Purpose:

Ammonium perchlorate (NH4ClO4) has been used since the 1940s in the United States as an oxidant in solid propellants and explosives. The testing and disposal of rocket motors, munitions, and other materials by the Department of Defense (DoD) has resulted in substantial perchlorate contamination in groundwater in several states including California, Utah, Nevada, Texas and Maryland. Biological treatment represents the most promising approach for perchlorate remediation, and several ex situ biological reactors are currently treating perchlorate-contaminated groundwater and process water. The objective of this project is to demonstrate in situ bioremediation of perchlorate in a contaminated aquifer using an innovative horizontal flow treatment well (HFTW) system to distribute and mix electron donor with perchlorate in the subsurface. The HFTW system is anticipated to be widely applicable for in situ perchlorate treatment at DoD sites.

Description:

This project will demonstrate and validate the combined use of the following two innovative technologies: (1) bioremediation of perchlorate-contaminated groundwater through electron donor addition, and (2) horizontal flow treatment wells to achieve in situ mixing of the electron donor with the perchlorate-contaminated water. The HFTW system employs dual-screened treatment wells that are placed in pairs to create a recirculation cell within a contaminated aquifer. Electron donor will be mixed with the groundwater passing through each well to promote perchlorate biodegradation within the recirculation zone. The HFTW system combines the best features of pump-and-treat and funnel-and-gate technologies to contain and treat contaminated groundwater.

Benefits:

The HFTW technology is particularly well-suited for treatment of perchlorate-contaminated groundwater in deep subsurface aquifers. Many competing in situ technologies are not feasible or cost-effective in deep groundwater. This application is important because much of the perchlorate contamination in groundwater in the western United States is found within deep aquifers. Drilling in such aquifers can be prohibitively expensive, particularly if many wells are required for injection of poorly dispersed substrates. Therefore, a system that effectively meters and mixes electron donor with a large zone of influence, such as the HFTW system, is anticipated to be the most effective and inexpensive in situ remediation option at such locations. (Anticipated Project Completion - 2007)

Contacts:

Technical Contact:
Dr. Paul Hatzinger
Shaw Environmental and Infrastructure, Inc.
Princeton Research Center
4100 Quakerbridge Road
Lawrenceville, NJ 08648
Telephone: (609) 936-9300 ext 162
Fax: (609) 936-9221
E-mail: paul.hatzinger@shawgrp.com

DoD Liaison Officer:
Mr. Bryan Harre
NFESC, Code 411
1100 23rd Avenue
Port Hueneme, CA 93043
Telephone: (805) 982-1795
Fax: (805) 982-4304
E-mail: harrebl@nfesc.navy.mil