12    REMOVAL AND TREATMENT OF DISSOLVED AND
FLOATING ORGANIC COMPOUNDS IN A
CONTAMINATED GROUNDWATER
D. Eric Strang, Project Manager
Samuel S. Tawney, Project Engineer
EDI Engineering & Science
Grand Rapids, Michigan 49506
Thomas F. Klumpp, Engineer
The Dow Chemical Company
Midland, Michigan 48667
INTRODUCTION
The focus of this presentation will be the removal of contaminants from groundwater by air
stripping at The Dow Chemical Company's Beaver Creek Site.
AquaDetox* Aqueous Purification Process —An Overview
In this chapter stripping is defined as a process to remove dissolved, volatile compounds from
water. A carrier gas, in this case air, is purged through the contaminated water with the volatile
components being stripped from the water into the gas phase.
Site Background
The natural gas compressor station is located approximately 10 miles southwest of the city of
Grayling, Michigan. The 9-acre site, shown in Figure 1, is leased from the State of Michigan and is
situated in the Au Sable State Forest. The nearest residence is 2 miles away. The nearest routinely used
water well is located approximately 1.5 miles east of the site. The operation is owned by The Dow
Chemical Co. and has been in service since 1951.
The Beaver Creek Oil Field (5000 acres) surrounds the site. This oil field, operated by Union Oil of
California (UNOCAL), is a water flood oil field with approximately 90 crude oil wells. The facility
receives natural gas from UNOCAL. The gas is dehydrated and natural gas liquids are removed. The
processed gas is used as fuel gas in the Beaver Creek oil field and at The Dow Chemical Company's
Midland, Michigan production facility.
The source of groundwater contamination resulted from a standard oil field practice for gas
compression stations. Liquids from knockout tanks and other vessels were discharged through gravity
sewer lines to an on-site impoundment, called the "south impoundment," to be burned. A second
impoundment, called the "west impoundment" was also used. This practice resulted in hydrocarbon
liquids migrating to the soils and groundwater.
In 1983 the Dow Chemical Company removed visibly impacted soils from both impoundments and
transported them to their Midland plant for proper disposal. At about the same time, hydrocarbon
insult to the groundwater was discovered. The water was sampled and analytical results of these tests
showed benzene, ethyl benzene and toluene were present. A more comprehensive investigation
followed.
•Trademark of The Dow Chemical Co.
43rd Purdue Industrial Waste Conference Proceedings,  <   1989 Lewis Publishers, Inc., Chelsea, Michigan 48118
Printed in U.S.A.
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