1988-04-11_PERMIT FILE - C1981008A ‎(9)‎

• Permit No: C1981008A
• IBM Index Class Name: PERMIT FILE
• Doc Date: 4/11/1988
• Doc Name: Hydrologic Description ‎(Part 1 of 2)‎
• Section_Exhibit Name: Tab 7
• Media Type: D
• Archive: Yes

2- sulfate reducing
SO + CH (organic matter)
4 4 bacteria �-
HS + HCO3 + H2O (8)
Depending on the hydrological, geochemical, and biological processes that predominate in
an area, the ground water can be of a calcium magnesium bicarbonate, sodium bicarbonate,
calcium magnesium sulfate, or sodium sulfate type.
Site Specific Ground Water Quality. The following section discusses the results of
chemical analyses for ground water samples collected within and adjacent to the Nucla and
Nucla East mining areas. The monitor well locations are 'presented on Exhibit 7-1 .
Water quality samples are collected by Peabody Coal Company personnel using a submersible
pump. Volumes of water pumped prior to sampling, field water chemical analyses,
calibration of field meters, field water sample preservation and handling procedures, and
laboratory analytical procedures are described in detail in Tab 15, Hydrologic Monitoring
Program.
In the following water quality discussions, aquifers in the two mining areas (Nucla and
Nucla East) comprising the Nucla Mine will be discussed separately so that any
significance of the mining disturbance at the Nucla mining area can be separated from the
undisturbed setting at the Nucla East mining area. Because of the significance of the
irrigation water on the local ground water hydrology, an attempt is made to separate
irrigation period effects from non-irrigation period effects. Additionally, any seasonal
variability irrespective of irrigation periods is addressed. Data presented for trace
elements is limited to the period from 1985 to the present, because of the questionable
nature of the chemical data from earlier analyses. A further qualifier is that lead
levels above the detection limit, even after 1985 are ignored, because the only measurable
values all occurred on the same date in 1986 and measurable levels have not been detected
since. Thus, the 1986 values are considered lab errors. The special chemical parameters
(Be, Co, Li and V) required under ground water agricultural standards from the Colorado
Water Quality Control Commission were analyzed for exclusively in the Nucla East mining
area and the one Nucla mining area spoils well .
Nucla Mining Area. One monitoring well in the Nucla mining area, GW-N9 is multiply
completed in both the overburden and Dakota coal aquifers. A statistical summary of the
7-30 Revised 04/11/88