source Area Operable Unit (SAOU) at the Rockets, Fireworks, and Flares Superfund Site in Southern California. The principal contaminant, perchlorate, has impacted municipal supply wells. The principal objective of the project was to perform a comparative evaluation of potential extraction well locations and pumping rates while minimizing pumping rates necessary to achieve hydraulic capture under a wide range of hydrologic conditions in the RCB.

The RCB is an alluvial basin located in southern California that is bounded by faults and bedrock outcroppings. The majority of water inflows to the RCB are in the subsurface across fault boundaries. The majority of outflows consist of groundwater extractions for municipal water supply. All groundwater extraction in the RCB, including that of the SAOU, is subject to operational constraints imposed by the 1961 RCB Decree as well as the capacity of the water treatment and supply infrastructure. Given these considerations and the project objective, it was necessary to begin model development with quarterly water balance of the RCB. The water balance components were compiled for 42 years (1970-2011) using extensive data collected from various water purveyors. The RCB water balance builds upon previous models of the RCB, as well as neighboring basins. However, it was also necessary to develop new parameterizations due to the complex relationship between inflows and stratigraphy in the RCB.


Based on predictive simulations, one extraction well was located such that a high degree of hydraulic capture was predicted.  The basin-wide model development approach, with its emphasis on a reasonable water balance, extensive calibration, and thorough examination of potential extraction options made it possible to optimize SAOU remedy pumping in the near term as well as anticipate potential future pumping requirements.

Steve Luis, ENVIRON International Corporation
Steve Luis has 20 years of experience in environmental consulting, focusing on chemical fate and transport analyses, site investigation and remediation, human health risk assessment, and litigation support. He holds a BS from Loyola Marymount University and an MS and CE from the Massachusetts Institute of Technology.

Alka Singhal, Ramboll Environ, Emeryville, CA
Alka Singhal has more than 10 years of experience in environmental geoscience and groundwater hydrology, with expertise in the areas of numerical and analytical modeling for fate and transport of chemicals in the subsurface, site assessment and remediation, hydrogeological characterization and geo-spatial data analysis for site remediation strategies. She has a PhD in Environmental Geoscience and Master’s degree in Applied Geology.

Truong Mai, ERM, Irvine, CA
Truong Mai is a Partner with ERM. He has 20 years of environmental consulting and client advocacy experience, focused on due diligence, site investigation and cleanup, property redevelopment, cost allocation/recovery, environmental compliance, regulatory negotiations, and litigation support. He holds a BS in Civil/Environmental Engineering from University of California at Davis.

George Linkletter, Ph.D., ENVIRON International Corporation, Little Deer Isle, ME
Dr. George Linkletter, a Principal Emeritus with ENVIRON, has over 40 years of experience in evaluating hydrogeologic and other environmental characteristics related to operations at industrial and waste disposal sites. He has an AB and AM from Dartmouth College and a PhD from the University of Washington.

Catherine Talbot, TBA, Louisville, CO
Catherine Talbot has 15 years of experience in groundwater flow modeling, analysis of environmental and hydrogeologic data, data management, data validation, GIS systems, field hydrogeologic investigation, and technical reporting. She holds MS and BS degrees in Geological Sciences from Indiana University.