EPA/625/R-01/001A

February 2001

Summary of Workshop on

Biodegradation of MTBE

February 1-3, 2000

Workshop Sponsored by the 

U.S. Environmental Protection Agency and

American Petroleum Institute

Prepared by:

Eastern Research Group, Inc.

Lexington, MA 02421-3136

Contract No. 68-D7-0001

Work Assignment 3-11

Technology Transfer and Support Division

National Risk Management Research Laboratory

Office of Research and Development

U.S. Environmental Protection Agency

Cincinnati, OH 45268
-iiNotice

The views expressed in these Proceedings are those of the individual authors and do not

necessarily reflect the views and policies of the U.S. Environmental Protection Agency (EPA).

Scientists in EPA’s Office of Research and Development have prepared the EPA sections and

those sections have been reviewed in accordance with EPA’s peer and administrative review

policies and approved for presentation and publication. Mention of trade names or commercial

products does not constitute endorsement or recommendation for use. 
-iiiForeword

The U.S. Environmental Protection Agency is charged by Congress with protecting the

Nation’s land, air, and water resources. Under a mandate of national environmental laws, the

Agency strives to formulate and implement actions leading to a compatible balance between

human activities and the ability of natural systems to support and nurture life. To meet this

mandate, EPA’s research program is providing data and technical support for solving

environmental problems today and building a science knowledge base necessary to manage our

ecological resources wisely, understand how pollutants affect our health, and prevent or reduce

environmental risks in the future.

The National Risk Management Research Laboratory is the Agency’s center for

investigation of technological and management approaches for reducing risks from threats to

human health and the environment. The focus of the Laboratory’s research program is on

methods for the prevention and control of pollution to air, land, water and subsurface resources;

protection of water quality in public water systems; remediation of contaminated sites and ground

water; and prevention and control of indoor air pollution. The goal of this research effort is to

catalyze development and implementation of innovative, cost-effective environmental

technologies; develop scientific and engineering information needed by EPA to support regulatory

and policy decisions; and provide technical support and information transfer to ensure effective

implementation of environmental regulations and strategies.

This publication has been produced as part of the Laboratory’s strategic long-term

research plan. It is published and made available by EPA’s Office of Research and Development

to assist the user community and to link researchers with their clients.

E. Timothy Oppelt, Director

National Risk Management Research Laboratory
-ivAcknowledgments

The workshop entitled Biodegradation of MTBE was organized and sponsored by the

U.S. Environmental Protection Agency (EPA) and the American Petroleum Institute (API).

Appreciation is given to all those who contributed to the workshop through presentations and

participation in the discussions. 

This workshop report was prepared by EPA’s National Risk Management Research

Laboratory (NRMRL) with support from Eastern Research Group, Inc. (ERG) and Battelle

Memorial Institute. Joan Colson, NRMRL, served as project officer. EPA wishes to acknowledge

the work performed by Lauren Lariviere of ERG and Andrea Leeson of Battelle Memorial

Institute for their contributions to the workshop and to the development of this report. 

A special acknowledgment is made to the following people who provided technical

consultation for the planning and organization of the workshop and for the editorial review of the

report:

Fran Kremer, US EPA

Bruce Bauman, API

Kirk O’Reilly, Chevron 

Benjamin Blaney, US EPA
-vTable of Contents

Notice .................................................................................................................................. ii

Foreword ............................................................................................................................ iii

Acknowledgments ............................................................................................................... iv

1.0 OVERVIEW ................................................................................................................. 1

2.0 SCOPE OF THE PROBLEM ......................................................................................... 2

3.0 CURRENT RESEARCH ............................................................................................... 4

3.1 Overview of MTBE Biodegradation .................................................................... 4

3.1.1 Aerobic Degradation of MTBE ............................................................ 4

3.1.2 Anaerobic Degradation of MTBE ........................................................ 6

3.1.3 Microbial Cometabolism of MTBE ........................................................ 7

3.2 Enhanced In Situ Bioremediation ........................................................................ 8

3.2.1 Bioaugmentation .................................................................................. 8

3.2.2 Stimulation of Indigenous Microorganisms ............................................ 9

3.3 Natural Attenuation .......................................................................................... 10

3.4 Ex Situ Bioremediation ..................................................................................... 12

4.0 RESEARCH NEEDS ................................................................................................... 15

5.0 COLLABORATIVE EFFORTS ................................................................................... 20

6.0 LITERATURE CITED ................................................................................................ 21

Attachment A - Agenda

Attachment B - Speaker List

Attachment C - Poster Presenter List

Attachment D - Attendee List

Tables

Table 1. State Drinking Water Regulations (Speth, 2000) ........................................................ 3

Figures

Figure 1. Proposed Degradation Pathway of MTBE by Bacterial strain PM1 (Church and

Tratnyek, 2000) ..................................................................................................... 5
1