Laboratory Studies on the Fate of MTBE, TBA, and Ethanol in

Aquifer Material

Introduction

The Federal Reformulated Gasoline Program was established
in the Clean Air Act Amendments of 1990, which called for
the reduction of air pollutant emissions from motor vehicles.
Methyl tertiary butyl ether (MTBE) was introduced as a fuel
additive for gasoline. MTBE is an oxygenate that allows
gasoline to burn cleaner, releasing fewer pollutants into the
atmosphere. The addition of MTBE created a risk to drinking
water and ground water resources.

Background

EPA commissioned a Blue Ribbon Panel to study MTBE and oxygenates in gasoline. On July 27, 1999, the panel
recommended ways to maintain air quality, while protecting water quality from the risks of MTBE. Hie goal was to
phase out the use of MTBE, while avoiding gasoline supply shortages and ensuring price stability. The panel
suggested the institution of an alternative fuel oxygenate, such as ethanol.

Objectives

The states use a risk-based approach to select remedies for spills of gasoline at underground storage tank sites. The
nsk evaluation requires an understanding of the rate and extent of biological degradation of fuel components in
ground water.

This project is a survey to gather information on the rates of transformation, the pathways of transformation, and
the important transformation products for fuel components that are major contaminants of ground water.

Approach

The project will use soil microcosms to determine the rate and extent of biodegradation and sorption of MTBE,
tertiary butyl alcohol (TBA), ethanol, and other oxygenates in sediment samples from six sites where gasoline spills
have resulted in methanogenic conditions in ground water.

Investigators

Cherri Adair and John T. Wilson
U.S. EPA

Ground Water and Ecosystem Restoration Division
Ada, Oklahoma 74820
580-436-8969

Naval Facilities Engineering Service Center at Port
Hueneme, California

University of California at Davis

The National Risk Management Research Laboratory's mission is to advance scientific and engineering
solutions that enable EPA and others to effectively manage current and future environmental risks.
NRMRL possesses unique strengths and capabilities and is dedicated to providing credible
technological information and scientific solutions that support national priorities
and protect human health and the environment.

Collaborators

Delta Environmental, Inc.

Group Environmental Management Company
(A BP-affiliated company)

Handex Environmental

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