WSP06828

• File Number: 7630.250
• Description: Wild and Scenic-Encampment River
• State: CO
• Date: 10/1/1976
• Author: Smith-Russell
• Title: Encampment River-Supporting Material-Water Quality Summary Upper Encampment River-Hahns Peak Ranger District-Routt National Forest
• Water Supply Pro - Doc Type: Report/Study

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The United States Geological Survey, using regression techniques on
existing data from Routt County, developed the follovling equation:
.

TDS = ~16.0 + .659 X Specific Conductance
(26 data points, range 65 to 95D (conductance))

FollowinG is a tahl" li~t.ina ,,~t.imiltp~ nf Tn". ripri\lpri usin') the
equa ti on - and an average of a 11 condu~ti ~ity - ~le~~u~~I~~nts for three
sites. Also included are average measured TDS values (6 samples)
at the same locations.

TABLE

Sampling
point

Ave. Measured
TDS (mg/l)
(6 samples)

Ave. Measured
Conductivity
/( Inl,r.:/cl1l
At 250C.

Calculated
TDS (mg/l)
(USGS equation)

DamfinoCr.
Stream
Gage

46

37.5

9

Eas.t Fk.
Weir

10

42

38.5

~1a i n Fk.
abv.
E.Fk.

13

44

44.1

The calculated values of TDS are much lower than those measured -
due probably to the fact that the USGS equation must be extra-
polated considerably to include streams of as high quality as the
Encampment. Probably the actua 1 average va lue 1 i es somewhere between
the calculated value and the average of the six samples given in the
Table.

The optimum levels of TDS for stream productivity is about 400 mg/l
while the maximum safe level for aquatic life is 1500 mg/l. The
drinking water standard is 500 mg/l. Not only are the TDS levels
of the Encampment much below the critical level, they are also much
below optimum. Thus though the chemical quality of the Encampment
is exce 11 ent it wou 1 J be ra ted lower in product i v ity than streams wi th
higher TDS levels. Usually "soft" water such as the Encampment has
reduced abundance and diversity of aquatic organisms.