Challenge

To support the planned redevelopment of a former industrial site into a 2,000-acre planned residential development in Henderson, Nevada, GLA needed to assess the extent of contamination resulting from former large-scale effluent disposal ponds associated with a World War II era magnesium ore refining facility, and subsequent chemical plant operations that further impacted soils and groundwater with arsenic, chromium, perchlorate, and radiochemicals. The local wastewater authority also discharged treated wastewater via Rapid Infiltration Ponds. Groundwater flows to the Las Vegas Wash, combines with treated effluent from the City of Las Vegas, and discharges into Lake Mead.

Solution

DBS&A staff have provided hydrogeologic and environmental consulting services to the client since 2002 to resolve a wide range of subbasin challenges facing this large-scale real estate development effort, including a comprehensive hydrogeologic subbasin site characterization, conceptual model development, design and oversight of aquifer testing, groundwater modeling, soil and groundwater remedial investigations, soil background chemical evaluation, landfill permitting support, groundwater remediation efficiency evaluation, and remedial alternative studies.

Results

Having served as BRC’s trusted advisor on this project for so long–nearly two decades–it’s been rewarding to see how far the site has come.

John Dodge, PG, CHG – Project Manager

GLA’s design and oversight of an aquifer and soil hydraulic testing program for the development of a highly complex subbasin water balance model; quantified recharge and discharge at the model water balance model boundaries; and numerical groundwater flow and chemical transport model using MODFLOW-SURFACT allowed the client to quantify the historical, current, and future hydrogeologic conditions and chemical impacts and aid in potential future remedial decision making.