Omaha, Nebraska, USA
For more than a century, the former American Smelting and Refining Company (Asarco) operated a lead refinery on the banks of the Missouri River in Omaha, Nebraska. Plant closure in 1997 presented an opportunity to reclaim the riverfront as public space. Led by HDR, this successful transformation became the largest voluntary clean up project under the Nebraska voluntary remediation program.
HDR designed an in-place remediation to overcome the complex engineering and environmental challenges of the 23-acre site. Demolition of more than 30 buildings and structures required control of airborne particulates so HDR installed high-volume air samplers around the site and even rented a snow-making machine to create an efficient but cost effective dust control system that also reduced overall water consumption. The no-dig project left soils in place with a multi-layered engineered cap and a geosynthetic clay liner placed over the entire site. HDR also developed a hard-armor design for the Missouri River shoreline, adding sufficient fill to construct the capping system while avoiding impact to the floodway or floodplain. HDR engineered a solution that included a combination of stocked cable reinforced concrete armoring mats and stone rip rap secured to a concrete deadman.