DENCO II LLC, an ethanol plant in Morris, has agreed to pay
a fine and take steps to prevent discharges of polluted stormwater and
wastewater into nearby surface waters, including wetlands that drain to the
Pomme de Terre River. The company also agreed to correct several other problems
following an investigation by the Minnesota Pollution Control Agency (MPCA).
The company’s discharge permit allows the plant to release stormwater
and wastewater containing limited concentrations of various pollutants to nearby
surface waters. The plant discharges directly to an 8.1-acre wetland complex
that flows to the Green River and then the Pomme de Terre River roughly a mile
from the facility.
An MPCA investigation into records and practices revealed
violations of the permit that included failure to adequately monitor, report,
and correct discharges containing excessive amounts of organic material, total
suspended solids, disinfectants used at the plant referred to as “residual
oxidants,” as well as other pollutants. High levels of organic matter, such as
dust from corn and distillers grains, can lower oxygen levels in waters into
which they flow. Residual oxidants can include chlorine and bromine that are
harmful to fish and other aquatic life. Records indicate these problems occurred
between May 2010 and January 2018.
Other violations identified included missing records, insufficient
and too few stormwater site inspections, monitoring deficiencies, water
sampling quality control deficiencies, inadequate equipment calibrations, and other
problems with documentation, reporting and operational controls.
In addition to paying a penalty of $22,141, the company
agreed to take numerous other actions to correct problems. Some involve achieving
the requirements of a schedule of compliance already in place to have the
facility eventually meet effluent discharge limits for various types of dissolved
salts that can be harmful to aquatic life. Currently, the facility discharges levels
that can be harmful downstream.
According to the schedule of compliance, facility discharges
must meet permit limits for salts (as measured by total hardness, total
dissolved solids and specific conductivity) no later than by the end of 2020.
The facility plans to switch its facility water supply from onsite groundwater
wells to treated water from the city of Morris once the city constructs a new water
supply treatment plant. Using treated city water will make it easier for the
ethanol plant to meet the permit limits for hardness and other salts in its
discharge water.
The penalty and required actions are part of a stipulation
agreement with the MPCA to achieve the plant’s compliance with environmental
laws. When determining penalties, the agency takes into account how seriously
violations affected the environment, the number of times the plant has received
penalties for similar violations, and also how promptly violations are reported
to appropriate authorities. The process also attempts to recover the calculated
economic benefit gained by the plant’s failure to comply with environmental
laws in a timely manner.
Broadcast version
DENCO II LLC, a Morris, Minnesota ethanol plant, agreed to
pay a $22,141 penalty and take steps to prevent discharges of polluted
stormwater and wastewater into nearby surface waters, including wetlands that
drain to the Pomme de Terre River.
A Minnesota Pollution Control Agency investigation revealed
violations of the company’s discharge permit between May 2010 and January 2018.
The penalty and required actions are part of a stipulation
agreement with the agency to achieve the plant’s compliance with environmental
laws.
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The mission of the MPCA is to protect and improve the environment and enhance human health.
St. Paul • Brainerd • Detroit Lakes • Duluth • Mankato • Marshall • Rochester www.pca.state.mn.us • Toll-free and TDD 800-657-3864
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