BRINGING SOLUTIONS TO THE SURFACE NorthWestern employee helps keep our commitment to the environment with manufactured gas plant cleanup. By Eric Thorsrud
Bill has been working in cooperation with the South Dakota Depart-
For more than 25 years, Bill Thompson, Senior Technical Advisor
ment of Agriculture & Natural Resources for several years characterizing
at NorthWestern Energy, has been involved in managing environmental
the environmental impacts due to the former Aberdeen MGP and imple-
characterization and remediation projects at historic manufactured gas
menting remedial actions.
plants for NorthWestern Energy. One such plant is the former Aberdeen Manufactured Gas Plant in South Dakota.
NorthWestern Energy’s commitment to environmental responsibility at the former plant is illustrated by the successful implementation of
From the early 1800s until the 1950s, prior to the availability of nat-
remedial actions such as the installation of a water treatment system to
ural gas, communities relied on manufactured gas – or town gas – to
prevent coal tar discharge to the storm sewer; lining a nearby section of
produce fuel for street lamps, cooking, heat and lights. Energy compa-
the sanitary sewer to prevent coal tar from entering the sewer system;
nies throughout the United States commonly manufactured gas from
removing contaminated sediment from a nearby creek; and installing col-
coal using technology of the day. At least 1,500 manufactured gas plants
lection trenches and recovery wells to remove coal tar from the ground.
(MGPs) operated within the U.S. at the time, including several in South
Looking ahead, NorthWestern Energy is considering new
Dakota. The Aberdeen Gas Company operated a plant in Aberdeen from
approaches in order to enhance coal tar recovery in 2024 and 2025 and
1888 until 1926 when it was sold to NorthWestern Energy. NorthWest-
will be continuing its ongoing operation, maintenance and ground water
ern Energy ended the MGP operations in 1948 as natural gas pipelines
monitoring responsibilities.
installed in Aberdeen replaced the need for the plant.
NorthWestern Energy’s dedication to environmental stewardship
Coal tar is a byproduct of the gas manufacturing process. Coal tar is
is unwavering and is encapsulated in our overall environmental policy
a black liquid similar in appearance and consistency to driveway sealer
statement. Through collaborative efforts with resource agencies and
and has different industrial uses. Environmental impacts from coal tar due
stakeholders, the company integrates compliance into daily operations,
to historical MGP operations are common.
balancing energy needs and environmental responsibility.
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