**Reductive Dechlorination   of Chlorinated Ethenes Under Oxidation-  Reduction Conditions and Potentiometric Surfaces in Two   Trichloroethene-Contaminated Zones at the Double Eagle and   Fourth Street Superfund Sites in Oklahoma City, Oklahoma**

Prepared under interagency agreement   with the  U.S. Environmental Protection Agency

U.S. GEOLOGICAL SURVEY  Scientific Investigations Report 2004-5050 version 2 —ONLINE ONLY 

By Christopher L. Braun

#### Errata Sheet

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pdf version 2 (713 KB)

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**Contents**

Abstract 

Introduction 

> 
Purpose and Scope 

Subsurface Description of the Study Area 

Data Collection and Analytical Methods 

Reductive Dechlorination   of Chlorinated Ethenes Under Oxidation-Reduction Conditions 

> 
Volatile Organic Compounds 

Dissolved Oxygen 

Nitrate and Nitrite 

Ferrous Iron and Total Iron 

Sulfate and Sulfide 

Methane

Potentiometric Surfaces 

Summary 

References Cited

**Figures**

| 1.          |   | Map showing location of study area, Oklahoma       City, Oklahoma                                                                                                                                                                        |
|-------------|--------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 2.          |   | Map showing locations of Double Eagle Refining Superfund       site and Fourth Street Abandoned Refinery Superfund site within the study       area                                                                                     |
| 3a–b. |   | Sequence diagrams showing concentrations of trichloroethene       (TCE), *cis*-dichloroethene (*cis*-DCE), vinyl chloride, ethene,       and chloride in the:                                                                           |
|             | a.     | Shallow zone of the Garber-Wellington aquifer, February 2002       (except ethene, December 2001)                                                                                                                                        |
|             | b.     | Deep zone of the Garber-Wellington aquifer, February 2002                                                                                                                                                                                 |
| 4a–b. |        | Sequence diagrams showing concentrations of dissolved oxygen,       nitrate, ferrous iron, sulfate, and methane in the:                                                                                                                  |
|             | a.     | Shallow zone of the Garber-Wellington aquifer, December 2001                                                                                                                                                                              |
|             | b.     | Deep zone of the Garber-Wellington aquifer, February–March       2002                                                                                                                                                              |
| 5.          |        | Map showing potentiometric surface and flow directions in       the shallow zone of the Garber-Wellington aquifer, Double Eagle Refining       Superfund site and Fourth Street Abandoned Refinery Superfund site, December       2001 |
| 6.          |        | Map showing potentiometric surface and flow directions in       the deep zone of the Garber-Wellington aquifer, Double Eagle Refining Superfund       site and Fourth Street Abandoned Refinery Superfund site, February 2002           |

**Tables**

| 1. | General information for wells sampled in the Garber-Wellington       aquifer at the Double Eagle Refining Superfund site and the Fourth Street       Abandoned Refinery Superfund site, Oklahoma City, Oklahoma, by the U.S.       Geological Survey and the Oklahoma Department of Environmental Quality,       December 2001 and February–March 2002 |
|----|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 2. | Selected constituents, methods, and procedures used to evaluate natural       attenuation processes in ground water at the Double Eagle Refining Superfund       site and the Fourth Street Abandoned Refinery Superfund site, Oklahoma City,       Oklahoma                                                                                                  |
| 3. | Analytical results for volatile organic compounds and chloride from well-water       samples at the Double Eagle Refining Superfund site and the Fourth Street       Abandoned Refinery Superfund site, Oklahoma City, Oklahoma, collected by       the Oklahoma Department of Environmental Quality, February 2002                                           |
| 4. | Historical analytical results for selected volatile organic compounds       from well-water samples at the Double Eagle Refining Superfund site and       the Fourth Street Abandoned Refinery Superfund site, Oklahoma City, Oklahoma,       collected by the Oklahoma Department of Environmental Quality                                                   |
| 5. | Analytical results for selected properties and inorganic constituents       from well-water samples at the Double Eagle Refining Superfund site and       the Fourth Street Abandoned Refinery Superfund site, Oklahoma City, Oklahoma,       collected by the U.S. Geological Survey, December 2001 and February–March       2002                     |
| 6. | Analytical results for carbon dioxide, methane, ethane, and ethene from       well-water samples at the Double Eagle Refinery Superfund site and the Fourth       Street Abandoned Refinery Superfund site, Oklahoma City, Oklahoma, collected       by the U.S. Geological Survey, December 2001 and February–March 2002                               |
| 7. | Measured and computed data from wells used to construct potentiometric       surfaces at the Double Eagle Refining Superfund site and the Fourth Street       Abandoned Refinery Superfund site, Oklahoma City, Oklahoma, December 2001       and February 2002                                                                                               |

**Vertical Datum**

Vertical coordinate information is referenced to the National Geodetic Vertical   Datum of 1929 (NGVD 29).

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**Abstract**

The Double Eagle Refining Superfund site and the Fourth Street Abandoned Refinery   Superfund site are in northeast Oklahoma City, Oklahoma, adjacent to one another.   The Double Eagle facility became a Superfund site on the basis of contamination   from lead and volatile organic compounds; the Fourth Street facility on the   basis of volatile organic compounds, pesticides, and acid-base neutral compounds.   The study documented in this report was done to investigate whether reductive   dechlorination of chlorinated ethenes under oxidation-reduction conditions is   occurring in two zones of the Garber-Wellington aquifer (shallow zone 30–60   to 75 feet below land surface, deep zone 75 to 160 feet below land surface)   at the sites; and to construct potentiometric surfaces of the two water-yielding   zones to determine the directions of ground-water flow at the sites. The presence   in some wells of intermediate products of reductive dechlorination, dichloroethene   and vinyl chloride, is an indication that reductive dechlorination of trichloroethene   is occurring. Dissolved oxygen concentrations (less than 0.5 milligram per liter)   indicate that consumption of dissolved oxygen likely had occurred in the oxygen-reducing   microbial process associated with reductive dechlorination. Concentrations of   nitrate and nitrite nitrogen (generally less than 2.0 and 0.06 milligrams per   liter, respectively) indicate that nitrate reduction probably is not a key process   in either aquifer zone. Concentrations of ferrous iron greater than 1.00 milligram   per liter in the majority of wells sampled indicate that iron reduction is probable.   Concentrations of sulfide less than 0.05 milligram per liter in all wells indicate   that sulfate reduction probably is not a key process in either zone. The presence   of methane in ground water is an indication of strongly reducing conditions   that facilitate reductive dechlorination. Methane was detected in all but one   well. In the shallow zone in the eastern part of the study area, ground water   flowing from the northwest and south coalesces in a potentiometric trough, then   moves westward and ultimately northwestward. In the western part of the study   area, ground water in the shallow zone flows northwest. In the deep zone in   the eastern part of the study area, ground water generally flows northwestward;   and in the western part of the study area, ground water in the deep zone generally   flows northward.