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Title: GROUDWATER REMEDIATION AT THE 100-HR-3 OPERABLE UNIT HANFORD SITE WASHINGTON USA - 11507

Conference ·
OSTI ID:1004613

The 100-HR-3 Groundwater Operable Unit (OU) at the Hanford Site underlies three former plutonium production reactors and the associated infrastructure at the 100-D and 100-H Areas. The primary contaminant of concern at the site is hexavalent chromium; the secondary contaminants are strontium-90, technetium-99, tritium, uranium, and nitrate. The hexavalent chromium plume is the largest plume of its type in the state of Washington, covering an area of approximately 7 km{sup 2} (2.7 mi{sup 2}) with concentrations greater than 20 {micro}g/L. Concentrations range from 60,000 {micro}g/L near the former dichromate transfer station in the 100-D Area to large areas of 20 to 100 {micro}g/L across much of the plume area. Pump-and-treat operations began in 1997 and continued into 2010 at a limited scale of approximately 200 gal/min. Remediation of groundwater has been fairly successful in reaching remedial action objectives (RAOs) of 20 {micro}g/L over a limited region at the 100-H, but less effective at 100-D. In 2000, an in situ, permeable reactive barrier was installed downgradient of the hotspot in 100-D as a second remedy. The RAOs are still being exceeded over a large portion of the area. The CH2M HILL Plateau Remediation Company was awarded the remediation contract for groundwater in 2008 and initiated a remedial process optimization study consisting of modeling and technical studies intended to enhance the remediation. As a result of the study, 1,400 gal/min of expanded treatment capacity are being implemented. These new systems are designed to meet 2012 and 2020 target milestones for protection of the Columbia River and cleanup of the groundwater plumes.

Research Organization:
Hanford Site (HNF), Richland, WA (United States)
Sponsoring Organization:
USDOE Assistant Secretary for Environmental Management (EM)
DOE Contract Number:
DE-AC06-08RL14788
OSTI ID:
1004613
Report Number(s):
CHPRC-01149-FP Rev 0; TRN: US1100624
Resource Relation:
Conference: WM2011 WASTE MANAGEMENT CONFERENCE DOE 03/07/2011 THRU 03/11/2011 PHOENIX AZ
Country of Publication:
United States
Language:
English