USGS - science for a changing world

Environmental Health - Toxic Substances


U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting Charleston South Carolina March 8-12,1999--Volume 3 of 3--Subsurface Contamination From Point Sources, Water-Resources Investigations Report 99-4018C

Table of Contents

Installation of Deep Reactive Walls at MMR using a Granular Iron-Guar Slurry

By David W. Hubble and Robert W. Gillham


The primary contaminant in the CS-10 plume at a military base on Cape Cod is tetrachloroethene (PCE) and site groundwater has been shown to be treatable using granular zero-valent iron. The plume, which extends over a depth interval of 24 to 37 m near its source, is considered to be deep (i.e. > 15 m below the ground surface) and not accessible for conventional means of installing granular iron. Thus, a novel method of vertical reactive wall installation was selected for a 15 m long, full depth, trial wall at the CS-10 plume. The method (hydraulic fracturing) uses special tools to mix granular iron in a guar-based biodegradable polymer and then inject it into a hydraulically created vertical fracture. Geotechnical and geophysical test results show that iron was successfully installed in a wall having an average thickness of 80 mm and between 24 and 37 m depth. The CS-10 demonstration is thus the deepest installation of any reactive material in a wall to date. Monitoring of inorganic and organic groundwater parameters has shown the effects of 1) wall installation, 2) a delayed break of the bio-polymer cross-link and 3) an amendment injected to hasten guar breakdown.

Table of Contents

USGS Home Water Land Resources Science Systems Ecosystems Energy and Minerals Environmental Health Hazards

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information:
Page Last Modified: Tuesday, 04-Aug-2015 15:15:54 EDT