REP20447

• Permit No: C1980001
• IBM Index Class Name: Report
• Doc Date: 3/3/1994
• Doc Name: EDNA PHC REVIEW TDS LOADING TO TROUT CREEK C-80-001
• From: DMG
• To: SUSAN BURGMAIER
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

III IIIIIIIIIIIIIIII
STATE
OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Depanmeni of Nalu ral Resources
l i l t Sherman 51., Room 21 5 q

Denver, ColoraAo BOLUS Il
~~

f hone' 13071 866-3567 I
FA>( (303) 8128106
DEPARTMENT OI
NATURAL
RESOURCE`
DATE: March 3, 1994 Rny Rn^rer
Go~erno~
T0: Susan Burgmaier he^sai.,,.,r
yJ.~ E.ecw ne Duen o~
~
~~ / 1 ~~
FROM: Kent Gorham Mi[ hael B. Loral;
Drviainn Dueonr
RE: Edna PHC Review, TDS Loading to Trout Creek, C-80-001

I have completed review of Appendix 2.5-A submitted by P&M for the Edna Mine.
My comments are as follows:
The operator characterizes the quality. of water in Trout Creek at TR-A
for the years 1980 and 1989-1993. It should be noted that the average
value for total dissolved solids (TDS) varied slightly from 1980 to
present (156mg/1 to 130mg/1). It is interesting to note that the maximum
value for TDS always occurs in April and May and the lowest value occurs
in June or July. This phenomenon exists because the runoff and
infiltration at the mine and its associated springs peaks during April
and May, at which time the flow in Trout Creek is still well below its
peak which occurs during June and July. It is also interesting to note
that observed low values for TDS for the period 1980 to present were
identical, 62mg/l. This low value confirms the source of the water as
snowmelt from higher elevations which has very little contact with the
type of rocks or soils which allow the water to pick up additional
dissolved solids. From inspection of the data it is apparent that few if
any activities above the mine have impacted Trout Creek TDS. It is my
opinion that the data at this key site is representative and its
integrity should be maintained through field inspection monitoring and
verification of sampling protocol.
In 1980 the average TDS at the downstream site TR-D was 280mg/l, an
increase of 124mg/1 over the upstream site TR-A. Presently, TR-D TDS
averages 498mg/l, an increase over the upstream site of 368 mg/1. This
data indicates a trend of gradual degradation of water quality relative
to upstream quality. The operator uses past flow and quality data from
known sources in calculations to deduce flow and quality from "other"
sources. These other sources are defined as:
Irrigation flow diverted above TR-A and returned above TR-B
Surface runoff from the mine
Watersheds from the west side of Trout Creek
East Ridge and Center Ridge groundwater
Groundwater from the west side of Trout Creek