Arrowhead Contracting, Inc.

Scope Of Work

Arrowhead was selected to implement a $5.9M design-build groundwater remedial action at the Arkema Chemical Superfund Site located in Portland, OR. The project included remedial system final design, construction, and operation & maintenance of a remediation system for groundwater source control that prevents offsite migration of site related contaminants. The site contains a wide variety of contaminants related to the former chemical manufacturing process, including perchlorate, pesticides (DDE, DDD, and DDT), metals, volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs). Primary components of the remediation system include a containment barrier wall that physically separates the affected upland portions and in-water portions of the site; a network of extraction wells to provide hydraulic control that prevents groundwater containing unacceptable concentrations of the site related contaminants from moving around, over, or under the containment barrier wall; and, management of treated groundwater from the ex situ treatment system, with treated effluent discharged to the Willamette River under a National Pollutant Discharge Elimination System (NPDES) Permit.

The groundwater extraction system is comprised of a network of 22 extraction wells designed to remove groundwater containing the site-related contaminants from three different zones of the aquifer. The extraction wells and wellhead are each fitted with a VFD controlled submersible pump, level transducer, and magnetic flow meter. A network of 36 piezometers fitted with level transducers was also installed to monitor and facilitate control of the hydraulic conditions.