Permeable Reactive Barriers (PRBs) Using Iron with a Bulking Agent as a Reactive Media, Various Locations

Site Name:

Multiple (8) Sites


- F.E. Warren Air Force Base, Cheyenne, Wyoming
- Lake City Army Ammunition Plant, Independence, Missouri
- Seneca Army Depot, Romulus, New York
- Somersworth Sanitary Landfill, Somersworth, New Hampshire
- Watervliet Arsenal, Watervliet, New York
- Rocky Flats Environmental Technology, Solar Ponds Plume, Golden, Colorado
- Rocky Flats Environmental Technology, East Trenches Site, Golden, Colorado
- Bodo Canyon/ Durango, Colorado

Period of

Installation dates ranging from 1995 (Bodo Canyon) to 2000 (Lake City Army Ammunition Plant and Somersworth Sanitary Landfill)


Full scale and field demonstrations

Permeable Reactive Barriers using iron with a bulking agent:
- F.E. Warren Air Force Base - Full-scale wall, supported excavation, using iron with sand
- Lake City Army Ammunition Plant - Full-scale wall, supported excavation, using iron with sand
- Seneca Army Depot - Full-scale wall, continuous trenching, using iron with sand
- Somersworth Landfill - Full-scale wall, supported excavation, using iron with sand
- Watervliet Arsenal - Full-scale wall, supported excavation, using iron with sand
- Rocky Flats, Solar Ponds - Full-scale reaction vessel, supported excavation, using iron with wood chips
- Rocky Flats, East Trenches - Full-scale reaction vessel, supported excavation, using iron with pea gravel
- Bodo Canyon - Pilot-scale reaction vessel, installation method not provided, iron with copper wool and steel wool

Cleanup Authority:
Varied by site

Varied by site

Chlorinated Solvents, Carbon Tetrachloride, Chloroform, Methylene Chloride, Metals, Inorganics, and Radionuclides
- Chlorinated solvents including TCE, PCE, DCE, VC
- Maximum influent concentrations for individual contaminants in each category were 21,100 µg/L (TCE) for chlorinated solvents; 4,700 µg/L (total VOCs ), and 170,000 µg/L (nitrate) for inorganics.

Waste Source:
Varied by site

Type/Quantity of Media Treated:

Purpose/Significance of Application:
Use of PRBs with a reactive media consisting of iron with a bulking agent to treat groundwater contaminated with chlorinated solvents

Regulatory Requirements/Cleanup Goals:
Varied by site, ranging from non-detect to 100 µg/L

Of the seven projects included in this case study, five (F.E. Warren Air Force Base, Somersworth Sanitary Landfill, Watervliet Arsenal, and both Rocky Flats sites) met or were meeting their goals at the time of report preparation. At these sites, individual contaminant concentrations were reduced to below site-specific cleanup goals ranging from non-detect to 100 µg/L. The Seneca Army Depot was not meeting its goals for DCE, and results were not yet available for the Lake City Army Ammunition Plant. The Bodo Canyon site was a pilot study, but results showed contaminants were substantially reduced.

Cost Factors:
Installation cost information was available for four of the eight projects in the case study (F.E. Warren Air Force Base - $2,400,000, Seneca Army Depot - $350,000, Somersworth Sanitary Landfill - $2,000,000, Watervliet Arsenal - $278,000).

This report provides an interim summary of information about eight projects (seven full-scale and one pilot-scale) involving the application of PRB technologies where iron with a bulking agent was used as a reactive media for the treatment of groundwater contaminated with chlorinated solvents, other organic contaminants, and/or inorganic contaminants.

Lessons learned at the PRB sites summarized in this report include those related to specific successes and issues associated with installing various configurations using iron with a bulking agent, and the suitability of these bulking agents for addressing contamination at specific sites. Bulking agents have been combined with iron for several reasons, including improving groundwater flow conditions within the reactive zone, treatment of additional contaminants not addressed by iron alone, and reducing project cost.