Resource Type: document --> case study 
Country: USA 
Language(s): English
Year: 2017 
Author 1/Producer: Washington State Department of Ecology 
Author / Producer Type: Agency, regulator or other governmental or inter-governmental body 
Report/Document number/description: Monitoring Report 
Publisher Country: USA 
Publisher web link (root): https://fortress.wa.gov/ecy/gsp/DocViewer.ashx?did=65705
Report / download web link (=direct link): https://fortress.wa.gov/ecy/gsp/DocViewer.ashx?did=65705  
EUGRIS Keyword(s): Contaminated land-->Contaminants-->Heavy metals
Contaminated land-->Remediation options-->In situ treatment technologies
Short description: The groundwater at the Barbee Mill Site, a former lumber mill located in Renton, Washington, is affected by occurrences of arsenic, zinc, and petroleum hydrocarbons. Cleanup actions have included the removal of 55,000 tons of As-contaminated soil from the source area in 2006 and the installation of several other measures: a passive attenuation zone (PAZ) along the downgradient boundary of the property to prevent As migration off site, a pump-and-treat system upgradient of the PAZ to remove additional As mass from the groundwater, and a network of monitoring wells and piezometers. The PAZ, installed in 2007, is designed to reduce groundwater As concentrations by at least 95% as the water flows through a permeable iron wall. Although As concentrations at two monitoring wells (CMW-1 and CMW-6) exceed the cleanup level of 20 µg/L, ongoing flushing of residual contamination upgradient of the PAZ is expected eventually to reduce As concentrations below the cleanup level 
Submitted By: Professor Paul Bardos WhoDoesWhat?      Last update: 09/10/2018