An Overview of Perchlorate Cleanup Technologies Applied at DoD Facilities
Bryan Harre, NFESC, US Navy, Port Hueneme, CA

Selection of Remedial Technologies for Perchlorate Impacted Sites
Harry Van Den Berg, ENSR International, Camarillo,  CA

Perchlorate: Groundwater Contamination and its Removal via Ion Exchange Technology
Peter Ritchey, Calgon Carbon Corporation, Pittsburgh, PA 

Ex-Situ Treatment of Perchlorate in Groundwater using Biological Reactor
Dr. Paul Hatzinger, Shaw Environmental, Lawrenceville, NJ
Dr. A. Paul Togna, William J. Guarini, Sam Frisch, Dave Enegess, Paul. M. Sutton

A State's Perspective on Perchlorate
Millie Garcie-Surrette, MA DEP, Lakeville, MA
Carol Rowan West, MA DEP

An Overview of Perchlorate Cleanup Technologies Applied at DoD Facilities

Bryan Harre, NFESC, Port Hueneme, CA

Ammonium perchlorate is manufactured for use as the oxidizer component and primary ingredient in solid propellant for rockets, missiles, fireworks, and some munitions.  Large-scale production began in the United States in the mid-1940s. Because of its shelf life, it must be periodically washed out of the country's missile and rocket inventory and replaced with a fresh supply. Thus, large volumes of the compound have been disposed of since the 1940s.

Since perchlorate was discovered in water supplies in California, Nevada, and Arizona, much progress has been made in developing treatment methods capable of removing perchlorate from water. Over 65 perchlorate treatment technology projects have been funded. Agencies funding this research include the American Waterworks Association Research Foundation, DOD’s Strategic Environmental Research and Development Program (SERDP), DOD’s Environmental Security Technology Certification Program (ESTCP), the National Science Foundation, several universities, water utilities, and Department of Defense activities. Most of the attention has been directed at two technologies: biological treatment and ion exchange.

In the biological treatment process, microbes destroy perchlorate by converting the perchlorate ion to oxygen and chloride. In most cases, nutrients must be added to sustain the microbes. Results for both in-situ and ex-situ systems have reduced the perchlorate concentration to the reporting limit of 4ppb. Barrier walls using biological treatment have been implemented at full-scale at the Naval Weapons Industrial Reserve Plant in McGregor, Texas. This site has also implemented the injection of carbon sources to form a biobarrier. ESTCP has funded and will be performing three demonstrations of in-situ bioremediation over the next two years.

In ion exchange the perchlorate ion is replaced by chloride, a chemically similar but nontoxic ion. Ion exchange processes have been used in homes and businesses for water softening for decades. Bench, pilot, and full-scale studies have demonstrated that ion exchange systems can reliably reduce perchlorate concentrations and are approved for drinking water use in California. This presentation will highlight the efforts of the DOD to develop treatment technologies. 

Selection of Remedial Technologies for Perchlorate Impacted Sites 

Harry Van Den Berg, PE, Sr. Program Manager, ENSR International, 1220 Avenida Acaso, Camarillo, CA 93012-8727, Tel: 805-388-3775 xt. 299, Fax: 805-388-3577, Email: hvandenberg@ensr.com

Perchlorate salts, such as ammonium, sodium and potassium perchlorate are widely used as strong oxidizers in various industries.  Dissolution of perchlorate salts yields the perchlorate anion, which is highly stable and mobile in surface and groundwater systems.  Although perchlorate is a powerful oxidizer when used in solid form, it resists reduction by strong reducing agents when dissolved in water due to unfavorable reaction kinetics.  Due to its mobility and stability in aqueous environments, perchlorate can be found at large distances from its release source.  Ongoing research of the inhibitory effects of perchlorate on the uptake of iodide by the thyroid gland combined with improvements in analytical detection methods since 1997 have prompted the regulatory community to propose increasingly stringent action levels. The current action level in California 4 micrograms per liter, and may possibly be set lower in the future. Several in-situ and ex-situ treatment technologies have been developed, or are currently under development that can address perchlorate in soil and/or groundwater either via biological reduction or removal via physical-chemical means.  Similar to other contaminants, the applicability, effectiveness and cost of these technologies are highly dependent upon site-specific conditions, such as hydrogeology, geochemistry, depth to groundwater, perchlorate distribution and the presence of other contaminants.  This presentation will provide an overview of the criteria affecting the selection process, descriptions of established and innovative treatment technologies and their typical applicability, and a presentation of relative cost.  Design and performance criteria for the technologies that have achieved some degree of success in field applications will be discussed.  Test or operational data will be presented for existing systems, utilizing in-situ and ex-situ bioremediation, reverse osmosis and selective anion exchange technologies.   

Perchlorate:  Water Contamination and its Groundwater Removal via Ion Exchange Technology

Peter Ritchey, Calgon Carbon Corporation, P. O. Box 717  Pittsburgh, PA  15230-0717, Tel: 412-787-6859,   Fax:  412-787-4523, Email: ritchey@calgoncarbon.com

Perchlorate removal from groundwater via ion exchange has been commercially accepted by the water treatment industry.  Three main options exist for perchlorate-removal treatment systems:  non-regenerable fixed bed, regenerable fixed bed, and regenerable moving bed.  

