PERMFILE112193

• Permit No: C1980001
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: pages 2.5-108 to end of Append 2.5-B
• Section_Exhibit Name: 2.5 Hydrology Part 2 & Appendix 2.5-A & -B
• Media Type: D
• Archive: No

• subsequently referred to as discharge from point 007. Flows from 002 and
003 have diminished in more recent years as vegetation on reclaimed areas
above these outfalls has matured (Center Ridge) and reclamation activities
of the areas have come closer to completion (West Ridge). However, both of
these sources contain some TDS laden water which originates from upland
springs. CDPS 009 (the most recent discharge point; 1990) contains surface
runoff and spoil spring water from the Moffat Area which is also TDS laden.
CDPS 006 is a spring below the reclaimed West Ridge mine area which is a
surficial expression of the West Ridge spoil aquifer. The West Ridge
spring and spoil aquifer supply TDS to Trout Creek in the vicinity of TR-B,
while the spoil aquifers in Center Ridge, East Ridge and Moffat may provide
additional contributions to TDS levels downstream.
TDS values at CDPS 002 for the 1961-May 1996 period averaged 1,556
mg/1 and had a range of 920 mg/1 (April 7, 1987) to 2,560 mg/1 (July 6,
1982). TDS values at CDPS 003 for the same period averaged 2,793 mg/1 with
a range of 999 mg/1 (April 7, 1992) to 6, B10 mg/1 (June 9, 1987) . TDS
values at CDPS 004 between April and October for the time period May 1990-
~Oc~ober 1996 average 9,285 mg/1 with a range of 2,700 mg/1 (June 8, 1995)
to 7,31-6 m_g/1 (May 6, 1991). TDS values at CDPS 006 between April and
October for the time period May 1986-May 1999 averaged 3,726 mg/1 and had a
• range from 1,172 mg/1 (April 7, 1992) to 4,958 mg/1 (May 5, 1993). TDS
values (including recorded and calculated values) at 007 between April 1981
and October 1996 averaged 3,297 mg/1 and had a range of 1,000 mg/1 (June 7,
1989) to 9,162 (July 11, 1995).
The annual mean streamflow at TR-a constituted 65.108 (99.07 cfs) of
the annual mean streamflow measured at TR-b (57.66 cfs) for the period from
April 1981 through October 1996. The annual mean flows from CDPS points
004, and 007 constituted 0.308 (0.173 cfs) and 2.309 (1.329 cfs) of the
average annual streamflow measured at TR-b for the period from April 1981
through October 1996, respectively.
The monitoring data does not account for all of the flow measured
at TR-b. However, a flow mass balance can be expressed as:
Fi = F1 + Fz + F3 + F,
Where:
F~ = Trout Creek flow at TR-b (1008)
F1 = Trout Creek flow at TR-a (85.108 of F~)
FZ = CDPS Outfall 009 flow (0.308 of F~)
• F3 = CDPS Outfall 007 flow (2.30$ of Fi)
Renewal 3 2.SA-9 June 13,1997