1987-12-01_PERMIT FILE - C1981017 ‎(275)‎

• Permit No: C1981017
• IBM Index Class Name: PERMIT FILE
• Doc Date: 12/1/1987
• Section_Exhibit Name: Chapter IV Mitigation of Mining Opration Impacts A.Air Pollution Control Plan
• Media Type: D
• Archive: No

Chapter IV
3. Erosion and Sedimentation.
• A U.S. Forest'Service Study investigated the water quality of Coal Basin drainage
(Ingwerson, J.B. 1979) to determine whether the mining operation is causing
accelerated erosion and stream sedimentation. Data from that study indicates that
suspended sediment in Dutch Creek does degrade downstream water in Coal Creek;
however, this could be caused by the natural erosional process. Beginning in 1973, the
U.S.F.S. has been collecting water samples in Coal Basin and vicinity in conjunction
with Mid-Continent. The properties analyzed include electrical conductivity, pH,
alkalinity and total suspended sediment. The results of the survey are summarized in
Table III-E-8.
The study compared water quality in the Dutch and Bear Creek watersheds. If the
sediment yield per acre were found to be significantly higher in Dutch Creek, one could
assume the difference is due to mining
activities since the geology, slopes and vegetation are similar. Although total sediment
yields for Dutch and Bear Creeks were not obtained during the study, it was apparent
sediment production from Dutch Creek was higher. The assessment also revealed that
the sediment in Dutch Creek had a finer texture than tyhat in Bear Creek and may be
related to erosion from mine platforms and haul roads.
The U.S.F.S. report states that the study was not able to quantify amounts of sediment
caused by mining activities, although visual inspection indicated that such activities do
contribute to increased stream sedimentation. "Most of the problems cannot be
• isolated to any point source, but appear to be the result of a combination of non-point
sources, some of which are related to the haul roads and mine platforms." The report
recommends "best management practices" be adopted.
As a result of this study and new State and Federal regulations, Mid-Continent has
implemented the following erosion control practices to minimize potential adverse
impacts on water quality from mining activities:
— Constructed sediment ponds to control sediment from
disturbed areas such as mine platforms and roads.
— Reduced the construction of outside road berms to
minimize road material spoilage.
— Constructed road ditches designed to convey runoff
from the two year storm event.
— Installed culverts to convey the peak runoff from the 10
year/24 hour storm event.
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