The non-regenerable fixed bed systems employ a highly-selective anion exchange resin which continues to remove perchlorate long after all other anionic species have reached breakthrough due to the high selectivity of the resin for perchlorate.  Several types of anionic resin are commercially available for the type of system ranging from a simple SBA Type 1 resin to the highly selective bifunctional resins.  Calgon Carbon Corporation (CCC) has also modified commercially-available resin in its CalMedia program to lower operating costs for perchlorate treatment.  Currently, > 12,000 gpm of groundwater is being treated with this technology with a 2-3 fold increase expected in 2003. 

The regenerable moving bed system, CCC’s ISEP technology, uses a more-easily regenerable acrylic resin with a brine regeneration.  The ISEP technology has the advantage of maximizing the performance of the system via reduced regenerate usage, a reduced resin requirement, and steady-state operation.  Currently, 2,500 gpm of groundwater is treated via this technology with  > 15,000 gpm of additional capacity expected to come online in 2003. 

The regenerable fixed-bed systems can utilize two types of resin.  First, acrylic regenerable resin can be utilized for perchlorate removal and regenerated with a brine solution.  This option has not been commercialized due to higher operating costs versus the ISEP system.  Second, a highly perchlorate selective resin such as the Oak Ridge Bi-Quat resin can be utilized.  This resin offers substantially longer run times between regenerations and can be regenerated with a FeCl₃/HCl solution.

Advantages and disadvantages between the three types of will be presented.

Ex-situ Treatment of Perchlorate in Groundwater using Biological Reactors

Paul B. Hatzinger, Ph.D., Shaw Environmental, Inc., Princeton Research Center, 4100 Quakerbridge Rd., Lawrenceville, NJ  08648, Tel: 609-936-9300, Email: paul.hatzinger@shawgrp.com
Co-Authors: Dr. A. Paul Togna, William J. Guarini, Sam Frisch, Dave Enegess, Paul. M. Sutton

Ammonium perchlorate (NH₄ClO₄) has been used for several decades in the United States as an oxidizer in solid propellants and explosives.  Past disposal practices of perchlorate-containing fuels and a variety of military testing and training activities have resulted in measurable perchlorate contamination in water in at least 18 states, including California, Massachusetts, Utah, Nevada, Maryland, and Texas. Current estimates suggest that the drinking water of as many as 15 million people may be contaminated with perchlorate. Biological treatment represents the most promising technology for economical remediation of perchlorate in water. During the past few years, we conducted laboratory pilot studies to evaluate the effectiveness of biological fluidized bed reactors (FBRs) for removing perchlorate from groundwater at several sites across the United States. These sites varied widely in geochemistry and perchlorate concentration. The treatment of influent perchlorate levels ranging from greater than 400 mg/L to less than 100 mg/L have been evaluated. The biological removal of co-contaminants, including chlorate, nitrate, and nitramine explosives has also been examined. A summary of the results from the pilot FBR studies will be presented. Based on the data from field pilot studies, three full-scale FBR systems have been constructed and are in operation. These FBRs are currently treating more than 5 million gallons of groundwater per day from influent perchlorate concentrations ranging from 2 to 35 mg/L to effluent concentrations of less than the method reporting limit of 4 mg/L.  Two additional full-scale systems are currently being designed and fabricated for installation in 2004.  In addition, the FBR has recently been approved by the California Department of Health Services (CDHS) as part of a treatment system for the production of drinking water from perchlorate-contaminated groundwater. The performance and design parameters for full-scale FBR systems and a comparison of these systems to other biological reactor types will be presented.

A State’s Perspective on Perchlorate

Millie Garcia-Surette, MPH and Carol Rowan West, Massachusetts Department of Environmental Protection

Ammonium perchlorate is widely used as a component of propellants for rockets, missiles, and fireworks.  It was discovered in surface and ground waters in the United States in the late 1990s, typically around military operations, defense contracting and manufacturing facilities.  Perchlorate has been detected in ground water at the Massachusetts Military Reservation.  In 2002, perchlorate was detected in the water supply of the abutting town of Bourne.  In one instance, the Massachusetts Department of Environmental Protection (DEP) has provided bottled water to a private home impacted by the release.  Currently there are no established drinking water standards for perchlorate.  This presentation will review the ongoing response by the DEP to the perchlorate release at the reservation.  The Department’s Bureau of Waste Site Cleanup has been actively overseeing the site investigation and is reviewing potential remediation strategies.  The Office of Research and Standards is developing a reference dose based on studies that characterize the endocrine disrupting effects of perchlorate on pregnant women, their fetuses, children and individuals suffering from hypothyroidism.  The reference dose will be based on a conservative interpretation of animal and human studies in order to ensure adequate protection of perchlorate-exposed populations.  The reference dose will be used to establish ground water and soil clean up standards under the Massachusetts Contingency Plan for use at hazardous waste sites in Massachusetts.   Actions taken by the U.S. EPA and other states on this issue will be discussed, as well as the need to respond in a timely fashion to perchlorate releases due to the potentially severe health consequences.

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